SHOCK VOLUME PREDICTS VENOUS THROMBOEMBOLISM AND BLEEDING COMPLICATIONS FOLLOWING ORTHOPAEDIC POLYTRAUMA

Venous thromboembolism (VTE) events are morbid complications that affect polytraumatized patients and are associated with the magnitude of hemorrhage. Shock Volume quantifies a patient-specific index of cumulative hypoperfusion integrating serial vital signs and is associated with acute complications, yet has not been evaluated as an index to risk-stratify VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE). Thrombelastography (TEG) provides individualized coagulation profiles and is predictive of VTE. Shock Volume is a novel non-invasive, patient-specific measure of hypoperfusion. This study aimed to evaluate measures of coagulopathy and hypoperfusion between those patients with and without VTE and bleeding complications. This is an a priori planned secondary analysis of the PRECISE prospective observational trial of polytrauma patients (18–55 years) with pelvis, acetabulum, femur, and/or tibia shaft fractures across 10 Level 1 North American trauma centers from 2018–2022. The primary outcome was a clinically diagnosed and image-confirmed VTE during the index admission. Secondary outcomes included bleeding events using critical administration threshold (CAT) definition of three units of packed red blood cells or more within 60 minutes Sequential measurements of shock index (heart rate/systolic blood pressure ratio) above a hypoperfusion threshold of 0.9 were temporally integrated in distinct 3-, 6-, 12-, and 24-hour periods post-injury to quantify corresponding Shock Volume indices. TEG analysis at admission was performed at the discretion of the clinical team. Univariate logistic regression models were used to assess variables associated with VTE and bleeding outcomes, followed by multivariable logistic regression analysis that accounted for age, sex, BMI, injury severity score (ISS), and Charlson Comorbidity Index. Receiver operating characteristic curves and the area under the curve (AUC) were calculated. A total of 322 patients were included in this analysis, with a mean age of 36.2 (± 11.1) years, and 72% being male. There were 37 VTE events in 34 participants (10.6%) and 68 bleeding events (21.1%). There were no demographic differences between the two groups for VTE events, but the mean ISS was significantly higher (22.8 [± 11.4]) in those with a bleeding event (p Shock Volume was significantly elevated at all timepoints for those who suffered VTE and bleeding events (all p Figure 1: Multivariable logistic regression analysis for 24-hour Shock Volume combined with TEG parameters for risk prediction for VTE events. This secondary analysis from a prospective cohort study confirmed the utility of Shock Volume as an early index for predicting VTE and bleeding events in polytraumatized patients. Shock Volume may serve as a noninvasive predictor associated with the development of VTE and bleeding as early as three hours post-admission. The combination of Shock Volume and TEG parameters warrants further investigation. For any figures or tables, please contact the authors directly.