Difficult airway characteristics associated with first-attempt failure at intubation using video laryngoscopy in the intensive care unit

Rationale: Video laryngoscopy has overcome the need to align the anatomic axes to obtain a view of the glottic opening to place a tracheal tube. However, despite this advantage, a large number of attempts are unsuccessful. There are no existing data on anatomic characteristics in critically ill patients associated with a failed first attempt at laryngoscopy when using video laryngoscopy. Objectives: To identify characteristics associated with first-attempt failure at intubation when using video laryngoscopy in the intensive care unit (ICU). Methods: This is an observational study of 906 consecutive patients intubated in the ICUwith a video laryngoscope between January 2012 and January 2016 in a single-center academic medical ICU. After each intubation, the operator completed a data collection form, which included information on difficult airway characteristics, device used, and outcome of each attempt. Multivariable regression models were constructed to determine the difficult airway characteristics associated with a failed first attempt at intubation. Measurements and Main Results: There were no significant differences in sex, age, reason for intubation, or device used between first-attempt failures and first-attempt successes. First-attempt successes more commonly reported no difficult airway characteristics were present (23.9%; 95% confidence interval [CI], 20.7-27.0% vs. 13.3%; 95% CI, 8.0-18.8%). In logistic regression analysis of the entire 906-patient database, blood in the airway (odds ratio [OR], 2.63; 95% CI, 1.64-4.20), airway edema (OR, 2.85; 95% CI, 1.48-5.45), and obesity (OR, 1.59; 95% CI, 1.08-2.32) were significantly associated with first-attempt failure. Data collection on limited mouth opening and secretions began after the first 133 intubations, and we fit a second logistic model to examine cases in which these additional difficult airway characteristics were collected. In this subset (n = 773), the presence of blood (OR, 2.73; 95% CI, 1.60-4.64), cervical immobility (OR, 3.34; 95% CI, 1.28-8.72), and airway edema (OR, 3.10; 95% CI, 1.42-6.70) were associated with first-attempt failure. Conclusions: In this single-center study, presence of blood in the airway, airway edema, cervical immobility, and obesity are associated with higher odds of first-attempt failure, when intubation was performed with video laryngoscopy in an ICU.