Impact of Obesity on Mortality in Adult Trauma Patients

Mitochondrial dysfunction in platelets from severe trauma patients - A prospective case-control study

INTRODUCTION

Trauma-induced coagulopathy (TIC) refers to an abnormal coagulation process, an imbalance between coagulation and fibrinolysis due to several pathological factors, such as haemorrhage and tissue injury. Platelet activation and subsequent clot formation are associated with mitochondrial activity, suggesting a possible role for mitochondria in TIC. Comprehensive studies of mitochondrial dysfunction in platelets from severe trauma patients have not yet been performed.

METHODS

In this prospective case-control study, patients with severe trauma (ISS≥16) had venous blood samples taken at arrival to the Emergency Unit of a Level 1 Trauma Centre. Mitochondrial functional measurements (Oxygraph-2k, Oroboros) were performed to determine oxygen consumption in different respiratory states, the H2O2 production and extramitochondrial Ca2+ movements. In addition, standard laboratory and coagulation tests, viscoelastometry (ClotPro) and aggregometry (Multiplate) were performed. Measurements data were compared with age and sex matched healthy control patients.

RESULTS

Severe trauma patients (n = 113) with a median age of 38 years (IQR, 20-51), a median ISS of 28 (IQR, 20-48) met our inclusion criteria. Oxidative phosphorylation in platelet mitochondria from severe trauma patients significantly decreased compared to controls (34.7 ± 8.8 pmol/s/mL vs. 48.0 ± 19.7 pmol/s/mL). The mitochondrial H2O2 production significantly increased and greater endogenous Ca2+ release was found in the polytrauma group. Consistent with these results, clotting time (CT) increased while maximum clot firmness (MCF) decreased with the EX-test and FIB-test in severe trauma samples. Multiplate aggregometry showed significantly decreased ADP-test (38 ± 12 AUC vs. 112 ± 14 AUC) and ASPI test (78 ± 22 AUC vs. 84 ± 28 AUC) also tended to decrease in mitochondria of polytrauma patients as compared with controls. Significant strong correlation has been demonstrated between mitochondrial OxPhos and MCF while it was negatively correlated with ISS (R2=0.448, P˂0.05), INR, CT and lactate level of patients.

CONCLUSIONS

The present study revealed that severe trauma is associated with platelet mitochondrial dysfunction resulting in reduced ATP synthesis and impaired extramitochondrial Ca2+ movement. These factors are required for platelet activation, recruitment and clot stability likely thus, platelet mitochondrial dysfunction contributes to the development of TIC.

Relationship of Obesity and Severe Penetrating Thoracic and Abdominal Injuries in Adolescent Patients

BACKGROUND

Over 20% of United States adolescents are obese. A thicker layer of subcutaneous adiposity might provide a protective "armor" layer against penetrating wounds. We hypothesized that adolescents with obesity presenting after isolated thoracic and abdominal penetrating trauma have lower rates of severe injury and mortality than adolescents without obesity.

METHODS

The 2017-2019 Trauma Quality Improvement Program database was queried for patients between 12 and 17 years old presenting with knife or gunshot wounds. Patients with body mass index (BMI) ≥30 (obese) were compared to patients with BMI <30. Sub-analyses were performed for adolescents with isolated abdominal trauma and isolated thoracic trauma. Severe injury was defined as an abbreviated injury scale grade >3. Bivariate analyses were performed.

RESULTS

12,181 patients were identified; 1603 (13.2%) had obesity. In isolated abdominal gunshot or knife wounds, rates of severe intra-abdominal injuries and mortality were similar (all P > .05) between groups. In isolated thoracic gunshot wounds, adolescents with obesity had a lower rate of severe thoracic injury (5.1% vs 13.4%, P = .005) but statistically similar mortality (2.2% vs 6.3%, P = .053) compared to adolescents without obesity. In isolated thoracic knife wounds, rates of severe thoracic injuries and mortality were similar (all P > .05) between groups.

DISCUSSION

Adolescent trauma patients with and without obesity presenting after isolated abdominal or thoracic knife wounds had similar rates of severe injury, operative intervention, and mortality. However, adolescents with obesity presenting after an isolated thoracic gunshot wound had a lower rate of severe injury. This may impact the future work-up and management of adolescents sustaining isolated thoracic gunshot wounds.

Subcutaneous and visceral fat are associated with worse outcomes in gunshot injuries but not stab injuries to the torso

Purpose

The effect of obesity in penetrating trauma outcomes is poorly understood. The purpose of this study was to determine if there is a protective effect of subcutaneous or visceral fat from stab and gunshot wounds.

Methods

443 patients admitted after penetrating traumatic injury of the torso were retrospectively identified from our institution's trauma registry. CT scans performed at presentation were used to determine cross-sectional area of visceral and subcutaneous fat at the level of the umbilicus via manual segmentation. Obesity-associated parameters including body mass index, visceral and subcutaneous fat were compared with injury severity score, length of hospital/intesive care unit (ICU) stay, and number of operating room (OR) visits. Parameters were compared between patients who sustained stab wounds versus gunshot injuries.

Results

Comparing all patients with gunshot injuries with those with stab injuries, gunshots resulted in increased hospital and ICU length of stay, and injury severity score (ISS). For patients with gunshot wounds, all obesity-related parameters correlated with increased length of stay and total ICU stay; subcutaneous fat and visceral fat were correlated with increased OR visits, but there was no significant correlation between obesity-related parameters and ISS. In contrast, with stab wounds there were no statistically significant associations between obesity parameters and any of the outcome measures.

Conclusion

For penetrating trauma in the torso, obesity is correlated with worse outcomes with gunshot injuries but not in stab injuries.

Level of evidence

Level III, prognostic and epidemiological.

Protective Role of Obesity on Trauma Impact: A Retrospective Analysis of Patients with Surgical Blunt Bowel Mesenteric Injury Due to Road Traffic Accidents

Background

The "cushion effect" theory proposes that increased body mass index (BMI) is associated with less severe abdomen injury following blunt abdomen trauma, while the "obesity paradox" describes the protective effect of obesity against mortality. However, most previous studies used the abdominal abbreviated injury scale as the outcomes seemed to be inadequate owing to the injuries to the abdominal organs, such as the spleen and liver, which may be attributable to the force that caused the chest trauma. This study aimed to use adult trauma patients with surgical blunt bowel mesenteric injuries (BBMIs) to investigate the influence of obesity on the clinical outcomes and overall morbidities.

Methods

This retrospective study reviewed the data of all hospitalized trauma patients between 2009 and 2019 and included all patients with surgically proven small bowel, colon, or mesenteric injuries due to a road traffic accident. Comparison of the outcomes was performed among 123 patients with surgically proven BBMI, who were categorized by BMI into the normal-weight (n = 73, BMI<25 kg/m²), overweight (n = 37, 25≤BMI≤30 kg/m²), and obese groups (n = 13, BMI>30 kg/m²).

Results

The obese group had a significantly lower incidence of isolated bowel injury (0%) compared with the normal-weight (35.6%) and overweight (16.2%) groups (p=0.005), but with higher incidence of isolated mesenteric injury or combined injury, although this was not significant. The obese group (92.3%) had a significantly higher percentage of overall morbidity than the normal-weight (61.6%) and overweight (70.3%) groups (p = 0.047). No significant difference was observed in the in-hospital mortality and 24-hour mortality among the three study groups.

Conclusion

The study findings do not support the existence of a cushion effect and obesity paradox of obesity in blunt abdominal trauma.