Pulmonary edema in obstetric patients is rapidly resolved except in the presence of infection or of nitroglycerin tocolysis after open fetal surgery

OBJECTIVES: This study was designed to determine the etiology, course, and severity of pulmonary edema in obstetric patients in a tertiary care center. STUDY DESIGN: A retrospective study was carried out on 16,810 deliveries from University of California, San Francisco, 1985-1995. Diagnosis and severity of lung injury were defined by a 4-point system that was based on the chest radiograph, oxygenation, positive end-expiratory pressure, and lung compliance. Resolution of pulmonary edema was defined by improvement in the chest radiograph and hypoxemia (ratio of arterial oxygen tension to inspired oxygen concentration) scores or by extubation. RESULTS: Pulmonary edema developed in 86 patients, or 0.5% of all obstetric cases. It usually showed extensive air space consolidation on the chest radiograph and arterial hypoxemia. Although 43% of the patients had severe pulmonary dysfunction, the average time to resolution of pulmonary edema was 2.4 days. Only 45% of patients required admission to the intensive care unit and only 15% required intubation and positive-pressure ventilation. Patients with infection (mean of 7.2 days) or fetal surgery (mean of 3.8 days) had the most severe, protracted course. CONCLUSION: Although obstetric pulmonary edema is associated with extensive radiographic infiltrates and severe hypoxemia, resolution occurs rapidly in most patients, limiting the need for intensive care support.