Prophylactic Administration of Vasopressors Prior to Emergency Intubation in Critically Ill Patients: A Secondary Analysis of Two Multicenter Clinical Trials

Abstract

Hypotension affects approximately 40% of critically ill patients undergoing emergency intubation and is associated with an increased risk of death. The objective of this study was to examine the association between prophylactic vasopressor administration and the incidence of peri-intubation hypotension and other clinical outcomes.

Design: A secondary analysis of two multicenter randomized clinical trials. The clinical effect of prophylactic vasopressor administration was estimated using a one-to-one propensity-matched cohort of patients with and without prophylactic vasopressors.

Setting: Seven emergency departments and 17 ICUs across the United States.

Patients: One thousand seven hundred ninety-eight critically ill patients who underwent emergency intubation at the study sites between February 1, 2019, and May 24, 2021.

Interventions: None.

Measurements and main results: The primary outcome was peri-intubation hypotension defined as a systolic blood pressure less than 90 mm Hg occurring between induction and 2 minutes after tracheal intubation. A total of 187 patients (10%) received prophylactic vasopressors prior to intubation. Compared with patients who did not receive prophylactic vasopressors, those who did were older, had higher Acute Physiology and Chronic Health Evaluation II scores, were more likely to have a diagnosis of sepsis, had lower pre-induction systolic blood pressures, and were more likely to be on continuous vasopressor infusions prior to intubation. In our propensity-matched cohort, prophylactic vasopressor administration was not associated with reduced risk of peri-intubation hypotension (41% vs 32%; p = 0.08) or change in systolic blood pressure from baseline (-12 vs -11 mm Hg; p = 0.66).

Conclusions: The administration of prophylactic vasopressors was not associated with a lower incidence of peri-intubation hypotension in our propensity-matched analysis. To address potential residual confounding, randomized clinical trials should examine the effect of prophylactic vasopressor administration on peri-intubation outcomes.

Keywords: airway management; critical care; hypotension; intratracheal intubation; mechanical ventilation; vasoconstrictor agents.

Figure 1.

Kaplan-Meier curve of 30-d survival from the time of emergency intubation in the propensity-matched cohort (374 patients). The difference in survival curves by prophylactic vasopressor exposure was statistically significant in log-rank test (hazard ratio, 1.37; 95% CI, 1.03–1.81; p = 0.03).

Figure 2.

Predicted probability of 30-d mortality by peri-intubation systolic blood pressures measured between induction and 2 min of successful intubation. Both the lowest systolic blood pressure (A) and change in systolic blood pressure from pre-induction baseline (B) were independently associated with an increased risk of 30-d mortality. The analyses included the overall cohort of 1,798 patients.