The laryngeal mask airway for pediatric adenotonsillectomy: predictors of failure and complications.

OBJECTIVES: We hypothesize that the laryngeal mask airway (LMA) is a safe technique for airway management in pediatric adenotonsillectomy (T&A).

METHODS: After institutional review board (I.R.B.) approval, we conducted a retrospective review of 1199 medical records of children who underwent T&A from 2002 to 2006 at Doernbecher Children's Hospital, a teaching institution in Portland, OR. There were no significant demographic differences between the LMA (n=451), endotracheal tube (ETT) (n=715), and failed LMA groups (n=33). Outcome variables were LMA failure (LMA replaced with endotracheal tube), and any complication. We collected demographic and medical data to determine the incidence and predictors of LMA failure, and to characterize the failed LMA group.

RESULTS: The incidence of LMA failure was 6.8%. Patients who underwent adenoidectomy had significantly lower odds of LMA failure compared to patients who had a tonsillectomy or adenotonsillectomy (OR 0.28, 95% CI 0.15-0.52, P<0.0001). One of the surgeons (OR 0.46, 95% CI 0.45-0.48, P<0.0001) was also associated with decreased odds of LMA failure. Controlled ventilation (OR 7.17, 95% CI 4.99-10.32, P<0.0001), and younger patients (OR 1.05 for each year decrease in age, 95% CI 1.03-1.07, P ≤ 0.0001) were associated with increased odds of LMA failure. The complication rate was 14.2% in the LMA group and 7.7% in the ETT group. Increased odds of developing any complication were seen in male patients (OR 1.4, 95% CI 1.01-1.7, P=0.04), and in patients with co-morbidities other than obstructive sleep apnea syndrome or upper respiratory tract infection (OR 4.2, 95% CI 1.03-17.2, P=0.04). The odds of developing a complication were lower in the ETT group compared to the LMA group (0.63, 0.46, 0.8, P=0.005).

CONCLUSIONS: LMA use for pediatric T&A is associated with a higher incidence of complications, mainly as a result of airway obstruction following insertion of the LMA or McIvor gag placement. Complications were more likely if tonsillectomy was performed when compared to adenoidectomy alone. Appropriate patient selection, careful insertion, and avoidance of controlled ventilation may decrease the incidence of LMA failure, especially if tonsillectomy is performed. The ability of surgeons to work around the LMA can modify the failure rate significantly.