Adverse events and their relation to mortality in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia

Abstract

Objectives: To investigate the association between adverse events recorded during critical care and mortality in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia.

Design: Prospective, observational, registry-based study.

Setting: Twenty-two hospitals in Europe and the United States.

Patients: Between October 2004 and October 2008, 765 patients were included.

Interventions: None.

Measurements and main results: Arrhythmias (7%-14%), pneumonia (48%), metabolic and electrolyte disorders (5%-37%), and seizures (24%) were common adverse events in the critical care period in cardiac arrest patients treated with therapeutic hypothermia, whereas sepsis (4%) and bleeding (6%) were less frequent. Sustained hyperglycemia (blood glucose >8 mmol/L for >4 hrs; odds ratio 2.3, 95% confidence interval 1.6-3.6, p < .001) and seizures treated with anticonvulsants (odds ratio 4.8, 95% confidence interval 2.9-8.1, p < .001) were associated with increased mortality in a multivariate model. An increased frequency of bleeding and sepsis occurred after invasive procedures (coronary angiography, intravascular devices for cooling, intra-aortic balloon pump), but bleeding and sepsis were not associated with increased mortality (odds ratio 1.0, 95% confidence interval 0.46-2.2, p = .91, and odds ratio 0.30, 95% confidence interval 0.12-0.79, p = .01, respectively).

Conclusions: Adverse events were common after out-of-hospital cardiac arrest. Sustained hyperglycemia and seizures treated with anticonvulsants were associated with increased mortality. Bleeding and infection were more common after invasive procedures, but these adverse events were not associated with increased mortality in our study.