Cuff filling volumes for pediatric classic laryngeal mask airways: comparison of clinical end points versus adjusted cuff pressure

Background Clinical end points are often used to guide inflation and adequacy of cuff seal after laryngeal mask airway placement. However, clinical end points for cuff inflation have been shown to have significantly higher intracuff pressure. The adjusted cuff pressure between 55 and 60 cm H2O causes significantly better seal of laryngeal mask airway. We prospectively assessed the cuff pressures generated by cuff inflation guided by clinical end points, and the actual volume of air required to achieve cuff pressures between 55 and 60 cm H2O for sizes 12.5 reusable classic laryngeal mask airway. Methods Two hundred and three ASA I and II children undergoing elective cataract surgery requiring general anesthesia receiving laryngeal mask airway sizes 12.5 were recruited to this study. The laryngeal mask airway was placed using standard technique. After insertion of laryngeal mask airway, the cuff was slowly inflated until a slight outward shift of device was noted. Cuff pressures were measured using calibrated hand held Portex Cuff Inflator Pressure Gauge (Portex Limited, Hythe, Kent, UK). If the cuff pressure was >60 cm H2O, the cuff was deflated to achieve a cuff pressure of 5560 cm H2O. The volume of air required to achieve this pressure was recorded. Results The volume of air required to achieve the pressure between 55 and 60 cm H2O in laryngeal mask airway size 1, 1.5, 2.0, and 2.5 were 2.750 +/- 0.2565, 4.951 +/- 0.5378, 6.927 +/- 0.6328, and 10.208 +/- 1.4535 ml, respectively. The difference between the initial and the final cuff volumes and pressures in all laryngeal mask airway sizes were statistically significant(P = 0.000). Conclusion Lower cuff volumes are required to achieve a pressure of 60 cm H2O than those required if clinical end points are used as a sole guide for determining cuff inflation for patients receiving pediatric laryngeal mask airways.