Obesity is Associated with Worse Outcomes Among Abdominal Trauma Patients Undergoing Laparotomy: A Propensity-Matched Nationwide Cohort Study

From Procedure to Prognosis: The Association Between Obesity and Outcomes of Iliac Artery Injuries

INTRODUCTION

The management of injuries to the iliac artery presents a challenging clinical scenario due to the impeded anatomical access. Obesity is a common comorbid condition known to affect the outcomes of trauma patients; however, there is a paucity of data on the association of obesity with the treatment and outcomes of iliac artery injuries. The aim of this study was to assess the association between body mass index (BMI) on the management and outcomes of patients with iliac artery injuries.

METHODS

This is a retrospective analysis of the American College of Surgeons-Trauma Quality Improvement Program (2017-2020). All adult (aged ≥18 y) trauma patients with iliac artery injuries who underwent open or endovascular repair were included. Patients were divided based on BMI (normal: BMI <25 kg/m2, overweight: BMI ≥25-30 kg/m2, obese: BMI ≥30 kg/m2) and compared. Outcomes included rates of open and endovascular repair, in-hospital mortality, and complications. Multivariable regression analysis was performed for these outcomes.

RESULTS

A total of 380 patients were identified who underwent repair (Open: 61%, Endovascular: 39%) for iliac artery injuries. The mean (standard deviation) age was 41 (19) y and 74% were male. There was no difference in the rates of open or endovascular repair among the BMI categories (P = 0.332). The median (interquartile range) injury severity score was 22 (9-29) with no difference among the BMI categories (P = 0.244). On univariate analysis, the rates of mortality and major complications were higher among obese patients compared to overweight and normal BMI groups (P < 0.05) (Table). On multivariable regression analysis, increasing BMI was not a predictor of open or endovascular repair of the iliac arteries; however, increasing BMI was independently associated with higher odds of major complications (adjusted odds ratio [aOR]: 1.09, 95% confidence interval [CI] [1.02-1.16], P = 0.007), acute kidney injury (aOR: 1.13, 95% CI [1.02-1.24], P = 0.015), acute respiratory distress syndrome (aOR: 1.18, 95% CI [1.01-1.38], P = 0.031), and mortality (aOR: 1.30, 95% CI [1.06-1.59], P = 0.009).

CONCLUSIONS

Although BMI was not identified as a predictor of the type of repair for iliac artery injuries, increasing BMI was significantly associated with mortality, complications, and acute kidney injury in patients who undergo repair of the iliac arteries. Future research is warranted to identify the optimal management approach for obese patients to improve the outcomes.

An evaluation of the "Obesity Paradox" in isolated blunt abdominal trauma in the United States

BACKGROUND

The obesity paradox theorizes a survival benefit in trauma patients secondary to the cushioning effect of adiposity. We aim to evaluate the impact of body mass index (BMI) on abdominal injury severity, morbidity, and mortality in adults with isolated, blunt abdominal trauma in the United States.

METHODS

We reviewed the National Trauma Data Bank (2013-2021) for adults sustaining isolated, blunt abdominal trauma stratified by BMI. We performed a doubly robust, augmented inverse-propensity weighted multivariable logistic regression to estimate the average treatment effect (ATE) of BMI on mortality and the presence of abdominal organ injury.

RESULTS

36,350 patients met the inclusion criteria. In our study, 41.4 % of patients were normal-weight (BMI 18.5-24.9), 20.6 % were obese (BMI 30-39.9), and 4.7 % were severely obese (BMI≥40). In these cohorts, the abdominal abbreviated injury scale (AIS) was 2 (2 -3). Obese and severely obese patients had significantly reduced presence of pancreas, spleen, liver, kidney, and small bowel injuries. The predicted probability of abdominal AIS severity decreased significantly with increasing BMI. Crude mortality was significantly higher in obese (1.3 %) and severely obese patients (1.3 %) compared to normal-weight patients (0.7 %). Obese and severely obese patients demonstrated non-statistically significant changes in the mortality of +26.4 % (ATE 0.264, 95 %CI -0.108-0.637, p = 0.164) and +55.5 % (ATE 0.555, 95 %CI -0.284-1.394, p = 0.195) respectively, compared to normal weight patients.

CONCLUSION

BMI may protect against abdominal injury in adults with isolated, blunt abdominal trauma. Mortality did not decrease in association with increasing BMI, as this may be offset by the increase in co-morbidities in this population.

Safety and Risk in Airway Management During Bariatric Air Medical Retrieval

OBJECTIVE

Bariatric anatomy and physiology present added clinical challenges to the provision of safe critical care and patient transport. LifeFlight Retrieval Medicine provides air medical retrieval services in Queensland, Australia, and performs over 6,000 retrieval missions annually using rotary wing, fixed wing, and ground ambulance platforms.

METHODS

Bariatric patient retrievals were identified from the LifeFlight Retrieval Medicine electronic patient database. These cases were interrogated to quantify and describe adverse events during patient transport.

RESULTS

Over the study period from July 2019 to December 2021 11,096 patient retrievals were completed. Of these patients, 816 (7.3%) had a body weight ≥ 120 kg (range, 120-246 kg; median = 146 kg). Bariatric patients were more likely to be male (70%) and to require critical care interventions than nonbariatric patients (25.9% vs. 19.9%). There was an absolute 1.5% increase of high-interest events during patient retrieval, corresponding to a 1.9-fold increased relative risk. Five hundred eleven of 11,096 patients were intubated by the retrieval team, and 61 of these weighed ≥ 120 kg. Bariatric patients undergoing intubation were of similar age and sex, weighed significantly more, had nonsignificant trends toward poorer airway visualization by Cormack-Lehane laryngoscopic grade, and tended toward reduced first-attempt success compared with nonbariatric patients. Rates of airway adverse events (AAEs) were significantly increased for the bariatric group (30/61, 49.2%) compared with the nonbariatric group (135/450, 30.0%) (χ2 likelihood ratio, P = .004). Postintubation desaturation was the most common AAE and was the only criterion significantly increased when comparing bariatric (26%) versus nonbariatric (12%) patients (χ2 likelihood ratio, P = .005). Using patient weight as a continuous variable, nominal logistic regression revealed a significant effect of increasing weight on AAEs (χ2 = 12.9, P = .0003) with a threshold of 105 kg providing an optimal 88% sensitivity for predicting AAEs. The odds of AAEs were increased significantly for those weighing 105 to 119 kg versus those weighing < 105 kg (odds ratio [OR] = 3.4; 95% confidence interval [CI], 1.6-7.5) and for those weighing ≥ 120 kg versus those weighing < 105 kg (OR = 2.5; 95% CI, 1.4-4.3). There was no difference between those weighing ≥ 120 kg versus those weighing 105 to 119 kg (OR = 0.73; 95% CI, 0.3-1.8).

CONCLUSION

Air medical retrieval of bariatric patients is safe despite an increased risk of adverse events. Strategies to optimize emergency anesthesia should be used to maximize safe intubation in bariatric patients.

Postoperative Staphylococcus aureus Infections in Patients With and Without Preoperative Colonization

Importance

Staphylococcus aureus surgical site infections (SSIs) and bloodstream infections (BSIs) are important complications of surgical procedures for which prevention remains suboptimal. Contemporary data on the incidence of and etiologic factors for these infections are needed to support the development of improved preventive strategies.

Objectives

To assess the occurrence of postoperative S aureus SSIs and BSIs and quantify its association with patient-related and contextual factors.

Design, Setting, and Participants

This multicenter cohort study assessed surgical patients at 33 hospitals in 10 European countries who were recruited between December 16, 2016, and September 30, 2019 (follow-up through December 30, 2019). Enrolled patients were actively followed up for up to 90 days after surgery to assess the occurrence of S aureus SSIs and BSIs. Data analysis was performed between November 20, 2020, and April 21, 2022. All patients were 18 years or older and had undergone 11 different types of surgical procedures. They were screened for S aureus colonization in the nose, throat, and perineum within 30 days before surgery (source population). Both S aureus carriers and noncarriers were subsequently enrolled in a 2:1 ratio.

Exposure

Preoperative S aureus colonization.

Main Outcomes and Measures

The main outcome was cumulative incidence of S aureus SSIs and BSIs estimated for the source population, using weighted incidence calculation. The independent association of candidate variables was estimated using multivariable Cox proportional hazards regression models.

Results

In total, 5004 patients (median [IQR] age, 66 [56-72] years; 2510 [50.2%] female) were enrolled in the study cohort; 3369 (67.3%) were S aureus carriers. One hundred patients developed S aureus SSIs or BSIs within 90 days after surgery. The weighted cumulative incidence of S aureus SSIs or BSIs was 2.55% (95% CI, 2.05%-3.12%) for carriers and 0.52% (95% CI, 0.22%-0.91%) for noncarriers. Preoperative S aureus colonization (adjusted hazard ratio [AHR], 4.38; 95% CI, 2.19-8.76), having nonremovable implants (AHR, 2.00; 95% CI, 1.15-3.49), undergoing mastectomy (AHR, 5.13; 95% CI, 1.87-14.08) or neurosurgery (AHR, 2.47; 95% CI, 1.09-5.61) (compared with orthopedic surgery), and body mass index (AHR, 1.05; 95% CI, 1.01-1.08 per unit increase) were independently associated with S aureus SSIs and BSIs.

Conclusions and Relevance

In this cohort study of surgical patients, S aureus carriage was associated with an increased risk of developing S aureus SSIs and BSIs. Both modifiable and nonmodifiable etiologic factors were associated with this risk and should be addressed in those at increased S aureus SSI and BSI risk.

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.

The impact of obesity on postoperative complications and short-term survival after liver transplantation

BACKGROUND AND AIMS

Obesity is considered a risk factor for perioperative complications, but its effect on patients undergoing liver transplantation (LT) remains unclear. This study was conducted to analyze the impact of obesity on early morbidity and mortality risk following LT.

METHODS

A multicenter study of outcomes in patients submitted to LT between 2009 and 2019 was conducted. Recipients were stratified into obese (BMI ≥ 30 kg/m2) and nonobese patients (BMI < 30 kg/m2). Early postoperative complications were compared and 30-day and 1-year patient and graft survival were assessed by Kaplan-Meier method. Primary graft nonfunction (PGNF) was defined as the presence of total bilirubin > 10 mg/dl, INR > 1.6 or ALT > 2000 U/l within the first week after LT.

RESULTS

A total of 1608 patients were included after applying exclusion criteria, nonobese (1149, 71.46%) and obese patients (459, 28.54%). There were no significant differences in age, sex, Model for End-stage Liver Disease, Charlson comorbidity score, ethnicity, waiting list time and ischemia time. There were significantly higher rates of vascular (17.58% vs 23.53%, P = 0.021) and biliary complications (27.68% vs 35.73%, P = 0.006) and PGNF (11.40% vs 12.20%, P = 0.021) in obese patients. There was a significantly increased risk for long-term graft failure; however, there was no significant difference in patient survival after LT.

CONCLUSION

Obese patients have significantly increased morbidity in terms of vascular and biliary complications and PGNF after LT. They have a higher risk for worse 1-year graft survival in comparison to controls.

Obesity Is Associated With Increased Risk for Adverse Postoperative Outcomes After Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Conflicting reports exist about the effect obesity has on adverse postoperative surgical outcomes after distal pancreatectomy (DP). The aim of this study is to explore the role of obesity in terms of morbidity and pancreas-specific complications following DP for pancreatic ductal adenocarcinoma (PDAC).

METHODS

All patients who underwent DP at a single institution over 10 y were analyzed (2009-2020). Patients were categorized as nonobese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). Independent predictors of adverse postoperative outcomes were calculated using multivariate logistic regression models. Overall survival was assessed using Kaplan-Meier survival analysis.

RESULTS

Of the 178 patients included, 58 (32.5%) were obese. Clinically relevant postoperative pancreatic fistula (CR-POPF) formation rate was significantly higher in the obese group (20.6% versus 7.5%, P value = 0.011). We did not identify any significant difference between obese and nonobese patients in median overall survival (30.2 mon versus 28.9 mon, P value = 0.811). On multivariate binary logistic regression analysis, BMI ≥ 30 was an independent predictor of morbidity (any complication) and CR-POPF formation after DP for PDAC.

CONCLUSIONS

Obesity is associated with a significantly increased risk for CR-POPF in patients undergoing DP for PDAC. Obesity should be considered as a variable in fistula risk calculators for DP.

Obesity and outcomes in trauma - a systematic review and meta-analysis

BACKGROUND

The physiological abnormalities relating to obesity and metabolic syndrome can contribute to worse outcomes following trauma especially in class 2 and 3 obesity. The aim of this systematic review was to determine whether patients with a higher class of obesity who suffer traumatic injury have a higher risk of worse outcomes including in-hospital mortality than normal-weight patients.

METHODS

A systematic search of MEDLINE, EMBASE, CENTRAL, Web of Science and CINAHL was performed for studies that reported a comparison of in-hospital obesity-related outcomes against normal-weight individuals aged 15 years and older following trauma. Single or multiple injuries from either blunt and/or penetrating trauma were included. Burn-related injuries, isolated head injury and studies focusing on orthopaedic related perioperative complications were excluded.

RESULTS

The search yielded 7405 articles; 26 were included in this systematic review. 945,511 patients had a BMI>30. A random-effects meta-analysis was performed for analysis of all four outcomes. Patients with class 3 obesity (BMI>40) have significantly higher odds of in-hospital mortality than normal-BMI individuals following blunt and penetrating trauma (OR, 1.75; 95% CI, 1.39-2.19, p=<0.00001), significantly longer hospital LOS (SMD, 0.23; 95% CI, 0.21-0.25; p<0.00001) and significantly longer ICU LOS (SMD, 0.19; 95% CI, 0.12-0.26; p<0.0001). In contrast, studies that examined blunt and penetrating trauma and classified obesity with a threshold of BMI>30 found no significant difference in the odds of in-hospital mortality (OR, 0.94; 95% CI, 0.86-1.02, p=0.13).

CONCLUSIONS

There is a higher risk of in-hospital mortality in patients living with class 3 obesity following trauma when compared with individuals with normal BMI. The management of patients with obesity is complex and trauma systems should develop specific weight related pathways to manage and anticipate the complications that arise in these patients. Systematic review registration number PROSPERO registration: CRD42021234482 Level of Evidence: Level 3.

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.

Dynamic Cushioning: Obesity and Trauma Patients Undergoing Exploratory Laparotomy

BACKGROUND

Traumatic injuries account for 10% of all mortalities in the United States. Annually the global estimated population of overweight and obese individuals rises in number. It is well established in the literature that obesity is associated with worse outcomes in trauma patients. While body mass index, or BMI is not an independent predictor of increased morbidity or mortality after trauma laparotomy, we hypothesized that it may place patients at increased risk of postoperative complications and have lasting significant negative effects on quality of life in a manner disproportionate to normal-weight patients.

METHODS

The trauma registry of an academic level 1 trauma hospital was queried for laparotomies following either blunt or penetrating traumatic injury from 2015 to 2019. Individual patient charts were reviewed. Patients were divided into three groups, according to Body Mass Index (BMI) cut-offs as normal weight (BMI < 25 kg/m²), overweight; BMI 25-29.9 kg/m²), and obese (BMI ≥ 30 kg/m²). Demographics, intraoperative management and outcomes were compared between groups, after which complications were regressed based on BMI to evaluate the impact BMI had on each.

RESULTS

Records of 197 trauma patients who underwent exploratory laparotomies were analyzed. There was no significant difference in demographics or injury severity score (ISS) between groups. BMI had a direct positive association with intensive care unit length of stay (r = 0.239 [0.103, 0.367]), P < 0.001), hospital length of stay (r = 0.197 [0.059, 0.328], P = 0.005) and return to OR (OR = 1.057, [1.010, 1.109], P = 0.017). There was no significant relationship between BMI and in-hospital or 90-d mortality.

CONCLUSIONS

Our findings show that with increasing BMI, postoperative complications increase following laparotomy for trauma. As rates of obesity increase, trauma surgeons must be prepared to anticipate plans of care from patient presentation to well beyond discharge to cope with more complex postoperative and post-hospital clinical courses.

Relationship of body mass index, serum creatine kinase, and acute kidney injury after severe trauma

OBJECTIVES

Body mass index (BMI) is associated with acute kidney injury (AKI) after trauma, but underlying mechanisms are unclear. Body mass index correlates with both excess adiposity and increased muscle mass. Since the latter could predispose to severe rhabdomyolysis after trauma, we hypothesized that the BMI-AKI association may be partially explained by a direct relationship of BMI with serum creatine kinase (CK).

METHODS

Prospective cohort study of 463 critically ill patients admitted to a level I trauma center from 2005 to 2015 with Injury Severity Score of >15 and serum CK measured in the first 7 days. We defined AKI by AKI Network creatinine criteria. We used simple linear regression to determine the association of BMI with peak CK and multivariable logistic regression to adjust the BMI-AKI association for peak CK and confounders.

RESULTS

Median age was 43 years, 350 (76%) were male, 366 (79%) had blunt mechanism, and median Injury Severity Score was 24. Body mass index was associated with peak CK (R = 0.05, p < 0.001). Acute kidney injury developed in 148 patients (32%), and median time to peak CK was 29 hours (interquartile range, 15-56 hours) after presentation. Body mass index was significantly associated with AKI in multivariable models adjusted for age, race, sex, diabetes, injury mechanism and severity, and red blood cell transfusions (odds ratio [OR], 1.31 per 5 kg/m; 95% confidence interval [CI], 1.09-1.58; p = 0.004). Adding peak CK to the model partially attenuated the association of BMI with AKI (OR, 1.26 per 5 kg/m; 95% CI, 1.04-1.52; p = 0.018), and peak CK was also associated with AKI (OR, 1.19 per natural log; 95% CI, 1.00-1.41; p = 0.049). Peak CK remained associated with AKI when restricted to patients with values of <5,000 U/L (OR, 1.31 per natural log; 95% CI, 1.01-1.69; p = 0.043).

CONCLUSION

Serum CK correlated with BMI and partially attenuated the association of BMI with AKI after major trauma, suggesting that excess muscle injury may contribute to the BMI-AKI association.

LEVEL OF EVIDENCE

Epidemiologic study, level III.