Re-expansion pulmonary edema: Evaluation of risk factors in 173 episodes of spontaneous pneumothorax

Background: The precise incidence and clinical features of re-expansion pulmonary edema (RPE) are unclear, and they vary among reports. In this study, we assessed the incidence, risk factors, and outcomes of patients with RPE over a 3-yr period in a general hospital, with the goal of proposing a primary intervention for pneumothorax. Methods: We retrospectively reviewed records of inpatients with spontaneous pneumothorax treated by tube thoracostomy between October 2007 and December 2010. Results: A total of 173 episodes of spontaneous pneumothorax occurred in 156 patients. The incidence of RPE was 27/173 (15.6%). Symptom duration and pneumothorax size were significant risk factors for RPE, and the occurrence of RPE was independent of primary treatment of spontaneous pneumothorax. Among the patients with RPE, 18 (67%) were symptomatic. Five patients (18.5%) were treated with temporary oxygen, however, 21 patients (78%) did not need any treatment. All patients survived and none required mechanical ventilation. The occurrence of RPE did not influence the clinical outcome. Conclusions: The risk of developing RPE increases with an increased duration or size of pneumothorax. Our results suggest that the methods of primary intervention, including prompt suction, do not affect the onset of RPE. Close observation is always required regardless of the intervention because of the potentially fatal complications.