Low oxygen delivery produced by anemia, hypoxia, and low cardiac output.
In pentobarbital-anesthetized dogs, oxygen delivery (DO2) was measured by thermodilution cardiac output and cooximeter determined oxygen content, while oxygen consumption (VO2) was measured independently by spirometry. Oxygen delivery was decreased by isovolemic dilutional anemia, breathing hypoxic gas mixtures, or cardiac tamponade to reduce cardiac output. Baseline VO2 (cc/kg/min) for the three groups was 5.9 +/- 0.7 (anemia), 5.4 +/- 0.4 (hypoxia), and 5.6 +/- 0.1 (low C.O.) (NS). A critical level of oxygen delivery (DO2crit) was found at 9-10 cc/kg/min (anemia), 10-11 cc/kg/min (hypoxia), and 9-10 cc/kg/min (low C.O.) (NS.). Below this level, VO2 fell (became supply dependent) and lactic acidosis occurred, regardless of the mechanism of impaired oxygen delivery.
Cilley
R E
RE
Section of General Surgery, University of Michigan Medical Center, Ann Arbor 48109-0331.
Scharenberg
A M
AM
Bongiorno
P F
PF
Guire
K E
KE
Bartlett
R H
RH
D000740:Anemia / Q000378:metabolism*; D000818:Animals; D002303:Cardiac Output, Low / Q000378:metabolism*; D004285:Dogs; D000860:Hypoxia / Q000378:metabolism*; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D010101:Oxygen Consumption; D013815:Thermodilution
D007773:Lactates; D019344:Lactic Acid