Applied forces during neonatal intubation with direct and video laryngoscopy at different bed elevations: a randomized crossover manikin study

Applied forces during neonatal intubation with direct and video laryngoscopy at different bed elevations: a randomized crossover manikin study | 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 Research Article Applied forces during neonatal intubation with direct and video laryngoscopy at different bed elevations: a randomized crossover manikin study Francesco Cavallin, Greta Pasquali, Sabina Maglio, Paolo Ernesto Villani, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6469496/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Nov, 2025 Read the published version in European Journal of Pediatrics → Version 1 posted 8 You are reading this latest preprint version Abstract We compared intubation forces, success of the first attempt, intubation time and participant’s opinions using direct and video laryngoscopy at umbilical and xiphoidal bed heights in a neonatal manikin. A randomized controlled crossover trial of intubation using direct and video laryngoscopes at two different table elevations (operator’s xiphoid or navel) in a neonatal manikin model. Thirty-two neonatologists and pediatric residents participated. The primary outcome measure was the force applied to epiglottis and palate of neonatal manikin during intubation. The secondary outcome measures included success of the first attempt, intubation time, and participants' opinion on the procedures. Intubating the neonatal manikin with the videolaryngoscope and the resuscitation table leveled at operator’s navel was associated with the lowest forces applied to the epiglottis and the hard palate. On the other hand, the combination of direct laryngoscope and resuscitation table leveled at operator’s xiphoid was associated with the highest applied forces. The success rate at the first attempt and the intubation time were not statistically different among the combinations of laryngoscopes and table elevations. In contrast to actual measurements, most participants believed to have used less forces when the table leveled at operator’s xiphoid. Conclusions In a neonatal manikin model, the lower force applied during intubation with a videolaryngoscope and the resuscitation table leveled at operator’s navel may be a desirable objective, but the clinical implications should be evaluated in clinical studies. Registration : clinicaltrial.gov NCT06474572 force intubation manikin neonate Figures Figure 1 Figure 2 What is known Intubation success may be influenced by procedure-related aspects such as the position of the patient in relation with the operator. The Neonatal Resuscitation Program recommends adjusting the bed height to align the baby's head with operator's upper abdomen or lower chest, while positioning the bed height at approximately elbow height is also suggested. The bed height might affect the applied forces during neonatal intubation and the intubation success, but such information is currently lacking. What is new In a neonatal manikin model, intubating with a videolaryngoscope and the resuscitation table leveled at operator’s navel was associated with the lowest forces applied to the epiglottis and the hard palate. The participants achieved a high success rate at the first attempt and comparable procedure times with all combinations of direct/video laryngoscope and low/high bed elevation. Applying lower forces during neonatal intubation may be desirable but the clinical implications remain to be evaluated in clinical studies. INTRODUCTION Intubating at birth is required in approximately 1% of neonates ( 1 ). Nonetheless, health care providers have limited exposure to neonatal intubation because of the implementation of less invasive procedures, such as continuous positive airway pressure and nasal intermittent positive pressure ventilation ( 2 , 3 ). Laryngoscopy is an invasive and potentially harmful procedure, which has been associated with adverse events including airway trauma, bradycardia, hypoxia, and intraventricular hemorrhage ( 4 – 6 ). Videolaryngoscopy improves the intubation success at the first attempt compared to direct laryngoscopy in neonates, and seems to decrease the incidence of adverse events ( 7 – 9 ). During the intubation procedure, the movements create compression forces on the soft tissues that can cause tissue ischemia or perforation, adverse clinical reactions, or future developmental issues in the surrounding structures (4,6,7,9–11). According to a neonatal manikin trial, lower forces are applied with videolaryngoscopy compared to direct laryngoscopy, suggesting possible benefits in reducing patient harm during intubation ( 12 ). Intubation success may be influenced by procedure-related aspects such as the position of the patient in relation with the operator. In adults, the literature offers conflicting findings, which include suggesting the bed height to the level of operator’s xiphoid ( 13 – 15 ), navel ( 14 , 16 ), or no preference among different bed height ( 17 , 18 ). The Neonatal Resuscitation Program recommends adjusting the bed height to align the baby's head with operator's upper abdomen or lower chest ( 11 ), while a recent study suggested positioning the bed height at approximately elbow height ( 19 ). We assumed that the bed height might affect the applied forces during neonatal intubation, but such information is currently lacking. This trial compared intubation forces applied with direct and video laryngoscopy at umbilical and xiphoidal bed heights in a neonatal manikin. Furthermore, success of the first attempt, intubation time and participant’s opinions about the procedures were investigated. METHODS Study design This was a randomized, controlled, crossover trial of intubation using direct and video laryngoscopes at two different table elevations in a neonatal manikin model (clinicaltrials.gov NCT06474572). The trial employed a 4-sequence, 4-period, 4-treatment scheme (ADBC/BACD/CBDA/DCAB) which is uniform within sequences and periods, and balanced with respect to first-order carryover effects ( 20 ). The Ethics Committees of the University Hospital of Padua (Italy) reviewed and approved this manikin study (Prot. 536n/AO/24). The participants provided their written informed consent. Setting This simulation study was performed at the University Hospital of Padua (Italy) between 1st and 5th July 2024. In the simulation, participants were asked to intubate a full-term neonatal manikin (NewBorn Anne, Laerdal, Stavanger, Norway) using a standard direct laryngoscope with Miller blade size 1 and a videolaryngoscope with Miller blade Spectrum S1 (Verathon Inc., Bothell, WA, USA) at two different table elevations to level operator’s xiphoid or navel (Fig. 1 ). Participants Eligible participants were level III neonatal intensive care unit (NICU) consultants and pediatric residents. Refusal to participate was the only exclusion criteriom. Randomization All participants were randomly assigned to one of the four sequences in a 1:1:1:1 ratio. Randomization was performed using a computer-generated random assignment list. Arm assignments were put in sequentially numbered, sealed, opaque envelopes. Procedures Participants in ADBC arm were assigned to perform the intubation with a direct laryngoscope and the resuscitation table height adjusted to level operator’s xiphoid (A), followed by the intubation with a videolaryngoscope and the resuscitation table height adjusted to level operator’s navel (D), by the intubation with a videolaryngoscope and the resuscitation table height adjusted to level operator’s xiphoid (B), and by the intubation with a direct laryngoscope and the resuscitation table height adjusted to level operator’s navel (C). Participants in different arms were assigned to perform the intubations in different sequences (ADBC/BACD/CBDA/DCAB). A washout period of three hours was included to reduce any carryover effect. Before the simulation, an expert in laryngoscopy intubation showed the intubation techniques performed with a videolaryngoscope and a laryngoscope equipped with a Miller blade on a neonatal manikin. Each participant practiced with both devices on the manikin before the study sessions. In the simulation, participants were asked to intubate the neonatal manikin with a 3.5-mm endotracheal tube using both laryngoscopes at two different table elevations to level operator’s xiphoid or navel. During each intubation attempt, a researcher documented the number of intubation attempts and the total intubation time. An intubation attempt was considered as failed if the endotracheal tube was not positioned in the trachea or if the attempt lasted more than 60 seconds ( 9 ). During each procedure, force measurements were acquired using three force sensors (FlexiForce A301; Tekscan, Inc., Norwood, MA, USA) as previously described ( 12 ). One sensor (epiglottic sensor) was placed on the distal surface of the blade in correspondence to the area in contact with the epiglottis during intubation and two sensors (palatal sensors) on the proximal surface of the blade at the area in touch with the upper gum and hard palate ( 12 ). Outcome measures The primary outcome measure was the measurement of the forces (peak, average peak, and standard deviation) applied to the epiglottis and the palate of the neonatal manikin during the intubation. The forces were expressed as Newton (N). The secondary outcome measures included the success of the first attempt, the total time of intubation (calculated as the sum of the duration of all intubation attempts) and participant’s opinions about the procedures. Participants were asked i) to indicate the preferred table elevation during the simulation, ii) to rate the difficulty in intubating with the two table elevations using a 5-point Likert scale, iii) to report troubles (postural discomfort, visualizing the anatomic structures, positioning the endotracheal tube, and managing the laryngoscope) with the two table elevations, iv) to indicate the preferred laryngoscope at each table elevation, and v) to state which table elevation was associated with less applied forces in their perception. Data collection and measurements All data were collected by an observer who was not involved in the simulation. Data were recorded on a data sheet designed for the study and stored in a password-protected computer. Data collection included participant characteristics (demographics, experience in neonatal or pediatric intensive care, experience with direct laryngoscopy and video laryngoscopy, clinical routine about table elevation during intubation), data on the outcome measures (applied forces, success of the first attempt, the total time of intubation and participant’s opinions about the procedures. Participant’s opinions were collected at the end of the simulation. Blinding The participants and the outcome assessors could not be masked due to the characteristics of the interventions. However, the statistician who analyzed the data was masked to treatment allocation. Statistical analysis As we were unable to predict the magnitude of the difference in forces applied with the different combinations of laryngoscope and table height, a formal sample size calculation could not be performed during study planning and a convenience sample size of 32 participants was chosen for the trial. In the analysis of the applied forces, 50th percentile (median) and top 10th percentile were calculated as relevant indicators of peak force, average force, and standard deviation of applied force, while median and top 10th percentile of the paired differences between two groups were used for comparisons. The top 10th percentile difference in forces was chosen to assess the maximum difference in forces ( 12 , 21 ). Bootstrap confidence intervals (CI) were calculated for percentiles and differences, and any CI for the difference not including zero suggested a statistically significant difference. Because of coverage error of bootstrap CIs for percentiles in small-sized samples, empirical bootstrap 99% CIs were calculated using re-sampling with replacement to create 1,000 samples of the same size as the original ( 21 ). In the analysis of the total time of intubation, the median was calculated as relevant indicator and the median of the paired differences between two groups were used for comparisons. Bootstrap CIs were calculated and interpreted as described above. The success rate at the first attempt was reported as absolute and relative frequency (percentage), and the difference in proportion for paired data was used for comparisons between two groups. Any 95% CI for the difference not including zero suggested a statistically significant difference. Participants’ opinions on the difficulty associated with the two table elevations were measured using a Likert scale and compared using the Wilcoxon test. Overall, participants’ opinions on the procedures were summarized using descriptive statistics. Statistical analysis was performed using R 4.4 (R Foundation for Statistical Computing, Vienna, Austria) ( 22 ). RESULTS Participants The study included 32 participants (23 females and nine males) with a median age of 32 years (IQR 30–44). They were 15 NICU consultants (47%) and 17 pediatric residents (53%). Median experience in neonatal or pediatric intensive care units was 5 years (IQR 4–10). Twenty participants (63%) were most acquainted with the direct laryngoscopy, eight (25%) with the videolaryngoscopy and two (6%) with both, while other two (6%) did not provide such information. Experience with direct laryngoscopy was > 10 intubations in 16 participants (50%), 1–10 intubations in nine participants (28%) and none in six participants (19%). Experience with videolaryngoscopy was > 10 intubations in six participants (19%), 1–10 intubations in 19 participants (59%) and none in six participants (19%). One participant (3%) did not provide such information. During their clinical activity, the participants reported to check the table elevation before performing an intubation always (n = 16), often (n = 7), sometimes (n = 5) and rarely (n = 3), while one participant did not provide such information. In addition, four of them (13%) usually adjust the table to level their xiphoid and four (13%) to level their navel, while 22 (68%) declared to opt for an intermediate elevation between the xiphoid and the navel (two participants, 6%, did not provide such information). Complete data for the outcome measures were obtained for all participants. All participants performed the allocated sequence and there was no loss to follow-up (Supplementary Figure S1 ). Applied forces Table 1 summarizes the forces applied by the participants during the procedures. Table 1 Primary outcome measures: forces applied by the participants during the intubation Area Outcome Percentile Direct laryngoscope and table at xiphoidal level (A) Videolaryngoscope and table at xiphoidal level (B) Direct laryngoscope and table at umbilical level (C) Videolaryngoscope and table at umbilical level (D) Paired difference (A-D) Paired difference (B-D) Paired difference (C-D) Epiglottic sensor Peak Median (bootstrap 99% CI) 5.6 (4.6 to 7.0) 3.5 (3.0 to 5.4) 4.4 (3.6 to 4.9) 3.1 (2.4 to 4.2) 2.3 (1.6 to 4.3) 1.2 (-0.4 to 2.1) 1.5 (0.6 to 2.1) Top 10th percentile (bootstrap 99% CI) 8.6 (6.9 to 15.3) 9.1 (5.3 to 10.1) 6.0 (4.8 to 7.9) 5.2 (4.1 to 7.0) 5.0 (4.2 to 10.9) 3.9 (2.0 to 8.1) 2.6 (2.0 to 4.5) Average peak Median (bootstrap 99% CI) 3.4 (2.7 to 3.8) 2.7 (1.5 to 4.0) 2.5 (2.0 to 3.3) 1.7 (1.2 to 2.6) 1.7 (0.5 to 2.8) 0.9 (0.1 to 1.6) 0.7 (0.1 to 1.5) Top 10th percentile (bootstrap 99% CI) 6.1 (3.7 to 7.1) 5.7 (3.8 to 6.1) 4.2 (3.2 to 6.1) 3.7 (2.5 to 4.9) 3.2 (2.8 to 4.5) 3.3 (1.3 to 5.1) 2.7 (1.3 to 3.8) Standard deviation Median (bootstrap 99% CI) 1.8 (1.2 to 2.1) 1.0 (0.8 to 1.6) 1.2 (1.1 to 1.5) 0.9 (0.7 to 1.2) 0.7 (0.2 to 1.2) 0.2 (-0.2 to 0.6) 0.3 (-0.1 to 0.6) Top 10th percentile (bootstrap 99% CI) 2.7 (2.1 to 3.2) 2.2 (1.6 to 3.3) 1.8 (1.5 to 3.0) 1.5 (1.2 to 1.9) 1.5 (1.1 to 2.0) 1.5 (0.5 to 1.8) 1.1 (0.5 t 1.6) Palatal sensor in contact with the hard palate Peak Median (bootstrap 99% CI) 1.0 (0.0 to 2.8) 0 (0.0 to 3.8) 0.9 (0.0 to 3.0) 0.4 (0.0 to 3.0) 0.0 (-1.1 to 0.9) 0.0 (0.0 to 0.1) 0.0 (-1.7 to 1.6) Top 10th percentile (bootstrap 99% CI) 4.8 (2.8 to 7.0) 9.7 (1.8 to 14.5) 4.3 (3.0 to 6.0) 9.1 (1.9 to 13.8) 3.8 (0.6 to 6.9) 5.4 (0.0 to 9.2) 3.3 (0.4 to 3.9) Average peak Median (bootstrap 99% CI) 0.7 (0.0 to 1.8) 0.0 (0.0 to 1.1) 0.7 (0.0 to 1.9) 0.3 (0.0 to 2.1) 0.0 (-0.9 to 0.9) 0.0 (-0.5 to 0.3) 0.0 (-0.3 to 0.7) Top 10th percentile (bootstrap 99% CI) 3.6 (1.7 to 5.4) 4.0 (0.9 to 7.5) 2.9 (1.8 to 3.9) 4.2 (1.7 to 9.1) 2.3 (0.6 to 5.3) 1.9 (0.0 to 5.5) 1.8 (0.4 to 2.6) Standard deviation Median (bootstrap 99% CI) 0.2 (0.0 to 1.0) 0.0 (0.0 to 0.5) 0.3 (0.0 to 0.9) 0.1 (0.0 to 0.8) 0.0 (-0.3 to 0.4) 0.0 (-0.1 to 0.2) 0.0 (-0.4 to 0.5) Top 10th percentile (bootstrap 99% CI) 1.8 (0.8 to 2.4) 2.7 (0.5 to 4.0) 1.4 (0.9 to 2.3) 2.0 (0.6 to 4.2) 1.3 (0.2 to 2.3) 1.2 (0.0 to 2.6) 1.1 (0.5 to 1.3) Palatal sensor in contact with the upper gum Peak Median (bootstrap 99% CI) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) Top 10th percentile (bootstrap 99% CI) 0.6 (0.0 to 1.8) 6.8 (0.0 to 11.7) 0.8 (0.0 to 8.7) 0.7 (0.0 to 13.3) 0.6 (0.0 to 1.8) 0.7 (0.0 to 11.6) 0.7 (0.0 to 8.7) Average peak Median (bootstrap 99% CI) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) Top 10th percentile (bootstrap 99% CI) 0.4 (0.0 to 1.0) 2.4 (0.0 to 7.8) 0.4 (0.0 to 9.0) 0.7 (0.0 to 4.6) 0.4 (0.0 to 1.0) 0.6 (0.0 to 7.6) 0.3 (0.0 to 8.5) Standard deviation Median (bootstrap 99% CI) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) 0.0 (0.0 to 0.0) Top 10th percentile (bootstrap 99% CI) 0.1 (0.0 to 0.6) 1.8 (0.0 to 4.1) 0.2 (0.0 to 2.2) 0.2 (0.0 to 2.8) 0.1 (0.0 to 0.6) 0.2 (0.0 to 4.1) 0.2 (0.0 to 2.2) Any CI for the difference between forces not including zero indicated a statistically significant difference. The epiglottic sensor recorded higher median and top 10th percentile of applied forces (peak, average peak and standard deviation) using the direct laryngoscope with the table at xiphoidal or umbilical level vs. the videolaryngoscope with the table at umbilical level. The epiglottic sensor also recorded higher median of applied forces (average peak) and higher top 10th percentile of applied forces (peak, average peak and standard deviation) using the videolaryngoscope when the table was set at xiphoidal vs. umbilical level. The hard palate sensor recorded higher top 10th percentile of applied forces (peak, average peak and standard deviation) using the direct laryngoscope with the table at xiphoidal or umbilical level vs. the videolaryngoscope with the table at umbilical level. The upper gum sensor did not record any statistically significant difference between the videolaryngoscope with the table at umbilical level and the other combinations in terms of applied forces. All numerical results are displayed in Table 1 . Success rate at the first attempt Table 2 shows the success rate at the first attempt. Using the direct laryngoscope, the success rate was 84% with the table at xiphoidal level and 91% with the table at umbilical level. Using the videolaryngoscope, the success rate was 97% with both table elevations. The success rate at the first attempt was not statistically different between the videolaryngoscope with the table at umbilical level and the other combinations (Table 2 ). Table 2 Secondary outcome measure: intubation success at the first attempt Outcome Direct laryngoscope and table at xiphoidal level (A) Videolaryngoscope and table at xiphoidal level (B) Direct laryngoscope and table at umbilical level (C) Videolaryngoscope and table at umbilical level (D) Difference in proportion for paired data (95% confidence interval) (A-D) Difference in proportion for paired data (95% confidence interval) (B-D) Difference in proportion for paired data (95% confidence interval) (C-D) Success at the first attempt, n (%) 27/32 (84%) 31/32 (97%) 29/32 (91%) 31/32 (97%) -13% (-29–3%) 0% (-14–14%) -6% (-21–7%) Any CI for the difference between forces not including zero indicated a statistically significant difference. Total intubation time Median total intubation time ranged from 17.5 seconds using the videolaryngoscope with the table at umbilical level to 19.5 seconds using the direct laryngoscope with the table at xiphoidal level (Table 3 ). The total intubation time was not statistically different between the videolaryngoscope with the table at umbilical level and the other combinations (Table 3 ). Table 3 Secondary outcome measure: total intubation time Outcome Percentile Direct laryngoscope and table at xiphoidal level (A) Videolaryngoscope and table at xiphoidal level (B) Direct laryngoscope and table at umbilical level (C) Videolaryngoscope and table at umbilical level (D) Paired difference (A-D) Paired difference (B-D) Paired difference (C-D) Total intubation time, seconds Median (bootstrap 99% CI) 19.5 (15.0 to 23.0) 18.0 (14.5 to 23.0) 19.0 (14.0–23.0) 17.5 (15.0 to 22.0) 2 (-3 to 4) 0 (-2 to 3) 0.5 (-2 to 4) Any CI for the difference between forces not including zero indicated a statistically significant difference. Participants’ opinions on the procedures Overall, 17 participants (53%) indicated the xiphoidal level and 15 (47%) the umbilical level as preferred table elevation during the simulation. They scored a median difficulty of 2 out of max 5 points (IQR 2–3) with the table at xiphoidal level and 3 out of max 5 points (IQR 2–3) with the table at umbilical level (p = 0.94). The reported troubles with the table at xiphoidal level included postural discomfort (n = 12), visualizing the anatomic structures (n = 5), positioning the endotracheal tube (n = 5) and managing the laryngoscope (n = 3). The reported troubles with the table at umbilical level included postural discomfort (n = 10), visualizing the anatomic structures (n = 9) and positioning the endotracheal tube (n = 5). When the table leveled the operator’s xiphoid, 17 participants (53%) preferred the videolaryngoscope and 15 (47%) the direct laryngoscope. When the table leveled the operator’s navel, 24 participants (75%) preferred the videolaryngoscope and 8 (25%) the direct laryngoscope. Overall, 23 participants (72%) believed to have used less force with the table at xiphoidal level and 9 (28%) with the table at umbilical level. Figure 2 offers a visual summary of participants’ opinions on the procedures. DISCUSSION Our trial compared intubation with direct and video laryngoscopy in a neonatal manikin positioned at umbilical and xiphoidal bed heights. We hypothesized that the combination of direct/video laryngoscopy and bed height might influence the applied forces during neonatal intubation. The literature suggests that videolaryngoscopy may involve lower applied forces compared to direct laryngoscopy in neonatal resuscitation, while the preferred elevation of the resuscitation table remains controversial ( 11 , 12 , 19 ). Our investigation provides further information about the potential differences in the forces applied by the resuscitator according to the combination of laryngoscope and bed height. Overall, our findings suggested that intubating a neonatal manikin with the videolaryngoscope and the resuscitation table leveled at operator’s navel was associated with the lowest forces applied to the epiglottis and the hard palate. On the other hand, the combination of direct laryngoscope and resuscitation table leveled at operator’s xiphoid was associated with the highest applied forces to the epiglottis and the hard palate. These results confirmed previous observations about the lower applied forces when using videolaryngoscopy compared to direct laryngoscopy ( 12 ). Furthermore, we hypothesize that a high table elevation may push the operator to act beyond the ergonomic levels, probably affecting the applied forces to perform the intubation maneuver. Of note, our data revealed that subjective perceptions of applied forces differed from the actual measurements, as most participants believed to have used less forces when the table leveled operator’s xiphoid. Such discrepancy may advocate for the implementation of a technology capable to provide force feedback to the operator during the intubation. Nevertheless, the reader should be aware that the magnitude of harmful applied forces during intubation remains unknown. Videolaryngoscopy has been associated with higher intubation success at the first attempt compared to direct laryngoscopy in neonates ( 7 – 9 ). In our simulation, the participants achieved a high success rate at the first attempt with all combinations of laryngoscope and bed height, alongside with comparable intubation times. Interestingly, the confidence intervals did not exclude that videolaryngoscopy might improve the success rate compared to direct laryngoscopy irrespectively of bed height. Noteworthy, one bed height did not prevail over the other according to participants’ preferences. This finding might be influenced by their clinical routine, when the resuscitation table was mostly set at an intermediate elevation between the xiphoid and the navel. Previous studies suggested that higher table positions (such as xiphoid or nipple level) might provide better laryngeal views and less operator’s discomfort when intubating with a direct laryngoscope, while umbilical table position might warrant better visibility and less shoulder joint flexion when using a videolaryngoscope ( 13 , 14 ). Our participants confirmed to prefer videolaryngoscopy with the umbilical table position, while one device did not prevail over the other with the xiphoidal table position. To our knowledge, this is the first trial investigating the combination of direct/video laryngoscopy and bed height during a simulated neonatal intubation. The strengths of our trial included the crossover design, the objective and reliable force measurement, and the enrolment of participants with heterogeneous experience with laryngoscopy and resuscitation table elevation. However, some limitations should be considered when reading the results. First, manikin tissue and anatomy could not replicate the exact texture, flexibility, and responsiveness of a living human body, and eliminated the anatomical heterogeneity among neonates ( 12 ). Second, the applied forces may differ in a real-life intubation. Third, the trial included only one model of neonatal manikin and two elevations of the resuscitation table. Lastly, the generalizability of the findings should be limited to operators with comparable experience. CONCLUSIONS In a neonatal manikin model, intubating with a videolaryngoscope and the resuscitation table leveled at operator’s navel was associated with the lowest forces applied to the epiglottis and the hard palate. The participants achieved a high success rate at the first attempt and comparable procedure times with all combinations of direct/video laryngoscope and low/high bed elevation. Subjective perceptions of applied forces differed from the actual measurements. Applying lower forces during neonatal intubation may be desirable but the clinical implications remain to be evaluated in clinical studies. Abbreviations IQR Interquartile range N Newton NICU Neonatal intensive care unit Declarations Acknowledgements We are very grateful to the participants. Funding : None. Conflicts of interest/Competing interests: The authors have no potential conflicts of interest to disclose. Availability of data and material: All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author. Code availability: not applicable. Authors' contributions: FC contributed to study concept and data analysis, wrote the initial draft and critically reviewed the manuscript. GP contributed to study concept, investigation, data collection, writing of the manuscript and critically reviewed the manuscript. SM contributed to study concept, data collection, writing of the manuscript and critically reviewed the manuscript. PEV contributed to study concept, supervision, writing of the manuscript and critically reviewed the manuscript. AM contributed to study concept, supervision, writing of the manuscript and critically reviewed the manuscript. ST contributed to study concept, methodology, supervision, writing of the manuscript and critically reviewed the manuscript. DT conceived the study, contributed to data interpretation, wrote the initial draft and critically reviewed the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. Ethics approval: The Ethics Committees of the University Hospital of Padua (Italy) reviewed and approved this manikin study (Prot. 536n/AO/24). Consent to participate: Written informed consent was obtained from participants. Consent for publication: Not applicable References Madar J, Roehr CC, Ainsworth S, Ersdal H, Morley C, Rüdiger M, Skåre C, Szczapa T, Te Pas A, Trevisanuto D, Urlesberger B, Wilkinson D, Wyllie JP (2021) European Resuscitation Council Guidelines 2021: Newborn resuscitation and support of transition of infants at birth. Resuscitation 161:291–326 Leone TA, Rich W, Finer NN (2005) Neonatal intubation: success of pediatric trainees. J Pediatr 146:638–641 Sawyer T, Foglia E, Hatch LD, Moussa A, Ades A, Johnston L, Nishisaki A (2017) Improving neonatal intubation safety: A journey of a thousand miles. J Neonatal Perinat Med 10:125–131 Hassan HG, El-Sharkawy TY, Renck H, Mansour G, Fouda A (1991) Hemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation. Acta Anaesthesiol Scand 35:442–447 Hatch LD, Grubb PH, Lea AS, Walsh WF, Markham MH, Whitney GM, Slaughter JC, Stark AR, Ely EW (2016) Endotracheal Intubation in Neonates: A Prospective Study of Adverse Safety Events in 162 Infants. J Pediatr 168:62–66e6 Foglia EE, Ades A, Sawyer T, Glass KM, Singh N, Jung P, Quek BH, Johnston LC, Barry J, Zenge J, Moussa A, Kim JH, DeMeo SD, Napolitano N, Nadkarni V, Nishisaki A, NEAR4NEOS Investigators (2019) Neonatal Intubation Practice and Outcomes: An International Registry Study. Pediatrics 143:e20180902 Pouppirt NR, Nassar R, Napolitano N, Nawab U, Nishisaki A, Nadkarni V, Ades A, Foglia EE (2018) Association Between Video Laryngoscopy and Adverse Tracheal Intubation-Associated Events in the Neonatal Intensive Care Unit. J Pediatr 201:281–284e1 Zhou M, Xi X, Li M, Wang S, Liu Z, Liu JQ (2020) Video Laryngoscopy Improves the Success of Neonatal Tracheal Intubation for Novices but Not for Experienced Medical Staff. Front Pediatr 8:445 Geraghty LE, Dunne EA, Ní Chathasaigh CM, Vellinga A, Adams NC, O'Currain EM, McCarthy LK, O'Donnell CPF (2024) Video versus Direct Laryngoscopy for Urgent Intubation of Newborn Infants. N Engl J Med 390(20):1885–1894 Hatch LD, Grubb PH, Lea AS et al (2016) Endotracheal intubation in neonates: a prospective study of adverse safety events in 162 infants. J Pediatr 168:62–66 Weiner GM (ed) (2021) Textbook of Neonatal Resuscitation, 8th edn. American Academy of Pediatrics and American Heart Association Cavallin F, Sala C, Maglio S, Bua B, Villani PE, Menciassi A, Tognarelli S, Trevisanuto D (2023) Applied forces with direct versus indirect laryngoscopy in neonatal intubation: a randomized crossover mannequin study. Can J Anaesth 70(5):861–868 Lee HC, Yun MJ, Hwang JW, Na HS, Kim DH, Park JY (2014) Higher operating tables provide better laryngeal views for tracheal intubation. Br J Anaesth 112(4):749–755 Kang D, Bae HB, Choi YH, Bom JS, Kim J (2022) A prospective randomized study of different height of operation table for tracheal intubation with videolaryngoscopy in ramped position. BMC Anesthesiol 22(1):378 Morrison G, Tobin JM (2018) Endotracheal Intubation: Oral and Nasal. In: Demetriades D, Inaba K, Lumb P (eds) Atlas of Critical Care Procedures. Springer, Cham Nikolla DA, Beaumont RR, Lerman JL, Datsko JS, Carlson JN (2020) Impact of bed angle and height on intubation success during simulated endotracheal intubation in the ramped position. J Am Coll Emerg Physicians Open 1(3):257–262 Kim W, Lee Y, Kim C, Lim TH, Oh J, Kang H, Lee S (2016) Comparison of the Pentax Airwayscope, Glidescope Video Laryngoscope, and Macintosh Laryngoscope During Chest Compression According to Bed Height. Med (Baltim) 95(5):e2631 Hong JY, Oh JH, Kim CW, Kim SE, Lee DH, Shin JH (2016) Effects of bed height on the performance of endotracheal intubation and bag mask ventilation. Signa Vitae 12(S1):47 Kane T, Tingay DG, Pellicano A, Sabato S (2023) The neonatal airway. Semin Fetal Neonatal Med 28(5):101483 Jones B, Kenward MG (2015) Design and analysis of cross-over trials, 3rd edn. Chapman & Hall/CRC, New York Gordon JK, Bertram VE, Cavallin F, Parotto M, Cooper RM (20209 Direct versus indirect laryngoscopy using a Macintosh video laryngoscope: a mannequin study comparing applied forces. Can J Anaesth 67:515–520 R Core Team R (2024) A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria Additional Declarations No competing interests reported. Supplementary Files FigureS1.tif Supplementary Figure 1. CONSORT flow diagram. Cite Share Download PDF Status: Published Journal Publication published 05 Nov, 2025 Read the published version in European Journal of Pediatrics → Version 1 posted Editorial decision: Revision requested 30 Aug, 2025 Reviews received at journal 27 Aug, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviewers agreed at journal 28 Jul, 2025 Reviewers invited by journal 02 May, 2025 Editor assigned by journal 26 Apr, 2025 Submission checks completed at journal 26 Apr, 2025 First submitted to journal 17 Apr, 2025 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. 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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-6469496","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":451744418,"identity":"2a5356b8-a920-4b43-bdba-307a91584a13","order_by":0,"name":"Francesco Cavallin","email":"","orcid":"","institution":"Independent statistician","correspondingAuthor":false,"prefix":"","firstName":"Francesco","middleName":"","lastName":"Cavallin","suffix":""},{"id":451744419,"identity":"a45ccc75-17e4-4489-b340-9500779a4573","order_by":1,"name":"Greta Pasquali","email":"","orcid":"","institution":"University Hospital of Padua","correspondingAuthor":false,"prefix":"","firstName":"Greta","middleName":"","lastName":"Pasquali","suffix":""},{"id":451744420,"identity":"4aa02c47-4e2d-4e16-b7d1-c10366808f23","order_by":2,"name":"Sabina Maglio","email":"","orcid":"","institution":"Scuola Superiore Sant'Anna","correspondingAuthor":false,"prefix":"","firstName":"Sabina","middleName":"","lastName":"Maglio","suffix":""},{"id":451744421,"identity":"c0630490-7337-4b00-9a79-ce2c802bc65f","order_by":3,"name":"Paolo Ernesto Villani","email":"","orcid":"","institution":"Poliambulanza Hospital, Fondazione Poliambulanza","correspondingAuthor":false,"prefix":"","firstName":"Paolo","middleName":"Ernesto","lastName":"Villani","suffix":""},{"id":451744422,"identity":"d9465317-50ad-45ea-8a39-0ba1d3088ce7","order_by":4,"name":"Arianna Menciassi","email":"","orcid":"","institution":"Scuola Superiore Sant'Anna","correspondingAuthor":false,"prefix":"","firstName":"Arianna","middleName":"","lastName":"Menciassi","suffix":""},{"id":451744423,"identity":"0133f434-365c-4428-8e2b-7bba362f7804","order_by":5,"name":"Selene Tognarelli","email":"","orcid":"","institution":"Scuola Superiore Sant'Anna","correspondingAuthor":false,"prefix":"","firstName":"Selene","middleName":"","lastName":"Tognarelli","suffix":""},{"id":451744424,"identity":"390a6448-ce8f-44d9-833f-c8140cfa00ea","order_by":6,"name":"Daniele Trevisanuto","email":"data:image/png;base64,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","orcid":"","institution":"University Hospital of Padua","correspondingAuthor":true,"prefix":"","firstName":"Daniele","middleName":"","lastName":"Trevisanuto","suffix":""}],"badges":[],"createdAt":"2025-04-17 08:08:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6469496/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6469496/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00431-025-06524-8","type":"published","date":"2025-11-05T15:57:01+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82311643,"identity":"6c7ed93c-d4f8-4d4a-af31-04c366f0eca6","added_by":"auto","created_at":"2025-05-09 01:58:25","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":86063,"visible":true,"origin":"","legend":"\u003cp\u003eParticipants performed the intubation with A) a direct laryngoscope and the resuscitation table height adjusted to level operator’s xiphoid, B) a videolaryngoscope and the resuscitation table height adjusted to level operator’s xiphoid, C) a direct laryngoscope and the resuscitation table height adjusted to level operator’s navel, and D) a videolaryngoscope and the resuscitation table height adjusted to level operator’s navel.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-6469496/v1/78a060de62e5efd83b9474a0.png"},{"id":82310234,"identity":"210e63b5-d240-405b-ad5e-af15922fd7db","added_by":"auto","created_at":"2025-05-09 01:50:24","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":57196,"visible":true,"origin":"","legend":"\u003cp\u003eVisual summary of participants’ opinions on the procedures: the participants slightly preferred intubating with the table at xiphoidal level (A); they reported different troubles according to the table elevation (B); the videolaryngoscope was largely preferred to the direct laryngoscope with the table at umbilical level (C); most participants believed to have used less force with the table at xiphoidal level (D).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-6469496/v1/9482a558013bef436aef9159.png"},{"id":95563931,"identity":"b7d559a6-9205-4dd3-8a09-203fff994f55","added_by":"auto","created_at":"2025-11-10 16:04:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1369632,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6469496/v1/0b4dd2bc-0b40-43e9-b244-2b985119d417.pdf"},{"id":82310240,"identity":"ea8720be-4ec9-4e28-a913-6a1093e533d7","added_by":"auto","created_at":"2025-05-09 01:50:25","extension":"tif","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":1019170,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Figure 1. CONSORT flow diagram.\u003c/p\u003e","description":"","filename":"FigureS1.tif","url":"https://assets-eu.researchsquare.com/files/rs-6469496/v1/2d99b7c79a0ac33bb9001c4e.tif"}],"financialInterests":"No competing interests reported.","formattedTitle":"Applied forces during neonatal intubation with direct and video laryngoscopy at different bed elevations: a randomized crossover manikin study","fulltext":[{"header":"What is known","content":"\u003cul\u003e\n \u003cli\u003eIntubation success may be influenced by procedure-related aspects such as the position of the patient in relation with the operator.\u003c/li\u003e\n \u003cli\u003eThe Neonatal Resuscitation Program recommends adjusting the bed height to align the baby\u0026apos;s head with operator\u0026apos;s upper abdomen or lower chest, while positioning the bed height at approximately elbow height is also suggested.\u003c/li\u003e\n \u003cli\u003eThe bed height might affect the applied forces during neonatal intubation and the intubation success, but such information is currently lacking.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is new\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eIn a neonatal manikin model, intubating with a videolaryngoscope and the resuscitation table leveled at operator\u0026rsquo;s navel was associated with the lowest forces applied to the epiglottis and the hard palate.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThe participants achieved a high success rate at the first attempt and comparable procedure times with all combinations of direct/video laryngoscope and low/high bed elevation.\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eApplying lower forces during neonatal intubation may be desirable but the clinical implications remain to be evaluated in clinical studies.\u003c/p\u003e"},{"header":"INTRODUCTION","content":"\u003cp\u003eIntubating at birth is required in approximately 1% of neonates (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Nonetheless, health care providers have limited exposure to neonatal intubation because of the implementation of less invasive procedures, such as continuous positive airway pressure and nasal intermittent positive pressure ventilation (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eLaryngoscopy is an invasive and potentially harmful procedure, which has been associated with adverse events including airway trauma, bradycardia, hypoxia, and intraventricular hemorrhage (\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Videolaryngoscopy improves the intubation success at the first attempt compared to direct laryngoscopy in neonates, and seems to decrease the incidence of adverse events (\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDuring the intubation procedure, the movements create compression forces on the soft tissues that can cause tissue ischemia or perforation, adverse clinical reactions, or future developmental issues in the surrounding structures (4,6,7,9\u0026ndash;11). According to a neonatal manikin trial, lower forces are applied with videolaryngoscopy compared to direct laryngoscopy, suggesting possible benefits in reducing patient harm during intubation (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIntubation success may be influenced by procedure-related aspects such as the position of the patient in relation with the operator. In adults, the literature offers conflicting findings, which include suggesting the bed height to the level of operator\u0026rsquo;s xiphoid (\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e), navel (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e), or no preference among different bed height (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). The Neonatal Resuscitation Program recommends adjusting the bed height to align the baby's head with operator's upper abdomen or lower chest (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), while a recent study suggested positioning the bed height at approximately elbow height (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). We assumed that the bed height might affect the applied forces during neonatal intubation, but such information is currently lacking.\u003c/p\u003e \u003cp\u003eThis trial compared intubation forces applied with direct and video laryngoscopy at umbilical and xiphoidal bed heights in a neonatal manikin. Furthermore, success of the first attempt, intubation time and participant\u0026rsquo;s opinions about the procedures were investigated.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eThis was a randomized, controlled, crossover trial of intubation using direct and video laryngoscopes at two different table elevations in a neonatal manikin model (clinicaltrials.gov NCT06474572). The trial employed a 4-sequence, 4-period, 4-treatment scheme (ADBC/BACD/CBDA/DCAB) which is uniform within sequences and periods, and balanced with respect to first-order carryover effects (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). The Ethics Committees of the University Hospital of Padua (Italy) reviewed and approved this manikin study (Prot. 536n/AO/24). The participants provided their written informed consent.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSetting\u003c/h3\u003e\n\u003cp\u003eThis simulation study was performed at the University Hospital of Padua (Italy) between 1st and 5th July 2024. In the simulation, participants were asked to intubate a full-term neonatal manikin (NewBorn Anne, Laerdal, Stavanger, Norway) using a standard direct laryngoscope with Miller blade size 1 and a videolaryngoscope with Miller blade Spectrum S1 (Verathon Inc., Bothell, WA, USA) at two different table elevations to level operator\u0026rsquo;s xiphoid or navel (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eEligible participants were level III neonatal intensive care unit (NICU) consultants and pediatric residents. Refusal to participate was the only exclusion criteriom.\u003c/p\u003e\n\u003ch3\u003eRandomization\u003c/h3\u003e\n\u003cp\u003eAll participants were randomly assigned to one of the four sequences in a 1:1:1:1 ratio. Randomization was performed using a computer-generated random assignment list. Arm assignments were put in sequentially numbered, sealed, opaque envelopes.\u003c/p\u003e\n\u003ch3\u003eProcedures\u003c/h3\u003e\n\u003cp\u003eParticipants in ADBC arm were assigned to perform the intubation with a direct laryngoscope and the resuscitation table height adjusted to level operator\u0026rsquo;s xiphoid (A), followed by the intubation with a videolaryngoscope and the resuscitation table height adjusted to level operator\u0026rsquo;s navel (D), by the intubation with a videolaryngoscope and the resuscitation table height adjusted to level operator\u0026rsquo;s xiphoid (B), and by the intubation with a direct laryngoscope and the resuscitation table height adjusted to level operator\u0026rsquo;s navel (C). Participants in different arms were assigned to perform the intubations in different sequences (ADBC/BACD/CBDA/DCAB). A washout period of three hours was included to reduce any carryover effect.\u003c/p\u003e \u003cp\u003eBefore the simulation, an expert in laryngoscopy intubation showed the intubation techniques performed with a videolaryngoscope and a laryngoscope equipped with a Miller blade on a neonatal manikin. Each participant practiced with both devices on the manikin before the study sessions.\u003c/p\u003e \u003cp\u003eIn the simulation, participants were asked to intubate the neonatal manikin with a 3.5-mm endotracheal tube using both laryngoscopes at two different table elevations to level operator\u0026rsquo;s xiphoid or navel. During each intubation attempt, a researcher documented the number of intubation attempts and the total intubation time. An intubation attempt was considered as failed if the endotracheal tube was not positioned in the trachea or if the attempt lasted more than 60 seconds (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDuring each procedure, force measurements were acquired using three force sensors (FlexiForce A301; Tekscan, Inc., Norwood, MA, USA) as previously described (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). One sensor (epiglottic sensor) was placed on the distal surface of the blade in correspondence to the area in contact with the epiglottis during intubation and two sensors (palatal sensors) on the proximal surface of the blade at the area in touch with the upper gum and hard palate (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eOutcome measures\u003c/h2\u003e \u003cp\u003eThe primary outcome measure was the measurement of the forces (peak, average peak, and standard deviation) applied to the epiglottis and the palate of the neonatal manikin during the intubation. The forces were expressed as Newton (N). The secondary outcome measures included the success of the first attempt, the total time of intubation (calculated as the sum of the duration of all intubation attempts) and participant\u0026rsquo;s opinions about the procedures. Participants were asked i) to indicate the preferred table elevation during the simulation, ii) to rate the difficulty in intubating with the two table elevations using a 5-point Likert scale, iii) to report troubles (postural discomfort, visualizing the anatomic structures, positioning the endotracheal tube, and managing the laryngoscope) with the two table elevations, iv) to indicate the preferred laryngoscope at each table elevation, and v) to state which table elevation was associated with less applied forces in their perception.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eData collection and measurements\u003c/h3\u003e\n\u003cp\u003eAll data were collected by an observer who was not involved in the simulation. Data were recorded on a data sheet designed for the study and stored in a password-protected computer. Data collection included participant characteristics (demographics, experience in neonatal or pediatric intensive care, experience with direct laryngoscopy and video laryngoscopy, clinical routine about table elevation during intubation), data on the outcome measures (applied forces, success of the first attempt, the total time of intubation and participant\u0026rsquo;s opinions about the procedures. Participant\u0026rsquo;s opinions were collected at the end of the simulation.\u003c/p\u003e\n\u003ch3\u003eBlinding\u003c/h3\u003e\n\u003cp\u003eThe participants and the outcome assessors could not be masked due to the characteristics of the interventions. However, the statistician who analyzed the data was masked to treatment allocation.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAs we were unable to predict the magnitude of the difference in forces applied with the different combinations of laryngoscope and table height, a formal sample size calculation could not be performed during study planning and a convenience sample size of 32 participants was chosen for the trial. In the analysis of the applied forces, 50th percentile (median) and top 10th percentile were calculated as relevant indicators of peak force, average force, and standard deviation of applied force, while median and top 10th percentile of the paired differences between two groups were used for comparisons. The top 10th percentile difference in forces was chosen to assess the maximum difference in forces (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). Bootstrap confidence intervals (CI) were calculated for percentiles and differences, and any CI for the difference not including zero suggested a statistically significant difference. Because of coverage error of bootstrap CIs for percentiles in small-sized samples, empirical bootstrap 99% CIs were calculated using re-sampling with replacement to create 1,000 samples of the same size as the original (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). In the analysis of the total time of intubation, the median was calculated as relevant indicator and the median of the paired differences between two groups were used for comparisons. Bootstrap CIs were calculated and interpreted as described above. The success rate at the first attempt was reported as absolute and relative frequency (percentage), and the difference in proportion for paired data was used for comparisons between two groups. Any 95% CI for the difference not including zero suggested a statistically significant difference. Participants\u0026rsquo; opinions on the difficulty associated with the two table elevations were measured using a Likert scale and compared using the Wilcoxon test. Overall, participants\u0026rsquo; opinions on the procedures were summarized using descriptive statistics. Statistical analysis was performed using R 4.4 (R Foundation for Statistical Computing, Vienna, Austria) (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eParticipants\u003c/h2\u003e \u003cp\u003eThe study included 32 participants (23 females and nine males) with a median age of 32 years (IQR 30\u0026ndash;44). They were 15 NICU consultants (47%) and 17 pediatric residents (53%). Median experience in neonatal or pediatric intensive care units was 5 years (IQR 4\u0026ndash;10). Twenty participants (63%) were most acquainted with the direct laryngoscopy, eight (25%) with the videolaryngoscopy and two (6%) with both, while other two (6%) did not provide such information.\u003c/p\u003e \u003cp\u003eExperience with direct laryngoscopy was \u0026gt;\u0026thinsp;10 intubations in 16 participants (50%), 1\u0026ndash;10 intubations in nine participants (28%) and none in six participants (19%). Experience with videolaryngoscopy was \u0026gt;\u0026thinsp;10 intubations in six participants (19%), 1\u0026ndash;10 intubations in 19 participants (59%) and none in six participants (19%). One participant (3%) did not provide such information.\u003c/p\u003e \u003cp\u003eDuring their clinical activity, the participants reported to check the table elevation before performing an intubation always (n\u0026thinsp;=\u0026thinsp;16), often (n\u0026thinsp;=\u0026thinsp;7), sometimes (n\u0026thinsp;=\u0026thinsp;5) and rarely (n\u0026thinsp;=\u0026thinsp;3), while one participant did not provide such information. In addition, four of them (13%) usually adjust the table to level their xiphoid and four (13%) to level their navel, while 22 (68%) declared to opt for an intermediate elevation between the xiphoid and the navel (two participants, 6%, did not provide such information).\u003c/p\u003e \u003cp\u003eComplete data for the outcome measures were obtained for all participants. All participants performed the allocated sequence and there was no loss to follow-up (Supplementary Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eApplied forces\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes the forces applied by the participants during the procedures.\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\u003ePrimary outcome measures: forces applied by the participants during the intubation\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eArea\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePercentile\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDirect laryngoscope and table at xiphoidal level (A)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVideolaryngoscope and table at xiphoidal level (B)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDirect laryngoscope and table at umbilical level (C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eVideolaryngoscope and table at umbilical level (D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(A-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(B-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(C-D)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003eEpiglottic sensor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePeak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.6 (4.6 to 7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.5 (3.0 to 5.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.4 (3.6 to 4.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.1 (2.4 to 4.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.3 (1.6 to 4.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.2 (-0.4 to 2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.5 (0.6 to 2.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.6 (6.9 to 15.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.1 (5.3 to 10.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.0 (4.8 to 7.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.2 (4.1 to 7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e5.0 (4.2 to 10.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e3.9 (2.0 to 8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2.6 (2.0 to 4.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAverage peak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.4 (2.7 to 3.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.7 (1.5 to 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.5 (2.0 to 3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.7 (1.2 to 2.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.7 (0.5 to 2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.9 (0.1 to 1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.7 (0.1 to 1.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.1 (3.7 to 7.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.7 (3.8 to 6.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.2 (3.2 to 6.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.7 (2.5 to 4.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.2 (2.8 to 4.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e3.3 (1.3 to 5.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2.7 (1.3 to 3.8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eStandard deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8 (1.2 to 2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.0 (0.8 to 1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.2 (1.1 to 1.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9 (0.7 to 1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.7 (0.2 to 1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.2 (-0.2 to 0.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.3 (-0.1 to 0.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.7 (2.1 to 3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.2 (1.6 to 3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.8 (1.5 to 3.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.5 (1.2 to 1.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.5 (1.1 to 2.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.5 (0.5 to 1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.1 (0.5 t 1.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003ePalatal sensor in contact with the hard palate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePeak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0 (0.0 to 2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0 to 3.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.9 (0.0 to 3.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.4 (0.0 to 3.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (-1.1 to 0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (0.0 to 0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (-1.7 to 1.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.8 (2.8 to 7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.7 (1.8 to 14.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.3 (3.0 to 6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e9.1 (1.9 to 13.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.8 (0.6 to 6.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e5.4 (0.0 to 9.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.3 (0.4 to 3.9)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAverage peak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.7 (0.0 to 1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0 (0.0 to 1.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.7 (0.0 to 1.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.3 (0.0 to 2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (-0.9 to 0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (-0.5 to 0.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (-0.3 to 0.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.6 (1.7 to 5.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.0 (0.9 to 7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.9 (1.8 to 3.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.2 (1.7 to 9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.3 (0.6 to 5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.9 (0.0 to 5.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.8 (0.4 to 2.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eStandard deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.2 (0.0 to 1.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0 (0.0 to 0.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3 (0.0 to 0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.1 (0.0 to 0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (-0.3 to 0.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (-0.1 to 0.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (-0.4 to 0.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8 (0.8 to 2.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.7 (0.5 to 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.4 (0.9 to 2.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.0 (0.6 to 4.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.3 (0.2 to 2.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.2 (0.0 to 2.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.1 (0.5 to 1.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003ePalatal sensor in contact with the upper gum\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePeak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.6 (0.0 to 1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.8 (0.0 to 11.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.8 (0.0 to 8.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.7 (0.0 to 13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.6 (0.0 to 1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.7 (0.0 to 11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.7 (0.0 to 8.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAverage peak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.4 (0.0 to 1.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.4 (0.0 to 7.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4 (0.0 to 9.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.7 (0.0 to 4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.4 (0.0 to 1.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.6 (0.0 to 7.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.3 (0.0 to 8.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eStandard deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.0 (0.0 to 0.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTop 10th percentile (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.1 (0.0 to 0.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.8 (0.0 to 4.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.2 (0.0 to 2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.2 (0.0 to 2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.1 (0.0 to 0.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.2 (0.0 to 4.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.2 (0.0 to 2.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003eAny CI for the difference between forces not including zero indicated a statistically significant difference.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe epiglottic sensor recorded higher median and top 10th percentile of applied forces (peak, average peak and standard deviation) using the direct laryngoscope with the table at xiphoidal or umbilical level vs. the videolaryngoscope with the table at umbilical level. The epiglottic sensor also recorded higher median of applied forces (average peak) and higher top 10th percentile of applied forces (peak, average peak and standard deviation) using the videolaryngoscope when the table was set at xiphoidal vs. umbilical level.\u003c/p\u003e \u003cp\u003eThe hard palate sensor recorded higher top 10th percentile of applied forces (peak, average peak and standard deviation) using the direct laryngoscope with the table at xiphoidal or umbilical level vs. the videolaryngoscope with the table at umbilical level.\u003c/p\u003e \u003cp\u003eThe upper gum sensor did not record any statistically significant difference between the videolaryngoscope with the table at umbilical level and the other combinations in terms of applied forces.\u003c/p\u003e \u003cp\u003eAll numerical results are displayed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eSuccess rate at the first attempt\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the success rate at the first attempt. Using the direct laryngoscope, the success rate was 84% with the table at xiphoidal level and 91% with the table at umbilical level. Using the videolaryngoscope, the success rate was 97% with both table elevations. The success rate at the first attempt was not statistically different between the videolaryngoscope with the table at umbilical level and the other combinations (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\u003eSecondary outcome measure: intubation success at the first attempt\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\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\u003eDirect laryngoscope and table at xiphoidal level (A)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eVideolaryngoscope and table at xiphoidal level (B)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDirect laryngoscope and table at umbilical level (C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVideolaryngoscope and table at umbilical level (D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDifference in proportion for paired data (95% confidence interval) (A-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eDifference in proportion for paired data (95% confidence interval) (B-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eDifference in proportion for paired data (95% confidence interval) (C-D)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuccess at the first attempt, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27/32 (84%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31/32 (97%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29/32 (91%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31/32 (97%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-13% (-29\u0026ndash;3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0% (-14\u0026ndash;14%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-6% (-21\u0026ndash;7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eAny CI for the difference between forces not including zero indicated a statistically significant difference.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eTotal intubation time\u003c/h2\u003e \u003cp\u003eMedian total intubation time ranged from 17.5 seconds using the videolaryngoscope with the table at umbilical level to 19.5 seconds using the direct laryngoscope with the table at xiphoidal level (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The total intubation time was not statistically different between the videolaryngoscope with the table at umbilical level and the other combinations (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSecondary outcome measure: total intubation time\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\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\u003ePercentile\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDirect laryngoscope and table at xiphoidal level (A)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eVideolaryngoscope and table at xiphoidal level (B)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eDirect laryngoscope and table at umbilical level (C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eVideolaryngoscope and table at umbilical level (D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(A-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(B-D)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003ePaired difference\u003c/p\u003e \u003cp\u003e(C-D)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal intubation time, seconds\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMedian (bootstrap 99% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.5 (15.0 to 23.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.0 (14.5 to 23.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19.0 (14.0\u0026ndash;23.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.5 (15.0 to 22.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2 (-3 to 4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0 (-2 to 3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.5 (-2 to 4)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"9\"\u003eAny CI for the difference between forces not including zero indicated a statistically significant difference.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eParticipants\u0026rsquo; opinions on the procedures\u003c/h2\u003e \u003cp\u003eOverall, 17 participants (53%) indicated the xiphoidal level and 15 (47%) the umbilical level as preferred table elevation during the simulation. They scored a median difficulty of 2 out of max 5 points (IQR 2\u0026ndash;3) with the table at xiphoidal level and 3 out of max 5 points (IQR 2\u0026ndash;3) with the table at umbilical level (p\u0026thinsp;=\u0026thinsp;0.94). The reported troubles with the table at xiphoidal level included postural discomfort (n\u0026thinsp;=\u0026thinsp;12), visualizing the anatomic structures (n\u0026thinsp;=\u0026thinsp;5), positioning the endotracheal tube (n\u0026thinsp;=\u0026thinsp;5) and managing the laryngoscope (n\u0026thinsp;=\u0026thinsp;3). The reported troubles with the table at umbilical level included postural discomfort (n\u0026thinsp;=\u0026thinsp;10), visualizing the anatomic structures (n\u0026thinsp;=\u0026thinsp;9) and positioning the endotracheal tube (n\u0026thinsp;=\u0026thinsp;5).\u003c/p\u003e \u003cp\u003eWhen the table leveled the operator\u0026rsquo;s xiphoid, 17 participants (53%) preferred the videolaryngoscope and 15 (47%) the direct laryngoscope. When the table leveled the operator\u0026rsquo;s navel, 24 participants (75%) preferred the videolaryngoscope and 8 (25%) the direct laryngoscope.\u003c/p\u003e \u003cp\u003eOverall, 23 participants (72%) believed to have used less force with the table at xiphoidal level and 9 (28%) with the table at umbilical level.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e offers a visual summary of participants\u0026rsquo; opinions on the procedures.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eOur trial compared intubation with direct and video laryngoscopy in a neonatal manikin positioned at umbilical and xiphoidal bed heights. We hypothesized that the combination of direct/video laryngoscopy and bed height might influence the applied forces during neonatal intubation.\u003c/p\u003e \u003cp\u003eThe literature suggests that videolaryngoscopy may involve lower applied forces compared to direct laryngoscopy in neonatal resuscitation, while the preferred elevation of the resuscitation table remains controversial (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Our investigation provides further information about the potential differences in the forces applied by the resuscitator according to the combination of laryngoscope and bed height. Overall, our findings suggested that intubating a neonatal manikin with the videolaryngoscope and the resuscitation table leveled at operator\u0026rsquo;s navel was associated with the lowest forces applied to the epiglottis and the hard palate. On the other hand, the combination of direct laryngoscope and resuscitation table leveled at operator\u0026rsquo;s xiphoid was associated with the highest applied forces to the epiglottis and the hard palate. These results confirmed previous observations about the lower applied forces when using videolaryngoscopy compared to direct laryngoscopy (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Furthermore, we hypothesize that a high table elevation may push the operator to act beyond the ergonomic levels, probably affecting the applied forces to perform the intubation maneuver. Of note, our data revealed that subjective perceptions of applied forces differed from the actual measurements, as most participants believed to have used less forces when the table leveled operator\u0026rsquo;s xiphoid. Such discrepancy may advocate for the implementation of a technology capable to provide force feedback to the operator during the intubation. Nevertheless, the reader should be aware that the magnitude of harmful applied forces during intubation remains unknown.\u003c/p\u003e \u003cp\u003eVideolaryngoscopy has been associated with higher intubation success at the first attempt compared to direct laryngoscopy in neonates (\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). In our simulation, the participants achieved a high success rate at the first attempt with all combinations of laryngoscope and bed height, alongside with comparable intubation times. Interestingly, the confidence intervals did not exclude that videolaryngoscopy might improve the success rate compared to direct laryngoscopy irrespectively of bed height.\u003c/p\u003e \u003cp\u003eNoteworthy, one bed height did not prevail over the other according to participants\u0026rsquo; preferences. This finding might be influenced by their clinical routine, when the resuscitation table was mostly set at an intermediate elevation between the xiphoid and the navel. Previous studies suggested that higher table positions (such as xiphoid or nipple level) might provide better laryngeal views and less operator\u0026rsquo;s discomfort when intubating with a direct laryngoscope, while umbilical table position might warrant better visibility and less shoulder joint flexion when using a videolaryngoscope (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Our participants confirmed to prefer videolaryngoscopy with the umbilical table position, while one device did not prevail over the other with the xiphoidal table position.\u003c/p\u003e \u003cp\u003eTo our knowledge, this is the first trial investigating the combination of direct/video laryngoscopy and bed height during a simulated neonatal intubation.\u003c/p\u003e \u003cp\u003eThe strengths of our trial included the crossover design, the objective and reliable force measurement, and the enrolment of participants with heterogeneous experience with laryngoscopy and resuscitation table elevation. However, some limitations should be considered when reading the results. First, manikin tissue and anatomy could not replicate the exact texture, flexibility, and responsiveness of a living human body, and eliminated the anatomical heterogeneity among neonates (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Second, the applied forces may differ in a real-life intubation. Third, the trial included only one model of neonatal manikin and two elevations of the resuscitation table. Lastly, the generalizability of the findings should be limited to operators with comparable experience.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eIn a neonatal manikin model, intubating with a videolaryngoscope and the resuscitation table leveled at operator\u0026rsquo;s navel was associated with the lowest forces applied to the epiglottis and the hard palate. The participants achieved a high success rate at the first attempt and comparable procedure times with all combinations of direct/video laryngoscope and low/high bed elevation. Subjective perceptions of applied forces differed from the actual measurements. Applying lower forces during neonatal intubation may be desirable but the clinical implications remain to be evaluated in clinical studies.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eIQR Interquartile range\u003c/p\u003e\n\u003cp\u003eN Newton\u003c/p\u003e\n\u003cp\u003eNICU Neonatal intensive care unit\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are very grateful to the participants.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest/Competing interests:\u003c/strong\u003e The authors have no potential conflicts of interest to disclose.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAvailability of data and material: All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCode availability:\u003c/strong\u003e not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eFC contributed to study concept and data analysis, wrote the initial draft and critically reviewed the manuscript. GP contributed to study concept, investigation, data collection, writing of the manuscript and critically reviewed the manuscript. SM contributed to study concept, data collection, writing of the manuscript and critically reviewed the manuscript. PEV contributed to study concept, supervision, writing of the manuscript and critically reviewed the manuscript. AM contributed to study concept, supervision, writing of the manuscript and critically reviewed the manuscript. ST contributed to study concept, methodology, supervision, writing of the manuscript and critically reviewed the manuscript. DT conceived the study, contributed to data interpretation, wrote the initial draft and critically reviewed the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval:\u003c/strong\u003e The Ethics Committees of the University Hospital of Padua (Italy) reviewed and approved this manikin study (Prot. 536n/AO/24).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate:\u003c/strong\u003e Written informed consent was obtained from participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMadar J, Roehr CC, Ainsworth S, Ersdal H, Morley C, R\u0026uuml;diger M, Sk\u0026aring;re C, Szczapa T, Te Pas A, Trevisanuto D, Urlesberger B, Wilkinson D, Wyllie JP (2021) European Resuscitation Council Guidelines 2021: Newborn resuscitation and support of transition of infants at birth. Resuscitation 161:291\u0026ndash;326\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeone TA, Rich W, Finer NN (2005) Neonatal intubation: success of pediatric trainees. J Pediatr 146:638\u0026ndash;641\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSawyer T, Foglia E, Hatch LD, Moussa A, Ades A, Johnston L, Nishisaki A (2017) Improving neonatal intubation safety: A journey of a thousand miles. J Neonatal Perinat Med 10:125\u0026ndash;131\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHassan HG, El-Sharkawy TY, Renck H, Mansour G, Fouda A (1991) Hemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation. Acta Anaesthesiol Scand 35:442\u0026ndash;447\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHatch LD, Grubb PH, Lea AS, Walsh WF, Markham MH, Whitney GM, Slaughter JC, Stark AR, Ely EW (2016) Endotracheal Intubation in Neonates: A Prospective Study of Adverse Safety Events in 162 Infants. J Pediatr 168:62\u0026ndash;66e6\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFoglia EE, Ades A, Sawyer T, Glass KM, Singh N, Jung P, Quek BH, Johnston LC, Barry J, Zenge J, Moussa A, Kim JH, DeMeo SD, Napolitano N, Nadkarni V, Nishisaki A, NEAR4NEOS Investigators (2019) Neonatal Intubation Practice and Outcomes: An International Registry Study. Pediatrics 143:e20180902\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePouppirt NR, Nassar R, Napolitano N, Nawab U, Nishisaki A, Nadkarni V, Ades A, Foglia EE (2018) Association Between Video Laryngoscopy and Adverse Tracheal Intubation-Associated Events in the Neonatal Intensive Care Unit. J Pediatr 201:281\u0026ndash;284e1\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhou M, Xi X, Li M, Wang S, Liu Z, Liu JQ (2020) Video Laryngoscopy Improves the Success of Neonatal Tracheal Intubation for Novices but Not for Experienced Medical Staff. Front Pediatr 8:445\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeraghty LE, Dunne EA, N\u0026iacute; Chathasaigh CM, Vellinga A, Adams NC, O'Currain EM, McCarthy LK, O'Donnell CPF (2024) Video versus Direct Laryngoscopy for Urgent Intubation of Newborn Infants. N Engl J Med 390(20):1885\u0026ndash;1894\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHatch LD, Grubb PH, Lea AS et al (2016) Endotracheal intubation in neonates: a prospective study of adverse safety events in 162 infants. J Pediatr 168:62\u0026ndash;66\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeiner GM (ed) (2021) Textbook of Neonatal Resuscitation, 8th edn. American Academy of Pediatrics and American Heart Association\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCavallin F, Sala C, Maglio S, Bua B, Villani PE, Menciassi A, Tognarelli S, Trevisanuto D (2023) Applied forces with direct versus indirect laryngoscopy in neonatal intubation: a randomized crossover mannequin study. Can J Anaesth 70(5):861\u0026ndash;868\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee HC, Yun MJ, Hwang JW, Na HS, Kim DH, Park JY (2014) Higher operating tables provide better laryngeal views for tracheal intubation. Br J Anaesth 112(4):749\u0026ndash;755\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKang D, Bae HB, Choi YH, Bom JS, Kim J (2022) A prospective randomized study of different height of operation table for tracheal intubation with videolaryngoscopy in ramped position. BMC Anesthesiol 22(1):378\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorrison G, Tobin JM (2018) Endotracheal Intubation: Oral and Nasal. In: Demetriades D, Inaba K, Lumb P (eds) Atlas of Critical Care Procedures. Springer, Cham\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNikolla DA, Beaumont RR, Lerman JL, Datsko JS, Carlson JN (2020) Impact of bed angle and height on intubation success during simulated endotracheal intubation in the ramped position. J Am Coll Emerg Physicians Open 1(3):257\u0026ndash;262\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim W, Lee Y, Kim C, Lim TH, Oh J, Kang H, Lee S (2016) Comparison of the Pentax Airwayscope, Glidescope Video Laryngoscope, and Macintosh Laryngoscope During Chest Compression According to Bed Height. Med (Baltim) 95(5):e2631\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHong JY, Oh JH, Kim CW, Kim SE, Lee DH, Shin JH (2016) Effects of bed height on the performance of endotracheal intubation and bag mask ventilation. Signa Vitae 12(S1):47\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKane T, Tingay DG, Pellicano A, Sabato S (2023) The neonatal airway. Semin Fetal Neonatal Med 28(5):101483\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJones B, Kenward MG (2015) Design and analysis of cross-over trials, 3rd edn. Chapman \u0026amp; Hall/CRC, New York\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGordon JK, Bertram VE, Cavallin F, Parotto M, Cooper RM (20209 Direct versus indirect laryngoscopy using a Macintosh video laryngoscope: a mannequin study comparing applied forces. Can J Anaesth 67:515\u0026ndash;520\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eR Core Team R (2024) A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejpe","sideBox":"Learn more about [European Journal of Pediatrics](https://www.springer.com/journal/431)","snPcode":"431","submissionUrl":"https://submission.nature.com/new-submission/431/3","title":"European Journal of Pediatrics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"force, intubation, manikin, neonate","lastPublishedDoi":"10.21203/rs.3.rs-6469496/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6469496/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe compared intubation forces, success of the first attempt, intubation time and participant\u0026rsquo;s opinions using direct and video laryngoscopy at umbilical and xiphoidal bed heights in a neonatal manikin. A randomized controlled crossover trial of intubation using direct and video laryngoscopes at two different table elevations (operator\u0026rsquo;s xiphoid or navel) in a neonatal manikin model. Thirty-two neonatologists and pediatric residents participated. The primary outcome measure was the force applied to epiglottis and palate of neonatal manikin during intubation. The secondary outcome measures included success of the first attempt, intubation time, and participants' opinion on the procedures. Intubating the neonatal manikin with the videolaryngoscope and the resuscitation table leveled at operator\u0026rsquo;s navel was associated with the lowest forces applied to the epiglottis and the hard palate. On the other hand, the combination of direct laryngoscope and resuscitation table leveled at operator\u0026rsquo;s xiphoid was associated with the highest applied forces. The success rate at the first attempt and the intubation time were not statistically different among the combinations of laryngoscopes and table elevations. In contrast to actual measurements, most participants believed to have used less forces when the table leveled at operator\u0026rsquo;s xiphoid. \u003cb\u003eConclusions\u003c/b\u003e In a neonatal manikin model, the lower force applied during intubation with a videolaryngoscope and the resuscitation table leveled at operator\u0026rsquo;s navel may be a desirable objective, but the clinical implications should be evaluated in clinical studies.\u003c/p\u003e \u003cp\u003e \u003cb\u003eRegistration\u003c/b\u003e: clinicaltrial.gov NCT06474572\u003c/p\u003e","manuscriptTitle":"Applied forces during neonatal intubation with direct and video laryngoscopy at different bed elevations: a randomized crossover manikin study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-09 01:50:20","doi":"10.21203/rs.3.rs-6469496/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-30T16:36:53+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-27T09:02:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"223338581165883678649399286203432200922","date":"2025-07-29T07:27:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170712160891740765631761276405993215609","date":"2025-07-28T09:04:49+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-02T14:06:38+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-26T15:09:55+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-26T05:59:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Pediatrics","date":"2025-04-17T07:54:19+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejpe","sideBox":"Learn more about [European Journal of Pediatrics](https://www.springer.com/journal/431)","snPcode":"431","submissionUrl":"https://submission.nature.com/new-submission/431/3","title":"European Journal of Pediatrics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"65c72a58-700e-42d1-b1ec-67aa27ddde40","owner":[],"postedDate":"May 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-10T15:59:13+00:00","versionOfRecord":{"articleIdentity":"rs-6469496","link":"https://doi.org/10.1007/s00431-025-06524-8","journal":{"identity":"european-journal-of-pediatrics","isVorOnly":false,"title":"European Journal of Pediatrics"},"publishedOn":"2025-11-05 15:57:01","publishedOnDateReadable":"November 5th, 2025"},"versionCreatedAt":"2025-05-09 01:50:20","video":"","vorDoi":"10.1007/s00431-025-06524-8","vorDoiUrl":"https://doi.org/10.1007/s00431-025-06524-8","workflowStages":[]},"version":"v1","identity":"rs-6469496","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6469496","identity":"rs-6469496","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}