Intraoperative cuff pressure measurements of supraglottic airway devices in the operating theatre : a prospective audit

Abstract

Introduction : Supraglottic airway devices (SADs) are used for airway management for an estimated half of surgical patients worldwide in preference to endotracheal tubes. Intracuff pressure (P_INTRACUFF) measurement of SADs, is a monitoring parameter that may be overlooked in daily anesthetic practice. Correct intracuff pressures, with a recommended range of 40 to 60 cmH₂O, are important from a clinical perspective to ensure adequate ventilation and to avoid complications due to cuff hypoinflation or hyperinflation. P_INTRACUFF may be measured with a dedicated measuring device or by widely used estimation techniques such as manual palpation of the cuff, listening to the disappearance of an audible air leak or injection of a standard volume of air into the cuff via the pilot balloon. These estimation methods do not allow quantification of the P_INTRACUFF value to ensure an exact value at the recommended level.

Methods : A prospective single-centre audit of P_INTRACUFF of 191 elective and emergency surgery patients with an SAD was performed measuring P_INTRACUFF values with a calibrated handheld cuff manometer following induction of anesthesia.

Results : At the commencement of surgery, only 38.2% of the patients had a P_INTRACUFF within the recommended range, with measurements exceeding the upper limit of 60 cmH2O for 62 patients (32.5%). While 29.3% showed values of underinflation, patients who had a size 4 SAD were 3 times more likely to have a P_INTRACUFF less than the lower limit of 40 cmH2O, compared to patients with a size 5 SAD (P=0.012). Patients who had a silicone SAD were 2.8 times more likely to have an inadequate P_INTRACUFF, compared to Polyvinyl Chloride SADs.

Conclusions : Our results confirm the need for accurate measurement of SAD P_INTRACUFF using a cuff manometer to provide exact intracuff pressure measurements instead of subjective methods.