Splanchnic hemodynamics and oxygen supply during acute normovolemic hemodilution alone and with isoflurane-induced hypotension in the anesthetized pig.
Safety of combined hemodilution and isoflurane-induced hypotension was assessed by studying their effects on splanchnic hemodynamics and oxygenation in nine anesthetized (ketamine/flunitrazepam) pigs. Acute normovolemic hemodilution (decrease in hematocrit from 29% to 15%) with 6% hydroxyethyl starch decreased (P < 0.05) O2 delivery despite increases in cardiac output and all splanchnic flows, as measured by electromagnetic flow probes. Superimposed isoflurane (1.45% end-tidal concentrations) caused marked decreases in arterial blood pressure, cardiac output, and splanchnic flows. Oxygen uptake of the liver became O2 supply dependent. A liver surface PO2 histogram (Clark-type electrode) showed 38% of PO2 values between 0 and 5 mm Hg. Hepatic lactate uptake decreased by 75%. These data suggest that depression of cardiovascular function during reduced O2-carrying capacity adversely affects hepatic perfusion, oxygenation, and function. Combined hemodilution and isoflurane-induced hypotension may not be appropriate in patients.
Nöldge
G F
GF
Department of Anesthesia, University Hospital, Freiburg, Germany.
Priebe
H J
HJ
Geiger
K
K
D000758:Anesthesia; D000818:Animals; D005260:Female; D006438:Hemodilution; D006439:Hemodynamics; D007023:Hypotension, Controlled; D007421:Intestine, Small / Q000378:metabolism; D007530:Isoflurane / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D013152:Splanchnic Circulation; D013552:Swine
D007530:Isoflurane; D010100:Oxygen