Using a modified syringe technique to adjust the intracuff pressure of a laryngeal mask airway

Abstract

Limiting the intracuff pressure of a laryngeal mask airway (LMA) to <60 cmH₂O is recommended in clinical practice. This report aimed to assess the efficacy of a modified syringe technique to adjust the intracuff pressure of an LMA. In a preclinical study, commercially available 20-mL syringes were attached to the pilot balloon of LMAs with different preset intracuff pressures (40 cmH₂O, 50 cmH₂O, 60 cmH₂O, 70 cmH₂O, 80 cmH₂O, 100 cmH₂O, and 120 cmH₂O). After attachment, the syringe plunger was allowed to passively rebound. If no rebound of the plunger was observed after attachment, 1 mL of air was withdrawn and the plunger was allowed to passively rebound again. This technique allowed the plunger to overcome static friction and avoid excessive deflation of the LMA cuffs. The intracuff pressure was measured using a manometer after the plunger ceased moving. In the preclinical study, the intracuff pressure was always less than or close to 60 cmH₂O after adjustment using this modified syringe technique. After evaluating the performance and characteristics of the syringe in the preclinical study, we concluded that the modified syringe technique may be useful for adjusting LMA intracuff pressure effectively.