Journal of Applied Physiology, Vol 71, Issue 1 83-93, Copyright © 1991 by American Physiological Society

ARTICLES

Effects of anesthetic agents on systemic critical O2 delivery

P. Van der Linden, E. Gilbart, E. Engelman, D. Schmartz and J. L. Vincent
Department of Anesthesiology, Erasme University Hospital, Brussels, Belgium.

The present study tested the hypothesis that anesthetic agents can alter tissue O2 extraction capabilities in a dog model of progressive hemorrhage. After administration of pentobarbital sodium (25 mg/kg iv) and endotracheal intubation, the dogs were paralyzed with pancuronium bromide, ventilated with room air, and splenectomized. A total of 60 dogs were randomized in 10 groups of 6 dogs each. The first group served as control (C). A second group (P) received a continuous infusion of pentobarbital (4 mg.kg-2.h-2), which was started immediately after the bolus dose. Three groups received enflurane (E), halothane (HL), or isoflurane (I) at the end-tidal concentration of 0.7 minimum alveolar concentration (MAC). The sixth group received halothane at the end-tidal concentration of 1 MAC (HH). Two groups received intravenous alfentanil at relatively low dose (AL) or high dose (AH). The last two groups received intravenous ketamine at either relatively low dose (KL) or high dose (KH). In each group, O2 delivery (Do2) was progressively reduced by hemorrhage. At each step, systemic Do2 and O2 consumption (VO2) were measured separately and the critical point was determined from a plot of Vo2 vs. Do2. The critical O2 extraction ratio (OER) in the control group was 65.0 +/- 7.8%. OER was lower in all anesthetized groups (P, 44.3 +/- 11.8%; E, 47.0 +/- 7.7%; HL, 45.7 +/- 11.2%; I, 44.3 +/- 7.1%; HH, 33.7 +/- 6.0%; AL, 56.5 +/- 9.6%; AH, 43.5 +/- 5.9%; KH, 57.7 +/- 7.1%), except in the KL group (78.3 +/- 10.0%). The effects of halothane and alfentanil on critical OER were dose dependent (P less than 0.05), whereas critical OER was significantly lower in the KH than in the KL group. Moreover, the effects of anesthetic agents on critical Do2 appeared related to their effects on systemic vascular resistance. Anesthetic agents therefore alter O2 extraction by their peripheral vascular effects. However, ketamine, with its unique sympathetic stimulant properties, had a lesser effect on OER than the other anesthetic agents. It could therefore be the anesthetic agent of choice in clinical situations when O2 availability is reduced.

This article has been cited by other articles:

				I. P. Torres Filho, B. D. Spiess, R. N. Pittman, R. W. Barbee, and K. R. Ward Experimental analysis of critical oxygen delivery Am J Physiol Heart Circ Physiol, March 1, 2005; 288(3): H1071 - H1079. [Abstract] [Full Text] [PDF]

				Y M Ganushchak, J G Maessen, and D S de Jong The oxygen debt during routine cardiac surgery: illusion or reality? Perfusion, May 1, 2002; 17(3): 167 - 173. [Abstract] [PDF]

				P. V. d. LINDEN, S. DE HERT, S. BELISLE, F. DE GROOTE, N. MATHIEU, S. D'EUGENIO, V. JULIEN, C. HUYNH, and C. MELOT Comparative Effects of Red Blood Cell Transfusion and Increasing Blood Flow on Tissue Oxygenation in Oxygen Supply-dependent Conditions Am. J. Respir. Crit. Care Med., June 1, 2001; 163(7): 1605 - 1608. [Abstract] [Full Text] [PDF]

				V. Alfaro, J. Pesquero, and L. Palacios Acid-base disturbance during hemorrhage in rats: significant role of strong inorganic ions J Appl Physiol, May 1, 1999; 86(5): 1617 - 1625. [Abstract] [Full Text] [PDF]

				F Cavaliere A nomogram to evaluate the arterial mixed venous oxygen saturation difference during cardiopulmonary bypass Perfusion, January 1, 1998; 13(1): 45 - 51. [Abstract] [PDF]

				A. W. SIELENKAMPER, I. H. CHIN-YEE, C. M. MARTIN, and W. J. SIBBALD Diaspirin Crosslinked Hemoglobin Improves Systemic Oxygen Uptake in Oxygen Supply-dependent Septic Rats Am. J. Respir. Crit. Care Med., October 1, 1997; 156(4): 1066 - 1072. [Abstract] [Full Text] [PDF]