Clinical decompensation after trauma laparotomy: It's probably not a pulmonary embolus

Introduction Computed Tomography (CT) to rule out pulmonary embolus (PE) is often ordered during post-trauma laparotomy clinical decompensation (CD) involving fever, tachycardia, tachypnea, and/or leukocytosis. We hypothesize this diagnostic modality is low-yield in the postoperative period when surgery-related sequelae are more probable. Methods This is a single-center retrospective cohort study of patients who underwent trauma laparotomy and had subsequent CT for CD from March 19, 2019 to June 30, 2022. Descriptive statistics and multiple logistic regression were performed. The primary outcome was saddle and lobar PE incidence. Results 1032 adult patients underwent trauma laparotomy with 434 undergoing CT for CD: 137 CT abdomen and pelvis only, 30 CTPE, 265 both. The majority (80.2 %) was male, age 33[interquartile range (IQR) 24-45], suffered penetrating mechanism (57 %), and had ISS 23[IQR16-30]. Injuries at laparotomy included 47 % solid organ, 62 % GI tract, 7 % biliary, 11 % vascular, and 42 % other. 176 (41 %) required damage control laparotomy. Median time to CT post-laparotomy was 174 h [111-235] with saddle and lobar PE in 3 (1 %), peripheral PE 18 (5 %), and abdominal abscess, leak, fluid, or pseudoaneurysm in 222 (51 %). Clinical management was altered (40 %) by antibiotics, therapeutic anticoagulation, drainage, aspiration, filter, thrombectomy, or surgical operation. Patients for whom CT findings changed management were more likely to have had GI tract surgery (69% vs 57 %, p = 0.021), higher white blood cell (WBC) (16.4 [13.1-20.5] vs 15.1 [9.9-19.5], p = 0.002), more hours between CT and laparotomy (184 [141-245] vs 162 [89-230], p = 0.002), and lower mortality (2% vs 8 %, p = 0.008). In-hospital mortality was 5 %; none were PE-related. Predictors of clinical intervention required based on CT imaging were GI tract injury (AOR: 1.65, p = 0.0182), and elevated WBC (AOR: 1.038, p = 0.010 Conclusion Saddle and lobar PE incidence post-trauma laparotomy is low. SIRS-type symptoms prompting postoperative CT commonly have no procedural or antibiotic requirement. Postoperative decompensation is more likely related post-operative complications, and less likely a PE.