+ Translate

Oxygen availability during hypothermic cardiopulmonary bypass

, : Oxygen availability during hypothermic cardiopulmonary bypass. Critical Care Medicine 5(3): 154-158

Oxygen availability during cardiopulmonary bypass was assessed in 22 patients under hypothermic and relatively normothermic conditions. The patients were divided into two groups, 17 of whom received ACD blood and 5, CPD blood. The mean P50 for all patients fell from a preoperative value of 25.9 +/- 2.4 (SD) to 15.6 +/- 2.1 during hypothermia confirming a leftward shift of the oxyhemoglobin dissociation curve. Oxygen uptake, calculated from a-v oxygen content differences (avDO2) and flow, was significantly lower during hypothermic bypass (65 +/- 27 ml/min) than during rewarming (121 +/- 41 ml/min). The increase in oxygen affinity during hypothermia was influenced also by changes in acid base and 2,3-DPG concentrations, the changes being similar in both the ACD and CPD groups of patients. During rewarming, however, oxygen availability was increased in the CPD group presumably from significantly increased 2,3-DPG concentrations. A "functional" value of hemoglobin, based upon the effects of the shift of the oxyhemoglobin dissociation curve and, therefore, reflecting the true capacity of hemoglobin to unload oxygen at the tissue level, was calculated. During the hypothermic phase of bypass, this functional hemoglobin was only 4.2 g/100 ml blood, suggesting that, in spite of reduced metabolic demands, oxygenation reserves are minimal.

(PDF 0-2 workdays service)

Accession: 038964445

PMID: 16730

Submit PDF Full Text: Here

Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:

Related references

Gothgen I.H.; Rasmussen J.P.; Siggaard Andersen O.; Wimberley P.D.; Fogh Andersen N., 1987: The oxygen status during hypothermic cardiopulmonary bypass. Acta Anaesthesiologica Scandinavica Supplementum (86)

Kai, Y.; Irita, K.; Taniyama, T.; Kandabashi, T.; Takahashi, S., 1995: Oxygen debt during hypothermic cardiopulmonary bypass. Anesthesiology (Hagerstown) 83(3A): A140

Maruyama, K.; Hashimoto, H.; Nakamura, K.; Nakai, Y.; Utsunomiya, H.; Maruyama, J.; Konishi, K.; Muneyuki, M., 1993: Whole body oxygen consumption after hypothermic cardiopulmonary bypass. Whole body oxygen consumption and the substrate for energy production during the post-bypass period have not been clarified. We hypothesized that the substrate composition for energy production during post-bypass period might be different from tha...

Delima L.G.R.; Wynands J.E.; Nathan H.J.; Hynes M.S.; Dupuis J.Y.; Bourke M.E.; Russell G.N., 1992: Accuracy of mixed venous blood oxygen saturation svo 2 monitoring to detect critical oxygen delivery in patients following hypothermic cardiopulmonary bypass. Canadian Journal of Anaesthesia 39(5 PART 2): A28

Dexter, F.; Kern, F.H.; Hindman, B.J.; Greeley, W.J., 1997: The brain uses mostly dissolved oxygen during profoundly hypothermic cardiopulmonary bypass. Background. During profoundly hypothermic cardiopulmonary bypass, cerebral venous oxygen saturation increases (e.g., to 98% at 15 degree C). We reanalyzed results of clinical studies to learn why. Methods. One hundred sixty-eight cerebral oxygen t...

Hickey, R.F.; Hoar, P.F., 1983: Whole-body oxygen consumption during low-flow hypothermic cardiopulmonary bypass. To assess the adequacy of tissue perfusion during low-flow, moderately hypothermic cardiopulmonary bypass (CPB), we measured whole-body oxygen consumption (VO2), serum lactate concentrations, and acid-base balance in 12 men undergoing myocardial r...

Werlhof, V.; Sessler, D.I., 1995: Pancuronium does not decrease oxygen consumption during hypothermic or normothermic cardiopulmonary bypass. Muscle relaxation reportedly reduces systemic oxygen consumption 30% during hypothermic cardiopulmonary bypass. A potential mechanism is inhibition of hypothermia-induced subclinical muscle tone ("microshivering"). Accordingly, we tested...

Tuppurainen, T.; Settergren, G.; Stensved, P., 1989: The effect of arterial pH on whole body oxygen uptake during hypothermic cardiopulmonary bypass in man. To test the hypothesis of Rahn and Reeves that the optimal arterial pH during hypothermia follows the alpha-stat concept, we studied 50 patients during coronary artery bypass grafting or valve replacement (or both) and aortic occlusion. Intravenou...

Murkin J.M.; Sharpe M.; Farrar J.K., 1990: Ph management during hypothermic cardiopulmonary bypass does not influence cerebral oxygen consumption. Anesthesiology (Hagerstown) 73(3A): A117

Aoki, S., 1995: The evaluation of cerebral oxygen balance during moderate hypothermic cardiopulmonary bypass. The aim of this study was to evaluate cerebral oxygen balance during moderate hypothermic cardiopulmonary bypass (CPB). We measured jugular bulb venous oxygen saturation (SjO-2), oxygen extraction ratio (O-2 ER), glucose extraction ratio (Glu ER),...