Oxygen extraction in pigs subjected to low-dose infusion of endotoxin after major abdominal surgery.
BACKGROUND
Sepsis may impair O(2) extraction due to blood flow redistribution or decreased utilization of the available oxygen.


METHODS
We assessed the effect of endotoxemia on systemic and regional O(2) extraction and lactate handling in pigs, randomized to receive either endotoxin (0.4 microg kg(-1) h(-1); n = 10) or saline infusion (controls; n = 9) for 12 h.


RESULTS
High baseline regional and systemic O(2) extraction in the endotoxin group (median 56%, range 45-77%) and in the controls (67%, 49-72%) was maintained until the end of the experiment (endotoxin group: 60%, 50-71%; controls: 60%, 50-74%) despite hypotension and a decrease in stroke volume in endotoxic animals. Hepatic lactate exchange decreased during endotoxemia from 14 micromol kg(-1) min(-1) (range 10-28 micromol kg(-1) min(-1)) to 10 (range 3-15) micromol kg(-1) min(-1); P < 0.01), but remained stable in the controls, with 13 micromol min(-1) (4-18 micromol min(-1)) at baseline and 7 micromol min(-1) (3-17 micromol min(-1)) after 12 h of saline infusion.


CONCLUSIONS
The high and sustained oxygen consumption and oxygen extraction in this endotoxemic model speak against any major impairment of hepatosplanchnic or systemic oxygen extraction and oxidative metabolism. The reduced hepatic lactate exchange despite an unchanged hepatic lactate influx suggests altered metabolic activities independent of oxygen consumption.
Porta
F
F
Surgical Research Unit, Dept. of Clinical Research and Clinic for Large Animals, University of Berne, CH-3010 Berne, Switzerland.
Takala
J
J
Kolarova
A
A
Ma
Y
Y
Redaelli
C A
CA
Brander
L
L
Bracht
H
H
Jakob
S M
SM
D000005:Abdomen / Q000601:surgery*; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D019446:Endotoxemia / Q000378:metabolism / Q000503:physiopathology; D004731:Endotoxins / Q000008:administration & dosage / Q000494:pharmacology*; D006325:Heart Atria; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D007267:Injections; D019344:Lactic Acid / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D012129:Respiratory Function Tests; D013552:Swine
D004731:Endotoxins; D006454:Hemoglobins; D008070:Lipopolysaccharides; D019344:Lactic Acid; C044101:endotoxin, Escherichia coli