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

Background:  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.
Methods:  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 cmH₂O, pressures exceeding the measurement range were set at 140 cmH₂O for statistical purposes) at induction of anesthesia.
Results:  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 cmH₂O. In contrast, when cuff pressures were <40 cmH₂O, 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 cmH₂O.
Conclusion:  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.