A randomised controlled trial of the effect of laryngeal mask airway manometry on postoperative sore throat in spontaneously breathing adult patients presenting for surgery at a university teaching hospital

Abstract

Background Laryngeal mask airways (LMAs) are widely used in anaesthesia and are considered to be generally safe. Postoperative sore throat (POST) is a frequent complication following LMA use and can be very distressing to patients. The use of an LMA cuff pressure of between 30 and 32cm of H 2 O in alleviating post-operative sore throat has not been investigated. Objective To compare the occurrence of POST between the intervention group in which LMA cuff pressures were adjusted to 30–32cm of H 2 O and the control group in which only monitoring of LMA cuff pressures was done, to compare the severity of POST between the two study groups and to compare the LMA cuff pressures between the two study groups. Methods Eighty consenting adult patients scheduled to receive general anaesthesia with use of an LMA were randomized into two groups of 40 patients each. Intervention group: LMA airway cuff pressures were adjusted to 30 to 32cm of H 2 O. Control group: Only had LMA cuff pressures monitored throughout the surgery. All patients were interviewed postoperatively at two, six and twelve hours. Data of their baseline characteristics, occurrence and severity of POST was collected. If POST was present; a Numerical Rating Scale (NRS) was used to assess the severity. Cuff pressures between the two study groups were also determined. Results The baseline demographic characteristics of the participants were similar. The use of manometry to limit LMA AMBU® AuraOnce™ intracuff pressure to 30–32cm H 2 O reduced POST in surgical patient's by 62% at 2 hours and 6 hours (Risk Ratio 0.38 95%CI 0.21–0.69)in the intervention group. The median POST pain score in the intervention group was significantly lower than the control group with scores of 0 at 2, 6 and 12 hours post operatively. Routine practice of LMA cuff inflation by anesthesiologists is variable, and the intracuff pressures in the control group were higher than in the intervention group. (P<0.001) Conclusion Among this population, reduction of LMA AMBU® AuraOnce™ intracuff pressure to 30–32cm H 2 O reduces the occurrence and severity of POST. The LMA cuff pressures should be measured routinely using manometry and reducing the intracuff pressures to 30–32 cm of H 2 O recommended as best practice.

Anestesisykepleieres metoder for å kontrollere cufftrykk – en observasjonsstudie

“…Studier viser at pasienter i generell anestesi som har fått sine luftveier sikret med endotrakealtube har skader i slimhinner eller opplever hoste, sår hals, heshet eller problemer med å svelge postoperativt (1)(2)(3). De samme skader rapporteres også ved bruk av larynxmasker (4)(5)(6). Skadene er rapportert til å vare opp mot 24 timer etter bruk av både endotrakealtuber og larynxmasker (2,5).…”

“…Skadene er rapportert til å vare opp mot 24 timer etter bruk av både endotrakealtuber og larynxmasker (2,5). Omfanget av skadene varierer, men intervensjonsgrupper med objektiv måling (manometer) har lavere insidens av skader enn kontrollgruppene med subjektiv måling (5,6). Seet (5) rapporterer en signifikant forskjell mellom gruppene med reduksjon av pharyngolaryngeale komplikasjoner på 70 % der cufftrykket i larynxmaske er målt med manometer og holdt under 60 cmH 2 O.…”

Prevalensi Nyeri Tenggorok Pascaoperasi dengan Pemberian Lubrikasi VCO pada Pemasangan LMA

“…Hal ini sesuai dengan penelitian Waruingi et al tahun 2015 yang menyatakan bahwa operasi yang lebih lama dapat meningkatkan prevalensi nyeri tenggorok. 27 Gilani et al juga mendapatkan hubungan yang bermakna antara lama operasi dengan dengan nyeri tenggorok. 18 Berdasarkan hasil yang didapatkan pada penelitian ini dan dibandingkan dengan penelitian lain yang sejenis, maka lubrikasi LMA dengan VCO dapat menurunkan prevalensi nyeri tenggorok pascaoperasi.…”

Sealing Mechanics Study of Laryngeal Mask Airways via 3D Modeling and Finite Element Analysis

“…On the one hand, an under-inflated LMA may not entirely block the oropharynx and hypopharynx, leading to air leakage. On the other hand, although sealing can be improved by increasing the cuff pressure (CP) of an LMA to fit the pharynx, unintended cuff hyperinflation can lead to severe complications in the upper airway by exerting high forces on pharynx structures, thus impairing mucosal perfusion [4][5][6][7] . Moreover, when an LMA is of the wrong size 8 , or not placed at the right sealing position 9,10 , it can be challenging to find an appropriate CP avoiding air leakage and high mucosal pressure (MP) at the same time.…”