Myocardial infarction rate in acute pulmonary edema: Noninvasive pressure support ventilation versus continuous positive airway pressure

Objective: Noninvasive pressure support ventilation (NIPSV) delivered by face mask has proved an effective treatment for patients with acute pulmonary edema. However, an increase in acute myocardial infarction rate has been reported with this ventilation modality. We investigated whether the use of NIPSV increases the incidence of acute myocardial infarction compared with continuous positive airway pressure (CPAP) in patients with acute pulmonary edema. Design. Randomized, prospective, controlled study. Setting. Emergency Department, Niguarda Hospital of Milano (Italy). Patients. Forty-six patients affected by acute pulmonary edema. Interventions. The patients received either NIPSV (24 patients) or CPAP (22 patients) through a face mask. Measurements and Main Results. Cardiac enzymes (myoglobin, creatine kinase isoenzyme MB, and troponin 1) were determined and electrocardiographic and physiologic measurements made over the subsequent 36 hrs. No significant differences were observed in the incidence of acute myocardial infarction in the CPAP group (13.6%) compared with the NIPSV group (8.3%). Both modalities of noninvasive ventilation improved ventilation and vital signs in patients with acute pulmonary edema. Two patients of the NIPSV group (8.3%) and one of the CPAP group (4.5%) required endotracheal intubation because vital signs and arterial blood gases worsened 1 hr after the start of noninvasive ventilation. No significant differences were found in in-hospital mortality rate. Conclusions. NIPSV proved to be equally effective in improving vital signs and ventilation without increasing acute myocardial infarction rate in patients with nonischemic acute pulmonary edema in comparison to CPAP alone. However, because the study lacked statistical power and excluded patients with acute coronary syndromes, caution is still advised when applying NIPSV to the latter subgroup of patients.