LAUSR

BACKGROUND Compensatory Reserve Measurement (CRM) is a novel noninvasive monitoring technology designed to assess physiologic reserve using feature interrogation of arterial pulse waveforms. This study was conducted to validate clinically relevant CRM values with a simplified color-coded dashboard view. METHODS We performed a prospective observational study of 300 injured patients admitted to a level I trauma center. CRM was recorded upon ER admission. Data collected to complement the analysis included Patient demographics, vital signs, life-saving interventions (LSI), injury severity score (ISS) and outcomes were recorded. Threshold values of CRM were analyzed for predictive capability of hemorrhage. RESULTS 285 patients met inclusion criteria. Mean age of the population was 47 years and 67% were male. Hemorrhage was present in 32 (11%) and LSI was performed in 40 (14%) patients. Transfusion of packed red blood cells (PRBC) was administered in 33 (11.6%) patients, and 21 (7.4%) were taken to the operating room for surgical or endovascular control of hemorrhage. Statistical analyses were performed to identify optimal threshold values for 3 zones of CRM to predict hemorrhage. Optimal levels for red, yellow, and green areas of the dashboard view were stratified as follows: red if CRM<30%, yellow if CRM=30-59%, and green if CRM≥60%. Odds of hemorrhage increased by 12-fold (OR, 12.2; 95%CI, 3.8-38.9) with CRM<30% (red) and 6.5-fold (OR, 6.5; 95%CI, 2.7-15.9) with CRM=30-59% (yellow) when compared to patients with CRM≥60%. ROCAUC for 3-zone CRM was similar to that of continuous CRM (0.77 vs. 0.79), but further increased the ability to predict hemorrhage after adjusting for ISS (ROCAUC = 0.87). CONCLUSION A 3-zone CRM could be a potentially useful predictor of hemorrhage in trauma patients with added capabilities of continuous monitoring and a real-time ISS assessment. These data substantiate easily interpretable threshold dashboard values for triage with potential to improve injury outcomes. LEVEL OF EVIDENCE Diagnostic, Level II.