Comparison of Compensatory Reserve During Lower Body Negative Pressure and Hemorrhage in Non-human Primates.

Comparison of Compensatory Reserve During Lower Body Negative Pressure and Hemorrhage in Non-human Primates. Am J Physiol Regul Integr Comp Physiol. 2016 Mar 30;:ajpregu.00304.2015 Authors: Hinojosa-Laborde C, Howard JT, Mulligan J, Grudic GZ, Convertino VA Abstract Compensatory reserve was measured in baboons (n=13) during hemorrhage (Hem) and lower body negative pressure (LBNP) using a machine learning algorithm developed to estimate compensatory reserve by detecting reductions in central blood volume during LBNP. The algorithm calculates compensatory reserve index (CRI) from normovolemia (CRI=1) to cardiovascular decompensation (CRI=0). The hypothesis was that Hem and LBNP will elicit similar CRI values, and that CRI would have higher specificity than stroke volume (SV) in predicting decompensation. Blood was removed in four steps: 6.25%, 12.5%, 18.75%, and 25% of total blood volume. Four weeks after Hem, the same animals were subjected to four levels of LBNP matched based on central venous pressure. Data (mean ± 95% confidence interval) indicate that CRI decreased (p<0.001) from baseline during Hem (0.69 ± 0.10, 0.57 ± 0.09, 0.36 ± 0.10, 0.16 ± 0.08, and 0.08 ± 0.03) and LBNP (0.76 ± 0.05, 0.66 ± 0.08, 0.36 ± 0.13, 0.23 ± 0.11, and 0.14 ± 0.09). CRI was not different between Hem and LBNP (p=0.20). Linear regression analysis between Hem CRI and LBNP CRI revealed a slope of 1.03 and an adjusted R2 of 0.96. CRI exhibit...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research