Is heart-rate complexity a surrogate measure of cardiac output before, during, and after hemorrhage in a conscious sheep model of multiple hemorrhages and resuscitation?

Abstract

HRC has potential utility as a noninvasive tool for assessing the response of CO to life-threatening injuries such as hemorrhagic shock. However, further investigation and other animal models or human studies are needed.

The Compensatory Reserve For Early and Accurate Prediction Of Hemodynamic Compromise

“…As such, the PPG has been proposed for use as a noninvasive tool for estimating stroke volume and cardiac output (14,18,(69)(70)(71), and subsequently track reductions in circulating blood volume as myocardial filling are reduced during hemorrhage. Similarly, measures of dynamic physiological responses such as pulse pressure variability (4, 72-75) and heart rate complexity (17) have been promoted as potential indicators of cardiac output in patients or animals with circulating blood volume compromise resulting from acute blood loss. Although proven to be responsive to reductions in central blood volume (i.e., sensitivity), the primary limitation of all these techniques is that they are based on population averages from clinical trials and fail to account for multiple features that construct each waveform obtained from individual patients.…”

“…One of the most challenging aspects of providing effective treatment of shock is our inability to recognize its early onset. Despite various attempts at applying advanced computational platforms for real-time analysis of vital signs (14)(15)(16)(17)(18), early and accurate assessment of shock is currently limited by measurement of ''legacy'' vital signs that may change very little in the early stages of hemorrhage because of the body's numerous mechanisms (e.g., tachycardia, vasoconstriction, deep inspiration) that regulate blood pressure (19)(20)(21)(22). As a result, too often the use of standard vital signs does not allow us to distinguish those trauma patients with severe hemorrhage who are at greatest risks of poor outcomes in the early stages of blood loss prior to cardiovascular collapse (19)(20)(21)(22)(23)(24) when interventions and triage decisions would be most effective.…”

A Nomogram Based on Clinical Characteristics for Predicting Multiple Organ Dysfunction Syndrome(MODS) Following Multiple Trauma Patients

“…HR is considered not only a physiological indicator but also a prognostic marker.Numerous studies have shown that increased heart rate (HR) was associated with higher mortality in several cardiac disorders [36] .Recently study demonstrated HR is also associated with mortality in trauma patients,which showed mortality after trauma increase outside the heart rate range of 70 to 89 beats per minute [37] .In addition,a heart rate≥90 bpm at the time of MODS diagnosis is an independent risk factor for increased 28-day mortality [38] .Heart rate is elevated beyond physiologically useful compensatory mechanism thus increasing myocardial oxygen demand,and contributing itself to a poor outcome [39] .MODS was a severe complication of multiple trauma,our study demonstrated increased HR may be predicting for MODS following multiple trauma patients.…”

Improving the Prediction of Mortality and the Need for Life-Saving Interventions in Trauma Patients Using Standard Vital Signs With Heart-Rate Variability and Complexity

“…The results of previous work (15) and this study have shown that even in the presence of noise, HRV and HRC may still be able to discriminate between patient groups and monitor patients over time. Furthermore, recent work has shown that HRC trends can be reproduced across subjects (25). However, like any vital sign, HRV or HRC alone may not provide a complete picture of patient status.…”