Background: Observative management of small traumatic pneumothoraces (PTX) has been shown to decrease chest tube utilization in non-mechanically ventilated patients without compromising outcomes. This approach could be used in mechanically ventilated (MV) patients, though many feel these patients are at increased risk of observation failure.
Methods: A single center retrospective study of all adults undergoing observation of a computed tomography (CT) diagnosed PTX from 2015-2019. Patients with chest tube placement within 4-hours of arrival, concurrent hemothorax, or death within 24-hours were excluded. Observation failure was defined as chest tube placement.
Results: Of 340 patients, 64 were on MV. The groups were of similar age, BMI, underlying pulmonary comorbidities, and PTX size (10.1 mm vs 8.8 mm, P = .20). The MV group was more severely injured (ISS [25+] [60.9% vs 11.2%, P < .001]). There was no difference in observation failure rates by MV status overall (6.3% vs 5.1%, P = .75) or by PTX size (<15 mm [5% vs 2.2%, P = .37], <20 mm [4.8% vs 3.1%, P = .45], <25 mm [4.8% vs 4.1%, P = .73], <30 mm [4.8% vs 4.1%, P = .73], <35 mm [4.8% vs 4.7%, P = 1.00]). MV was not an independent predictor of observation failure on multivariable analysis (OR .64, 95% CI .18-2.20), though PTX size was (OR 1.11, 95% CI 1.05-1.17). When comparing those who failed vs those who did not, the only difference was PTX size (9.34 mm vs 19.41 mm, P < .001).
Conclusion: MV is not an independent predictor of PTX observation failure. While PTX size appears to play a role, further studies are needed to outline safe parameters for observation in those undergoing MV.
Keywords: chest tube; mechanical ventilation; pneumothorax observation; thoracostomy.