Special Report

Figure: spontaneous pneumothoraxSpontaneous pneumothorax is a common presentation in the emergency department, but controversy persists around its management. For small primary spontaneous pneumothoraces—less than 3 cm—the American College of Chest Physicians guidelines recommend observation in the ED for three to six hours followed by a repeat chest x-ray and discharge if the imaging excludes progression. But for pneumothoraces of 3 cm or greater, the college has long recommended chest tube placement regardless of symptoms or clinical stability, while its European counterparts, the British Thoracic Society and the Belgian Society of Pneumology, recommend simple aspiration as the first-line treatment for primary spontaneous pneumothoraces requiring intervention. In practice, many emergency physicians at least sometimes employ the same watchful waiting conservative management approach with larger pneumothoraces as they do with smaller ones. After all, chest tube insertion is painful for the patient and comes with a not insignificant degree of risk, including complications such as organ injury, bleeding, and infection at rates of up to 30 percent. (Can J Surg. 2007;50[6]:450; https://bit.ly/3o8BQnn.) And smaller retrospective studies have suggested that conservative management, regardless of size, leads to no complications, an equal recurrence rate, and a significantly shorter length of stay. (Acute Med Surg. 2014;1[4]:195; https://bit.ly/2IT7Vzn.) Until recently, however, no randomized clinical trials have compared the two approaches with primary spontaneous pneumothorax management. That changed in early 2020 with the publication of the first such trial by a group of investigators at 39 metropolitan and rural hospitals throughout Australasia. This trial provided promising evidence that conservative management of even larger pneumothoraces is noninferior to chest tube placement, although it is laden with more than a few caveats. A Conservative Approach The investigators randomized 316 patients with moderate to large primary spontaneous pneumothoraces (greater than 6 cm), aged 14-50, to intervention (154) or conservative management (162). (N Engl J Med. 2020;382[5]:405; https://bit.ly/31u2SMa.) A small bore (<12 Fr) Seldinger drain was inserted and attached to an underwater seal without suction in the intervention group. If the lung had re-expanded on a chest x-ray conducted one hour later and the underwater drain no longer bubbled, the drain was closed and a repeat x-ray was conducted four hours later. If the lung remained reinflated, the patient was discharged. The conservative group was observed for a minimum of four hours, after which a repeat chest x-ray was performed and the patients were discharged if they were walking comfortably and did not need supplementary oxygen. All patients received analgesia and supplementary oxygen if they had a saturation of <92% on room air. On the primary outcome of complete radiological resolution (lung re-expansion) at eight weeks, the conservative group (94.4%) was noninferior to the intervention group (98.5%) by the prespecified noninferiority margin of nine percent. The study “challenges the fundamental concept of whether initial routine drainage is required in all patients with primary spontaneous pneumothorax,” wrote lead author Simon G.A. Brown, PhD, of Royal Perth Hospital and the University of Western Australia, and his colleagues. Because data were only available on 256 of the original study participants, the authors acknowledged that if all missing data were presumed to be the worst-case scenario, the intervention group had a reinflation rate of 93.5 percent compared with 82.5 percent in the conservative group, which was not within the noninferiority margin. “Although the primary outcome was not statistically robust to conservative assumptions about missing data, the trial provides modest evidence that conservative management of primary spontaneous pneumothorax was noninferior to interventional management, with a lower risk of serious adverse events,” the authors wrote. A Few Caveats Other limitations were observed. The study was unblinded, out of obvious necessity, and a significant crossover was seen between the two groups, with 15 percent of the conservative management group ultimately getting a chest tube and seven percent of the intervention group being treated conservatively instead. Nonetheless, the authors wrote that the trial provided “modest, but statistically fragile, evidence that conservative management was noninferior to interventional management for radiographic resolution within 8 weeks, with the use of a 9-percentage-point margin.” Secondary outcomes also favored the nonintervention group, including a shorter mean time to radiographic resolution (16 days v. 30 days), lower recurrence rates (16.8% v. 8.8%), fewer adverse events (49 in 41 patients v. 16 in 13 patients), and fewer mean days off from work (10.9 v. 6). Why would recurrence rates be so much lower in the nonintervention group? In an accompanying editorial, V. Courtney Broaddus, MD, a professor emeritus of pulmonary, critical care, allergy, and sleep medicine at the University of California-San Francisco, proposed that the chest tube drain may actually impede healing by pulling open the lung defect and causing leakage, while slow, natural lung re-expansion may promote more complete healing. (N Engl J Med. 2020;382[5]:469.) “Notably, no patients in the conservative management group required emergency intervention, so within this relatively small group of patients in the trial it was safe,” said British emergency physician Simon Carley, MD, on his St. Emlyn's blog. (Feb. 10, 2020; https://bit.ly/35k6Nwi.) “However, this trial is too small to assure us of the safety of this approach if applied in practice.” Weighing the Risks But the findings were definitely intriguing for many emergency physicians. “Not only did patients in the conservative management group not fare worse than the ‘standard-of-care’ chest tube placement, but they also had fewer adverse events, fewer hospitalization days, fewer days off work, less radiographic imaging, and fewer subsequent interventions,” wrote Tarlan Hedayati, MD, the chair of education and an associate professor at Cook County Health and Hospitals System in Chicago, in a RebelEM blog post on the trial. (March 12, 2020; https://bit.ly/3m1T9EK.) “Interestingly, patients in the conservative management group also had less recurrence rates than the intervention group. Of note, patient satisfaction scores did not differ between the 2 groups, which is surprising as one would presume that an approach that spares the patient a painful procedure would result in higher patient satisfaction.” This study provides more confidence to treat at least some large pneumothoraces without a chest tube, wrote Richard Malthaner, MD, a cardiothoracic surgeon in the division of thoracic surgery and the department of epidemiology and biostatistics at London Health Sciences Centre in Ontario, Canada, on the Skeptics' Guide to Emergency Medicine podcast. (Aug. 27, 2020; https://bit.ly/2Ho2cBc.) “It would be reasonable to provide conservative management for a patient with a large first-time spontaneous pneumothorax as long as you can ensure close follow-up,” he said. To translate these findings to patient care at the bedside, Dr. Malthaner advised having the following conversation with patients: “You have a collapsed lung. This can happen randomly in some people. It seems to be stable at the moment, and you're not getting any worse. We're going to keep an eye on you and not put a tube into your chest to reinflate your lung. While a chest tube is very safe, the procedure always has some risks. New research has shown that 90 percent of patients do just fine without a chest tube, so if a repeat x-ray in four hours is OK, we will send you home with a follow-up referral to a thoracic surgeon, and you should come back to the ED if you are feeling worse.” A more consistent approach to managing primary spontaneous pneumothorax worldwide is needed, said Dr. Broaddus in her editorial. (N Engl J Med. 2020;382[5]:469.) “We are all over the map with treatment,” she said. “These patients are managed very differently in the U.S., the U.K., Canada, and Australia. That tells us that until now there has simply not been enough data to standardize treatment.” Share this article on Twitter and Facebook. Access the links in EMN by reading this on our website, www.EM-News.com. Comments? Write to us at [email protected]. Ms. Shawis a freelance writer with more than 20 years of experience writing about health and medicine. She is also the author of Having Children After Cancer, the only guide for cancer survivors hoping to build their families after a cancer diagnosis. You can find her work atwww.writergina.com.

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