Purpose: The incidence of postoperative pharyngolaryngeal complications after laryngeal mask airway (LMA) insertion can be as high as 50%. Over-inflation of the LMA cuff may be a causal factor. We conducted a single-centre parallel group randomised trial to determine whether maintaining LMA-ProSeal intra-cuff pressures below 60 cm H2O decreases postoperative pharyngolaryngeal complications.
Methods: We recruited 120 adult patients who were scheduled to undergo elective surgery under general anaesthesia. Appropriate sized LMA-ProSeal was inserted and the cuff was inflated with air (to no more than the maximum recommended volume) until there was no audible leak. Patients were randomised to either the control group (n = 60), where the intra-cuff pressure was noted and no further action was taken, or to the pressure-monitored group (n = 60), where intra-cuff pressure was maintained below 60 cm H2O. Pharyngolaryngeal complications consisting of sore throat, dysphonia and dysphagia were assessed at 1, 2, and 24 h postoperatively. Patients, anaesthesiologists and assessors were blinded to group allocation. The primary outcome was a composite endpoint of any pharyngolaryngeal complication at any of the three time points. Secondary outcomes were the incidence of individual outcomes at each time point.
Results: The incidence of pharyngolaryngeal complications at any time point was 42% in the routine care group and 32% in the pressure-monitored group (95% CI for difference +28 to -7%, p = 0.26). There was no difference between groups for any of the secondary outcomes.
Conclusion: Our study failed to demonstrate a statistically significant reduction in postoperative pharyngolaryngeal complications by limiting intra-cuff pressures in the LMA-Proseal.