Aspiration for primary pneumothorax: higher failure rate than drainage, but less pain

Reference

Marx T, Joly LM, Parmentier AL, et al. Simple aspiration versus drainage for complete pneumothorax: a randomized noninferiority trial. Am J Respir Crit Care Med 2023;207(11):1475-1485.

Synopsis

These researchers, supported by government and foundation grants, recruited adults aged 18 to 50 years who arrived in emergency departments with their first symptomatic (chest pain or dyspnea or both) acute primary pneumothorax. The authors randomized the patients to receive a simple aspiration (using a thoracentesis system; n = 189) or chest tube drainage (n = 190). The thoracentesis system consisted of a safety catheter mounted on a blunt needle attached to a syringe. The system had a stopcock that could be opened for aspiration and closed to seal off the system. Both the chest tube drainage system and the thoracentesis system were left to drain for 15 to 30 minutes, after which a chest radiograph was performed. If the aspiration-assigned patients’ lung had re-expanded, the device was removed, and the patient was x-rayed again 24 hours later. If the lung had not re-expanded, a second aspiration was performed; if that failed, a chest tube was inserted, the patient was hospitalized, and the tube was removed 72 hours later if the lung was completely re-expanded. The researchers x-rayed the patients assigned to traditional drainage after 24 hours and if their lungs had re-expanded, the chest tube was removed. Although their main interest was outcomes at 24 hours, the researchers also evaluated patients 7 days and 1 year later. Of the patients assigned to simple aspiration, 73 (38.6%) failed to re-expand after the first aspiration, of whom 55 failed on the second procedure, for a net 29.1% failure rate. Only 37 (19.5%) of the patients receiving chest tubes failed to re-expand at 24 hours. By 7 days, the 2 groups had similar failure rates (16% and 15%, respectively). The rate of recurrences within a year was slightly lower in the aspiration-treated patients (20% vs 27%), but this difference was not statistically significant. Using intention-to-treat analysis, patients treated with aspiration had slightly less pain after 24 hours than those treated with chest tube drainage (mean difference −1.4 on a 10-point scale), but there was no significant difference in dyspnea, anxiety, or hospital length of stay. After 7 days and 1 year, there were no differences in any of these outcomes between the groups.