M. B. Bloom1, E. J. Ley1, D. Z. Liou1, T. Tran1, R. Chung1, N. Melo1, D. R. Margulies1 1Cedars-Sinai Medical Center,Los Angeles, CA, USA
Introduction: Several authors have examined the relationship between trauma patient Body Mass Index (BMI) and blunt and polytrauma outcomes. Less attention has been paid to the need for therapeutic intervention in penetrating trauma. We sought to determine whether increasing BMI is protective in abdominal stab wounds, and predictive of need for intervention.
Methods: We conducted a review of all patients presenting with abdominal and flank stab wounds at an urban level I trauma center from January 1, 2000 to December 31, 2012. Patients were divided into four groups based on their BMI. Abstracted data includes baseline demographics, physiologic data, and characterization of whether the stab wound had violated the peritoneum, caused intra-abdominal injury, or required an operation that was ultimately therapeutic. Patients who were safely observed without an operation were considered as having no intra-abdominal injuries, but were excluded from the peritoneal violation analysis. The one-sided Cochran-Armitage Trend was used for significance testing of the protective effect.
Results: Of 281 patients with abdominal stab wounds, 249 had complete data for evaluation, grouped as BMI<18.5(underweight, n=6), BMI 18.5-29.9(normal to overweight, n=195), BMI 30-35(obese, n=38), and BMI>35(severely obese, n=10). There were no statistically significance differences between groups with respect to age, GCS score, SBP, ISS, AIS subtypes, and mortality, but greater BMI was more prevalent in females (p=0.015). All 6 patients with BMI<18.5 had peritoneal violation, and 5/6 (83%) had intra-abdominal injury. The rate of peritoneal violation trended downward as BMI increased (100%, 86%, 77%, 75%; p=0.147). Increasing BMI was associated with a significant decrease in actual visceral injury (83%, 56%, 50%, 30%; p=0.022). Of 6 patients with BMI<18.5, 4 (67%) had intra-abdominal injury requiring an operation that was therapeutic, whereas in BMI>35, only 2/10 (20%) did. The rate progressively decreased as BMI rose (67%, 44%, 39%, 20%; p=0.041).
Conclusion: Increased BMI protects patients with abdominal stab wounds and is associated with both lower rates of injured viscera and a reduced need for operations. Heavier patients may be more suitable to observation and serial exams, while very thin patients are more likely to require an operation.
