Risk factors for posttraumatic empyema in diaphragmatic injuries

BACKGROUND: Penetrating diaphragmatic injuries are associated with a high incidence of posttraumatic empyema. We analyzed the contribution of trauma severity, specific organ injury, contamination severity, and surgical management to the risk of posttraumatic empyema in patients who underwent surgical repair of diaphragmatic injuries at a level 1 trauma center. METHODS: This is a retrospective review of the patients who survived more than 48 h. Univariate OR calculations were performed to identify potential risk factors. Multiple logistic regression was used to calculate adjusted ORs and identify independent risk factors. RESULTS: We included 192 patients treated from 2011 to 2020. There were 169 (88.0) males. The mean interquartile range, (IQR) of age, was 27 (22–35) years. Gunshot injuries occurred in 155 subjects (80.7%). Mean (IQR) NISS and ATI were 29 (18–44) and 17 (10–27), respectively. Thoracic AIS was > 3 in 38 patients (19.8%). Hollow viscus was injured in 105 cases (54.7%): stomach in 65 (33.9%), colon in 52 (27.1%), small bowel in 42 (21.9%), and duodenum in 10 (5.2%). Visible contamination was found in 76 patients (39.6%). Potential thoracic contamination was managed with a chest tube in 128 cases (66.7%), with transdiaphragmatic pleural lavage in 42 (21.9%), and with video-assisted thoracoscopy surgery or thoracotomy in 22 (11.5%). Empyema occurred in 11 patients (5.7%). Multiple logistic regression identified thoracic AIS > 3 (OR 6.4, 95% CI 1.77–23. 43), and visible contamination (OR 5.13, 95% IC 1.26–20.90) as independent risk factors. The individual organ injured, or the method used to manage the thoracic contamination did not affect the risk of posttraumatic empyema. CONCLUSION: The severity of the thoracic injury and the presence of visible abdominal contamination were identified as independent risk factors for empyema after penetrating diaphragmatic trauma.