Objective: To determine whether the reported clinical presentation of tension pneumothorax differs between patients who are breathing unassisted versus receiving assisted ventilation.
Background: Animal studies suggest that the pathophysiology and physical signs of tension pneumothorax differ by subject ventilatory status.
Methods: We searched electronic databases through to October 15, 2013 for observational studies and case reports/series reporting clinical manifestations of tension pneumothorax. Two physicians independently extracted clinical manifestations reported at diagnosis.
Results: We identified 5 cohort studies (n = 310 patients) and 156 case series/reports of 183 cases of tension pneumothorax (n = 86 breathing unassisted, n = 97 receiving assisted ventilation). Hypoxia was reported among 43 (50.0%) cases of tension pneumothorax who were breathing unassisted versus 89 (91.8%) receiving assisted ventilation (P < 0.001). Pulmonary dysfunction progressed to respiratory arrest in 9.3% of cases breathing unassisted. As compared to cases who were breathing unassisted, the adjusted odds of hypotension and cardiac arrest were 12.6 (95% confidence interval, 5.8-27.5) and 17.7 (95% confidence interval, 4.0-78.4) times higher among cases receiving assisted ventilation. One cohort study reported that none of the patients with tension pneumothorax who were breathing unassisted versus 39.6% of those receiving assisted ventilation presented without an arterial pulse. In contrast to cases breathing unassisted, the majority (70.4%) of those receiving assisted ventilation who experienced hypotension or cardiac arrest developed these signs within minutes of clinical presentation.
Discussion: The reported clinical presentation of tension pneumothorax depends on the ventilatory status of the patient. This may have implications for improving the diagnosis and treatment of this life-threatening disorder.