B. Murray2, S. Deveraj2, A. Sanford2, T. Saclarides1, D. M. Hayden1 1Rush University Medical Center,Department Of General Surgery,Chicago, IL, USA 2Loyola University Medical Center,Department Of General Surgery,Maywood, IL, USA
Introduction: Loss of lean muscle mass has been associated with worse outcomes in cancer patients. Although there have been studies that have examined outcomes related to metabolic derangements in burn patients, the prevalence of sarcopenia and specifically sarcopenic obesity and their effects on the outcomes of severely burned patients has yet to be described.
Methods: Skeletal muscle mass index was measured for patients with at least 20% total surface area burn (partial or full thickness injury) admitted to the ICU with computed tomography scan performed between January 2007 and January 2017. Using Mimics® software (Belgium), skeletal muscle area was measured at the L3 level and then used to calculate the skeletal muscle mass index (cm2/m2). Sarcopenia was defined as two standard deviations below the index level defined in healthy adults. Statistical analysis using SPSS (Chicago, IL) evaluating demographics, co-morbidities and outcomes in relation to sarcopenia was performed.
Results: Of the nineteen patients included in the study, mean age was 43.2 (21-67) and 68.4% were male. Mean BMI was 29.3 (21.2-41.8). The mean percentage of total surface area burn was 43.9% (20-77.5). All patients underwent surgery; mean number of burn-specific operations per patient was 8.6 (1-27). 47.4% of skin grafts healed after the first attempt and overall healing was 73.7%. Mean length of stay (LOS) was 99.4 days (median 91, range 16-257). Sarcopenia was found in 68.4% of patients; 69.2% of males and 66.7% of females. Sarcopenia was significantly related to use of parenteral nutrition (p=0.045) and enteral supplementation (p=0.031). Sarcopenia was also associated with overall postoperative complications (p=0.007), superficial wound infections (p=0.012) and pneumonia (p=0.013). There were 6 (31.5%) patients categorized as having sarcopenic obesity. These patients were more likely to use or have used alcohol (p=0.004, 0.009) and had increased number of overall and burn-specific operations (p=0.006 and 0.011, respectively). Although just trending toward significance for overall postoperative complications (p=0.057), they were more likely to have pulmonary embolism (p=0.028). Sarcopenia was not significantly associated with gender, race, co-morbidities, LOS, readmissions or mortality.
Conclusion: Our findings suggest that even in this small study population, decreased lean muscle mass at time of burn injury is associated with worse postoperative outcomes, especially if the patient is both sarcopenic and obese. Interestingly, co-morbidities, race and age were not associated with sarcopenia. In these patients, it did appear that the ICU team recognized the risk of malnutrition since supplemental nutrition was started. However, it may require interventions targeting muscle strengthening, even during these lengthy hospitalizations to help improve operative outcomes in severely burned patients.