Cardiac arrest is a predictor of difficult tracheal intubation independent of operator experience in hospitalized patients

BACKGROUND Placement of advanced airways has been associated with worsened neurologic outcome in survivors of out-of-hospital cardiac arrest. These findings have been attributed to factors such as inexperienced operators, prolonged intubation times and other airway related complications. As an initial step to examine outcomes of advanced airway placement during in-hospital cardiac arrest (IHCA), where immediate assistance and experienced operators are continuously available, we examined whether cardiopulmonary resuscitation efforts affect intubation difficulty. Additionally, we examined whether or not the use of videolaryngoscopy increases the odds of first attempt intubation success compared with traditional direct laryngoscopy. METHODS The study setting is a large urban university-affiliated teaching hospital where experienced airway managers are available to perform emergent intubation for any indication in any out-of-the-operating room location 24 hours a day, 7 days-a-week, 365 days-a-year. Intubations occurring in all adults >18 years-of-age who required emergent tracheal intubation outside of the operating room between January 1, 2008 and December 31, 2012 were examined retrospectively. Multivariate logistic regression was used to estimate the odds of difficult intubation during IHCA compared to other emergent non-IHCA indications with adjustment for a priori defined potential confounders (body mass index, operator experience, use of videolaryngoscopy versus direct laryngoscopy, and age). RESULTS In adjusted analyses, the odds of difficult intubation were higher when taking place during IHCA (OR=2.63; 95% CI 1.1-6.3, p=0.03) compared to other emergent indications. Use of video versus direct laryngoscopy for initial intubation attempts during IHCA, however, did not improve the odds of success (adjusted OR = 0.71; 95% CI 0.35-1.43, p = 0.33). CONCLUSIONS Difficult intubation is more likely when intubation takes place during IHCA compared to other emergent indications, even when experienced operators are available. Under these conditions, direct laryngoscopy (versus videolaryngoscopy) remains a reasonable first choice intubation technique.