Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival

Abstract

Importance: Tracheal intubation is common during adult in-hospital cardiac arrest, but little is known about the association between tracheal intubation and survival in this setting.

Objective: To determine whether tracheal intubation during adult in-hospital cardiac arrest is associated with survival to hospital discharge.

Design, setting, and participants: Observational cohort study of adult patients who had an in-hospital cardiac arrest from January 2000 through December 2014 included in the Get With The Guidelines-Resuscitation registry, a US-based multicenter registry of in-hospital cardiac arrest. Patients who had an invasive airway in place at the time of cardiac arrest were excluded. Patients intubated at any given minute (from 0-15 minutes) were matched with patients at risk of being intubated within the same minute (ie, still receiving resuscitation) based on a time-dependent propensity score calculated from multiple patient, event, and hospital characteristics.

Exposure: Tracheal intubation during cardiac arrest.

Main outcomes and measures: The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation (ROSC) and a good functional outcome. A cerebral performance category score of 1 (mild or no neurological deficit) or 2 (moderate cerebral disability) was considered a good functional outcome.

Results: The propensity-matched cohort was selected from 108 079 adult patients at 668 hospitals. The median age was 69 years (interquartile range, 58-79 years), 45 073 patients (42%) were female, and 24 256 patients (22.4%) survived to hospital discharge. Of 71 615 patients (66.3%) who were intubated within the first 15 minutes, 43 314 (60.5%) were matched to a patient not intubated in the same minute. Survival was lower among patients who were intubated compared with those not intubated: 7052 of 43 314 (16.3%) vs 8407 of 43 314 (19.4%), respectively (risk ratio [RR] = 0.84; 95% CI, 0.81-0.87; P < .001). The proportion of patients with ROSC was lower among intubated patients than those not intubated: 25 022 of 43 311 (57.8%) vs 25 685 of 43 310 (59.3%), respectively (RR = 0.97; 95% CI, 0.96-0.99; P < .001). Good functional outcome was also lower among intubated patients than those not intubated: 4439 of 41 868 (10.6%) vs 5672 of 41 733 (13.6%), respectively (RR = 0.78; 95% CI, 0.75-0.81; P < .001). Although differences existed in prespecified subgroup analyses, intubation was not associated with improved outcomes in any subgroup.

Conclusions and relevance: Among adult patients with in-hospital cardiac arrest, initiation of tracheal intubation within any given minute during the first 15 minutes of resuscitation, compared with no intubation during that minute, was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding by indication, these findings do not support early tracheal intubation for adult in-hospital cardiac arrest.

Figure 1. Diagram of Derivation of the Study Population

^a Cardiac arrests that were not the first cardiac arrest during the current admission.

Figure 2. Forest Plot of Subgroup Analyses of Survival to Hospital Discharge in the Propensity-Matched Cohort

Risk ratios with 95% confidence intervals for predefined subgroup analyses. The P value represents the type III P value for the interaction between intubation and a given subgroup. The dashed vertical line represents the risk ratio in the overall cohort; the dotted vertical line, a risk ratio of 1.0 (ie, no effect). Except for the time of the matching, there were significant differences according to all other subgroups. ^a The minute at which patients in the intubation group were intubated and matched with a patient not intubated before or within that same minute. ^b Evidence of acute or chronic respiratory insufficiency within 4 hours up to the time of the event (see eTable 1 in the Supplement for additional details).