Increased blood oxygen affinity decreases canine brain oxygen consumption
Woodson, R.D.; Fitzpatrick, J.H.; Costello, D.J.; Gilboe, D.D.
Journal of Laboratory and Clinical Medicine 100(3): 411-424
1982
ISSN/ISBN: 0022-2143 PMID: 7108350 Document Number: 187591
The effect of increased blood O2 affinity on O2 delivery to the isolated canine brain was studied. After surgical isolation, the brain, enclosed in the calvarium, was perfused alternately from 2 pump-oxygenators with normal blood (P50 = 17.3 torr). With flow rates equal for both normal and experimental blood, PVO2 averaged 31 .+-. 4 (SD) and 21 .+-. 3 torr (P < 0.001), respectively, and .ovrhdot.VO2 averaged 4.33 .+-. 0.52 ml/min per 100 g and 3.18 .+-. 0.52 (P < 0.001). With pH at 7.4 and 7.8, .ovrhdot.VO2 averaged 4.42 .+-. 0.77 ml/min per 100 g and 3.66 .+-. 0.99, respectively (P < 0.01). A reduced P50 limits O2 diffusion to brain at a normal but fixed blood flow rate despite capillary recruitment.