Standpoint

Clearing the Air - A Conservative Option for Spontaneous Pneumothorax

For the patient who presents with a large primary pneumothorax (i.e., a pneumothorax with no clear underlying lung disease), there is little evidence to guide management.¹ There is general agreement that the air in the pleural space should be removed. If any disagreement exists, it has been about how best to remove it. The British Thoracic Society guidelines advise using a needle to aspirate the pneumothorax and if not successful to place a chest tube²; the American College of Chest Physicians guidelines dispense with the needle and recommend chest-tube placement.³ And yet, whether the intervention, along with the added pain and the risks associated with chest-tube placement and hospitalization, is necessary has not been seriously considered … or studied.⁴

Certainly, for patients in distress and those with a secondary pneumothorax (i.e., with underlying lung disease), an interventional approach is warranted, often followed by treatments to prevent recurrence. However, when the patient with a large pneumothorax has no apparent lung disease and is symptomatic but not in distress, do we need to drain the air? Indeed, before the era of chest tubes, observation was the standard approach; in more modern times, there are cohort studies ^5-7 suggesting that pneumothorax in such patients can be managed safely without intervention.

Why have we been so ready to intervene? For one thing, we worry about the continued leak of air and the dreaded complication of tension pneumothorax, a complication that, although a real concern in those receiving positive-pressure ventilation, is rarely described in spontaneously breathing patients.⁸ For another, there is the practical problem of monitoring patients as outpatients and the lack of knowledge in the medical community about what to expect. Finally, there is the sense that the problem will be managed more quickly and recurrence will be less likely if we take action. In balancing these considerations, there has not been guidance from well-designed randomized trials comparing conservative with interventional approaches.

Thus, the trial by Brown et al.⁹ reported in this issue of the Journal is of unusual significance. Carried out at 39 hospitals in Australia and New Zealand, the trial involved 316 patients 14 to 50 years of age with a moderate-to-large pneumothorax (≥32% on chest radiography as measured by a volumetric Collins equation¹⁰) who were randomly assigned to a conservative or an interventional approach. In the conservative-management group, patients were observed for at least 4 hours in the emergency department and then, if repeat chest radiographs showed no enlargement and the patients did not need oxygen and could walk without difficulty, they were discharged with written instructions and analgesia to be followed as outpatients. In the intervention group, a small-bore Seldinger-type chest tube was placed and attached to a water seal for 1 hour; if the lung had reexpanded and there was no air leak, the tube was clamped for 4 hours and, if the lung remained fully expanded, the chest tube was removed and the patient was discharged. In both groups, if the pneumothorax grew, the patient was admitted to the hospital for pleural drainage. Note that the “interventional” approach used by these investigators is less interventional than what is routinely practiced in the United States.

We have learned much from this trial. Almost 85% of the patients in the conservative-management group did not undergo any intervention. Of those who could be followed, almost all had full reexpansion within 8 weeks, the primary outcome; these results were noninferior to those in the intervention group. Because of problems in accounting for all patients at 8 weeks, the statistical evidence is described as “fragile,” but the basic point is that the conservative-management group did well. Their symptoms resolved as quickly as the symptoms in the intervention group, and they had fewer days in the hospital, fewer days off from work, and less need for surgery. The conservative-management group also had fewer adverse events. It turns out, not surprisingly, that most of the complications came from the chest drains themselves. The conservative approach was quite safe.

Now, the strange part — the conservative-management group had fewer recurrences during the next 12 months than the intervention group. Why would this be? One possible explanation is that chest-tube drainage interfered with healing by pulling open the defect in the lung, whereas allowing the lung to reexpand slowly on its own permitted the defect to heal.¹¹

On the basis of this randomized trial and the earlier reports, we should now be prepared to offer this conservative approach to the young, healthy person with a large primary spontaneous pneumothorax if there is no hemodynamic compromise and with the following provisos: the patient is informed and agrees to the approach, is readily available for outpatient follow-up, and is not planning air travel or scuba diving. It is time to incorporate these findings into new guidelines to help standardize the approach across continents. With this trial, we can include a conservative approach as a reasonable management option for moderate-to-large pneumothoraxes in otherwise healthy young people.

(V. Courtney Broaddus. N Engl J Med 2020; 382:469-470. DOI: 10.1056/NEJMe1916844)

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10. AJR Am J Roentgenol 1995;165:1127-1130.
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