Laryngeal Mask Airway Cuff Pressure Research Articles

Comparison of Laryngeal Mask Airway Cuff Pressure Changes with Nitrous Oxide and Oxygen vs Room Air Used for LMA Cuff Inflation: A Prospective Randomized Study

Comparison of Laryngeal Mask Airway Cuff Pressure Changes with Nitrous Oxide and Oxygen vs Room Air Used for LMA Cuff Inflation: A Prospective Randomized Study

Laryngeal Mask Airway Cuff Pressure and its Influence on the Incidence of Pharyngolaryngeal Adverse Effects: Need for Regular Monitoring

Laryngeal Mask Airway Cuff Pressure and its Influence on the Incidence of Pharyngolaryngeal Adverse Effects: Need for Regular Monitoring

Clinical Outcomes of a Modified Laryngeal Mask Airway (LMA® Gastro™ Airway) During Esophagogastroduodenoscopy in Children and Adolescents: A Randomized Study.

IntroductionDuring esophagogastroduodenoscopy (EGD), general anesthesia (GA) may be provided using a laryngeal mask airway (LMA) with the endoscope inserted behind the cuff of the LMA into the esophagus. Passage of the endoscope may increase the intracuff of the LMA. We evaluated a newly designed LMA (LMA® Gastro™ Airway) which has an internal channel exiting from its distal end to facilitate EGD. The current study compared the change of LMA cuff pressure between this new LMA and a standard clinical LMA (Ambu® AuraOnce™) during EGD.MethodsPatients less than 21 years of age and weighing more than 30 kg were randomized to receive airway management with one of the two LMAs during EGD. After anesthetic induction and successful LMA placement, the intracuff pressure of the LMAs was continuously monitored during the procedure. The primary outcome was the change of intracuff pressure of the LMAs.ResultsThe study cohort included 200 patients (mean age 13.6 years and weight 56.6 kg) who were randomized to the LMA® Gastro™ Airway (n=100) or the Ambu® AuraOnce™ LMA (n=100). Average intracuff pressures during the study period (before and after endoscope insertion) were not different between the two LMAs. Ease of the procedure was slightly improved with the LMA® Gastro™ Airway (p<0.001).DiscussionThe LMA® Gastro™ Airway blunted, but did not prevent an increase in intracuff pressure during EGD when compared to the Ambu® AuraOnce™ LMA. Throat soreness was generally low, and complications were infrequent in both groups. The ease of the procedure was slightly improved with the LMA® Gastro™ Airway compared to the Ambu® AuraOnce™ LMA.

Clinical application of limiting laryngeal mask airway cuff pressures utilizing inflating syringe intrinsic recoil.

Overinflation of the laryngeal mask airway (LMA) cuff may cause many of the complications associated with the use of the LMA. There is no clinically acceptable (cost effective and practical) method to ensure cuff pressure is maintained below the manufacturer's recommended maximum value of 60 cm H2O (44 mmHg). We studied the use of the intrinsic recoil of the LMA inflating syringe as an effective and practical way to limit cuff pressures at or below the manufacturer's recommended values. We enrolled 332 patients into three separate groups: LMAs inserted and inflated per standard practice at the institution with only manual palpation of the pilot balloon; LMA cuff pressures measured by a pressure transducer and reduced to < 60 cm H2O (44 mmHg); and LMA intra-cuff pressure managed by the intrinsic recoil of the syringe. There were no statistically significant differences between the pressure transducer group and the syringe recoil group for initial cuff pressure or cuff pressure 1 hour after surgery. Both the syringe recoil group and pressure transducer group were less likely than the standard practice group to have sore throat and dysphagia 1 hour after surgery. These differences remained 24 hours after surgery. Syringe recoil provides an efficient and reproducible method similar to manometry in preventing overinflation of the LMA cuff and decreasing the incidence of postoperative laryngopharyngeal complications.

Postoperative pharyngolaryngeal adverse events with laryngeal mask airway (LMA Supreme) in laparoscopic surgical procedures with cuff pressure limiting 25 cmH₂O: prospective, blind, and randomised study.

To reduce the incidence of postoperative pharyngolaryngeal adverse events, laryngeal mask airway (LMA) manufacturers recommend maximum cuff pressures not exceeding 60 cmH2O. We performed a prospective randomised study, comparing efficacy and adverse events among patients undergoing laparoscopic surgical procedures who were allocated randomly into low (limiting 25 cmH2O, L group) and high (at 60 cmH2O, H group) LMA cuff pressure groups with LMA Supreme. Postoperative pharyngolaryngeal adverse events were evaluated at discharge from postanaesthetic care unit (PACU) (postoperative day 1, POD 1) and 24 hours after discharge from PACU (postoperative day 2, POD 2). All patients were well tolerated with LMA without ventilation failure. Before pneumoperitoneum, cuff volume and pressure and oropharyngeal leak pressure (OLP) showed significant differences. Postoperative sore throat at POD 2 (3 versus 12 patients) and postoperative dysphagia at POD 1 and POD 2 (0 versus 4 patients at POD 1; 0 versus 4 patients at POD 2) were significantly lower in L group, compared with H group. In conclusion, LMA with cuff pressure limiting 25 cmH2O allowed both efficacy of airway management and lower incidence of postoperative adverse events in laparoscopic surgical procedures. This clinical trial is registered with KCT0000334.

Acute unilateral submandibular gland swelling associated with the laryngeal mask airway

We describe a rare complication of acute unilateral submandibular gland swelling following the use of laryngeal mask airway (LMA) in two patients with otherwise uneventful perioperative airway management. This is likely to be a consequence of the pressure exerted by the airway cuff on the tissues within the submandibular triangle. As this complication is rarely reported, its true incidence may in fact be higher, suggesting a need for greater attention on LMA cuff pressures and degree of cuff inflation. We discuss the presenting clinical features, pathophysiology and utilisation of ultrasonographic confirmation of sialadenopathy, and review the current anaesthetic literature to raise awareness of this unusual and under-reported complication of LMA. This complication can be mitigated by incorporating routine manometric checks and limiting intracuff pressures to < 60 cmH2O, potentially avoiding LMA insertions in patients with sialolithiasis and avoiding the use of nitrous oxide.

Comparison of postoperative complication between Laryngeal Mask Airway and endotracheal tube during low-flow anesthesia with controlled ventilation

To compare the postoperative complications between Laryngeal Mask Airway (LMA) and endotracheal tube (ETT) during low-flow anesthesia with controlled ventilation. Eighty adult Patients with ASA class I or II were randomly allocated into two forty-patient groups (ETT or LMA). Cuff pressure was monitored during anesthesia. After high uptake period, fresh gas flow (FGF) was decreased to 1 lit/min and isoflurane set to 1%. Monitoring during anesthesia included non-invasive blood pressure, ECG, ETCO2 and pulse oximetry. System leakage (>100 ml/min), rebreathing and any attempt to increase FGF to overcome the leak were monitored during anesthesia. Later, patients were extubated and transferred to Post Anesthesia Care Unit (PACU). In PACU, the incidence of sore throat, cough, difficulty in swallowing and shivering was monitored for all patients. Leakage was observed in two and three cases in ETT and LMA groups respectively (P>0.05). Postoperative cough, sore throat and difficulty in swallowing were significantly less in LMA than ETT group. No significant difference was observed regarding ETCo2 values between 2 groups. If careful measures regarding insertion techniques, correct LMA position and routine monitoring of LMA cuff pressure are taken, LMA can be used as a safe alternative with lower incidence of post operation complication compared with ETT during low-flow controlled anesthesia with modern anesthetic machines.

An implementation program targeted at non-physician, anaesthesia assistants improves the quality of laryngeal mask anaesthesia.

The laryngeal mask airway (LMA) is used to facilitate adequate ventilation in the majority of procedures requiring general anaesthesia in the UK. Excessive LMA cuff pressure and/or volume, generated by injection of air to form an adequate seal within the upper airway, has been associated with pharyngolaryngeal morbidity, an indicator of quality in anaesthetic practice. However, measurement of LMA cuff pressure to limit excessive cuff pressure is not routine practice, despite trial data showing this reduces adverse outcomes. Our aim was to reduce morbidity from the LMA through the implementation of an educational and interventional program targeted at anaesthetic nurses and operating department assistants (ODA), to alter their physician colleagues’ practice. LMA cuff pressure measurements were made, and postoperative outcomes recorded, in an observational cohort of surgical patients over an initial 2-month period. These results, including patient morbidity and the evidence for LMA cuff pressure measurement, were presented to anaesthesia providers and their assistants. An implementation plan to adjust pressures within recommended levels was then undertaken by anaesthesia assistants.In 90 patients, >95% of LMA pressures were beyond the recommended level; higher volumes of injected air correlated with excess pressure (r=0.58; p<0.0001) and were associated with pharyngolaryngeal morbidity in 28% patients (P=0.04). There was no association with difficulty in LMA insertion, duration or type of surgical procedure. In the implementation cohort (102 patients), pharyngolaryngeal morbidity was reduced to 11% (P=0.001) in the 45 patients where LMA cuff pressure was reduced to within normal limits (absolute risk reduction: 38% (95% CI: 22-54%). LMA manometry in three patients (95% CI: 2-5) was required to prevent an episode of postoperative pharyngolaryngeal morbidity.A systematic educational and interventional program targeted at the entire perioperative anaesthesia team, but implemented by anaesthesia assistants, can improve perioperative safety and quality.

ProSeal TM laryngeal mask airway cuff pressure changes with and without use of nitrous oxide during laparoscopic surgery

Background:The ProSeal™ laryngeal mask (PLMA) is increasingly being used as an airway device for laparoscopic surgery. Its silicone cuff allows diffusion of nitrous oxide, carbon dioxide and other gases with resultant rise in its intracuff pressure during anesthesia. The present study was designed to investigate the intracuff pressure changes during anesthesia with and without nitrous oxide in patients undergoing laparoscopic surgery lasting up to two hours.Materials and Methods:One hundred patients, American Society of Anesthesiologists physical status 2 and 3, undergoing general anesthesia with muscle paralysis, were randomized into two groups of 50 patients each to receive an anesthetic gas mixture containing either oxygen and nitrous oxide (group N) or oxygen and air (group A). Following insertion of an appropriate size PLMA, its cuff was inflated with air to an intracuff pressure of 45 mm Hg. The cuff pressure was measured every 10 minutes for the entire course of anesthesia. The position of the device was also assessed fiberoptically and postoperative airway complications were recorded.Results:The maximum intracuff pressure recorded in group N was 103 ± 4.7 mm Hg vs. 45.5 ± 1.5 mm Hg in group A. The percentage rise in cuff pressure every 10 minutes was also highly significant (P < 0.001) being maximum in first 10 min in group N. The incidence of postoperative airway complications was comparable between the two groups.Conclusion:The results of this study demonstrate that the intracuff pressure of the PLMA increases progressively over time when the breathing gas mixture contains nitrous oxide.

The laryngeal mask in infants and children: What is the cuff pressure?

Background Unintended hyperinflation of the cuff of a laryngeal mask airway (LMA) has been associated with increased airway morbidity and postoperative pain. While the manufacturers recommend a cuff pressure of less than 60 cmH 2O, in usual clinical practice, there is no method used to determine intracuff pressure of an LMA. The purpose of this prospective quality assurance study is to evaluate the incidence of LMA hyperinflation and excessive intracuff pressure in a busy tertiary care pediatric hospital. Methods There was no change dictated in clinical practice for these patients. Per our usual practice, the LMA was removed from the package and inserted with the cuff partially inflated. The cuff was further inflated as needed to ensure a seal during positive pressure ventilation to a peak inflating pressure of 20–25 cmH 2O. During the first 30 min of the case, the pressure in the cuff of the LMA was measured using a hand held manometer. Additional data collected included the patient's demographic data (age, weight, and gender), the size of the ETT, and whether nitrous oxide was in use. Results Of the 200 subjects in the current study, 106 had an LMA cuff pressure ≥60 cmH 2O (53%). Patients who were greater than 8 years of age had significantly higher average cuff pressures and significantly more LMAs with an intracuff pressure ≥60 cmH 2O when compared to patients younger than 4 years of age and patients 4–8 years of age. Similarly, larger LMAs were found to have significantly higher intracuff pressures. Conclusions Using current clinical practice to inflate the cuff of the LMA, a significant percentage of pediatric patients have an intracuff pressure greater than the generally recommended upper limit of 60 cmH 2O. Risk factors identified in our study included age of the patient and the size of the LMA.

Using the inflating syringe as a safety valve to limit laryngeal mask airway cuff pressure

Hyperinflation of the laryngeal mask airway (LMA) cuff is thought to be the etiology underlying many of the complications associated with the use of this device. Until now, there has not been a clinically acceptable method (besides direct measurement) to assure that the cuff pressure is maintained less than the recommended maximum value of 44 mm Hg (60 cm H(2)O). We inflated sizes #2 and #5 LMAs with air to 40, 60, or 120 mm Hg starting pressures, using 30- and 60-ml BD™ and B Braun™ syringes; we then allowed the syringe plungers to recoil to equilibrium before removing the syringe from the LMA inflation port. Residual LMA cuff pressures following complete passive recoil were measured and recorded. A number of combinations of syringes (30 and 60 ml) and starting pressures (40, 60, 120 mm Hg) resulted in safe residual (#2 and #5 LMA) cuff pressures of <44 mm Hg. When using specific combinations of syringes, LMA sizes and inflation pressures, these data demonstrate an efficient, practical and easy method to achieve an initial equilibrium recoil LMA cuff pressure that is less than, or very near to, the recommended upper safe limit of 44 mm Hg.

Endotracheal Tube and Laryngeal Mask Airway Cuff Pressures Can Exceed Critical Values During Ascent to Higher Altitude

Tracheal mucosal perfusion is compromised at an endotracheal tube (ETT) cuff pressure of 30 cm H(2)O, and blood flow is obstructed at a pressure of 50 cm H(2)O. We measured the change in pressure of air-filled cuffs of 6.0 and 7.5 ETTs and a size 4 laryngeal mask airway (LMA) from sea level to 2400 m. The ETTs and LMA cuff measurements were done with the devices uncontained, and an additional 6.0 ETT was placed in a 10-mL syringe barrel to mimic placement in a trachea. This restricted cuff expansion simulating what would occur when it is placed within the trachea. The pressure of fluid-filled 6.0 ETT cuffs was also measured. Intracuff pressure increases linearly with increasing altitude, in all air-filled ETT and LMAs. Water-filled cuffs demonstrated no significant change in pressure with changes in altitude. The rate of ETT cuff pressure increase was greater for the ETT restricted within the syringe barrel compared with the unrestricted ETT cuff. The rate of LMA cuff pressure increase was greater than the rate of increase for all the ETTs (restricted and unrestricted). This model indicates that ETT cuffs inflated before air transport are likely to exceed critical pressure levels rapidly during flight. In addition, there will be loss of ETT cuff pressure, with loss of a good seal, during descent if a cuff is initially inflated at peak altitudes. Therefore, we suggest ETT cuff pressures should be monitored and adjusted continuously during ascent and decent.

Reduced air leakage by adjusting the cuff pressure in pediatric laryngeal mask airways during spontaneous ventilation

Optimal inflation of the laryngeal mask airway (LMA) cuff should allow ventilation with low leakage volumes and minimal airway morbidity. Manufacturer's recommendations vary, and clinical end-points have been shown to be associated with cuff hyperinflation and increased leak around the LMA. However, measurement of the intra-cuff pressure of the LMA is not routine in most pediatric institutions, and the optimal intra-cuff pressure in the LMA has not been determined in clinical studies. This was a prospective audit in 100 pediatric patients undergoing elective general anesthesia breathing spontaneously via LMA (size 1.5-3). Cuff pressure within the LMA was adjusted using a calibrated pressure gauge to three different values (60, 40, and 20 cmH2O) within the manufacturers' recommended LMA cuff pressure range (< or = 60 cmH2O). Three corresponding inspiratory and expiratory tidal volumes were recorded, and the differences were calculated as the 'leak volume'. Compared with 20 and 60 cmH2O intra-cuff pressure, measured leakage volumes were the lowest at cuff inflation pressures of 40 cmH2O [median (range) 0.42 (0.09-1.00) ml x kg(-1)] in most patients (83%), while 17% of children demonstrated minimally smaller leakages at 20 cmH2O [0.51 (0.11-1.79) ml x kg(-1)]. Maximum leakage values occurred with cuff pressures of 60 cmH2O in all groups [0.65 (0.18-1.27) ml x kg(-1)] and were not associated with the smallest value of air leakage in any patient. Using cuff manometry, an intra-cuff pressure of 40 cmH2O was associated with reduced leak around the LMA while higher (60 cmH2O) and lower (20 cmH2O) cuff pressures resulted in higher leak volumes during spontaneous ventilation. In spontaneously breathing children, reducing the intra-cuff pressure of pediatric-sized LMAs even below the manufacturers' recommendations allows ventilation with minimized leakage around the LMA cuff.

Use of Manometry for Laryngeal Mask Airway Reduces Postoperative Pharyngolaryngeal Adverse Events

Adverse events such as pharyngolaryngeal complications are indicators of quality patient care. Use of manometry to limit the laryngeal mask airway (LMA) intracuff pressure is not currently a routine practice. This double-blind randomized trial compared pharyngolaryngeal complications in patients managed with manometers to limit the LMA intracuff pressure (<44 mmHg) with patients under routine care. Two hundred consenting patients who underwent ambulatory surgery were randomly allocated to pressure-limiting and routine care groups. Anesthesia was induced with propofol and fentanyl, and maintained with desflurane in air-oxygen. An LMA was inserted, and the cuff was inflated as per usual practice. The patients breathed spontaneously. Research assistants measured the LMA intracuff pressure. In the pressure-limiting group, LMA intracuff pressure was adjusted to less than 44 mmHg. No intervention was performed in the routine care group. Sore throat, dysphonia, and dysphagia were assessed at 1, 2, and 24 h postoperatively. Composite pharyngolaryngeal complications were compared using chi-square test. Baseline demographic data were comparable between groups. Mean LMA intracuff pressure was less in the pressure-limiting group versus the routine care group (40 +/- 6 vs. 114 +/- 57 mmHg, P < 0.001). The incidence of composite pharyngolaryngeal complications was significantly lower in the pressure-limiting group versus the routine care group (13.4 vs. 45.6%, P < 0.001), with a relative risk reduction of 70.6%, and a number needed to treat of three (95% CI 2.2-7.5). Reduction of LMA intracuff pressure to less than 44 mmHg lowers the incidence of postoperative pharyngolaryngeal complications. The LMA cuff pressures should be measured routinely using manometry, and deflating the intracuff pressure to less than 44 mmHg should be recommended as anesthetic best practice.

Laryngeal mask airways – to inflate or to deflate after insertion?

Hyperinflation of the laryngeal mask airway (LMA) cuff is known to be a risk factor for airway morbidity and increased leakage around the LMA. While the manufacturers' recommendation is to inflate the cuff with the maximum recommended volumes and/or to adjust the cuff pressure to <60 cmH2O, cuff pressures below 40 cmH2O have been shown to be associated with a minimal rate of sore throat and minimal leakage. However, it remains to be determined whether inflation or deflation is needed to achieve favorable pressures. Therefore, we assessed the need for cuff-volume adjustment following insertion of the LMA unchanged straight from the sterile packaging in a prospective audit. One thousand children (0-16 years) undergoing elective surgery were consecutively included in this quality of care audit. After taking the LMA from its sterile packaging, the LMA cuff was emptied and the amount of air recorded. Then, the same amount of air was returned into the LMA, the LMA was inserted into the patient, and the cuff pressure was measured using a calibrated cuff manometer. Following insertion of the LMA (without further inflation or deflation of the cuff), 20.5% of children had cuff pressures > or = 60 cmH2, while 55.7% had LMA cuff pressures <40 cmH2O. Cuff pressures were also significantly higher in size 1 LMAs (66.6% had cuff pressures > or = 60 cmH2O and 2% <40 cmH2O) compared with all other sizes (P < 0.05). Furthermore, cuff pressures in LMAs with a poly vinyl chloride (PVC) surface were higher compared to LMAs with a silicone surface (65.2% > or = 60 cmH2O and 9.3% <40 cmH2O vs 9% > or = 60 cmH2O and 67.6% <40 cmH2O, respectively). This study demonstrates that LMAs, particularly when using small-sized LMAs or LMAs with a more rigid PVC surface, need to be deflated following insertion of the device rather than inflated to avoid cuff hyperinflation. Hence, cuff pressures should be measured routinely using a manometer to minimize potential pressure-related airway complications.

Transient isolated lingual nerve neuropraxia associated with general anaesthesia and laryngeal mask use: two case reports and a review of the literature

Transient, isolated lingual nerve neuropraxia is a rare complication following general anaesthesia. Reports implicate airway manipulation and we describe two new cases associated with laryngeal mask airway (LMA) and review the related English language literature. Unilateral numbness and loss of taste on the anterior tongue were the characteristic symptoms. Collation of literature data (median and range) with that from the new cases showed: patient age was 38 (20-61) years and female to male ratio was 1.2:1. Surgery time was 62.5 (20-150) min and symptom duration was 28 (7-120) days. Lingual neuropraxias reported have been transient and patients can be advised, despite disturbing symptoms, that recovery is anticipated in about 1 month. Lingual neuropraxia reports are becoming more frequent, perhaps associated with increasing LMA use. Research is recommended as modification to LMA cuff volume, pressure and/or position within the oral cavity might ameliorate the entity.

Impact of laryngeal mask airway cuff pressures on the incidence of sore throat in children

Hyperinflation of laryngeal mask airway cuffs can cause harm to the upper airway mainly by exerting high pressures on pharyngeal and laryngeal structures thus impairing mucosal perfusion. Although cuff manometers can be used to guide the monitoring of cuff pressures, their use is not routine in many institutions. In a prospective audit, we assessed the incidence of sore throat following day-case-surgery in relation to the intracuff pressure within the laryngeal mask airway. Four hundred children (3-21 years) were consecutively included in this study. The laryngeal mask airway was inflated as deemed necessary by the attending anesthetist. Cuff pressures were measured using a calibrated cuff manometer (Portex Limited, Hythe, Kent, UK, 0-120 cm H2O, pressures exceeding the measurement range were set at 140 cm H2O for statistical purposes) at induction of anesthesia. Forty-five children (11.25%) developed sore throat, 32 (8%) sore neck and 17 (4.25%) sore jaw. Of those that developed sore throat, 56.5% had cuff pressures exceeding >100 cm H2O. In contrast, when cuff pressures were <40 cm H2O, there were no episodes of sore throat, whilst there was only a 4.6% occurrence of sore throat if cuff pressures were between 40-60 cm H2O. We have demonstrated that intra cuff pressure in laryngeal mask airways is closely related to the development of sore throat with higher pressures increasing its likelihood. Hence, cuff pressures should be measured routinely using a manometer to minimize the incidence of sore throat.

Lower cuff pressures improve the seal of pediatric laryngeal mask airways

Hyperinflation of laryngeal mask airway (LMA) cuffs may be harmful because of the exertion of high pressures on pharyngeal and laryngeal structures. Although cuff manometers may be used to monitor cuff pressure, their use is not routine in many institutions and clinical endpoints are used instead. Furthermore, it is common clinical practice to add air to the cuff in the presence of an air leak to obtain a better seal. In a prospective audit, the authors assessed air leakage around pediatric sized LMAs (n = 200) following inflation guided by common clinical endpoints (slight outward movement of the LMA) and then following adjustment of the cuff pressure to the recommended pressure range (<60 cmH(2)O) according to institutional guidelines with the use of a calibrated cuff manometer, directly after induction of anesthesia. Following induction, all children were gently ventilated with pressure control ventilation with 10 cmH(2)O and a positive end-expiratory pressure of 5 cmH(2)O. Following inflation of the cuff guided by clinical endpoints, the median initial cuff pressure (LMA size 1-3) was 92 (size 3) to >120 cmH(2)O (size 1) and the median leakage around the cuff ranged from 0.66 to 1.07 ml x kg(-1). Following cuff pressure adjustment according to the recommended pressure range (<60 cmH(2)O), the leakage decreased significantly to 0.51-0.79 ml x kg(-1) (P = 0.002 for size 1, P < 0.001 for size 1.5-3). The use of clinical endpoints to inflate LMA cuffs is not only associated with significant hyperinflation in the majority of patients but also with an increased leakage around the LMA cuff when compared with adjusted LMA cuff pressures. Therefore, cuff manometers should routinely be used not only to avoid unnecessary hyperinflation but also to improve cuff sealing of LMA in children.

Problems with laryngeal mask airway cuff pressure

Problems with laryngeal mask airway cuff pressure

The Laryngeal Mask Airway at Altitude

The Laryngeal Mask Airway (LMA) is an accepted adjunct for airway management in emergency patients. There are a number of case reports describing its use in transport medicine for infant to adult patients, including during flight. Although studies of the effect altitude has on air-filled tracheal tubes exists, we were unable to find documentation of the effect of altitude on laryngeal mask airways. Our objective was to assess the effect of altitude on the LMA in both fixed wing and rotary wing models. We performed an in vitro study of the effect of altitude on the LMA cuff. Infant and adult airway trainer mannequins with properly sized and inserted LMA-Classic laryngeal mask airways were monitored for cuff pressure changes while flown at altitudes commonly encountered during air medical transport. Both models demonstrated that LMA cuff pressures may exceed manufacturer recommended levels for safe use even at the relatively low altitudes experienced during rotor wing flight. Properly inserted and inflated laryngeal mask airways at ground level may result in overinflated LMA cuffs when flown to altitudes commonly used for rotor and fixed wing medical transport unless monitored and corrected.