N. A. Lee1, A. Khetarpal3, L. Wolfe1, S. Demasi2, A. Stiles2, M. Aboutanos1, P. Ferrada1 1Virginia Commonwealth University,Department Of Surgery,Richmond, VA, USA 2Virginia Commonwealth University,School Of Medicine,Richmond, VA, USA 3Virginia Commonwealth University,Department Of Radiology,Richmond, VA, USA
Introduction:
As the population of the United States ages, there has been a disproportionately larger increase in the amount of elderly trauma patients. Elderly patients have worse outcomes when controlling for injury severity independent of age. Frailty, a syndrome characterized by increased vulnerability to stressors leading to functional impairment and adverse outcomes, has been found to negatively affect the outcomes of surgical patients and critically ill patients, but evaluating frailty in trauma patients has proven difficult. Sarcopenia, or decreased muscle mass and function, is a measurable factor associated with frailty. We hypothesize that sarcopenia can be used as a surrogate for frailty to independently predict risk of mortality.
Methods:
In this retrospective cohort study, trauma patients aged 45 years or greater requiring ICU care at our level-1 trauma center between April 2015 and January 2016 were assessed for sarcopenia by averaging the psoas muscle body cross-sectional area at the level of the L4 pedicles, and dividing by the cross-sectional area of the L4 body at the same level. Patients were excluded if there was traumatic injury in the L4 area, or if no CT was obtained. This psoas:lumbar vertebral index (PLVI) was then cross-referenced with data from the local trauma registry including outcomes, comorbidities, complications, and injury severity scores. Our primary outcome was in-hospital mortality. Statistical analyses including Wilcoxon rank sum test and stepwise logistic regression was performed with SAS 9.4 with a significance level of 0.05.
Results:
Over the study period, 715 patients were identified, of which 528 were eligible and assessed for sarcopenia by calculating the PLVI (median 0.95, range 0.34 – 1.91). There were 41 deaths in the study population. Patients who died had smaller PLVI (0.79, 0.40 – 1.28 vs 0.96, 0.34 – 1.91, p=0.0014), were older (72, 47 – 92 vs 62, 45 – 98, p < 0.0001), and had higher injury severity scores (26, 1 – 45 vs 14, 1 – 75, p<0.0001). Stepwise logistic regression was performed with comorbidities and complications which were approaching significance on univariate analysis. With these factors included, age was not a significant predictor of mortality; however, ISS and PLVI were included as significant contributors to mortality in addition to history of renal failure, malignancy, and prehospital DNR status, and new onset stroke, and renal failure. The odds ratio of 0.135 (0.029 – 0.623) demonstrates a strong association with lower PLVI and mortality.
Conclusion:
Sarcopenia as measured by PLVI is an independent predictor of mortality in trauma patients older than 45 requiring critical care. This may provide an opportunity to further risk-stratify this high-risk patient population on admission.