Ultrasound-guided suprazygomatic maxillary nerve blocks for pediatric cleft palate repair: a retrospective analysis

Ultrasound-guided suprazygomatic maxillary nerve blocks for pediatric cleft palate repair: a retrospective analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Ultrasound-guided suprazygomatic maxillary nerve blocks for pediatric cleft palate repair: a retrospective analysis Amanda M. Bunnell, Gwyneth Bradley, Jennifer V. Smith, Bethany J. Wolf, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8900945/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 11 You are reading this latest preprint version Abstract Background Effective opioid-sparing analgesia is essential in pediatric cleft palate repair, as infants and young children are vulnerable to opioid-related adverse effects. Ultrasound-guided suprazygomatic maxillary nerve (SZMN) blocks have emerged as a promising regional anesthesia technique, but evidence supporting their effectiveness remains limited. Methods We conducted a retrospective observational cohort study of pediatric patients younger than 18 years who underwent cleft palate repair at a single tertiary academic medical center between January 2020 and February 2023. The primary outcome was total perioperative opioid consumption, measured as morphine milligram equivalents per kilogram (MME/kg). Secondary outcomes included intraoperative and postoperative opioid use, time to first successful feeding, and length of hospital stay. Multivariable linear regression was used to adjust for potential confounders, including cleft type and perioperative factors. Results Seventy-four patients met inclusion criteria, of whom 28 received an ultrasound-guided SZMN block. Patients who did not receive an SZMN block consumed significantly more opioids (57% higher; 95% confidence interval [CI], 11.7–121.5; P = 0.012). After adjustment for cleft type and perioperative variables, absence of an SZMN block remained independently associated with higher opioid consumption (48.9% increase; 95% CI, 4.41–112.4; P = 0.031). Intraoperative opioid use was also significantly lower in the SZMN block group. No differences were observed in postoperative opioid use, time to first feeding, or hospital length of stay. Conclusions Ultrasound-guided SZMN blocks were associated with significantly reduced perioperative opioid consumption in pediatric cleft palate repair without prolonging recovery. Prospective studies are warranted to confirm these findings. Health sciences/Diseases Health sciences/Health care Health sciences/Medical research cleft palate nerve block pediatric anesthesia pain management maxillary nerve regional anesthesia Figures Figure 1 Figure 2 Figure 3 BACKGROUND Cleft palate is one of the most common congenital abnormalities, with an incidence of approximately 1 per 1623 live births in the United States [ 1 ]. To optimize speech outcomes in patients with cleft palate, experimental and large-cohort data support palatal repair before or very early in speech onset. For example, in the Timing Of Primary Surgery for Cleft Palate (TOPS) trial, palatal repair at 6 months old yielded lower velopharyngeal insufficiency at 5 years old and better early babbling and hearing than repair at 12 months old [ 2 ]. Also, in a large observational study, earlier repair was linked to superior speech and language at 20 months old and 5 years old [ 3 ]. Interestingly, surgical repair before 6 months old has similar outcomes to repair between 6 and 18 months old. However, repair before 6 months old carries a higher risk of perioperative complications, readmissions, and reoperations [ 4 ]. Also, cleft palate repair is often complicated by postoperative airway obstruction, respiratory distress, and significant perioperative pain [ 5 , 6 ]. Furthermore, postoperative agitation and crying increase the risk of wound dehiscence and fistula formation, highlighting the need for effective perioperative analgesia in pediatric patients undergoing palatoplasty [ 7 ]. To manage postoperative pain and improve surgical outcomes for cleft palate repair, various analgesic regimens are used. Many protocols combine opioid analgesics with alternating acetaminophen, nonsteroidal anti-inflammatory drugs, or cyclooxygenase-2-specific inhibitors during both the intraoperative and postoperative periods [ 7 – 10 ]. However, opioids and non-opioid adjuncts can contribute to respiratory complications and exacerbate postoperative bleeding [ 11 ]. In particular, infants are vulnerable to opioid-induced respiratory depression due to slower elimination and varied drug clearance [ 12 – 14 ]. Also, opioids can lead to lethargy and reduced oral intake, which are crucial indicators of recovery after cleft palate repair [ 8 ]. As an alternative analgesic strategy, regional nerve blocks have gained increasing acceptance. Regional nerve blocks show effective postoperative pain relief, reduced opioid consumption, rapid recovery of alertness, and earlier initiation of feeding—potentially leading to earlier discharge [ 15 – 17 ]. In palatal surgery, regional anesthesia offers the advantage of a lower risk of respiratory depression than that associated with opioids [ 5 , 15 ]. A particularly promising regional anesthesia technique is ultrasound-guided suprazygomatic maxillary nerve (SZMN) block, which is a safe, feasible, and efficacious approach for perioperative analgesia [ 18 – 21 ]. Patients who received an SZMN block before palatoplasty had significantly lower postoperative opioid consumption [ 9 , 15 , 22 ]. Furthermore, SZMN blocks have been associated with a shorter hospital length of stay (LOS) [ 22 ], less intraoperative opioid use [ 17 , 22 ], and reduced time to first oral intake [ 9 ]. However, many of these studies did not use the ultrasound-guided technique nor show reduced intraoperative opioid consumption [ 9 , 10 ]. To assess how ultrasound-guided bilateral SZMN blocks affect pain management for cleft palate repair, we compared outcomes between pediatric patients who did and did not receive an ultrasound-guided SZMN block for this repair surgery. We used opioid consumption as a surrogate measure of analgesic efficacy. METHODS Study Design and Population In this retrospective observational study, we reviewed the electronic health records of pediatric patients under the age of 18 years who underwent cleft palate repair at the Medical University of South Carolina (MUSC) between January 1, 2020, and February 15, 2023. Exclusion criteria included patients who (1) were admitted to the intensive care unit postoperatively or (2) underwent additional invasive surgical procedures during the cleft palate repair, with a few exceptions. Certain invasive surgical procedures (myringotomy tube placement, nasal endoscopy, microlaryngoscopy, bronchoscopy, and correction of lip or tongue ties) were excepted because they do not typically require postoperative opioid analgesia. This retrospective observational study was reviewed by the Medical University of South Carolina Institutional Review Board (Pro00127080) and determined to be exempt. The requirement for informed consent was waived. This study was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. The primary outcome of the study was the total amount of opioids consumed during the hospital stay, measured as morphine milligram equivalents per kilogram (MME/kg). Secondary outcomes included postoperative opioid consumption (within 72 hours of surgery), intraoperative opioid consumption, opioid use in the post-anesthesia care unit (PACU), postoperative opioid use, PACU and hospital length of stay, and time to first feeding. Demographic and medical data were collected, including age at the time of surgery (in months), biological sex, proxy-reported race and ethnicity, American Society of Anesthesiologists (ASA) status, cleft palate type (submucous, Veau class I-IV), procedures performed, and operative details (eg, timing of surgery). If Veau classification was not explicitly documented, it was inferred from operative and chart notes. Also, data on the use of non-opioid medications both intraoperatively and postoperatively were recorded. This study is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Anesthetic and Block Techniques Anesthetic management was at the discretion of the anesthesiologist, though all patients received general endotracheal anesthesia. The decision to perform a block was made collaboratively by the anesthesiologist and surgeon, with parental consent. The ultrasound-guided SZMN block was placed after induction of general anesthesia. A 15 − 6 MHz linear ultrasound probe (Sonosite, Bothell, WA) was placed in the infrazygomatic area over the maxilla, at approximately a 45-degree angle in the frontal and horizontal planes. This placement allowed visualization of the pterygopalatine fossa with the maxilla anteriorly and the greater wing of the sphenoid posteriorly. Then a 27-gauge, 30-mm needle (BD PrecisionGlide, Franklin Lakes, NJ) was inserted with an out-of-plane technique at the estimated angle formed by the superior edge of the zygomatic arch and the posterior orbital rim, lateral to the corner of the eye, at approximately a 45-degree angle, with a trajectory toward the midline. Local anesthetic was injected with visualization of spread in the pterygopalatine fossa (Figs. 1 and 2 ). Statistical Analysis Power Analysis Before the study, statistical power was approximated. We estimated that MUSC performs approximately 50 cleft palate repairs per year, of which approximately 40 involve pediatric patients who receive an ultrasound-guided SZMN block. Therefore, we anticipated a study population of approximately 80 pediatric patients who underwent cleft palate repair, with 40 of them receiving the ultrasound-guided SZMN block. A recent study evaluated postoperative opioid consumption after cleft palate repair [ 9 ]. This study found that pediatric patients who received standard care consumed an average of 0.7 ± 0.4 oral MME/kg, whereas pediatric patients in the Enhanced Recovery After Surgery pathway consumed 0.35 ± 0.25 oral MME/kg. We hypothesized that patients who did not receive an ultrasound-guided SZMN block would have an average opioid consumption of 0.7 ± 0.4 oral MME/kg, and patients who did receive an ultrasound-guided SZMN block would have an average opioid consumption of approximately 0.53 oral MME/kg (25% reduction). We also assumed a standard deviation of 0.25 MMEs in the ultrasound-guided SZMN block group, with a 2-sided test and significance level of α = 0.05. Based on these assumptions, a sample size of 80 patients who did not receive an SZMN block and 40 patients who received an ultrasound-guided SZMN block would provide 80% power to detect a 25% reduction in opioid consumption. Data Analysis Descriptive statistics were computed for all patient characteristics by SZMN block status. Continuous variables are presented as mean (SD) or median (IQR), depending on data distribution, while categorical variables are expressed as No. (%). Differences in patient characteristics between groups were assessed using 2-sample t-tests or Wilcoxon rank-sum tests for continuous and ordinal variables, and chi-square tests or Fisher’s exact tests for categorical variables. For the primary outcome, initial comparisons of opioid consumption between the 2 groups and with other variables were conducted using a series of univariate linear regression models. To account for potential confounders and variability, we also developed a linear regression model that considered all variables with univariate significance ( P < 0.2). Backward stepwise selection was used to determine the final model. Covariates that remained significant in the final multivariable model ( P < 0.05) were retained. Total MME/kg was natural log-transformed to meet model assumptions, and results are presented as the percentage difference in total MME/kg consumed. All statistical analyses were performed using SAS v.9.4 (SAS Institute, Cary, NC). All statistical tests were two-sided, and a P value < 0.05 was considered statistically significant. RESULTS The total study population included 74 pediatric patients, of whom 46 did not receive an ultrasound-guided SZMN block and 28 received an ultrasound-guided SZMN block. The population was predominantly male (female: 41% [30 of 74]; male: 59% [44 of 74]) and White (Black: 21.6% [16 of 74]; White: 64.9% [48 of 74]; Other/Unknown: 13.5% [10 of 74]). The median (IQR) age was 11.4 (10.1–15.6) months. There was no difference in age, sex, race, ethnicity, weight, ASA status, or type of surgery (Supplemental Table S1 ) between patients who did and did not receive the SZMN block (Table 1 ). Table 1 Patient and Procedural Characteristics by Block Group (N = 74) Characteristic No SZMN block (n = 46) SZMN block (n = 28) P value Age, months 11.8 (10.1, 16.2) 10.5 (9.7, 14.1) 0.153 Weight, kg 9.5 (8.1, 10.7) 8.7 (8.0, 9.7) 0.214 Sex 0.509 Female 20 (43.5) 10 (35.7) Male 26 (56.5) 18 (64.3) Race 0.989 Black 10 (21.7) 6 (21.4) White 30 (65.2) 18 (64.3) Other/Unknown 6 (13.0) 4 (14.3) Ethnicity 0.703 Hispanic 5 (10.9) 2 (7.14) Non-Hispanic 41 (89.1) 26 (92.9) ASA status 0.241 I 4 (8.7) 6 (21.4) II 33 (71.7) 19 (67.9) III 9 (19.6) 3 (10.7) *Type of cleft palate 0.003 Veau I 6 (13.3) 3 (10.7) Veau II 23 (51.1) 4 (14.3) Veau III 6 (13.3) 3 (10.7) Veau IV 6 (13.3) 10 (35.7) Submucosal 4 (8.9) 8 (28.6) Surgery type Cleft palate only 19 (41.3) 8 (28.6) 0.270 Cleft palate and ear tubes 26 (56.5) 19 (67.9) 0.333 Cleft palate and other 22 (47.8) 16 (57.1) 0.437 Values are presented as median (Q1, Q3) or number (%). SZMN: suprazygomatic maxillary nerve; ASA: American Society of Anesthesiologists. *Data for cleft palate type were available for 45 patients. It was unavailable for some patients due to incomplete documentation in the electronic health record. The type of cleft palate differed between groups (global P = 0.003). A greater proportion of patients in the SZMN block group had Veau IV and submucosal cleft palates, whereas a greater proportion of patients in the no-SZMN block group had Veau III cleft palates. Patients in the SZMN block group also had a significantly longer time from induction to anesthesia-ready ( P = 0.002). However, there was no difference in total anesthesia time or intraoperative time between patients who did and did not receive an SZMN block (Table 2 ). Table 2 Procedural, Analgesia, and Postoperative Outcomes by Block Group (N = 74) Outcome No SZMN block (n = 46) SZMN block (n = 28) P value Type of local anesthetic NA Ropivacaine NA 24 (85.7) Bupivacaine NA 4 (14.3) Total block time, min NA 4.5 (3.0, 8.0) Time from induction to anesthesia-ready, min 14.5 (10.0, 19.0) 21.5 (14.5, 29.0) 0.002 Total anesthesia time, min 288 (237.0, 339.0) 307 (286.0, 344.0) 0.086 PACU LOS, min 60 (44.0, 91.0) 47 (36.0, 67.5) 0.053 Intraoperative time, min 284 (239.0, 329.0) 321 (286.5, 354.0) 0.075 Intraoperative opioids, MME/kg 0.35 (0.15, 0.52) 0.21 (0.13, 0.33) 0.016 Other intraoperative medications 0.173 Acetaminophen 33 (71.7) 25 (89.3) Ketamine 1 (2.2) 0 (0.00) None 12 (26.1) 3 (10.7) PACU opioids, MME/kg 0 (0, 0.048) 0 (0, 0.049) 0.966 Other PACU medications 0.028 Acetaminophen 14 (30.4) 2 (7.1) Ibuprofen 1 (2.2) 1 (3.6) None 31 (67.4) 25 (89.3) Floor opioids, MME/kg 0 (0, 0.076) 0 (0, 0.05) 0.279 Other floor medications 0.651 Acetaminophen 34 (73.9) 22 (78.6) Ibuprofen 12 (26.1) 6 (21.4) Total opioids, MME/kg 0.44 (0.23, 0.58) 0.24 (0.16, 0.38) 0.017 Time to first successful feeding, min 302.5 (189.0, 607.0) 304.5 (168.5, 482.5) 0.881 Hospital LOS, min 1630.5 (1267.0, 2776.0) 2317.5 (1275.0, 2825.0) 0.863 Values are presented as number (%) or median (Q1, Q3). SZMN: suprazygomatic maxillary nerve; NA: not applicable; PACU: post-anesthesia care unit; LOS: length of stay; MME: morphine milligram equivalents. Primary Outcome In a univariate analysis, there was a significant difference in overall opioids consumed between patients who did and did not receive an ultrasound-guided SZMN block. Patients who did not receive an SZMN block consumed, on average, 57% more opioids than patients who received an SZMN block (mean percent difference [95% CI]: 57.2 [11.7, 121.5]; P = 0.012). We also examined associations between opioid consumption and additional patient and procedural factors. In a univariate model, less opioid consumption was associated with a longer time from induction to anesthesia-ready ( P = 0.003), and greater opioid consumption was associated with higher ASA status ( P = 0.043). Also, the global test revealed a significant association between opioid consumption and palate type ( P = 0.050). In pairwise comparisons, patients with submucosal cleft palate consumed less opioids on average than patients with Veau II, III, or IV cleft palates. Also, patients with Veau III cleft palates consumed less opioids than patients with Veau I cleft palates (Global F-test, P = 0.050) (Fig. 3 ). To determine associations of ultrasound-guided SZMN blocks after controlling for other factors, we developed a multivariable regression model of opioid consumption. All variables significant at P < 0.2 in univariate models were considered. The final model included block group, palate type, whether patients received additional non-narcotic medications intraoperatively, and time from induction to anesthesia-ready. Patients who did not receive an ultrasound-guided SZMN block had a 49% higher opioid consumption than that of patients who received an SZMN block when controlling for complete cleft palate status, use of non-narcotic medications intraoperatively, and time from induction to anesthesia-ready (mean percent increase [95% CI]: 48.9 [4.41, 112.4]; P = 0.031). Patients with submucosal cleft palates consumed significantly less opioids than patients with Veau III and Veau IV cleft palates, and patients with Veau III cleft palates consumed significantly more opioids than patients with Veau I or II cleft palates. Patients who had a complete cleft palate repair consumed, on average, 70% more opioids than patients with other types of surgeries, when adjusting for block group, use of non-narcotic medications intraoperatively, and induction time ( P = 0.003). Patients who received adjuvant pain medications intraoperatively also consumed 36% less opioids than those who did not, when controlling for other factors ( P = 0.029). A 5-minute increase in induction time was associated with a 10% reduction in overall opioids consumed, when controlling for other factors ( P = 0.034) (Table 2 ). Secondary Outcomes We also examined opioid use intraoperatively, in the PACU, on the floor, and total overall postoperatively (PACU + floor). There were no notable differences in opioids received in the PACU ( P = 0.966), on the floor ( P = 0.279), or overall postoperatively ( P = 0.568). However, patients who did not receive an SZMN block consumed significantly more opioids intraoperatively than patients who did receive an SZMN block ( P = 0.016) (Table 2 ). We also examined PACU LOS, time to first successful feeding, and hospital LOS. Patients who did not receive an ultrasound-guided SZMN block had a longer PACU LOS (median, 60 minutes) than patients who received an ultrasound-guided SZMN block (median, 47 minutes), though the difference was not significant ( P = 0.053) (Table 2 ). There were no notable differences in the time to first successful feeding ( P = 0.881) or hospital LOS ( P = 0.863) between the groups (Table 2 ). DISCUSSION Effective perioperative analgesia that minimizes opioid exposure remains a central goal in contemporary pediatric anesthesia practice, particularly for infants and young children undergoing procedures associated with significant postoperative pain, such as cleft palate repair. In this retrospective observational study, we found that ultrasound-guided bilateral suprazygomatic maxillary nerve blocks were associated with substantially lower perioperative opioid consumption without adversely affecting recovery milestones. These findings contribute to the growing international literature supporting ultrasound-guided regional anesthesia as a feasible and opioid-sparing component of multimodal analgesia strategies in pediatric perioperative care. In pediatric cleft palate repair, effective pain management is essential. Pain management not only improves comfort but also prevents complications, such as poor oral intake, delayed recovery, and wound dehiscence from agitation or crying [ 7 ]. Although pain is commonly managed with opioid analgesics, these drugs are associated with significant risks, including respiratory depression, sedation, and gastrointestinal effects (eg, nausea, vomiting, constipation) [ 6 , 17 ]. Also, in infants and young children, repeated exposure to high doses of opioids may pose risks to neurodevelopment [ 23 ]. These findings underscore the need to reduce opioid use in pediatric anesthesia and pain management. In our study, we found that ultrasound-guided blocks were associated with significantly reduced opioid consumption in pediatric patients undergoing cleft palate repair. Thus, integrating these blocks into enhanced recovery pathways for cleft palate repair could further advance safe, efficient, and patient-centered care while minimizing the risks of long-term opioid exposure in this vulnerable population. Our findings align with prior findings that regional anesthesia techniques, including SZMN blocks, can reduce opioid requirements and improve perioperative outcomes [ 15 , 17 , 19 , 22 ]. Indeed, Stanek et al found a 57% reduction in total intraoperative opioid requirements, while controlling for syndromic status and cleft phenotype [ 22 ]. However, other findings have been inconsistent. For example, Mesnil et al [ 17 ] and Chiono et al [ 15 ] reported no significant difference in intraoperative opioid consumption. Also, Echaniz et al [ 16 ] found a reduction in intraoperative nalbuphine and a weak reduction in fentanyl consumption. However, their study combined cleft lip and palate repair, which are remarkably different procedures, and did not use the ultrasound technique. In our study, we exclusively used the ultrasound-guided technique. However, other studies used this approach inconsistently or not at all [ 21 , 22 ]. Although limited evidence specifically supports ultrasound-guided SZMN blocks, ultrasound guidance for regional anesthesia increased block success, reduced procedure time, lowered incidence of vascular puncture, decreased the required local anesthetic volume, and increased safety through real-time needle and anatomy visualization [ 24 ]. Also, from a technical standpoint, ultrasound-guided SZMN blocks can be performed quickly in a median of 4.5 minutes in our dataset. This timeframe underscores the feasibility of using this approach without significantly prolonging anesthesia time in pediatric patients undergoing cleft palate repair. Also, ultrasound guidance offers real-time visualization of relevant anatomy and needle trajectory, which may enhance block accuracy, safety, and reproducibility. These features make SZMN blocks an attractive addition to multimodal analgesia protocols, particularly in centers with regional anesthesia expertise. In future work, multicenter studies could assess the reproducibility of our results in settings with varying pediatric anesthesia expertise and also examine the learning curve for SZMN block placement to inform training guidelines. Although we observed a shorter PACU LOS among the SZMN block group, this finding was not statistically significant. However, the shorter trend suggests improved recovery in the early postoperative period and could reflect better pain control, less need for rescue analgesics, and more rapid emergence from anesthesia. We also observed no differences in the time to first feeding or hospital LOS. These findings were not unexpected, because these endpoints are often influenced more by institutional feeding protocols, surgeon-specific discharge criteria, and non-pain-related factors, such as airway monitoring needs or family readiness for discharge. However, our study may have been underpowered to detect small but clinically meaningful differences in these outcomes. Thus, future studies should be powered to evaluate not only opioid consumption but also functional recovery outcomes, such as feeding tolerance, readiness for discharge, speech development, and parental satisfaction. We completed multivariate analysis to account for key potential confounders, including cleft type, intraoperative non-narcotic medication use, and time from induction to anesthesia-ready. We found that the association between SZMN block use and reduced opioid consumption persisted after adjustment, further supporting a causal effect. Nonetheless, unmeasured variables—such as anesthetic depth, subtle differences in surgical technique, or provider preferences for pain management—may still have contributed to the observed differences. To validate our findings and minimize residual confounding, prospective randomized controlled trials are needed. Our findings need to be interpreted in the context of a few limitations. First, the retrospective design precludes definitive causal inference. Second, although our power calculation indicated the need for a larger sample size, the final cohort was smaller because this was a retrospective analysis restricted to the available cases of cleft palate repair during the study period. As a result, the sample size was determined by existing clinical records rather than prospective recruitment, which may have limited the statistical power to detect differences in some secondary outcomes. Third, there is a possibility of selection bias given the unequal distribution of cleft types between groups—the SZMN block group had more Veau IV and submucosal clefts, whereas the no-SZMN block group had more Veau III clefts. Although cleft type was adjusted for in multivariate models, residual confounding is possible. Fourth, if Veau classification was not explicitly documented, it was inferred from operative and chart notes, which may have led to misclassification. Finally, at our institution, there is not a standard opioid order for patients after cleft palate repair on the floor, and nursing staff were required to obtain physician approval for opioid orders. Thus, true analgesic needs may have been misestimated, and our findings may not be generalizable to institutions with different prescribing models. Nevertheless, these results provide clinically relevant evidence supporting the feasibility and potential opioid-sparing benefits of ultrasound-guided SZMN blocks in pediatric cleft palate repair. With standardized postoperative analgesia protocols, the true effect of SZMN blocks can be better clarified and compared across institutions. CONCLUSIONS We found that ultrasound-guided SZMN blocks were associated with significantly reduced opioid consumption by nearly 50% and improved recovery profiles in pediatric patients undergoing cleft palate repair. SZMN blocks were placed rapidly and safely, demonstrating the feasibility of using this approach in this population. By substantially reducing opioid requirements while maintaining effective pain control, SZMN blocks offer a safe, efficient, and reproducible option for perioperative analgesia in a population particularly vulnerable to opioid-related adverse effects. This approach also aligns with current priorities in pediatric anesthesia for opioid-sparing, multimodal pain management. Although prospective randomized trials are needed to confirm our findings and evaluate broader recovery outcomes, our findings support the incorporation of SZMN blocks into standard analgesic protocols for pediatric cleft palate repair. Abbreviations ASA : American Society of Anesthesiologists CI : Confidence Interval ICU : Intensive Care Unit IQR : Interquartile Range LOS : Length of Stay MME : Morphine Milligram Equivalents MME/kg : Morphine Milligram Equivalents per Kilogram MUSC : Medical University of South Carolina NA : Not Applicable PACU : Post-Anesthesia Care Unit SD : Standard Deviation SZMN : Suprazygomatic Maxillary Nerve Declarations Ethics approval and consent to participate - This retrospective study was reviewed by the Medical University of South Carolina Institutional Review Board (Pro00127080) and determined to be exempt.The requirement for informed consent was waived by the institutional review board. Consent for publication – Not applicable Availability of data and materials – The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests – The authors declare that they have no competing interests. Funding - This research did not receive any specific external funding. This work was supported by internal departmental support (Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina). This project was also supported by the South Carolina Clinical & Translational Research Institute, Medical University of South Carolina’s CTSA, NIH/NCRR Grant Number 1UL1TR001450. Authors’ contributions AMB contributed to study conception, data acquisition, and manuscript drafting and revision. GB and JVS contributed to data collection and manuscript drafting. BJW performed statistical analysis. NRB contributed to data collection and manuscript drafting. All authors reviewed and approved the final manuscript. Acknowledgements - The authors acknowledge Dr. Phayvanh Pecha, MD, MPH, and Dr. Krishna Patel, MD, PhD, for their support of this study and their role in adopting the suprazygomatic maxillary nerve block in our clinical practice. 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Esfahanian M, Marcott SC, Hopkins E, Burkart B, Khosla RK, Lorenz HP, et al. Enhanced recovery after cleft palate repair: A quality improvement project. Paediatr Anaesth. 2022;32(10):1104-12. Moffitt JK, Cepeda A, Jr., Ekeoduru RA, Teichgraeber JF, Nguyen PD, Greives MR. Enhanced recovery after surgery protocol for primary cleft palate repair: Improving transition of care. J Craniofac Surg. 2021;32(1):e72-e6. Oberhofer HM, Breslin N, Heindel H, Ching J. Analgesic efficacy of intraoperative nerve blocks for primary palatoplasty. J Craniofac Surg. 2021;32(2):594-6. Emoto C, Johnson TN, Neuhoff S, Hahn D, Vinks AA, Fukuda T. Pbpk model of morphine incorporating developmental changes in hepatic oct1 and ugt2b7 proteins to explain the variability in clearances in neonates and small infants. CPT Pharmacometrics Syst Pharmacol. 2018;7(7):464-73. Olkkola KT, Hamunen K, Maunuksela EL. Clinical pharmacokinetics and pharmacodynamics of opioid analgesics in infants and children. Clin Pharmacokinet. 1995;28(5):385-404. Pokela ML, Anttila E, Seppälä T, Olkkola KT. Marked variation in oxycodone pharmacokinetics in infants. Paediatr Anaesth. 2005;15(7):560-5. Chiono J, Raux O, Bringuier S, Sola C, Bigorre M, Capdevila X, et al. Bilateral suprazygomatic maxillary nerve block for cleft palate repair in children: A prospective, randomized, double-blind study versus placebo. Anesthesiology. 2014;120(6):1362-9. Echaniz G, De Miguel M, Merritt G, Sierra P, Bora P, Borah N, et al. Bilateral suprazygomatic maxillary nerve blocks vs. Infraorbital and palatine nerve blocks in cleft lip and palate repair: A double-blind, randomised study. Eur J Anaesthesiol. 2019;36(1):40-7. Mesnil M, Dadure C, Captier G, Raux O, Rochette A, Canaud N, et al. A new approach for peri-operative analgesia of cleft palate repair in infants: The bilateral suprazygomatic maxillary nerve block. Paediatr Anaesth. 2010;20(4):343-9. Lin C, Abboud S, Zoghbi V, Kasimova K, Thein J, Meister KD, et al. Suprazygomatic maxillary nerve blocks and opioid requirements in pediatric adenotonsillectomy: A randomized clinical trial. JAMA Otolaryngol Head Neck Surg. 2024;150(7):564-71. Molins G, Valls-Ontañón A, De Nadal M, Hernández-Alfaro F. Ultrasound-guided suprazygomatic maxillary nerve block is effective in reducing postoperative opioid use following bimaxillary osteotomy. J Oral Maxillofac Surg. 2024;82(4):412-21. Neupane A, Jain D, Arora S, Gandhi K, Singla V, Goel N, et al. Evaluation of ultrasound-guided suprazygomatic maxillary nerve block in functional endoscopic sinus surgery for postoperative pain relief: A randomised controlled trial. Indian J Anaesth. 2024;68(8):706-11. Sola C, Raux O, Savath L, Macq C, Capdevila X, Dadure C. Ultrasound guidance characteristics and efficiency of suprazygomatic maxillary nerve blocks in infants: A descriptive prospective study. Paediatr Anaesth. 2012;22(9):841-6. Stanek K, Alrayashi W, Nussbaum L, Ganske IM, Rogers-Vizena CR. Suprazygomatic maxillary nerve block in palatoplasty: A retrospective cohort study of perioperative outcomes in syndromic and non-syndromic children. Cleft Palate Craniofac J. 2025;62(6):976-84. Squillaro A, Mahdi EM, Tran N, Lakshmanan A, Kim E, Kelley-Quon LI. Managing procedural pain in the neonate using an opioid-sparing approach. Clin Ther. 2019;41(9):1701-13. Neal JM, Brull R, Chan VW, Grant SA, Horn JL, Liu SS, et al. The asra evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary. Reg Anesth Pain Med. 2010;35(2 Suppl):S1-9. Additional Declarations No competing interests reported. Supplementary Files AppendixA.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 27 Mar, 2026 Reviews received at journal 25 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviews received at journal 22 Mar, 2026 Reviewers agreed at journal 12 Mar, 2026 Reviewers invited by journal 06 Mar, 2026 Editor assigned by journal 06 Mar, 2026 Editor invited by journal 24 Feb, 2026 Submission checks completed at journal 20 Feb, 2026 First submitted to journal 20 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8900945","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":603762049,"identity":"f77dea7b-ce2e-4298-a59d-956d1eb45b8b","order_by":0,"name":"Amanda M. Bunnell","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAuklEQVRIiWNgGAWjYBACAzBZwMDADxVgbCBOC5CUbCBZi8EBYrWYS+Qee/DBwC7a+NoZ4w8/GGxkNxwgoMVyRl664QyD5Nxtt3PMJHsY0owJajG4kWMmzWPADNbCzMBwOJE4LX8M6nM3z84x/szA8J9ILQwGh3M3SOcYSDMwHCCsxbLnDdALBsdzZ9xOKwMyko1nEtJizp5jJvGjojq3f3by5g8/Kuxk+whpQXcnacpHwSgYBaNgFOAAABeVQWzJ/4FiAAAAAElFTkSuQmCC","orcid":"","institution":"Medical University of South Carolina","correspondingAuthor":true,"prefix":"","firstName":"Amanda","middleName":"M.","lastName":"Bunnell","suffix":""},{"id":603762050,"identity":"ba478419-32fb-43dd-b44a-98b57bc53184","order_by":1,"name":"Gwyneth Bradley","email":"","orcid":"","institution":"Medical University of South Carolina","correspondingAuthor":false,"prefix":"","firstName":"Gwyneth","middleName":"","lastName":"Bradley","suffix":""},{"id":603762051,"identity":"c2a7f5f9-dfc2-442a-883c-b84ecf342fbd","order_by":2,"name":"Jennifer V. Smith","email":"","orcid":"","institution":"Medical University of South Carolina","correspondingAuthor":false,"prefix":"","firstName":"Jennifer","middleName":"V.","lastName":"Smith","suffix":""},{"id":603762052,"identity":"9b99a52a-72d0-4eda-b667-abd1ca9d1cf5","order_by":3,"name":"Bethany J. Wolf","email":"","orcid":"","institution":"Medical University of South Carolina","correspondingAuthor":false,"prefix":"","firstName":"Bethany","middleName":"J.","lastName":"Wolf","suffix":""},{"id":603762053,"identity":"06c0d089-6655-476c-8212-ab5df200ed85","order_by":4,"name":"Natalie R. Barnett","email":"","orcid":"","institution":"Medical University of South Carolina","correspondingAuthor":false,"prefix":"","firstName":"Natalie","middleName":"R.","lastName":"Barnett","suffix":""}],"badges":[],"createdAt":"2026-02-17 12:23:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8900945/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8900945/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104782161,"identity":"0a2a6c69-1600-4f32-95fc-c1340ad27359","added_by":"auto","created_at":"2026-03-17 07:56:53","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":132808,"visible":true,"origin":"","legend":"\u003cp\u003ePlacement of linear ultrasound probe. Placement was inferior to the zygomatic arch, with a 45-degree angle to obtain optimal view of the pterygopalatine fossa. Needle placement was lateral to the corner of the eye, diving under the zygomatic arch, with a trajectory toward midline.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8900945/v1/9145729b2b159fa5d1841f1e.png"},{"id":104546819,"identity":"a84434e3-5f83-4bf1-adc6-41adad9312cf","added_by":"auto","created_at":"2026-03-13 07:29:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":62230,"visible":true,"origin":"","legend":"\u003cp\u003eUltrasound image showing the maxilla anteriorly, the pterygopalatine fossa, and the sphenoid posteriorly. Asterisk represents the needle target for local deposition.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8900945/v1/88771a38d5aa9bb3588510b3.png"},{"id":104781511,"identity":"ac9e71c8-abe0-4a5a-9591-46b310f30639","added_by":"auto","created_at":"2026-03-17 07:55:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":187536,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplots of the distribution of opioid consumption by block group and palate type. Boxes show the 25th, 50th, and 75th percentiles of the data, whiskers extend 1.5 x IQR from the median. MME, morphine milligram equivalents.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8900945/v1/49fc5f933f38888f60fe9cc2.png"},{"id":104784799,"identity":"ed6eec1b-bb1b-4213-bd98-2f784165fb8f","added_by":"auto","created_at":"2026-03-17 08:08:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1146968,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8900945/v1/21b69989-6d9b-4b6e-b6fb-f1e7108402bb.pdf"},{"id":104781728,"identity":"6585da04-f8a9-4520-a2ee-fce7f44e34e6","added_by":"auto","created_at":"2026-03-17 07:56:15","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":16406,"visible":true,"origin":"","legend":"","description":"","filename":"AppendixA.docx","url":"https://assets-eu.researchsquare.com/files/rs-8900945/v1/bda4781f1c1c552bec8ee854.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ultrasound-guided suprazygomatic maxillary nerve blocks for pediatric cleft palate repair: a retrospective analysis","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eCleft palate is one of the most common congenital abnormalities, with an incidence of approximately 1 per 1623 live births in the United States [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. To optimize speech outcomes in patients with cleft palate, experimental and large-cohort data support palatal repair before or very early in speech onset. For example, in the Timing Of Primary Surgery for Cleft Palate (TOPS) trial, palatal repair at 6 months old yielded lower velopharyngeal insufficiency at 5 years old and better early babbling and hearing than repair at 12 months old [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Also, in a large observational study, earlier repair was linked to superior speech and language at 20 months old and 5 years old [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Interestingly, surgical repair before 6 months old has similar outcomes to repair between 6 and 18 months old. However, repair before 6 months old carries a higher risk of perioperative complications, readmissions, and reoperations [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Also, cleft palate repair is often complicated by postoperative airway obstruction, respiratory distress, and significant perioperative pain [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Furthermore, postoperative agitation and crying increase the risk of wound dehiscence and fistula formation, highlighting the need for effective perioperative analgesia in pediatric patients undergoing palatoplasty [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo manage postoperative pain and improve surgical outcomes for cleft palate repair, various analgesic regimens are used. Many protocols combine opioid analgesics with alternating acetaminophen, nonsteroidal anti-inflammatory drugs, or cyclooxygenase-2-specific inhibitors during both the intraoperative and postoperative periods [\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, opioids and non-opioid adjuncts can contribute to respiratory complications and exacerbate postoperative bleeding [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In particular, infants are vulnerable to opioid-induced respiratory depression due to slower elimination and varied drug clearance [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Also, opioids can lead to lethargy and reduced oral intake, which are crucial indicators of recovery after cleft palate repair [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAs an alternative analgesic strategy, regional nerve blocks have gained increasing acceptance. Regional nerve blocks show effective postoperative pain relief, reduced opioid consumption, rapid recovery of alertness, and earlier initiation of feeding\u0026mdash;potentially leading to earlier discharge [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In palatal surgery, regional anesthesia offers the advantage of a lower risk of respiratory depression than that associated with opioids [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. A particularly promising regional anesthesia technique is ultrasound-guided suprazygomatic maxillary nerve (SZMN) block, which is a safe, feasible, and efficacious approach for perioperative analgesia [\u003cspan additionalcitationids=\"CR19 CR20\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Patients who received an SZMN block before palatoplasty had significantly lower postoperative opioid consumption [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Furthermore, SZMN blocks have been associated with a shorter hospital length of stay (LOS) [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], less intraoperative opioid use [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], and reduced time to first oral intake [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, many of these studies did not use the ultrasound-guided technique nor show reduced intraoperative opioid consumption [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo assess how ultrasound-guided bilateral SZMN blocks affect pain management for cleft palate repair, we compared outcomes between pediatric patients who did and did not receive an ultrasound-guided SZMN block for this repair surgery. We used opioid consumption as a surrogate measure of analgesic efficacy.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Population\u003c/h2\u003e \u003cp\u003e In this retrospective observational study, we reviewed the electronic health records of pediatric patients under the age of 18 years who underwent cleft palate repair at the Medical University of South Carolina (MUSC) between January 1, 2020, and February 15, 2023. Exclusion criteria included patients who (1) were admitted to the intensive care unit postoperatively or (2) underwent additional invasive surgical procedures during the cleft palate repair, with a few exceptions. Certain invasive surgical procedures (myringotomy tube placement, nasal endoscopy, microlaryngoscopy, bronchoscopy, and correction of lip or tongue ties) were excepted because they do not typically require postoperative opioid analgesia. This retrospective observational study was reviewed by the Medical University of South Carolina Institutional Review Board (Pro00127080) and determined to be exempt. The requirement for informed consent was waived. This study was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.\u003c/p\u003e \u003cp\u003eThe primary outcome of the study was the total amount of opioids consumed during the hospital stay, measured as morphine milligram equivalents per kilogram (MME/kg). Secondary outcomes included postoperative opioid consumption (within 72 hours of surgery), intraoperative opioid consumption, opioid use in the post-anesthesia care unit (PACU), postoperative opioid use, PACU and hospital length of stay, and time to first feeding. Demographic and medical data were collected, including age at the time of surgery (in months), biological sex, proxy-reported race and ethnicity, American Society of Anesthesiologists (ASA) status, cleft palate type (submucous, Veau class I-IV), procedures performed, and operative details (eg, timing of surgery). If Veau classification was not explicitly documented, it was inferred from operative and chart notes. Also, data on the use of non-opioid medications both intraoperatively and postoperatively were recorded.\u003c/p\u003e \u003cp\u003e This study is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eAnesthetic and Block Techniques\u003c/h3\u003e\n\u003cp\u003eAnesthetic management was at the discretion of the anesthesiologist, though all patients received general endotracheal anesthesia. The decision to perform a block was made collaboratively by the anesthesiologist and surgeon, with parental consent.\u003c/p\u003e \u003cp\u003eThe ultrasound-guided SZMN block was placed after induction of general anesthesia. A 15\u0026thinsp;\u0026minus;\u0026thinsp;6 MHz linear ultrasound probe (Sonosite, Bothell, WA) was placed in the infrazygomatic area over the maxilla, at approximately a 45-degree angle in the frontal and horizontal planes. This placement allowed visualization of the pterygopalatine fossa with the maxilla anteriorly and the greater wing of the sphenoid posteriorly. Then a 27-gauge, 30-mm needle (BD PrecisionGlide, Franklin Lakes, NJ) was inserted with an out-of-plane technique at the estimated angle formed by the superior edge of the zygomatic arch and the posterior orbital rim, lateral to the corner of the eye, at approximately a 45-degree angle, with a trajectory toward the midline. Local anesthetic was injected with visualization of spread in the pterygopalatine fossa (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003ePower Analysis\u003c/h2\u003e \u003cp\u003eBefore the study, statistical power was approximated. We estimated that MUSC performs approximately 50 cleft palate repairs per year, of which approximately 40 involve pediatric patients who receive an ultrasound-guided SZMN block. Therefore, we anticipated a study population of approximately 80 pediatric patients who underwent cleft palate repair, with 40 of them receiving the ultrasound-guided SZMN block.\u003c/p\u003e \u003cp\u003eA recent study evaluated postoperative opioid consumption after cleft palate repair [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. This study found that pediatric patients who received standard care consumed an average of 0.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4 oral MME/kg, whereas pediatric patients in the Enhanced Recovery After Surgery pathway consumed 0.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 oral MME/kg. We hypothesized that patients who did not receive an ultrasound-guided SZMN block would have an average opioid consumption of 0.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4 oral MME/kg, and patients who did receive an ultrasound-guided SZMN block would have an average opioid consumption of approximately 0.53 oral MME/kg (25% reduction). We also assumed a standard deviation of 0.25 MMEs in the ultrasound-guided SZMN block group, with a 2-sided test and significance level of α\u0026thinsp;=\u0026thinsp;0.05. Based on these assumptions, a sample size of 80 patients who did not receive an SZMN block and 40 patients who received an ultrasound-guided SZMN block would provide 80% power to detect a 25% reduction in opioid consumption.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eData Analysis\u003c/h2\u003e \u003cp\u003eDescriptive statistics were computed for all patient characteristics by SZMN block status. Continuous variables are presented as mean (SD) or median (IQR), depending on data distribution, while categorical variables are expressed as No. (%). Differences in patient characteristics between groups were assessed using 2-sample t-tests or Wilcoxon rank-sum tests for continuous and ordinal variables, and chi-square tests or Fisher\u0026rsquo;s exact tests for categorical variables.\u003c/p\u003e \u003cp\u003eFor the primary outcome, initial comparisons of opioid consumption between the 2 groups and with other variables were conducted using a series of univariate linear regression models. To account for potential confounders and variability, we also developed a linear regression model that considered all variables with univariate significance (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.2). Backward stepwise selection was used to determine the final model. Covariates that remained significant in the final multivariable model (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) were retained. Total MME/kg was natural log-transformed to meet model assumptions, and results are presented as the percentage difference in total MME/kg consumed. All statistical analyses were performed using SAS v.9.4 (SAS Institute, Cary, NC). All statistical tests were two-sided, and a P value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003e The total study population included 74 pediatric patients, of whom 46 did not receive an ultrasound-guided SZMN block and 28 received an ultrasound-guided SZMN block. The population was predominantly male (female: 41% [30 of 74]; male: 59% [44 of 74]) and White (Black: 21.6% [16 of 74]; White: 64.9% [48 of 74]; Other/Unknown: 13.5% [10 of 74]). The median (IQR) age was 11.4 (10.1\u0026ndash;15.6) months. There was no difference in age, sex, race, ethnicity, weight, ASA status, or type of surgery (Supplemental Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e) between patients who did and did not receive the SZMN block (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatient and Procedural Characteristics by Block Group (N\u0026thinsp;=\u0026thinsp;74)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo SZMN block \u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;46)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSZMN block \u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;28)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e11.8 (10.1, 16.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.5 (9.7, 14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.153\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight, kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.5 (8.1, 10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8.7 (8.0, 9.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.214\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.509\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20 (43.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10 (35.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26 (56.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18 (64.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRace\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.989\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlack\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10 (21.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6 (21.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWhite\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e30 (65.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18 (64.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther/Unknown\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6 (13.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (14.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEthnicity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.703\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHispanic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5 (10.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2 (7.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-Hispanic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e41 (89.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26 (92.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASA status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.241\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4 (8.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6 (21.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33 (71.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19 (67.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9 (19.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e*Type of cleft palate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVeau I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVeau II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23 (51.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (14.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVeau III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVeau IV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10 (35.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSubmucosal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4 (8.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8 (28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgery type\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleft palate only\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19 (41.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8 (28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.270\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleft palate and ear tubes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26 (56.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19 (67.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.333\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleft palate and other\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22 (47.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16 (57.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.437\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eValues are presented as median (Q1, Q3) or number (%). SZMN: suprazygomatic maxillary nerve; ASA: American Society of Anesthesiologists. *Data for cleft palate type were available for 45 patients. It was unavailable for some patients due to incomplete documentation in the electronic health record.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe type of cleft palate differed between groups (global \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003). A greater proportion of patients in the SZMN block group had Veau IV and submucosal cleft palates, whereas a greater proportion of patients in the no-SZMN block group had Veau III cleft palates. Patients in the SZMN block group also had a significantly longer time from induction to anesthesia-ready (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.002). However, there was no difference in total anesthesia time or intraoperative time between patients who did and did not receive an SZMN block (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProcedural, Analgesia, and Postoperative Outcomes by Block Group (N\u0026thinsp;=\u0026thinsp;74)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo SZMN block (n\u0026thinsp;=\u0026thinsp;46)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSZMN block (n\u0026thinsp;=\u0026thinsp;28)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of local anesthetic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRopivacaine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24 (85.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBupivacaine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (14.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal block time, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.5 (3.0, 8.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime from induction to anesthesia-ready, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.5 (10.0, 19.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21.5 (14.5, 29.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal anesthesia time, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e288 (237.0, 339.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e307 (286.0, 344.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.086\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePACU LOS, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60 (44.0, 91.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e47 (36.0, 67.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.053\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative time, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e284 (239.0, 329.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e321 (286.5, 354.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.075\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative opioids, MME/kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.35 (0.15, 0.52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.21 (0.13, 0.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther intraoperative medications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.173\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcetaminophen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33 (71.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25 (89.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKetamine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0 (0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePACU opioids, MME/kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 0.048)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 0.049)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.966\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther PACU medications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcetaminophen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (30.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2 (7.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIbuprofen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1 (3.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (67.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25 (89.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFloor opioids, MME/kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 0.076)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.279\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther floor medications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.651\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcetaminophen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34 (73.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22 (78.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIbuprofen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6 (21.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal opioids, MME/kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.44 (0.23, 0.58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.24 (0.16, 0.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime to first successful feeding, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e302.5 (189.0, 607.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e304.5 (168.5, 482.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.881\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHospital LOS, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1630.5 (1267.0, 2776.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2317.5 (1275.0, 2825.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.863\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eValues are presented as number (%) or median (Q1, Q3). SZMN: suprazygomatic maxillary nerve; NA: not applicable; PACU: post-anesthesia care unit; LOS: length of stay; MME: morphine milligram equivalents.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003ePrimary Outcome\u003c/h3\u003e\n\u003cp\u003eIn a univariate analysis, there was a significant difference in overall opioids consumed between patients who did and did not receive an ultrasound-guided SZMN block. Patients who did not receive an SZMN block consumed, on average, 57% more opioids than patients who received an SZMN block (mean percent difference [95% CI]: 57.2 [11.7, 121.5]; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.012). We also examined associations between opioid consumption and additional patient and procedural factors. In a univariate model, less opioid consumption was associated with a longer time from induction to anesthesia-ready (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003), and greater opioid consumption was associated with higher ASA status (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.043). Also, the global test revealed a significant association between opioid consumption and palate type (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.050). In pairwise comparisons, patients with submucosal cleft palate consumed less opioids on average than patients with Veau II, III, or IV cleft palates. Also, patients with Veau III cleft palates consumed less opioids than patients with Veau I cleft palates (Global F-test, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.050) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo determine associations of ultrasound-guided SZMN blocks after controlling for other factors, we developed a multivariable regression model of opioid consumption. All variables significant at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.2 in univariate models were considered. The final model included block group, palate type, whether patients received additional non-narcotic medications intraoperatively, and time from induction to anesthesia-ready. Patients who did not receive an ultrasound-guided SZMN block had a 49% higher opioid consumption than that of patients who received an SZMN block when controlling for complete cleft palate status, use of non-narcotic medications intraoperatively, and time from induction to anesthesia-ready (mean percent increase [95% CI]: 48.9 [4.41, 112.4]; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.031). Patients with submucosal cleft palates consumed significantly less opioids than patients with Veau III and Veau IV cleft palates, and patients with Veau III cleft palates consumed significantly more opioids than patients with Veau I or II cleft palates. Patients who had a complete cleft palate repair consumed, on average, 70% more opioids than patients with other types of surgeries, when adjusting for block group, use of non-narcotic medications intraoperatively, and induction time (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003). Patients who received adjuvant pain medications intraoperatively also consumed 36% less opioids than those who did not, when controlling for other factors (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.029). A 5-minute increase in induction time was associated with a 10% reduction in overall opioids consumed, when controlling for other factors (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.034) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003ch3\u003eSecondary Outcomes\u003c/h3\u003e\n\u003cp\u003eWe also examined opioid use intraoperatively, in the PACU, on the floor, and total overall postoperatively (PACU\u0026thinsp;+\u0026thinsp;floor). There were no notable differences in opioids received in the PACU (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.966), on the floor (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.279), or overall postoperatively (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.568). However, patients who did not receive an SZMN block consumed significantly more opioids intraoperatively than patients who did receive an SZMN block (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWe also examined PACU LOS, time to first successful feeding, and hospital LOS. Patients who did not receive an ultrasound-guided SZMN block had a longer PACU LOS (median, 60 minutes) than patients who received an ultrasound-guided SZMN block (median, 47 minutes), though the difference was not significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.053) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). There were no notable differences in the time to first successful feeding (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.881) or hospital LOS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.863) between the groups (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eEffective perioperative analgesia that minimizes opioid exposure remains a central goal in contemporary pediatric anesthesia practice, particularly for infants and young children undergoing procedures associated with significant postoperative pain, such as cleft palate repair. In this retrospective observational study, we found that ultrasound-guided bilateral suprazygomatic maxillary nerve blocks were associated with substantially lower perioperative opioid consumption without adversely affecting recovery milestones. These findings contribute to the growing international literature supporting ultrasound-guided regional anesthesia as a feasible and opioid-sparing component of multimodal analgesia strategies in pediatric perioperative care.\u003c/p\u003e \u003cp\u003eIn pediatric cleft palate repair, effective pain management is essential. Pain management not only improves comfort but also prevents complications, such as poor oral intake, delayed recovery, and wound dehiscence from agitation or crying [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Although pain is commonly managed with opioid analgesics, these drugs are associated with significant risks, including respiratory depression, sedation, and gastrointestinal effects (eg, nausea, vomiting, constipation) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Also, in infants and young children, repeated exposure to high doses of opioids may pose risks to neurodevelopment [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. These findings underscore the need to reduce opioid use in pediatric anesthesia and pain management. In our study, we found that ultrasound-guided blocks were associated with significantly reduced opioid consumption in pediatric patients undergoing cleft palate repair. Thus, integrating these blocks into enhanced recovery pathways for cleft palate repair could further advance safe, efficient, and patient-centered care while minimizing the risks of long-term opioid exposure in this vulnerable population.\u003c/p\u003e \u003cp\u003eOur findings align with prior findings that regional anesthesia techniques, including SZMN blocks, can reduce opioid requirements and improve perioperative outcomes [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Indeed, Stanek et al found a 57% reduction in total intraoperative opioid requirements, while controlling for syndromic status and cleft phenotype [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. However, other findings have been inconsistent. For example, Mesnil et al [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] and Chiono et al [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] reported no significant difference in intraoperative opioid consumption. Also, Echaniz et al [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] found a reduction in intraoperative nalbuphine and a weak reduction in fentanyl consumption. However, their study combined cleft lip and palate repair, which are remarkably different procedures, and did not use the ultrasound technique.\u003c/p\u003e \u003cp\u003eIn our study, we exclusively used the ultrasound-guided technique. However, other studies used this approach inconsistently or not at all [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Although limited evidence specifically supports ultrasound-guided SZMN blocks, ultrasound guidance for regional anesthesia increased block success, reduced procedure time, lowered incidence of vascular puncture, decreased the required local anesthetic volume, and increased safety through real-time needle and anatomy visualization [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Also, from a technical standpoint, ultrasound-guided SZMN blocks can be performed quickly in a median of 4.5 minutes in our dataset. This timeframe underscores the feasibility of using this approach without significantly prolonging anesthesia time in pediatric patients undergoing cleft palate repair. Also, ultrasound guidance offers real-time visualization of relevant anatomy and needle trajectory, which may enhance block accuracy, safety, and reproducibility. These features make SZMN blocks an attractive addition to multimodal analgesia protocols, particularly in centers with regional anesthesia expertise. In future work, multicenter studies could assess the reproducibility of our results in settings with varying pediatric anesthesia expertise and also examine the learning curve for SZMN block placement to inform training guidelines.\u003c/p\u003e \u003cp\u003eAlthough we observed a shorter PACU LOS among the SZMN block group, this finding was not statistically significant. However, the shorter trend suggests improved recovery in the early postoperative period and could reflect better pain control, less need for rescue analgesics, and more rapid emergence from anesthesia. We also observed no differences in the time to first feeding or hospital LOS. These findings were not unexpected, because these endpoints are often influenced more by institutional feeding protocols, surgeon-specific discharge criteria, and non-pain-related factors, such as airway monitoring needs or family readiness for discharge. However, our study may have been underpowered to detect small but clinically meaningful differences in these outcomes. Thus, future studies should be powered to evaluate not only opioid consumption but also functional recovery outcomes, such as feeding tolerance, readiness for discharge, speech development, and parental satisfaction.\u003c/p\u003e \u003cp\u003eWe completed multivariate analysis to account for key potential confounders, including cleft type, intraoperative non-narcotic medication use, and time from induction to anesthesia-ready. We found that the association between SZMN block use and reduced opioid consumption persisted after adjustment, further supporting a causal effect. Nonetheless, unmeasured variables\u0026mdash;such as anesthetic depth, subtle differences in surgical technique, or provider preferences for pain management\u0026mdash;may still have contributed to the observed differences. To validate our findings and minimize residual confounding, prospective randomized controlled trials are needed.\u003c/p\u003e \u003cp\u003eOur findings need to be interpreted in the context of a few limitations. First, the retrospective design precludes definitive causal inference. Second, although our power calculation indicated the need for a larger sample size, the final cohort was smaller because this was a retrospective analysis restricted to the available cases of cleft palate repair during the study period. As a result, the sample size was determined by existing clinical records rather than prospective recruitment, which may have limited the statistical power to detect differences in some secondary outcomes. Third, there is a possibility of selection bias given the unequal distribution of cleft types between groups\u0026mdash;the SZMN block group had more Veau IV and submucosal clefts, whereas the no-SZMN block group had more Veau III clefts. Although cleft type was adjusted for in multivariate models, residual confounding is possible. Fourth, if Veau classification was not explicitly documented, it was inferred from operative and chart notes, which may have led to misclassification. Finally, at our institution, there is not a standard opioid order for patients after cleft palate repair on the floor, and nursing staff were required to obtain physician approval for opioid orders. Thus, true analgesic needs may have been misestimated, and our findings may not be generalizable to institutions with different prescribing models. Nevertheless, these results provide clinically relevant evidence supporting the feasibility and potential opioid-sparing benefits of ultrasound-guided SZMN blocks in pediatric cleft palate repair. With standardized postoperative analgesia protocols, the true effect of SZMN blocks can be better clarified and compared across institutions.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003e We found that ultrasound-guided SZMN blocks were associated with significantly reduced opioid consumption by nearly 50% and improved recovery profiles in pediatric patients undergoing cleft palate repair. SZMN blocks were placed rapidly and safely, demonstrating the feasibility of using this approach in this population. By substantially reducing opioid requirements while maintaining effective pain control, SZMN blocks offer a safe, efficient, and reproducible option for perioperative analgesia in a population particularly vulnerable to opioid-related adverse effects. This approach also aligns with current priorities in pediatric anesthesia for opioid-sparing, multimodal pain management. Although prospective randomized trials are needed to confirm our findings and evaluate broader recovery outcomes, our findings support the incorporation of SZMN blocks into standard analgesic protocols for pediatric cleft palate repair.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eASA\u003c/em\u003e:\u003c/strong\u003e American Society of Anesthesiologists\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCI\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eConfidence Interval\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eICU\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eIntensive Care Unit\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eIQR\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eInterquartile Range\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eLOS\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eLength of Stay\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMME\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eMorphine Milligram Equivalents\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMME/kg\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eMorphine Milligram Equivalents per Kilogram\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMUSC\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eMedical University of South Carolina\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eNA\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePACU\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003ePost-Anesthesia Care Unit\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSD\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003eStandard Deviation\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSZMN\u003c/em\u003e:\u0026nbsp;\u003c/strong\u003e Suprazygomatic Maxillary Nerve\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e- This retrospective study was reviewed by the Medical University of South Carolina Institutional Review Board (Pro00127080) and determined to be exempt.The requirement for informed consent was waived by the institutional review board.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e \u0026ndash; Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e \u0026ndash; The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e \u0026ndash; The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e - This research did not receive any specific external funding. This work was supported by internal departmental support (Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina). This project was also supported by the South Carolina Clinical \u0026amp; Translational Research Institute, Medical University of South Carolina\u0026rsquo;s CTSA, NIH/NCRR Grant Number 1UL1TR001450.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAMB contributed to study conception, data acquisition, and manuscript drafting and revision.\u003cbr\u003e\u0026nbsp;GB and JVS contributed to data collection and manuscript drafting.\u003cbr\u003e\u0026nbsp;BJW performed statistical analysis.\u003cbr\u003e\u0026nbsp;NRB contributed to data collection and manuscript drafting.\u003cbr\u003e\u0026nbsp;All authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e - The authors acknowledge Dr. Phayvanh Pecha, MD, MPH, and Dr. Krishna Patel, MD, PhD, for their support of this study and their role in adopting the suprazygomatic maxillary nerve block in our clinical practice. We also thank Haley Nitchie, MHA, Research Program Manager, for her invaluable support throughout the study. Professional editorial support in preparing the manuscript was provided by Crystal Herron, PhD, ELS(D), of Redwood Ink, LLC.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMai CT, Isenburg JL, Canfield MA, Meyer RE, Correa A, Alverson CJ, et al. National population-based estimates for major birth defects, 2010-2014. Birth Defects Res. 2019;111(18):1420-35.\u003c/li\u003e\n\u003cli\u003eGamble C, Persson C, Willadsen E, Albery L, Soegaard Andersen H, Zattoni Antoneli M, et al. Timing of primary surgery for cleft palate. N Engl J Med. 2023;389(9):795-807.\u003c/li\u003e\n\u003cli\u003eShaffer AD, Ford MD, Losee JE, Goldstein J, Costello BJ, Grunwaldt LJ, et al. The association between age at palatoplasty and speech and language outcomes in children with cleft palate: An observational chart review study. Cleft Palate Craniofac J. 2020;57(2):148-60.\u003c/li\u003e\n\u003cli\u003ePeck CJ, Gowda AU, Shultz BN, Wu RT, Bourdillon A, Singh A, et al. The effect of surgical timing on 30-day outcomes in cleft palate repair. Plast Reconstr Surg. 2021;147(1):131-7.\u003c/li\u003e\n\u003cli\u003eFell M, Fenner L, Fallico N. Demystifying the suprazygomatic maxillary nerve block in paediatric cleft palate surgery. Cleft Palate Craniofac J. 2024:10556656241284514.\u003c/li\u003e\n\u003cli\u003eJacobs-El H, Samuel A, Chen X, Yemen T, Gampper T, Black J. Utility of regional maxillary nerve blocks in improving cleft palate postoperative outcomes. J Craniofac Surg. 2023;34(5):1511-4.\u003c/li\u003e\n\u003cli\u003eSuleiman NN, Luedi MM, Joshi G, Dewinter G, Wu CL, Sauter AR. Perioperative pain management for cleft palate surgery: A systematic review and procedure-specific postoperative pain management (prospect) recommendations. Reg Anesth Pain Med. 2024;49(9):635-41.\u003c/li\u003e\n\u003cli\u003eCepeda A, Jr., Johnson ML, Kelagere K, Obinero CG, Nguyen PD, Greives MR. The limit is zero: A prospective evaluation of ketorolac in patients undergoing primary palatoplasty to reduce narcotic utilization. J Craniofac Surg. 2023;34(6):1713-6.\u003c/li\u003e\n\u003cli\u003eEsfahanian M, Marcott SC, Hopkins E, Burkart B, Khosla RK, Lorenz HP, et al. Enhanced recovery after cleft palate repair: A quality improvement project. Paediatr Anaesth. 2022;32(10):1104-12.\u003c/li\u003e\n\u003cli\u003eMoffitt JK, Cepeda A, Jr., Ekeoduru RA, Teichgraeber JF, Nguyen PD, Greives MR. Enhanced recovery after surgery protocol for primary cleft palate repair: Improving transition of care. J Craniofac Surg. 2021;32(1):e72-e6.\u003c/li\u003e\n\u003cli\u003eOberhofer HM, Breslin N, Heindel H, Ching J. Analgesic efficacy of intraoperative nerve blocks for primary palatoplasty. J Craniofac Surg. 2021;32(2):594-6.\u003c/li\u003e\n\u003cli\u003eEmoto C, Johnson TN, Neuhoff S, Hahn D, Vinks AA, Fukuda T. Pbpk model of morphine incorporating developmental changes in hepatic oct1 and ugt2b7 proteins to explain the variability in clearances in neonates and small infants. CPT Pharmacometrics Syst Pharmacol. 2018;7(7):464-73.\u003c/li\u003e\n\u003cli\u003eOlkkola KT, Hamunen K, Maunuksela EL. Clinical pharmacokinetics and pharmacodynamics of opioid analgesics in infants and children. Clin Pharmacokinet. 1995;28(5):385-404.\u003c/li\u003e\n\u003cli\u003ePokela ML, Anttila E, Sepp\u0026auml;l\u0026auml; T, Olkkola KT. Marked variation in oxycodone pharmacokinetics in infants. Paediatr Anaesth. 2005;15(7):560-5.\u003c/li\u003e\n\u003cli\u003eChiono J, Raux O, Bringuier S, Sola C, Bigorre M, Capdevila X, et al. Bilateral suprazygomatic maxillary nerve block for cleft palate repair in children: A prospective, randomized, double-blind study versus placebo. Anesthesiology. 2014;120(6):1362-9.\u003c/li\u003e\n\u003cli\u003eEchaniz G, De Miguel M, Merritt G, Sierra P, Bora P, Borah N, et al. Bilateral suprazygomatic maxillary nerve blocks vs. Infraorbital and palatine nerve blocks in cleft lip and palate repair: A double-blind, randomised study. Eur J Anaesthesiol. 2019;36(1):40-7.\u003c/li\u003e\n\u003cli\u003eMesnil M, Dadure C, Captier G, Raux O, Rochette A, Canaud N, et al. A new approach for peri-operative analgesia of cleft palate repair in infants: The bilateral suprazygomatic maxillary nerve block. Paediatr Anaesth. 2010;20(4):343-9.\u003c/li\u003e\n\u003cli\u003eLin C, Abboud S, Zoghbi V, Kasimova K, Thein J, Meister KD, et al. Suprazygomatic maxillary nerve blocks and opioid requirements in pediatric adenotonsillectomy: A randomized clinical trial. JAMA Otolaryngol Head Neck Surg. 2024;150(7):564-71.\u003c/li\u003e\n\u003cli\u003eMolins G, Valls-Onta\u0026ntilde;\u0026oacute;n A, De Nadal M, Hern\u0026aacute;ndez-Alfaro F. Ultrasound-guided suprazygomatic maxillary nerve block is effective in reducing postoperative opioid use following bimaxillary osteotomy. J Oral Maxillofac Surg. 2024;82(4):412-21.\u003c/li\u003e\n\u003cli\u003eNeupane A, Jain D, Arora S, Gandhi K, Singla V, Goel N, et al. Evaluation of ultrasound-guided suprazygomatic maxillary nerve block in functional endoscopic sinus surgery for postoperative pain relief: A randomised controlled trial. Indian J Anaesth. 2024;68(8):706-11.\u003c/li\u003e\n\u003cli\u003eSola C, Raux O, Savath L, Macq C, Capdevila X, Dadure C. Ultrasound guidance characteristics and efficiency of suprazygomatic maxillary nerve blocks in infants: A descriptive prospective study. Paediatr Anaesth. 2012;22(9):841-6.\u003c/li\u003e\n\u003cli\u003eStanek K, Alrayashi W, Nussbaum L, Ganske IM, Rogers-Vizena CR. Suprazygomatic maxillary nerve block in palatoplasty: A retrospective cohort study of perioperative outcomes in syndromic and non-syndromic children. Cleft Palate Craniofac J. 2025;62(6):976-84.\u003c/li\u003e\n\u003cli\u003eSquillaro A, Mahdi EM, Tran N, Lakshmanan A, Kim E, Kelley-Quon LI. Managing procedural pain in the neonate using an opioid-sparing approach. Clin Ther. 2019;41(9):1701-13.\u003c/li\u003e\n\u003cli\u003eNeal JM, Brull R, Chan VW, Grant SA, Horn JL, Liu SS, et al. The asra evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary. Reg Anesth Pain Med. 2010;35(2 Suppl):S1-9.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"cleft palate, nerve block, pediatric anesthesia, pain management, maxillary nerve, regional anesthesia","lastPublishedDoi":"10.21203/rs.3.rs-8900945/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8900945/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eEffective opioid-sparing analgesia is essential in pediatric cleft palate repair, as infants and young children are vulnerable to opioid-related adverse effects. Ultrasound-guided suprazygomatic maxillary nerve (SZMN) blocks have emerged as a promising regional anesthesia technique, but evidence supporting their effectiveness remains limited.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective observational cohort study of pediatric patients younger than 18 years who underwent cleft palate repair at a single tertiary academic medical center between January 2020 and February 2023. The primary outcome was total perioperative opioid consumption, measured as morphine milligram equivalents per kilogram (MME/kg). Secondary outcomes included intraoperative and postoperative opioid use, time to first successful feeding, and length of hospital stay. Multivariable linear regression was used to adjust for potential confounders, including cleft type and perioperative factors.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eSeventy-four patients met inclusion criteria, of whom 28 received an ultrasound-guided SZMN block. Patients who did not receive an SZMN block consumed significantly more opioids (57% higher; 95% confidence interval [CI], 11.7\u0026ndash;121.5; P\u0026thinsp;=\u0026thinsp;0.012). After adjustment for cleft type and perioperative variables, absence of an SZMN block remained independently associated with higher opioid consumption (48.9% increase; 95% CI, 4.41\u0026ndash;112.4; P\u0026thinsp;=\u0026thinsp;0.031). Intraoperative opioid use was also significantly lower in the SZMN block group. No differences were observed in postoperative opioid use, time to first feeding, or hospital length of stay.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eUltrasound-guided SZMN blocks were associated with significantly reduced perioperative opioid consumption in pediatric cleft palate repair without prolonging recovery. Prospective studies are warranted to confirm these findings.\u003c/p\u003e","manuscriptTitle":"Ultrasound-guided suprazygomatic maxillary nerve blocks for pediatric cleft palate repair: a retrospective analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-13 07:29:42","doi":"10.21203/rs.3.rs-8900945/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-27T12:51:09+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-25T22:42:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"291545618748997176564402338824388442869","date":"2026-03-25T19:57:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"251711425727352593965681757836184993323","date":"2026-03-25T13:26:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-22T20:54:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250984040265449992989305779007084501312","date":"2026-03-12T18:10:21+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-06T09:31:26+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-06T09:29:25+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-24T06:24:51+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-20T16:00:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-02-20T15:55:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d6cac3a6-d691-49e1-b8ba-a5f3035ea777","owner":[],"postedDate":"March 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":64245325,"name":"Health sciences/Diseases"},{"id":64245326,"name":"Health sciences/Health care"},{"id":64245327,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2026-03-27T13:21:09+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-13 07:29:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8900945","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8900945","identity":"rs-8900945","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}