The risk factors and prognostic implication of acute pulmonary edema in resuscitated cardiac arrest patients

OBJECTIVE Pulmonary edema is frequently observed after a successful resuscitation in out-of-hospital cardiac arrest (OHCA) patients. Currently, its risk factors and prognostic implications are mostly unknown. METHODS Adult OHCA patients with a presumed cardiac etiology who achieved sustained return of spontaneous circulation (ROSC) in emergency department were retrospectively analyzed. The patients were grouped according to the severity of consolidation on their initial chest X-ray (group I, no consolidation; group II, patchy consolidations; group III, consolidation involving an entire lobe; group IV, total white-out of any lung). The primary objective was to identify the risk factors of developing severe pulmonary edema (group III or IV). The secondary objective was to evaluate the association between long-term prognosis and the severity of pulmonary edema. RESULTS One hundred and seven patients were included. Total duration of cardiopulmonary resuscitation (CPR) and initial pCO2 level were both independent predictors of developing severe pulmonary edema with their odds ratio (OR) being 1.02 (95% confidence interval [CI], 1.00 to 1.04; per 1 minute) and 1.04 (95% CI, 1.01 to 1.07; per 1 mmHg), respectively. The long term prognosis was significantly poor in patients with severe pulmonary edema with a OR for good outcome (6-month cerebral performance category 1 or 2) being 0.22 (95% CI, 0.06 to 0.79) in group III and 0.16 (95% CI, 0.04 to 0.63) in group IV compared to group I. CONCLUSION The duration of CPR and initial pCO2 level were both independent predictors for the development of severe pulmonary edema after resuscitation in emergency department. The severity of the pulmonary edema was significantly associated with long-term outcome.