Noninvasive Cerebral Perfusion and Oxygenation Monitoring Augment Prolonged Field Care in a Non-Human Primate Model of Decompensated Hemorrhage and Resuscitation

Abstract

Background: Decompensated hemorrhagic shock (DHS) is the leading cause of preventable death in combat casualties. ''Golden hour'' resuscitation effects on cerebral blood flow and perfusion following DHS in prolonged field care (PFC) are not well investigated. Using an established non-human primate model of DHS, we hypothesized noninvasive regional tissue oxygenation (rSO 2 ) and Transcranial Doppler (TCD) would correlate to the invasive measurement of partial pressure of oxygen (PtO 2 ) and mean arterial pressure (MAP) in guiding hypotensive resuscitation in a PFC setting. Methods: Ten rhesus macaques underwent DHS followed by a 2 h PFC phase (T0-T120), and subsequent 4 h hospital resuscitation phase (T120-T360). Invasive monitoring (PtO 2 , MAP) was compared against noninvasive monitoring systems (rSO 2 , TCD). Results were analyzed using t tests and one-way repeated measures ANOVA. Linear correlation was determined via Pearson r. Significance ¼ P < 0.05. Results: MAP, PtO 2 , rSO 2 , and mean flow velocity (MFV) significantly decreased from baseline at T0. MAP and PtO 2 were restored to baseline by T15, while rSO 2 was delayed through T30. At T120, MFV returned to baseline, while the Pulsatility Index significantly elevated by T120 (1.50 AE 0.31). PtO 2 versus rSO 2 (R 2 ¼ 0.2099) and MAP versus MFV (R 2 ¼ 0.2891) shared very weak effect sizes, MAP versus rSO 2 (R 2 ¼ 0.4636) displayed a low effect size, and PtO 2 versus MFV displayed a moderate effect size (R 2 ¼ 0.5540). Conclusions: Though noninvasive monitoring methods assessed here did not correlate strongly enough against invasive methods to warrant a surrogate in the field, they do effectively augment and direct resuscitation, while potentially serving as a substitute in the absence of invasive capabilities.

Prehospital Plasma Is Noninferior to Whole Blood for Restoration of Cerebral Oxygenation in a Rhesus Macaque Model of Traumatic Shock and Hemorrhage

“…A priori and post-hoc power analyses were performed using G*Power 3.1 Statistical Power Analysis program (Heinrich Heine Universitat Dusseldorf, Dusseldorf, Germany). A priori power calculations compared historical data for the model of CrSO 2 changes between start and end of posthemorrhage resuscitations (24). The CrSO 2 mean ± SDs of 38.6 ± 11.3% and 67.2 ± 7.2% yielded an average SD σ = 9.3% and Δ = 28.6% between means.…”

“…Ten naive adult male rhesus macaques (Macaca mulatta) weighing 12.9 ± 1.8 kg, age 7.7 ± 1.2 years under single housing, were acclimated to the facility for a minimum of 35 days before utilization in the study. Preoperative procedures were carried out as previously described (24)(25)(26). Briefly, animals were sedated with Telazol (3.0 mg/kg; Zoetis, Inc, Kalamazoo, MI) and given buprenorphine (0.03 mg/kg; Reckitt & Colman Pharmaceuticals, Inc, Richmond, VA) for analgesia, before intubation via 4-to 5.5-mm endotracheal tubes (Rusch -Teleflex, Research Triangle Park, NC).…”

“…The right femoral vein was percutaneously cannulated with a 7Fr triple lumen catheter (Cook Medical, Bloomington, IN) for resuscitation fluids. The Sensmart X-100 (Nonin Medical, Inc, Plymouth, MN) noninvasive near-infrared monitor was used to measure cerebral (forehead) and peripheral (biceps brachii) regional tissue oxygen saturation (rSO 2 ) (24,25). Blood pressures, end-tidal carbon dioxide (EtCO 2 ), and heart rate (HR) were monitored continuously throughout the protocol via the Draeger Apollo.…”

“…A priori power calculations compared historical data for the model of CrSO 2 changes between start and end of posthemorrhage resuscitations (24). The CrSO 2 mean ± SDs of 38.6 ± 11.3% and 67.2 ± 7.2% yielded an average SD σ = 9.3% and Δ = 28.6% between means.…”

What's New in Shock, March 2021?

“…Both Morgan et al and Necsoiu et al provide studies that seek to improve acute treatment of hemorrhagic shock (13,14). With an eye toward the next generation of personalized medicine in critical care, Morgan et al have assessed the combination of near-infrared spectroscopy and transcranial Doppler ultrasonography as tools for measuring cerebral oxygenation to guide resuscitation during hemorrhagic shock.…”