Increased risk of ventilator-associated pneumonia in patients after cardiac arrest treated with mild therapeutic hypothermia.

Background: We aimed at investigating the incidence, characteristics and outcome of ventilator-associated pneumonia (VAP) in patients after cardiac arrest (CA) and its potential association with mild therapeutic hypothermia (MTH). We hypothesized, that MTH might increase the risk of VAP.

Methods: Prospective observational study including comatose adult patients after successful resuscitation from out-of-hospital or in-hospital CA with presumed cardiac cause admitted to ICU and treated with MTH at 33°C for 24 h or normothermia (NT) with treatment of fever ≥38°C by pharmacological means. The primary outcome measure was the development of VAP. VAP diagnosis included mechanical ventilation >48 h combined with clinical and radiologic criteria. For a microbiologically confirmed VAP (mcVAP), a positive respiratory culture was required.

Results: About 23% of 171 patients developed VAP, 6% presented with mcVAP. VAP was associated with increased ICU-LOS (9 (IQR 5-14) vs. 6 (IQR 3-9) days; p < .01), ventilator-dependent days (6 (IQR 4-9) vs. 4 (IQR 2-7) days; p < .01) and duration of antibiotic treatment (9 (IQR 5-13) vs. 5 (IQR 2-9) days; p < .01), but not with mortality (OR 0.88 (95% CI: 0.43-1.81); p = .74). Patients treated with MTH (47%) presented higher VAP (30% vs. 17%; p = .04) and mcVAP rates (11% vs. 2%; p = .03). MTH was associated with VAP in multivariable logistic regression analysis with an OR of 2.67 (95% CI: 1.22-5.86); p = .01.

Conclusions: VAP appears to be a common complication in patients after CA, accompanied by more ventilator-dependent days, prolonged antibiotic treatment, and ICU-LOS. Treatment with MTH is significantly associated with development of VAP.