The role of the American Society of anesthesiologists physical status classification in predicting trauma mortality and outcomes.

BACKGROUND: Trauma prediction scores such as Revised Trauma Score (RTS) and Trauma and Injury Severity Score (TRISS)) are used to predict mortality, but do not include comorbidities. We analyzed the American Society of Anesthesiologists physical status (ASA PS) for predicting mortality in trauma patients undergoing surgery. METHODS: This multicenter, retrospective study compared the mortality predictive ability of ASA PS, RTS, Injury Severity Score (ISS), and TRISS using a complete case analysis with mixed effects logistic regression. Associations with mortality and AROC were calculated for each measure alone and tested for differences using chi-square. RESULTS: Of 3,042 patients, 230 (8%) died. The AROC for mortality for TRISS was 0.938 (95%CI 0.921, 0.954), RTS 0.845 (95%CI 0.815, 0.875), and ASA PS 0.886 (95%CI 0.864, 0.908). ASA PS + TRISS did not improve mortality predictive ability (p = 0.18). CONCLUSIONS: ASA PS was a good predictor of mortality in trauma patients, although combined with TRISS it did not improve predictive ability.

Hyperlipidemia affects multiscale structure and strength of murine femur.

To improve bone strength prediction beyond limitations of assessment founded solely on the bone mineral component, we investigated the effect of hyperlipidemia, present in more than 40% of osteoporotic patients, on multiscale structure of murine bone. Our overarching purpose is to estimate bone strength accurately, to facilitate mitigating fracture morbidity and mortality in patients. Because (i) orientation of collagen type I affects, independently of degree of mineralization, cortical bone׳s micro-structural strength; and, (ii) hyperlipidemia affects collagen orientation and µCT volumetric tissue mineral density (vTMD) in murine cortical bone, we have constructed the first multiscale finite element (mFE), mouse-specific femoral model to study the effect of collagen orientation and vTMD on strength in Ldlr(-/-), a mouse model of hyperlipidemia, and its control wild type, on either high fat diet or normal diet. Each µCT scan-based mFE model included either element-specific elastic orthotropic properties calculated from collagen orientation and vTMD (collagen-density model) by experimentally validated formulation, or usual element-specific elastic isotropic material properties dependent on vTMD-only (density-only model). We found that collagen orientation, assessed by circularly polarized light and confocal microscopies, and vTMD, differed among groups and that microindentation results strongly correlate with elastic modulus of collagen-density models (r(2)=0.85, p=10(-5)). Collagen-density models yielded (1) larger strains, and therefore lower strength, in simulations of 3-point bending and physiological loading; and (2) higher correlation between mFE-predicted strength and 3-point bending experimental strength, than density-only models. This novel method supports ongoing translational research to achieve the as yet elusive goal of accurate bone strength prediction.