By Betty Tran, MD, MSc
Associate Professor of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago
SYNOPSIS: The investigators found a higher rate of failure with simple aspiration as a first-line intervention for primary spontaneous pneumothorax compared to chest tube drainage, but it was better tolerated with fewer adverse events.
SOURCE: 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;207:1475-1485.
The Exsufflation of Primary Spontaneous Pneumothorax versus Chest Tube Drainage (EXPRED) study was a prospective, open-label, randomized noninferiority trial aiming to compare simple aspiration to chest tube drainage as first-line management of the first episode of a primary, spontaneous, complete pneumothorax. Patients were recruited from multiple emergency departments (EDs) in France, with inclusion criteria consisting of age 18-50 years, first episode of primary and complete pneumothorax (defined as complete separation of visceral from parietal pleura extending from apex to base), and symptoms for less than 48 hours. Patients with tension, traumatic, secondary, recurrent pneumothorax and primary pneumothorax with pleural effusion were excluded.
Patients were randomized to either simple aspiration or chest tube drainage. For simple aspiration, an aspiration device consisting of a polyurethane catheter mounted on a blunt needle was placed in the second intercostal space midclavicular line. For chest tube drainage, a 16- or 20-French chest tube was placed in the fourth or fifth intercostal space midaxillary line. Both groups initially had free drainage for 15 minutes, then aspiration at -25 cm H2O for 30 minutes. Based on a chest radiograph done at 30 minutes, the aspiration group could either have the aspiration device removed if the lung showed re-expansion or an additional 30 minutes of -25 cm H2O aspiration applied if there was no lung re-expansion. If the pneumothorax still persisted, chest tube drainage was subsequently performed.
The chest tube group had continuous aspiration at -25 cm H2O. Chest radiographs were performed at 30 minutes, 24 hours, seven days, and one year after study inclusion. The primary outcome was pulmonary expansion (defined as pneumothorax resolution or residual less than 2 cm) 24 hours after the procedure. Simple aspiration was considered a failure after a second attempt with need for chest tube drainage. Secondary outcomes included pulmonary expansion at seven days, pneumothorax recurrence within one year, procedural tolerance based on a visual analog scale for pain, dyspnea, and anxiety at 24 hours and seven days, and adverse events at 24 hours and seven days.
Overall, 402 patients were randomized; most participants were male (82%) and current smokers (83%). Notably, there was substantial discordance between the inputs used for trial planning and actual trial rates in terms of the primary outcome, prompting an unplanned interim re-evaluation of the trial analysis plan. Using a synthesis approach for the primary outcome, the failure rate of simple aspiration compared to chest tube drainage was 29% vs. 19% (difference in failure rate, 0.113; 95% confidence interval [CI], 0.026 to 0.200). In terms of secondary outcomes, the aspiration group had less pain and pain-limited breathing at 24 hours. Other secondary outcomes were similar between the groups.
COMMENTARY
A prior Cochrane review, which included some data from the current study that was ongoing at the time, concluded that chest tube drainage resulted in more immediate success compared to simple aspiration (risk ratio, 0.78; 95% CI, 0.69 to 0.89), although simple aspiration was associated with shorter hospital length of stay and fewer adverse events with no difference in one-year success rates or patient satisfaction.1 However, the quality of evidence overall was rated as low to moderate. With completion of this randomized noninferiority trial, the findings appear concordant with the prior review noting more immediate success with first-line chest tube drainage, but overall better tolerance with simple aspiration (which was not concluded in the Cochrane review).
Despite these results, the true role for simple aspiration in the management of first-occurrence pneumothorax is unclear when applied more broadly in various settings. First, although it is a less invasive procedure than chest tube drainage, it still requires some training regarding appropriate placement and proper aspiration and monitoring afterward.
Second, this trial focused on a very specific population of patients presenting with pneumothorax; it is unlikely that simple aspiration would be an option for most intensive care unit patients or even the majority of patients presenting with pneumothorax to the ED. Finally, given the trend toward using smaller-bore catheters to manage pneumothorax, the degree of tolerance and adverse events may be less than expected with larger-bore chest tubes. Regardless, this study would suggest that in experienced ED hands for a specific patient population with pneumothorax, many patients may benefit from simple aspiration and a short monitoring time rather than defaulting to chest tube drainage and hospitalization.
REFERENCE
- Carson-Chahhoud KV, Wakai A, van Agteren JE, et al. Simple aspiration versus intercostal tube drainage for primary spontaneous pneumothorax in adults. Cochrane Database Syst Rev 2017;9:CD004479.
