Physiology of Human Hemorrhage and Compensation

Efficacy of the compensatory reserve measurement in an emergency department trauma population

“…16 The measurement of compensatory reserve (CRM) is based on alterations in features of the arterial wave form during dynamic changes in hemodynamic status of bleeding patients. 4,[16][17][18][19] In other words, the CRM algorithm provides a single measurement that integrates the totality of all compensatory mechanisms that impact vital signs (e.g. blood pressure, oxygen saturation, respirations, pulse rate), thus simplifying the interpretation for medical personnel with less clinical experience.…”

Compensatory reserve detects subclinical shock with more expeditious prediction for need of life‐saving interventions compared to systolic blood pressure and blood lactate

“…A conceptual framework for the physiology of hemorrhage has been proposed that includes reduced systemic delivery of oxygen (DO 2 ) contributed by immediate decrease in cardiac filling and output due to lost blood volume concurrent with lower oxygen carrying capacity from lost red blood cells. 6,23,24 Despite progressive reduction in DO 2 , a state of compensated shock is manifested by no change in systemic oxygen uptake and LAC. The CRM has been shown to track DO 2 from the onset of hemorrhage to time of decompensation.…”

“…The CRM device consisting of a standard pulse oximeter sensor (PureLight model 8000AA, Nonin Medical Inc., Plymouth, MN) was placed on the finger and remained in place until discharge or transfer to the operating room or inpatient unit. The CRM was derived using a proprietary machine‐learning algorithm capable of analyzing continuous real‐time changes in specific features of the photoplehtysmogram that calculates a quantified scale from 100% (complete reserve) to 0% (depleted reserve) of the proportion of the sum total capacity of an individual patient to compensate for blood loss 6, 11, 12 . The CRM device was developed for investigational use only.…”

“…Early recognition of bleeding relies extensively on clinical cues and experience, but hemorrhage may be occult and difficult to identify clinically. These difficulties are further magnified by our continued reliance on basic vital signs such as blood pressure, heart rate, and oxygen saturation that display poor discriminatory ability 6‐10 . In addition, a late recognition of hemorrhage when identified through vital signs means the patient is already experiencing the effects of significant volume loss and the window of opportunity to effectively intervene has more than likely passed.…”

“…These difficulties are further magnified by our continued reliance on basic vital signs such as blood pressure, heart rate, and oxygen saturation that display poor discriminatory ability. [6][7][8][9][10] In addition, a late recognition of hemorrhage when identified through vital signs means the patient is already experiencing the effects of significant volume loss and the window of opportunity to effectively intervene has more than likely passed. The latency in the current parameters used to identify shock in the field highlights the critical necessity to find more accurate assessment tools to effectively and continuously monitor those experiencing or likely to develop shock shortly after injury.…”