Identification of in-hospital cardiac arrest aetiologies and return of spontaneous circulation

Guidelines emphasise that reversible causes of cardiac arrest are identified to improve the chance of successful resuscitation and return of spontaneous circulation (ROSC). In this study, we investigated the effect of correct identification of in-hospital cardiac arrest (IHCA) aetiologies on the rate of ROSC in patients without obvious aetiology.

This study was a post-hoc analysis of the WHY-IHCA study and leveraged data on presumed IHCA aetiologies and on expert panel-assessed IHCA aetiologies from this study. Correct identification of aetiology was defined as patients where the presumed aetiology was the same as the aetiology assessed by at least 3 of 4 experts. The effect of correct identification of IHCA aetiologies on the rate of ROSC was assessed using logistic regression with adjustment for age, witnessed status, monitored status, shockable status, and actual aetiology.

A total of 150 patients were included of which the aetiology was correctly identified in 80 (53%) patients. The rate of ROSC was 54% and 41% in those with and without correct identification of aetiology, respectively. After adjustment for confounders, correct aetiology identification resulted in a 1.88 (95% confidence interval: 0.77-4.57) times higher odds of ROSC. Results were similar in exploratory analyses of more stringent and more liberal definitions of correct aetiology identification.

The rate of ROSC is higher in patients in whom the aetiology of IHCA is correctly recognised. After adjustment for confounders, correct identification of aetiologies resulted in a numerically higher, although not statistically significant, odds of ROSC.