V. Cheng1, K. Inaba1, T. Haltmeier1, A. Gutierrez1, S. Siboni1, E. Benjamin1, L. Lam1, D. Demetriades1 1University Of Southern California,Division Of Trauma And Surgical Critical Care, Department Of Surgery, LAC+USC Medical Center,Los Angeles, CA, USA
Introduction:
In surgical patients, low preoperative serum Transthyretin (TTR) level is associated with significantly longer hospital and intensive care unit (ICU) stays, higher infectious complication rates, and mortality rates. However, the predictive value of TTR levels on outcomes after major trauma has not yet been studied.
Methods:
After IRB approval, a retrospective analysis was conducted on critically ill trauma patients admitted to the Surgical ICU at the LAC+USC Medical Center between January 2008 and May 2014. The study included all patients who underwent a surgical procedure for trauma and had their TTR measured ≤24 hours after ICU admission. Outcome metrics included hospital length of stay (LOS), ICU LOS, ventilator days (VD), infectious complication rate, and mortality rate. Significance of TTR on outcome metrics was determined using univariable (Mann-Whitney U test and Fisher’s exact test) and multivariable (linear and binary logistic regressions) analyses. In univariable analysis, patients were stratified into two TTR groups: Normal (≥19 mg/dL) and Low (<19 mg/dL). In multivariable analysis, TTR level was maintained as a continuous variable.
Results:
348 patients met inclusion criteria (median age 36 years, 79.6% male, median Injury Severity Score 17, 71.0% blunt trauma). The Normal and Low TTR groups consisted of 189 (54.3%) and 159 (45.7%) patients, respectively. Compared to the Normal TTR group, the Low TTR group was associated with longer hospital LOS (median: 17 vs. 9 days, p < 0.001), longer ICU LOS (6 vs. 4 days, p < 0.001), increased VD (1 vs. 0 days, p < 0.001), higher infectious complication rates (45.3% vs. 20.1%, p < 0.001), and higher mortality rates (17.0% vs. 7.4%, p = 0.007). Even after adjusting for age, sex, and Injury Severity Score in multivariable regression analyses, TTR level was a significant independent predictor of clinical outcomes. Lower TTR levels were associated with longer hospital LOS (p < 0.001), longer ICU LOS (p = 0.005), increased VD (p = 0.018), higher infectious complication rates (p < 0.001), and higher mortality rates (p = 0.017).
Conclusion:
In critically ill trauma patients, low serum TTR level is associated with longer hospital LOS, longer ICU LOS, increased VD, higher infectious complication rates, and higher mortality rates. These results warrant prospective validation of the utility of TTR levels as an outcome predictor for critically ill trauma patients.