Objective The obesity paradox is the association of increased survival for overweight and obese patients compared to normal and underweight patients, despite an increased risk of morbidity. The obesity paradox has been demonstrated in many disease states but has yet to be studied in trauma. The objective of this study is to elucidate the presence of the obesity paradox in trauma patients by evaluating the association between BMI and outcomes. Methods Using the 2014-2015 National Trauma Database (NTDB), adults were categorized by WHO BMI category. Logistic regression was used to assess the odds of mortality associated with each category, adjusting for statistically significant covariables. Length of stay (LOS), ICU LOS and ventilator days were also analyzed, adjusting for statistically significant covariables. Results A total of 415,807 patients were identified. Underweight patients had increased odds of mortality (OR 1.378, p \ 0.001 95% CI 1.252-1.514), while being overweight had a protective effect (OR 0.916, p = 0.002 95% CI 0.867-0.968). Class I obesity was not associated with increased mortality compared to normal weight (OR 1.013, p = 0.707 95% CI 0.946-1.085). Class II and Class III obesity were associated with increased mortality risk (Class II OR 1.178, p = 0.001 95% CI 1.069-1.299; Class III OR 1.515, p \ 0.001 95% CI 1.368-1.677). Hospital and ICU LOS increased with each successive increase in BMI category above normal weight. Obesity was associated with increased ventilator days; Class I obese patients had a 22% increase in ventilator days (IRR 1.217 95% CI 1.171-1.263), and Class III obese patients had a 54% increase (IRR 1.536 95% CI 1.450-1.627). Conclusion The obesity paradox exists in trauma patients. Further investigation is needed to elucidate what specific phenotypic aspects confer this benefit and how these can enhance patient care. Level of evidence Level III, prognostic study This work has not been presented at a meeting or conference.

BACKGROUND Outcomes after surgical stabilization of rib fractures (SSRF) have not been studied in patients with multiple rib fractures and traumatic brain injury (TBI). We hypothesized that SSRF, as compared with nonoperative management, is associated with favorable outcomes in patients with TBI. METHODS A multicenter, retrospective cohort study was performed in patients with rib fractures and TBI between January 2012 and July 2019. Patients who underwent SSRF were compared to those managed nonoperatively. The primary outcome was mechanical ventilation-free days. Secondary outcomes were intensive care unit length of stay and hospital length of stay, tracheostomy, occurrence of complications, neurologic outcome, and mortality. Patients were further stratified into moderate (GCS score, 9–12) and severe (GCS score, ≤8) TBI. RESULTS The study cohort consisted of 456 patients of which 111 (24.3%) underwent SSRF. The SSRF was performed at a median of 3 days, and SSRF-related complication rate was 3.6%. In multivariable analyses, there was no difference in mechanical ventilation-free days between the SSRF and nonoperative groups. The odds of developing pneumonia (odds ratio [OR], 0.59; 95% confidence interval [95% CI], 0.38–0.98; p = 0.043) and 30-day mortality (OR, 0.32; 95% CI, 0.11–0.91; p = 0.032) were significantly lower in the SSRF group. Patients with moderate TBI had similar outcome in both groups. In patients with severe TBI, the odds of 30-day mortality was significantly lower after SSRF (OR, 0.19; 95% CI, 0.04–0.88; p = 0.034). CONCLUSION In patients with multiple rib fractures and TBI, the mechanical ventilation-free days did not differ between the two treatment groups. In addition, SSRF was associated with a significantly lower risk of pneumonia and 30-day mortality. In patients with moderate TBI, outcome was similar. In patients with severe TBI a lower 30-day mortality was observed. There was a low SSRF-related complication risk. These data suggest a potential role for SSRF in select patients with TBI. LEVEL OF EVIDENCE Therapeutic, level IV.

Background Morbid obesity is usually accompanied by both subcutaneous and visceral fat accumulation. Fat can mimic an air bag, absorbing the force of a collision. We hypothesized that morbid obesity is mechanically protective for hollow viscus organs in blunt abdominal trauma (BAT). Methods The National Trauma Data Bank (NTDB) was queried for BAT patients from 2013 to 2015. We looked at the rate of gastrointestinal (GI) tract injuries in all BAT patients with different BMIs. A subset analysis of BAT patients with operative GI tract injuries was performed to evaluate the need for abdominal operation. Multivariate analyses were carried out to identify factors independently associated with increased GI tract injuries and associated abdominal operations. Results A total of 100,459 BAT patients were evaluated in the NTDB. Patients with GI tract injury had a lower proportion of morbidly obese patients [body weight index (BMI) C 40 kg/m2)] (3.7% vs. 4.2%, p = 0.015) and instead had more underweight patients (BMI \ 18.5) (5.9% vs. 5.0%, p \ 0.001). The risk of GI tract injury decreased 11.6% independently in morbidly obese patients and increased 15.7% in underweight patients. Of the patients with GI tract injuries (N = 11,467), patients who needed a GI operation had a significantly lower proportion of morbidly obese patients (3.2% vs. 5.3%, p \ 0.001). The risk of abdominal operation for GI tract injury decreased 57.3% independently in morbidly obese patients. Compared with underweight patients, morbidly obese patients had significantly less GI tract injury (6.0% vs. 13.3%, p \ 0.001) and associated abdominal operation rates (65.2% vs. 73.3%, p \ 0.001). Conclusion Obesity is protective in BAT. This translates into lower rates of GI tract injury and operation in morbidly obese patients. In contrast, underweight patients appear to suffer a higher rate of GI tract injury and associated GI operations.

BACKGROUND The recognition of the relationship between volume and outcomes led to the regionalization of trauma care. The relationship between trauma mechanism-subtype and outcomes has yet to be explored. We hypothesized that trauma centers with a high volume of penetrating trauma patients might be associated with a higher survival rate for penetrating trauma patients. METHODS A retrospective cohort analysis of penetrating trauma patients presenting between 2011 and 2015 was conducted using the National Trauma Database and the trauma registry at the Stroger Cook County Hospital. Linear regression was used to determine the relationship between mortality and the annual volume of penetrating trauma seen by the treating hospital. RESULTS Nationally, penetrating injuries account for 9.5% of the trauma cases treated. Patients treated within the top quartile penetrating-volume hospitals (≥167 penetrating cases per annum) are more severely injured (Injury Severity Score: 8.9 vs. 7.7) than those treated at the lowest quartile penetrating volume centers (<36.6 patients per annum). There was a lower mortality rate at institutions that treated high numbers of penetrating trauma patients per annum. A penetrating trauma mortality risk adjustment model showed that the volume of penetrating trauma patients was an independent factor associated with survival rate. CONCLUSION Trauma centers with high penetrating trauma patient volumes are associated with improved survival of these patients. This association with improved survival does not hold true for the total trauma volume at a center but is specific to the volume of the penetrating trauma subtype. LEVEL OF EVIDENCE Prognostic/Epidemiology Study, Level-III; Therapeutic/Care Management, Level IV.