Yugeesh R Lankadeva1,2, Clive N May1,2, Andrew D Cochrane3, Bruno Marino4, Sally G Hood1, Peter R McCall5, Nobuki Okazaki1,6, Rinaldo Bellomo2,7, Roger G Evans8. 1. Pre-Clinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia. 2. Centre for Integrated Critical Care, Department of Medicine and Radiology, The University of Melbourne, Melbourne, VIC, Australia. 3. Department of Cardiothoracic Surgery, Monash Health and Department of Surgery (School of Clinical Sciences at Monash Health), Monash University, Melbourne, VIC, Australia. 4. Cellsaving and Perfusion Resources, Melbourne, VIC, Australia. 5. Department of Anaesthesia, Austin Health, Heidelberg, VIC, Australia. 6. Department of Anesthesiology and Resuscitology, Okayama University, Okayama, Japan. 7. Department of Intensive Care, Austin Health, Heidelberg, VIC, Australia. 8. Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia.
Abstract
AIM: Blood 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. METHODS: 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]. RESULTS: 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]. CONCLUSIONS: 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.
AIM: Blood 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. METHODS: 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]. RESULTS: 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]. CONCLUSIONS: 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.
Authors: Micael Taavo; Mats Rundgren; Peter Frykholm; Anders Larsson; Stephanie Franzén; Karin Vargmar; Jean F Valarcher; Gerald F DiBona; Robert Frithiof Journal: Function (Oxf) Date: 2021-08-20