Renal hemodynamics and oxygenation during experimental cardiopulmonary bypass in sheep under total intravenous anesthesia.

Renal hemodynamics and oxygenation during experimental cardiopulmonary bypass in sheep under total intravenous anesthesia. Am J Physiol Regul Integr Comp Physiol. 2019 Dec 11;: Authors: Evans RG, Iguchi N, Cochrane AD, Marino B, Hood SG, Bellomo R, McCall PR, May CN, Lankadeva YR Abstract Renal medullary hypoxia may contribute to the pathophysiology of acute kidney injury, including that associated with cardiac surgery requiring cardiopulmonary bypass (CPB). When performed under volatile (isoflurane) anesthesia in sheep, CPB causes renal medullary hypoxia. There is evidence that total intravenous anesthesia (TIVA) may preserve renal perfusion and renal oxygen delivery better than volatile anesthesia. Therefore, we assessed the effects of CPB on renal perfusion and oxygenation in sheep under propofol/fentanyl-based TIVA. Sheep (n = 5) were chronically instrumented for measurement of whole renal blood flow and cortical and medullary perfusion and oxygenation. Five days later, these variables were monitored under TIVA using propofol and fentanyl and then on CPB at a pump flow of 80 mL kg-1min-1 and target mean arterial pressure of 70 mmHg. Under anesthesia, prior to CPB, renal blood flow was preserved under TIVA (mean difference ± standard deviation from conscious state: -16 ± 14%). However, during CPB renal blood flow was reduced (-55 ± 13%), and renal medullary tissue became hypoxic (-20 ± 13 mmHg versus conscious sheep). We concl...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research