Unanticipated difficult intubation in the medical-surgical intensive care unit: its effect on outcome of critically-ill adults.

Abstract

Background: Difficult intubation (DI) occurs more frequently in the intensive care unit (ICU) than in the operating room and is associated with severe complications including hypotension, hypoxemia, and even cardiac arrest.Objective: To investigate the effects of unanticipated difficult intubations on intensive care related outcomes in adults.Methods: Retrospective chart-review of intubations performed in the medical/surgical ICU of a University hospital by the anesthesia service over a 12-month period where direct laryngoscopy (DL) was attempted initially. DI was defined as > 3 attempts at DL or > 2 attempts with an airway adjunct. Dependent variables were ventilator days, tracheostomy, ICU length of stay (LOS), and ICU mortality. ICU mortality was adjusted by calculating the standardized mortality ratio (SMR) using APACHE-predicted mortality as the denominator. The relationship between intubation attempts and mortality was assessed by Spearman nonparametric correlation (r 2 ).Results: 22% of 113 intubations were difficult. Baseline characteristics, predicted mortality, and indication for intubation were similar between groups. The most used medications and airway adjunct were Etomidate and Succinylcholine and the Eschmann tracheal tube introducer, respectively. Overall, SMR was not significantly higher in DI group (1.76, 1.01). A correlation between number of airway manipulations (>2) and mortality was found (r 2 =0.8, p=0.04). The odds of tracheostomy were higher in DI [OR=3.7 (95% CI 1.1-12), p=0.03]. Ventilator days and LOS were similar between groups.Conclusion: Unanticipated difficulty with intubating adult ICU patients increases the odds of tracheostomy and may lead to higher than expected ICU mortality.