Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis

Abstract

Rationale: The use of neuromuscular blocking agents (NMBAs) has been shown to be valuable in improving successful tracheal intubation in the operating room and emergency department. However, data on NMBA use in critically ill intensive care unit (ICU) patients are lacking. Furthermore, there are no data on NMBA use with video laryngoscopy.

Objectives: To evaluate the effect of NMBA use on first-attempt success (FAS) with tracheal intubation in the ICU.

Methods: Single-center observational study of 709 consecutive patients intubated in the medical ICU of a university medical center from January 1, 2012 to June 30, 2014. Data were collected prospectively through a continuous quality improvement program on all patients intubated in the ICU over the study period. Data relating to patient demographics, intubation, and complications were analyzed. We used propensity score (propensity to use an NMBA) matching to generate 5,000 data sets of cases (failed first intubation attempts) matched to controls (successful first attempts) and conditional logistic regression to analyze the results.

Measurements and main results: There were no significant differences in patient demographics, except median total difficult airway characteristics were higher in the non-NMBA group (2 vs. 1, P < 0.001). There were significant differences in the sedative used between groups and the operator level of training. More patients who were given NMBAs received etomidate (83 vs. 35%) and more patients in the non-NMBA group received ketamine (39 vs. 9%) (P < 0.001). The FAS for NMBA use was 80.9% (401/496) compared with 69.6% (117/168) for non-NMBA use (P = 0.003). The summary odds ratio for FAS when an NMBA was used from the propensity matched analyses was 2.37 (95% confidence interval, 1.36-4.88). In the subgroup of patients intubated with a video laryngoscope, propensity-adjusted odds of FAS with the use of an NMBA was 2.50 (1.43-4.37; P < 0.001). There were no differences in procedurally related complications between groups.

Conclusions: After controlling for potential confounders, this propensity-adjusted analysis demonstrates improved odds of FAS at intubation in the ICU with the use of an NMBA. This improvement in FAS is seen even with the use of a video laryngoscope.

Keywords: airway management; intensive care; intubation; neuromuscular blockade; rapid sequence intubation.

Figure 1.

Histogram of the regression coefficients (natural log of the odds ratio [OR]) from the conditional logistic regression analyses of 5,000 propensity score–matched case–control data sets sampled from the complete data set. Shown are the 1st, 5th, 50th, 95th, and 99th percentiles of the regression coefficients from the. 5,000 iterations along with the associated ORs (OR = log OR raised to the power of e, the base of the natural logarithm). FAS = first-attempt success; NMBA = neuromuscular blocking agent.