Morbid Obesity’s Silver Lining: An Armor for Hollow Viscus in Blunt Abdominal Trauma

Abstract

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.

Does a “Cushion Effect” Really Exist? A Morphomic Analysis of Vulnerable Road Users with Serious Blunt Abdominal Injury

“…Arbabi et al introduced the "cushion effect" in 2003, suggesting that increased abdominal adiposity provides a "cushion" for abdominal trauma during the injury event [20]. Wang et al and Fu et al also found that obesity protects patients from severe abdominal injury [21,22]. A computational study found that an obese dummy model had increased risks for head, thorax, and lower extremity injury due to greater torso and pelvic excursions, while increased subcutaneous fat may cushion subjects from abdominal injury [23].…”

The Impact of Obesity on Renal Trauma Outcome: An Analysis of the National Trauma Data Bank from 2013 to 2016

“…In a population-based cohort by Schott et al, hip fracture risk was reduced by 40% for a standard deviation increase in fat mass, while changes in lean body mass did not affect fracture rates [ 25 ]. Furthermore, Fu et al found that obese patients with blunt abdominal trauma sustained less gastrointestinal tract injuries and associated surgery [ 26 ]. These reports support the hypothesis that fat mass could aid better tolerating mechanical force incurred in trauma.…”

Does a “Cushion Effect” Really Exist? A Morphomic Analysis of Vulnerable Road Users with Serious Blunt Abdominal Injury

“…Studies have shown that obesity is associated with a higher risk for posttrauma complications 4 and mortality [5][6][7] . In contrast, some studies found that obesity protects patients from severe injury 8,9 . The "Cushion Effect" was introduced by Arbabi et al in 2003 10 and suggests that increased abdominal adiposity provides a "Cushion" for abdominal trauma during the injury event.…”