Yugeesh R Lankadeva, Clive N May, Andrew D Cochrane, Bruno Marino, Sally G Hood, Peter R McCall, Nobuki Okazaki, Rinaldo Bellomo, Roger G Evans
Acta physiologica (Oxford, England) 2021 MarBlood transfusion may improve renal oxygenation during cardiopulmonary bypass (CPB). In an ovine model of experimental CPB, we tested whether increasing blood haemoglobin concentration [Hb] from ~7 g dL-1 to ~9 g dL-1 improves renal tissue oxygenation. Ten sheep were studied while conscious, under stable isoflurane anaesthesia, and during 3 hours of CPB. In a randomized cross-over design, 5 sheep commenced bypass at a high target [Hb], achieved by adding 600 mL donor blood to the priming solution. After 90 minutes of CPB, PlasmaLyte® was added to the blood reservoir to achieve low target [Hb]. For the other 5 sheep, no blood was added to the prime, but after 90 minutes of CPB, 800-900 mL of donor blood was given to achieve a high target [Hb]. Overall, CPB was associated with marked reductions in renal oxygen delivery (-50 ± 12%, mean ± 95% confidence interval) and medullary tissue oxygen tension (PO2 , -54 ± 29%). Renal fractional oxygen extraction was 17 ± 10% less during CPB at high [Hb] than low [Hb] (P = .04). Nevertheless, no increase in tissue PO2 in either the renal medulla (0 ± 6 mmHg change, P > .99) or cortex (-19 ± 13 mmHg change, P = .08) was detected with high [Hb]. In experimental CPB blood transfusion to increase Hb concentration from ~7 g dL-1 to ~9 g dL-1 did not improve renal cortical or medullary tissue PO2 even though it decreased whole kidney oxygen extraction. © 2020 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
Yugeesh R Lankadeva, Clive N May, Andrew D Cochrane, Bruno Marino, Sally G Hood, Peter R McCall, Nobuki Okazaki, Rinaldo Bellomo, Roger G Evans. Influence of blood haemoglobin concentration on renal haemodynamics and oxygenation during experimental cardiopulmonary bypass in sheep. Acta physiologica (Oxford, England). 2021 Mar;231(3):e13583
PMID: 33222404
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