Multiply injured patients (MIPs) in hemorrhagic shock develop oxygen debt which causes organ dysfunction and can lead to death. We developed a noninvasive patient-specific index, Shock Volume (SV), to quantify the magnitude of hypoperfusion. SV integrates the magnitude and duration that incremental shock index values are elevated above known thresholds of hypoperfusion using serial individual vital sign data. SV can be monitored in real time to assess ongoing hypoperfusion. The goal of this study was to determine how SV corresponded to transfusion requirements and organ dysfunction in a retrospective cohort of 74 MIPs. We measured SV in 6-h increments for 48 h after injury in multiply injured adults (18–65; Injury Severity Score ≥18). Patients who had accumulated 40 units of SV within 6 h of injury and 100 units of SV within 12 h of injury were at high risk for requiring massive transfusion or multiple critical administration transfusions. SV measurements were equally sensitive and specific as compared with base deficit values in predicting transfusions. SV measurements at 6 h after injury stratified patients at risk for multiple organ failure determined by Denver scores. In addition, SV values corresponded to the magnitude of organ failure determined by Sequential Organ Failure Assessment scores. SV is a patient-specific index that can be quantified in real time in critically injured patients. It is a surrogate for cumulative hypoperfusion and it predicts high-volume transfusions and organ dysfunction.