Impact of the anesthetic technique: desflurane, sevoflurane or propofol on the performance of the LMA Protector TM in anesthetized adult patients. A comparative study of non-inferiority

Impact of the anesthetic technique: desflurane, sevoflurane or propofol on the performance of the LMA Protector TM in anesthetized adult patients. A comparative study of non-inferiority | 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 Impact of the anesthetic technique: desflurane, sevoflurane or propofol on the performance of the LMA Protector TM in anesthetized adult patients. A comparative study of non-inferiority Matilde Zaballos, Maite Portas, Ana-Gloria Pizarro, Almudena Reyes, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5763413/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: The laryngeal mask (LM) Protector™ (LMP) is a second-generation supraglottic airway device associated with high oropharyngeal leak pressure (OLP). Anesthetic technique is one factor influencing OLP. Objective: To evaluate the OLP of the LMP using desflurane, comparing it for non-inferiority to sevoflurane and propofol, and to assess the relationship between respiratory adverse events and anesthetic agent. Methods: This prospective, observational cohort study included 180 ASA physical status I-III adult patients (aged 18-75 years) undergoing outpatient surgery requiring an LMA. All patients received midazolam (1 mg IV), remifentanil (0.25 µg kg⁻¹ min⁻¹), and propofol (2.5-3 mg kg⁻¹) before LMP insertion without neuromuscular blockade. Anesthesia was maintained with desflurane, sevoflurane, or propofol. OLP and respiratory complications were recorded. Results: Demographic parameters were similar across groups, except for a lower percentage of women in the sevoflurane group and similar rates of advanced airway use. OLP [median (range), cm H₂O] was 28 (22-34) for desflurane, 26 (22-32) for sevoflurane, and 28 (25-34) for propofol (p = 0.62). Initial and maintenance ventilation characteristics were comparable across groups, as was the incidence of respiratory complications (coughing, laryngospasm, desaturation), which were generally mild. Conclusion: The LMP provides effective airway management with high OLP, irrespective of the anesthetic agent (desflurane, sevoflurane, or propofol) used. No significant differences in OLP or respiratory complications were observed among the anesthetic groups. Supraglottic devices desflurane propofol sevoflurane oropharyngeal leak pressure Figures Figure 1 Figure 2 Figure 3 Introduction The laryngeal mask (LM) Protector™ (LMP) Teleflex Medical; Athlone, Ireland) is a recently introduced device in anesthesia practice. Designed to allow a high oropharyngeal leak pressure (OLP), it incorporates features of second-generation supraglottic airway devices (SADs), such as dual gastric access channels, potentially enhancing patient safety against regurgitation (Figure 1). Its "cuff pilot" with pressure indicators helps prevent cuff overdistension [1]. Anesthetic agents for outpatient surgery should facilitate rapid patient recovery and minimize adverse effects. A recent meta-analysis found no significant differences among desflurane, sevoflurane, and propofol regarding hospital discharge times in day surgery; however, propofol was associated with a lower incidence of postoperative nausea and vomiting compared to inhaled agents [2]. Desflurane offers predictability and easy adjustability, making it suitable for procedures of varying durations in day surgery [3]. However, its use with LMAs remains controversial due to potential airway irritation [4, 5, 6]. Therefore, avoiding the combination of desflurane and SADs would mean foregoing the advantages offered by both approaches in ambulatory surgery. Previous meta-analyses yielded conflicting results; some reported increased adverse respiratory events with desflurane, while others found no difference compared to other anesthetic agents [4, 5]. Previous studies have investigated the efficacy of desflurane with SADs in various clinical settings, examining safety, wake-up times, LMA removal, and adverse respiratory events [7, 8]. OLP is a critical determinant of SAD safety and efficacy. The anesthetic technique, its depth, and its impact on pharyngeal muscle tone all influence OLP [9]. While the efficacy of the LMP has been assessed in various settings [10, 11], no studies have examined the impact of different anesthetic techniques on its OLP. This study aimed to evaluate the OLP of the LMP and its relationship to the maintenance anesthetic agent (desflurane, sevoflurane, or propofol). Secondary objectives included analyzing the incidence of adverse respiratory effects and their association with the anesthetic agent. We hypothesized that desflurane would yield comparable OLP values to sevoflurane and propofol when used with the LMP in patients undergoing ambulatory surgery. Methods Study Design This study represents an extension of the original study published by Zaballos et al. in 2019. Approval was obtained from the hospital's Institutional Review Board (IRB #255/16) of Hospital General Universitario Gregorio Marañón, Madrid, Spain on September 7, 2018. A prospective, non-randomized, longitudinal, single-center cohort study was conducted. Consecutive patients meeting the inclusion criteria—American Society of Anesthesiologists (ASA) physical status I-III undergoing ambulatory surgery under general anesthesia and suitable for SAD management—were enrolled. Written informed consent was obtained from all participants. Exclusion criteria for SAD use in our outpatient surgery unit included: history of difficult airway; and/or more than three difficult airway parameters of the following: Mallampati class IV, mouth opening <2.5 cm, cervical spine stiffness); high risk of aspiration; and recent respiratory infection. Intervention Standard monitoring, including bispectral index monitoring (BIS-VISTA™, Aspect Medical Systems Inc., Norwood, MA, USA), was employed for all patients. Preoxygenation was followed by premedication with midazolam (1 mg IV). Anesthesia was induced using a continuous intravenous infusion of remifentanil (0.25 µg kg⁻¹ min⁻¹) and a titrated propofol bolus (2-2.5 mg kg⁻¹) prior to LMP insertion. Neuromuscular blocking agents were not administered during placement. LMP size selection followed manufacturer recommendations (size 3: ≤50 kg; size 4: 51-70 kg; size 5: >70 kg). After insertion, the cuff was inflated until the black line was visible within the green zone; additional maneuvers were used if mild resistance was encountered. Effective ventilation was confirmed by a tidal volume of 6-8 mL kg⁻¹, adequate chest movements, a normal capnography curve, and the absence of leaks. Anesthesia was maintained using either total intravenous anesthesia (TIVA) with propofol or volatile anesthetics (4-5% desflurane or 1.2-1.4% sevoflurane) at the anesthesiologist's discretion. A continuous propofol infusion (5-10 mg kg⁻¹ h⁻¹) was used via an infusion pump for TIVA. Anesthetic agent dosage was adjusted to maintain BIS values between 40 and 60, while remifentanil infusion was titrated according to surgical requirements and hemodynamic parameters, consistent with standard clinical practice. For volatile agents, a 10-minute equilibration period was allowed to ensure alveolar, arterial, and cerebral tissue gas concentrations were in equilibrium before OLP measurement. OLP was measured using a fresh gas flow of 3 L min⁻¹ with the expiratory valve closed until equilibrium pressure (up to a maximum of 40 cm H₂O) was reached [12]. The BIS value was recorded during OLP determination. Advanced clinical scenarios were categorized as: co-existing diseases; obesity; laparoscopic, shoulder, ear, nose, and throat surgery; and lateral or prone patient positioning. Neuromuscular blocking agents were used only as needed, always after OLP measurement. All airway insertions were performed by experienced anesthesiologists with at least ten years of experience in supraglottic airway management, each having performed at least 20 LMP insertions. Hemodynamic parameters (systolic/diastolic blood pressure and heart rate) were recorded at baseline, immediately before, and five minutes after LMA insertion; BIS values were recorded during OLP measurement. The ease of gastric tube insertion through the gastric channel of the LMA (female or male) was also assessed. Other parameters evaluated included ventilation characteristics, adverse effects during maintenance, procedural complications, and the anesthesiologist's satisfaction with the device and the anesthetic technique used. Statistical Analyses Statistical analyses were performed using SPSS version 29.0 (IBM Corp., Armonk, NY, USA). Normality of continuous data was assessed using the Kolmogorov-Smirnov test. Comparisons of continuous variables among the three groups were performed using analysis of variance (ANOVA) with Bonferroni correction for multiple comparisons. Categorical variables were analyzed using the chi-squared test or Fisher's exact test, as appropriate. A p-value < 0.05 was considered statistically significant. Sample Size Calculation A sample size of 58 patients per group was required to achieve 80% power for demonstrating the non-inferiority of desflurane compared to propofol and sevoflurane regarding OLP. This calculation was based on a hypothesized mean difference in OLP of 2 cmH₂O and a standard deviation of 6 cmH₂O among the three anesthetic groups. The standard deviation was derived from a pilot study. Results Data from 180 patients were prospectively analyzed (Figure 2). Table 1 presents patient demographic characteristics. While patients in the sevoflurane group exhibited greater weight and height, the proportion with a body mass index (BMI) >30 kg/m² was comparable across all three groups. The sevoflurane group had a higher proportion of female participants and a lower proportion of patients undergoing vascular surgery (varicose veins). No differences in the frequency of advanced SGA use were observed among the groups. Table 2 shows the success rate, insertion time, and anesthesiologist satisfaction with the anesthetic agents. The overall success rate, encompassing both insertion and maintenance periods, was 175/180 (97%; 95% CI, 93-99%), with no significant differences among the groups. Size 3 were significantly more frequently used in the propofol group (p = 0.0001). No significant differences in OLP were observed among the three groups [median (interquartile range [range]): 28 (24-32 [10-40]) cm H₂O] (Figure 3). Similarly, BIS values during OLP measurement were comparable among the groups (desflurane: 38 ± 11; sevoflurane: 36 ± 9; propofol: 35 ± 12; p = 0.28). The proportion of patients with an OLP >30 cm H₂O was also similar across groups (desflurane: 45%; sevoflurane: 38%; propofol: 43%; p = 0.72). Gastric tube insertion was equally facile across the groups. Initial ventilation characteristics and those during maintenance of anesthesia were comparable among the three groups (Table 2). Hemodynamic parameters remained stable throughout the procedure and were comparable across the three groups (Table 3). Table 4 summarizes the complications recorded during the study. Significantly more patients in the desflurane group experienced gastric fluid accumulation compared to the sevoflurane and propofol groups (p = 0.016). Discussion The primary finding of this study is that the choice of anesthetic agent (desflurane, sevoflurane, or propofol) did not significantly influence the OLP of the LMP. Several factors contribute to OLP in SADs, including LMA size, cuff inflation volume, the radial pressure exerted by the cuff on the oropharyngeal mucosa, and the depth of anesthesia [9, 13]. While our study included more patients using size 3 LMP in the desflurane and propofol groups, this did not translate to lower OLP values. This finding is noteworthy given the established influence of LMA size on OLP. The cuff inflation was standardized to 60 cm H₂O, (which coincided in all patients with the marker position in the green zone of the pilot balloon) minimizing the influence of volume and pressure variations on OLP [9]. Depth of anesthesia, muscle relaxation, and ventilation mode can also affect OLP by altering oropharyngeal muscle tone [14]. Keller and Brimacombe [14] demonstrated, using sensors at multiple pharyngeal locations, that neuromuscular blockade (NMB) did not alter pressure exerted by the Classic LMA on the pharyngeal mucosa at a minimum alveolar concentration of 2% sevoflurane (mean OLP: 20 cm H₂O, 95% CI: 18-22). However, their study did not assess OLP under other anesthetic conditions. In our study, OLP was measured before NMB administration, and comparable BIS values across groups suggest similar depths of anesthesia. A previous study showed that adding remifentanil to propofol increased OLP by 18% (26 vs. 22 cm H₂O) during LMA Supreme insertion [15], suggesting that remifentanil's influence on muscle tone and pharyngeal reflexes may increase OLP. Goldmann et al. [16] found that NMB generally did not affect OLP with the LMA Proseal, although a small subset of patients experienced a >10% decrease in OLP, possibly due to cuff-pharyngeal mismatch [16]. Conversely, Fujiwara et al. [17] reported that NMB increased OLP. The inconsistent effects of NMB across studies highlight the complexity of this interaction. Our study found no significant differences in respiratory adverse events among the anesthetic groups. This observation is consistent with the findings of Kowark et al. [8], who also reported no differences in respiratory adverse effects or recovery characteristics among desflurane, sevoflurane, and propofol with remifentanil and LMA use in 352 patients. However, their study did not specify the LMA type; therefore, these findings may not be directly comparable to ours, given that second-generation LMAs (like the LMA-ProSeal) are bulkier, potentially requiring deeper anesthesia and more complex insertion techniques [9, 18]. Limitations Although the observational, non-randomized study design is a limitation, the comparability of patient characteristics relevant to SAD use (BMI, smoking status, and frequency of advanced procedures) across the three groups mitigates this concern to some degree. However, the concomitant use of remifentanil, which reduces the minimum alveolar concentration of inhalational agents and the effective concentration of propofol, limits the generalizability of the findings to other anesthetic techniques and combinations. This limitation is partially mitigated by the fact that remifentanil use with a hypnotic agent is a common clinical practice, particularly in ambulatory surgery. Conclusion This study demonstrates that the LMP's performance, in terms of OLP and respiratory complications, is not significantly affected by the use of desflurane, sevoflurane, or propofol, when administered with remifentanil in ambulatory surgery. These findings suggest that the choice of anesthetic agent may not be a critical factor influencing the success of LMP insertion and use in this setting. Abbreviations LMP laryngeal mask Protector OLP oropharyngeal leak pressure SADs supraglottic airway devices ASA American Society of Anesthesiologists Declarations Acknowledgment We would like to thank Mrs. Maria Cruz for her support of the study. Authors’ contributions MZ designed and conducted the study, analysed the data, and wrote the text. MP helped to write the main text. AR, PAG and VA contributed to the design and conduction of the study. HJ contributed to the analysis of the results. All authors read and approved the final manuscript. Funding: This work was financially supported by a grant from Teleflex Medical that covered the costs of editing, English revision and statistical analysis. Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate: This study represents an extension of the original study published by Zaballos et al. in 2019. Approval was obtained from the Ethics Committee of Hospital General Universitario Gregorio Marañón, Madrid, (Chairman Dr. Felipe Atienza) Spain on September 7, 2018. Consent for publication Not applicable. Competing interests MZ previously received fees for lecturing from Teleflex Medical Company; MZ have no financial interest in the company. The remaining authors declare that they have no competing interests. Authors’ information Not applicable. References LMA Protector™ Cuff. Pilot™ and LMA Protector™ Instructions for use. Teleflex Incorporated. 2015. Kumar G, Stendall C, Mistry R, Gurusamy K, Walker D. A comparison of total intravenous anaesthesia using propofol with sevoflurane or desflurane in ambulatory surgery: systematic review and meta-analysis. Anaesthesia. 2014;69(10):1138–50. Jakobsson J. Desflurane: a clinical update of a third-generation inhaled anaesthetic. Acta Anaesthesiol Scand. 2012;56(4):420–32. de Oliveira GS Jr, Girao W, Fitzgerald PC, McCarthy RJ. The effect of sevoflurane versus desflurane on the incidence of upper respiratory morbidity in patients undergoing general anesthesia with a Laryngeal Mask Airway: a meta-analysis of randomized controlled trials. J Clin Anesth. 2013;25(6):452–8. Stevanovic A, Rossaint R, Fritz HG, Froeba G, Heine J, Puehringer FK, Tonner PH, Coburn M. Airway reactions and emergence times in general laryngeal mask airway anaesthesia: a meta-analysis. Eur J Anaesthesiol. 2015;32(2):106–16. Kondo T, Izumi H, Kitagawa M. Comparison of the Effects of Desflurane, Sevoflurane, and Propofol on the Glottic Opening Area during Remifentanil-Based General Anesthesia Using a Supraglottic Airway Device. Anesthesiol Res Pract. 2020;2020:1302898. 10.1155/2020/1302898 . PMID: 32636879; PMCID: PMC7321498. Rossi M, Corcione A, Esposito C, Micaglio M, Monzani R, Ori C. Safety aspects of desflurane anesthesia and laryngeal mask airway. Minerva Anestesiol. 2017 Nov;83(11):1199–206. Kowark A, Rossaint R, Pühringer F, Keszei AP, Fritz H, Fröba G, Rex C, Haas H, Otto V, Coburn M, Study Collaborators. Emergence times and airway reactions during general anaesthesia with remifentanil and a laryngeal mask airway: A multicentre randomised controlled trial. Eur J Anaesthesiol. 2018;35(8):588–97. Brimacombe JR, editor. Laryngeal Mask Anesthesia. Principles and practice. 2nd Edition. New York, Saunders, 2005. Eckardt F, Engel J, Mann ST, Müller M, Zajonz T, Koerner CM, Sander M, Mann V. LMA Protector™ Airway: first experience with a new second generation laryngeal mask. Minerva Anestesiol. 2019;85(1):45–52. Zaballos M, Zaballos J, López S, Fernández-Dïez AI, Lluch-Oltra A, Mexedo C, López A. The LMA® Protector ™ in anaesthetised, non-paralysed patient: a multicentre prospective observational study. Anaesthesia. 2019. 10.1111/anae.14534 . Keller C, Brimacombe JR, Keller K, Morris R. Comparison of four methods for assessing airway sealing pressure with the laryngeal mask airway in adult patients. Br J Anaesth. 1999;82:286–7. Brimacombe J, Keller C. A comparison of pharyngeal mucosal pressure and airway sealing pressure with the laryngeal mask airway in anesthetized adult patients. Anesth Analg. 1998;87(6):1379–82. Keller C, Brimacombe J. Influence of neuromuscular block, mode of ventilation and respiratory cycle on pharyngeal mucosal pressures with the laryngeal mask airway. Br J Anaesth. 1999;83(3):480–2. Zaballos M, Bastida E, Agustí S, Portas M, Jiménez C, López-Gil M. Effect-site concentration of propofol required for LMA-Supreme™ insertion with and without remifentanil: a randomized controlled trial. BMC Anesthesiol. 2015;15:131. Goldmann K, Hoch N, Wulf H. [Influence of neuromuscular blockade on the airway leak pressure of the ProSeal laryngeal mask airway]. Anasthesiol Intensivmed Notfallmed Schmerzther. 2006;41(4):228–32. Fujiwara A, Komasawa N, Nishihara I, Miyazaki S, Tatsumi S, Nishimura W, Minami T. Muscle relaxant effects on insertion efficacy of the laryngeal mask ProSeal(®) in anesthetized patients: a prospective randomized controlled trial. J Anesth. 2015;29(4):580–4. Maitra S, Khanna P, Baidya DK. Comparison of laryngeal mask airway Supreme and laryngeal mask airway Pro-Seal for controlled ventilation during general anaesthesia in adult patients: systematic review with meta-analysis. Eur J Anaesthesiol. 2014;31:266–73. Brimacombe J, Keller C, Fullekrug B, et al. A multicenter study comparing the ProSealTM and ClassicTM laryngeal mask airway in anesthetized, nonparalyzed patients. Anesthesiology. 2002;96:289–95. Tables Table 1 to 4 are available in the Supplementary Files section. Additional Declarations Competing interest reported. MZ previously received fees for lecturing from Teleflex Medical Company; MZ have no financial interest in the company. The remaining authors declare that they have no competing interests. Supplementary Files Table1.docx Table2.docx Table3..docx Table4.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5763413","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":398817973,"identity":"feaeb150-9da5-4e19-bf3e-f5d3a6a7cb79","order_by":0,"name":"Matilde Zaballos","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxElEQVRIiWNgGAWjYJCCAx8YLEjSwMxwcAaDBJwrgUcpQgszD0ladNvPHzxsu0NCXt797MMHjDts6ghqMTuTzHA494yE4cYz6cYGjGfSCNtidgCkpU2CcWNDGpsEY9thIrScf8xw2LJNwn5j/zOQlv9EaLkBtIWxTSJxvgTYlgPEaHlscLD3jETyBolnzAaJbcmSDYQdlvj4w88dNrbz+9MYH3xss+MnaAsYMAJNNjgAZCQQpx6qRZ6gg0bBKBgFo2DEAgBrDTxEjQ0B5gAAAABJRU5ErkJggg==","orcid":"","institution":"Hospital Universitario Gregorio Marañón","correspondingAuthor":true,"prefix":"","firstName":"Matilde","middleName":"","lastName":"Zaballos","suffix":""},{"id":398817974,"identity":"e55f0525-f0ae-4b80-9d44-6bcfcb327eb1","order_by":1,"name":"Maite Portas","email":"","orcid":"","institution":"Hospital Universitario Gregorio Marañón","correspondingAuthor":false,"prefix":"","firstName":"Maite","middleName":"","lastName":"Portas","suffix":""},{"id":398817975,"identity":"27ef2091-70ff-4e18-aaf1-2343e7cdc082","order_by":2,"name":"Ana-Gloria Pizarro","email":"","orcid":"","institution":"Hospital Universitario Gregorio Marañón","correspondingAuthor":false,"prefix":"","firstName":"Ana-Gloria","middleName":"","lastName":"Pizarro","suffix":""},{"id":398817976,"identity":"830ba0a5-8463-4bb6-b68d-b56d048a1de5","order_by":3,"name":"Almudena Reyes","email":"","orcid":"","institution":"Hospital Universitario Gregorio Marañón","correspondingAuthor":false,"prefix":"","firstName":"Almudena","middleName":"","lastName":"Reyes","suffix":""},{"id":398817977,"identity":"8989e6b3-bacd-47a9-85f1-afe5a6609b5c","order_by":4,"name":"Olalla Varela","email":"","orcid":"","institution":"Hospital Universitario de A Coruña","correspondingAuthor":false,"prefix":"","firstName":"Olalla","middleName":"","lastName":"Varela","suffix":""},{"id":398817978,"identity":"03504b1b-8ec7-4c14-b060-fbcd9fd5f6bb","order_by":5,"name":"Javier Hortal","email":"","orcid":"","institution":"Hospital Universitario Gregorio Marañón","correspondingAuthor":false,"prefix":"","firstName":"Javier","middleName":"","lastName":"Hortal","suffix":""}],"badges":[],"createdAt":"2025-01-04 12:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5763413/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5763413/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":73339114,"identity":"0c1865b2-0b19-4ab0-91c1-30c952a06585","added_by":"auto","created_at":"2025-01-09 05:00:36","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":243425,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/4e40bf38be9d3cd43410b538.png"},{"id":73338126,"identity":"2acc4fe3-8ecf-481d-8736-46962555c3d9","added_by":"auto","created_at":"2025-01-09 04:52:36","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":96901,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/da3e91621df9ed48c186ec3f.png"},{"id":73339111,"identity":"12e94053-c0c9-4ce1-8ca0-18a65365ea15","added_by":"auto","created_at":"2025-01-09 05:00:36","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":74361,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/98ffb18c97c822be8a79a550.png"},{"id":97328588,"identity":"60341353-36ca-44bf-afba-6c6200b0b9d7","added_by":"auto","created_at":"2025-12-03 08:55:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":825818,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/da3e1f7b-7636-4dba-83c2-0fd9cf1c5f3f.pdf"},{"id":73338127,"identity":"4e13c8bb-4bc8-4d83-987e-8a7b89ed4d51","added_by":"auto","created_at":"2025-01-09 04:52:36","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":17231,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/e08293b7823894d20850295a.docx"},{"id":73338120,"identity":"078150c3-e61c-4f7f-9a0f-2b7a2134022f","added_by":"auto","created_at":"2025-01-09 04:52:36","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":17722,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/506d4f5bd38a179a31e3821c.docx"},{"id":73339686,"identity":"a1d93db2-8330-4141-bf29-208aea499497","added_by":"auto","created_at":"2025-01-09 05:08:36","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":16211,"visible":true,"origin":"","legend":"","description":"","filename":"Table3..docx","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/f5dcd0e0e75843e2986ade02.docx"},{"id":73338124,"identity":"53563048-0482-435a-af96-7f0933adddb6","added_by":"auto","created_at":"2025-01-09 04:52:36","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":14854,"visible":true,"origin":"","legend":"","description":"","filename":"Table4.docx","url":"https://assets-eu.researchsquare.com/files/rs-5763413/v1/af1de902e6bb4d26e6e2a62e.docx"}],"financialInterests":"Competing interest reported. MZ previously received fees for lecturing from Teleflex Medical Company; MZ have no financial interest in the company. The remaining authors declare that they have no competing interests.","formattedTitle":"Impact of the anesthetic technique: desflurane, sevoflurane or propofol on the performance of the LMA Protector TM in anesthetized adult patients. A comparative study of non-inferiority","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe laryngeal mask (LM) Protector\u0026trade;\u0026nbsp;(LMP)\u0026nbsp;Teleflex Medical; Athlone, Ireland) is a recently introduced device in anesthesia practice. Designed to allow a high oropharyngeal leak pressure (OLP), it incorporates features of second-generation supraglottic airway devices (SADs), such as dual gastric access channels, potentially enhancing patient safety against regurgitation (Figure 1). Its \u0026quot;cuff pilot\u0026quot; with pressure indicators helps prevent cuff overdistension [1].\u003c/p\u003e\n\u003cp\u003eAnesthetic agents for outpatient surgery should facilitate rapid patient recovery and minimize adverse effects. A recent meta-analysis found no significant differences among desflurane, sevoflurane, and propofol regarding hospital discharge times in day surgery; however, propofol was associated with a lower incidence of postoperative nausea and vomiting compared to inhaled agents [2].\u003c/p\u003e\n\u003cp\u003eDesflurane offers predictability and easy adjustability, making it suitable for procedures of varying durations in day surgery [3]. However, its use with LMAs remains controversial due to potential airway irritation [4, 5, 6].\u003c/p\u003e\n\u003cp\u003eTherefore, avoiding the combination of desflurane and SADs would mean foregoing the advantages offered by both approaches in ambulatory surgery. Previous meta-analyses yielded conflicting results; some reported increased adverse respiratory events with desflurane, while others found no difference compared to other anesthetic agents [4, 5].\u003c/p\u003e\n\u003cp\u003ePrevious studies have investigated the efficacy of desflurane with SADs in various clinical settings, examining safety, wake-up times, LMA removal, and adverse respiratory events [7, 8].\u003c/p\u003e\n\u003cp\u003eOLP is a critical determinant of SAD safety and efficacy. The anesthetic technique, its depth, and its impact on pharyngeal muscle tone all influence OLP [9]. While the efficacy of the LMP has been assessed in various settings [10, 11], no studies have examined the impact of different anesthetic techniques on its OLP.\u003c/p\u003e\n\u003cp\u003eThis study aimed to evaluate the OLP of the LMP and its relationship to the maintenance anesthetic agent (desflurane, sevoflurane, or propofol). Secondary objectives included analyzing the incidence of adverse respiratory effects and their association with the anesthetic agent. We hypothesized that desflurane would yield comparable OLP values to sevoflurane and propofol when used with the LMP in patients undergoing ambulatory surgery.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study represents an extension of the original study published by Zaballos et al. in 2019. Approval was obtained from the hospital\u0026apos;s Institutional Review Board (IRB #255/16) of Hospital General Universitario Gregorio Mara\u0026ntilde;\u0026oacute;n, Madrid, Spain on September 7, 2018. A prospective, non-randomized, longitudinal, single-center cohort study was conducted. Consecutive patients meeting the inclusion criteria\u0026mdash;American Society of Anesthesiologists (ASA) physical status I-III undergoing ambulatory surgery under general anesthesia and suitable for SAD management\u0026mdash;were enrolled. Written informed consent was obtained from all participants.\u003c/p\u003e\n\u003cp\u003eExclusion criteria for SAD use in our outpatient surgery unit included: history of difficult airway; and/or more than three difficult airway parameters of the following: Mallampati class IV, mouth opening \u0026lt;2.5 cm, cervical spine stiffness); high risk of aspiration; and recent respiratory infection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIntervention\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStandard monitoring, including bispectral index monitoring (BIS-VISTA\u0026trade;, Aspect Medical Systems Inc., Norwood, MA, USA), was employed for all patients. Preoxygenation was followed by premedication with midazolam (1 mg IV). Anesthesia was induced using a continuous intravenous infusion of remifentanil (0.25 \u0026micro;g kg⁻\u0026sup1; min⁻\u0026sup1;) and a titrated propofol bolus (2-2.5 mg kg⁻\u0026sup1;) prior to LMP insertion. Neuromuscular blocking agents were not administered during placement.\u003c/p\u003e\n\u003cp\u003eLMP size selection followed manufacturer recommendations (size 3: \u0026le;50 kg; size 4: 51-70 kg; size 5: \u0026gt;70 kg). After insertion, the cuff was inflated until the black line was visible within the green zone; additional maneuvers were used if mild resistance was encountered. Effective ventilation was confirmed by a tidal volume of 6-8 mL kg⁻\u0026sup1;, adequate chest movements, a normal capnography curve, and the absence of leaks.\u003c/p\u003e\n\u003cp\u003eAnesthesia was maintained using either total intravenous anesthesia (TIVA) with propofol or volatile anesthetics (4-5% desflurane or 1.2-1.4% sevoflurane) at the anesthesiologist\u0026apos;s discretion. A continuous propofol infusion (5-10 mg kg⁻\u0026sup1; h⁻\u0026sup1;) was used via an infusion pump for TIVA. Anesthetic agent dosage was adjusted to maintain BIS values between 40 and 60, while remifentanil infusion was titrated according to surgical requirements and hemodynamic parameters, consistent with standard clinical practice. For volatile agents, a 10-minute equilibration period was allowed to ensure alveolar, arterial, and cerebral tissue gas concentrations were in equilibrium before OLP measurement. OLP was measured using a fresh gas flow of 3 L min⁻\u0026sup1; with the expiratory valve closed until equilibrium pressure (up to a maximum of 40 cm H₂O) was reached [12]. The BIS value was recorded during OLP determination.\u003c/p\u003e\n\u003cp\u003eAdvanced clinical scenarios were categorized as: co-existing diseases; obesity; laparoscopic, shoulder, ear, nose, and throat surgery; and lateral or prone patient positioning. Neuromuscular blocking agents were used only as needed, always after OLP measurement.\u003c/p\u003e\n\u003cp\u003eAll airway insertions were performed by experienced anesthesiologists with at least ten years of experience in supraglottic airway management, each having performed at least 20 LMP insertions.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHemodynamic parameters (systolic/diastolic blood pressure and heart rate) were recorded at baseline, immediately before, and five minutes after LMA insertion; BIS values were recorded during OLP measurement. The ease of gastric tube insertion through the gastric channel of the LMA (female or male)\u0026nbsp;was also assessed.\u003c/p\u003e\n\u003cp\u003eOther parameters evaluated included ventilation characteristics, adverse effects during maintenance, procedural complications, and the anesthesiologist\u0026apos;s satisfaction with the device and the anesthetic technique used.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using SPSS version 29.0 (IBM Corp., Armonk, NY, USA). \u0026nbsp;Normality of continuous data was assessed using the Kolmogorov-Smirnov test. \u0026nbsp; Comparisons of continuous variables among the three groups were performed using analysis of variance (ANOVA) with Bonferroni correction for multiple comparisons. Categorical variables were analyzed using the chi-squared test or Fisher\u0026apos;s exact test, as appropriate. A p-value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample Size Calculation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA sample size of 58 patients per group was required to achieve 80% power for demonstrating the non-inferiority of desflurane compared to propofol and sevoflurane regarding OLP. \u0026nbsp;This calculation was based on a hypothesized mean difference in OLP of 2 cmH₂O and a standard deviation of 6 cmH₂O among the three anesthetic groups. The standard deviation was derived from a pilot study.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eData from 180 patients were prospectively analyzed (Figure 2). \u0026nbsp;Table 1 presents patient demographic characteristics. \u0026nbsp;While patients in the sevoflurane group exhibited greater weight and height, the proportion with a body mass index (BMI) \u0026gt;30 kg/m\u0026sup2; was comparable across all three groups. \u0026nbsp;The sevoflurane group had a higher proportion of female participants and a lower proportion of patients undergoing vascular surgery (varicose veins). \u0026nbsp;No differences in the frequency of advanced SGA use were observed among the groups.\u003c/p\u003e\n\u003cp\u003eTable 2 shows the success rate, insertion time, and anesthesiologist satisfaction with the anesthetic agents. The overall success rate, encompassing both insertion and maintenance periods, was 175/180 (97%; 95% CI, 93-99%), with no significant differences among the groups. \u0026nbsp;Size 3 were significantly more frequently used in the propofol group (p = 0.0001).\u003c/p\u003e\n\u003cp\u003eNo significant differences in OLP were observed among the three groups [median (interquartile range [range]): 28 (24-32 [10-40]) cm H₂O] (Figure 3). \u0026nbsp;Similarly, BIS values during OLP measurement were comparable among the groups (desflurane: 38 \u0026plusmn; 11; sevoflurane: 36 \u0026plusmn; 9; propofol: 35 \u0026plusmn; 12; p = 0.28). \u0026nbsp; The proportion of patients with an OLP \u0026gt;30 cm H₂O was also similar across groups (desflurane: 45%; sevoflurane: 38%; propofol: 43%; p = 0.72). \u0026nbsp; Gastric tube insertion was equally facile across the groups. \u0026nbsp;Initial ventilation characteristics and those during maintenance of anesthesia were comparable among the three groups (Table 2). \u0026nbsp;Hemodynamic parameters remained stable throughout the procedure and were comparable across the three groups (Table 3).\u003c/p\u003e\n\u003cp\u003eTable 4 summarizes the complications recorded during the study. \u0026nbsp;Significantly more patients in the desflurane group experienced gastric fluid accumulation compared to the sevoflurane and propofol groups (p = 0.016).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe primary finding of this study is that the choice of anesthetic agent (desflurane, sevoflurane, or propofol) did not significantly influence the OLP of the LMP. \u0026nbsp;Several factors contribute to OLP in SADs, including LMA size, cuff inflation volume, the radial pressure exerted by the cuff on the oropharyngeal mucosa, and the depth of anesthesia [9, 13].\u003c/p\u003e\n\u003cp\u003eWhile our study included more patients using size 3 LMP in the desflurane and propofol groups, this did not translate to lower OLP values. This finding is noteworthy given the established influence of LMA size on OLP.\u003c/p\u003e\n\u003cp\u003eThe cuff inflation was standardized to 60 cm H₂O, (which coincided in all patients with the marker position in the green zone of the pilot balloon) minimizing the influence of volume and pressure variations on OLP [9].\u003c/p\u003e\n\u003cp\u003eDepth of anesthesia, muscle relaxation, and ventilation mode can also affect OLP by altering oropharyngeal muscle tone [14]. \u0026nbsp; Keller and Brimacombe [14] demonstrated, using sensors at multiple pharyngeal locations, that neuromuscular blockade (NMB) did not alter pressure exerted by the Classic LMA on the pharyngeal mucosa at a minimum alveolar concentration of 2% sevoflurane (mean OLP: 20 cm H₂O, 95% CI: 18-22). \u0026nbsp; However, their study did not assess OLP under other anesthetic conditions. In our study, OLP was measured before NMB administration, and comparable BIS values across groups suggest similar depths of anesthesia.\u003c/p\u003e\n\u003cp\u003eA previous study showed that adding remifentanil to propofol increased OLP by 18% (26 vs. 22 cm H₂O) during LMA Supreme insertion [15], suggesting that remifentanil\u0026apos;s influence on muscle tone and pharyngeal reflexes may increase OLP. \u0026nbsp;Goldmann et al. [16] found that NMB generally did not affect OLP with the LMA Proseal, although a small subset of patients experienced a \u0026gt;10% decrease in OLP, possibly due to cuff-pharyngeal mismatch [16]. Conversely, Fujiwara et al. [17] reported that NMB increased OLP. \u0026nbsp;The inconsistent effects of NMB across studies highlight the complexity of this interaction.\u003c/p\u003e\n\u003cp\u003eOur study found no significant differences in respiratory adverse events among the anesthetic groups. This observation is consistent with the findings of Kowark et al. [8], who also reported no differences in respiratory adverse effects or recovery characteristics among desflurane, sevoflurane, and propofol with remifentanil and LMA use in 352 patients. \u0026nbsp;However, their study did not specify the LMA type; therefore, these findings may not be directly comparable to ours, given that second-generation LMAs (like the LMA-ProSeal) are bulkier, potentially requiring deeper anesthesia and more complex insertion techniques [9, 18].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAlthough the observational, non-randomized study design is a limitation, the comparability of patient characteristics relevant to SAD use (BMI, smoking status, and frequency of advanced procedures) across the three groups mitigates this concern to some degree. However, the concomitant use of remifentanil, which reduces the minimum alveolar concentration of inhalational agents and the effective concentration of propofol, limits the generalizability of the findings to other anesthetic techniques and combinations. \u0026nbsp;This limitation is partially mitigated by the fact that remifentanil use with a hypnotic agent is a common clinical practice, particularly in ambulatory surgery.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study demonstrates that the LMP\u0026apos;s performance, in terms of OLP and respiratory complications, is not significantly affected by the use of desflurane, sevoflurane, or propofol, when administered with remifentanil in ambulatory surgery. \u0026nbsp;These findings suggest that the choice of anesthetic agent may not be a critical factor influencing the success of LMP insertion and use in this setting.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLMP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003elaryngeal mask Protector\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOLP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eoropharyngeal leak pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSADs\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003esupraglottic airway devices\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAmerican Society of Anesthesiologists\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgment\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank Mrs. Maria Cruz for her support of the study.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMZ designed and conducted the study, analysed the data, and wrote the text. MP helped to write the main text. AR, PAG and VA contributed to the design and conduction of the study. HJ contributed to the analysis of the results. All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was financially supported by a grant from Teleflex Medical that covered the costs of editing, English revision and statistical analysis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study represents an extension of the original study published by Zaballos et al. in 2019. Approval was obtained from the Ethics Committee of Hospital General Universitario Gregorio Mara\u0026ntilde;\u0026oacute;n, Madrid, (Chairman Dr. Felipe Atienza) Spain on September 7, 2018.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMZ previously received fees for lecturing from Teleflex Medical Company; MZ have no financial interest in the company. The remaining authors declare that they have no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; information\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLMA Protector\u0026trade; Cuff. Pilot\u0026trade; and LMA Protector\u0026trade; Instructions for use. Teleflex Incorporated. 2015.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar G, Stendall C, Mistry R, Gurusamy K, Walker D. A comparison of total intravenous anaesthesia using propofol with sevoflurane or desflurane in ambulatory surgery: systematic review and meta-analysis. Anaesthesia. 2014;69(10):1138\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJakobsson J. Desflurane: a clinical update of a third-generation inhaled anaesthetic. Acta Anaesthesiol Scand. 2012;56(4):420\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Oliveira GS Jr, Girao W, Fitzgerald PC, McCarthy RJ. The effect of sevoflurane versus desflurane on the incidence of upper respiratory morbidity in patients undergoing general anesthesia with a Laryngeal Mask Airway: a meta-analysis of randomized controlled trials. J Clin Anesth. 2013;25(6):452\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStevanovic A, Rossaint R, Fritz HG, Froeba G, Heine J, Puehringer FK, Tonner PH, Coburn M. Airway reactions and emergence times in general laryngeal mask airway anaesthesia: a meta-analysis. Eur J Anaesthesiol. 2015;32(2):106\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKondo T, Izumi H, Kitagawa M. Comparison of the Effects of Desflurane, Sevoflurane, and Propofol on the Glottic Opening Area during Remifentanil-Based General Anesthesia Using a Supraglottic Airway Device. Anesthesiol Res Pract. 2020;2020:1302898. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1155/2020/1302898\u003c/span\u003e\u003cspan address=\"10.1155/2020/1302898\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 32636879; PMCID: PMC7321498.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRossi M, Corcione A, Esposito C, Micaglio M, Monzani R, Ori C. Safety aspects of desflurane anesthesia and laryngeal mask airway. Minerva Anestesiol. 2017 Nov;83(11):1199\u0026ndash;206.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKowark A, Rossaint R, P\u0026uuml;hringer F, Keszei AP, Fritz H, Fr\u0026ouml;ba G, Rex C, Haas H, Otto V, Coburn M, Study Collaborators. Emergence times and airway reactions during general anaesthesia with remifentanil and a laryngeal mask airway: A multicentre randomised controlled trial. Eur J Anaesthesiol. 2018;35(8):588\u0026ndash;97.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrimacombe JR, editor. Laryngeal Mask Anesthesia. Principles and practice. 2nd Edition. New York, Saunders, 2005.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEckardt F, Engel J, Mann ST, M\u0026uuml;ller M, Zajonz T, Koerner CM, Sander M, Mann V. LMA Protector\u0026trade; Airway: first experience with a new second generation laryngeal mask. Minerva Anestesiol. 2019;85(1):45\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZaballos M, Zaballos J, L\u0026oacute;pez S, Fern\u0026aacute;ndez-D\u0026iuml;ez AI, Lluch-Oltra A, Mexedo C, L\u0026oacute;pez A. The LMA\u0026reg; Protector\u003csup\u003e\u0026trade;\u003c/sup\u003e in anaesthetised, non-paralysed patient: a multicentre prospective observational study. Anaesthesia. 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/anae.14534\u003c/span\u003e\u003cspan address=\"10.1111/anae.14534\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeller C, Brimacombe JR, Keller K, Morris R. Comparison of four methods for assessing airway sealing pressure with the laryngeal mask airway in adult patients. Br J Anaesth. 1999;82:286\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrimacombe J, Keller C. A comparison of pharyngeal mucosal pressure and airway sealing pressure with the laryngeal mask airway in anesthetized adult patients. Anesth Analg. 1998;87(6):1379\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeller C, Brimacombe J. Influence of neuromuscular block, mode of ventilation and respiratory cycle on pharyngeal mucosal pressures with the laryngeal mask airway. Br J Anaesth. 1999;83(3):480\u0026ndash;2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZaballos M, Bastida E, Agust\u0026iacute; S, Portas M, Jim\u0026eacute;nez C, L\u0026oacute;pez-Gil M. Effect-site concentration of propofol required for LMA-Supreme\u0026trade; insertion with and without remifentanil: a randomized controlled trial. BMC Anesthesiol. 2015;15:131.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldmann K, Hoch N, Wulf H. [Influence of neuromuscular blockade on the airway leak pressure of the ProSeal laryngeal mask airway]. Anasthesiol Intensivmed Notfallmed Schmerzther. 2006;41(4):228\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFujiwara A, Komasawa N, Nishihara I, Miyazaki S, Tatsumi S, Nishimura W, Minami T. Muscle relaxant effects on insertion efficacy of the laryngeal mask ProSeal(\u0026reg;) in anesthetized patients: a prospective randomized controlled trial. J Anesth. 2015;29(4):580\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaitra S, Khanna P, Baidya DK. Comparison of laryngeal mask airway Supreme and laryngeal mask airway Pro-Seal for controlled ventilation during general anaesthesia in adult patients: systematic review with meta-analysis. Eur J Anaesthesiol. 2014;31:266\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrimacombe J, Keller C, Fullekrug B, et al. A multicenter study comparing the ProSealTM and ClassicTM laryngeal mask airway in anesthetized, nonparalyzed patients. Anesthesiology. 2002;96:289\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 to 4 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Supraglottic devices, desflurane, propofol, sevoflurane, oropharyngeal leak pressure","lastPublishedDoi":"10.21203/rs.3.rs-5763413/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5763413/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eThe laryngeal mask (LM) Protector™ (LMP) is a second-generation supraglottic airway device associated with high oropharyngeal leak pressure (OLP). Anesthetic technique is one factor influencing OLP.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective: \u003c/strong\u003eTo evaluate the OLP of the LMP using desflurane, comparing it for non-inferiority to sevoflurane and propofol, and to assess the relationship between respiratory adverse events and anesthetic agent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eThis prospective, observational cohort study included 180 ASA physical status I-III adult patients (aged 18-75 years) undergoing outpatient surgery requiring an LMA. All patients received midazolam (1 mg IV), remifentanil (0.25 µg kg⁻¹ min⁻¹), and propofol (2.5-3 mg kg⁻¹) before LMP insertion without neuromuscular blockade. Anesthesia was maintained with desflurane, sevoflurane, or propofol. OLP and respiratory complications were recorded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eDemographic parameters were similar across groups, except for a lower percentage of women in the sevoflurane group and similar rates of\u003cstrong\u003e \u003c/strong\u003eadvanced airway use. OLP [median (range), cm H₂O] was 28 (22-34) for desflurane, 26 (22-32) for sevoflurane, and 28 (25-34) for propofol (p = 0.62). Initial and maintenance ventilation characteristics were comparable across groups, as was the incidence of respiratory complications (coughing, laryngospasm, desaturation), which were generally mild.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eThe LMP provides effective airway management with high OLP, irrespective of the anesthetic agent (desflurane, sevoflurane, or propofol) used. No significant differences in OLP or respiratory complications were observed among the anesthetic groups.\u003c/p\u003e","manuscriptTitle":"Impact of the anesthetic technique: desflurane, sevoflurane or propofol on the performance of the LMA Protector TM in anesthetized adult patients. A comparative study of non-inferiority","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-09 04:52:32","doi":"10.21203/rs.3.rs-5763413/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"02cde0ee-ece6-4cfe-8406-9209fb5fe707","owner":[],"postedDate":"January 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-03T08:54:50+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-09 04:52:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5763413","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5763413","identity":"rs-5763413","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}