Enhanced central organ oxygenation after application of bovine cell-free hemoglobin HBOC-201.
OBJECTIVE
While the effects of dilutional anemia or isovolemic hemodilution (IHD) on the oxygen extraction and tissue oxygenation in peripheral organs after application of hemoglobin-based oxygen carriers like HBOC-201 have been studied intensively, little is known about tissue oxygenation properties of hemoglobin solutions in central organs like the liver.


METHODS
Twelve Foxhounds were anesthetized and then randomized to either a control group without hemodilution (Group 1) or underwent first step isovolemic hemodilution (pulmonary artery occlusion pressure constant) with Ringer's solution (Group 2) to a hematocrit of 25% with second step infusion of HBOC-201 until a hemoglobin concentration of +0.6 g.dL(-1) was reached. Tissue oxygen tensions (tpO2) were measured in the gastrocnemius muscle using a polarographic needle probe, and in the liver using a flexible polarographic electrode.


RESULTS
While arterial oxygen content and oxygen delivery decreased with hemodilution in Group 2, global liver and muscle oxygen extraction ratio increased after hemodilution and additional application of HBOC-201. Hemodilution and application of HBOC-201 provided augmentation of the mean liver tpO2 (baseline: 48 +/- 9, 20 min: 53 +/- 10, 60 min: 67 +/- 11*, 100 min: 68 +/- 7*; *P < 0.05 vs baseline and Group 1), while oxygen tensions in Group 1 remained unchanged. Oxygen tension in the skeletal muscle increased after hemodilution and additionally after application of HBOC-201 in comparison to baseline and to the control group (P < 0.05).


CONCLUSIONS
In the present animal model, IHD with Ringer's solution and additional application of HBOC-201 increased oxygen extraction and tpO(2) in the liver and skeletal muscle, in parallel and in comparison with baseline values and a control group.
Freitag
Marc
M
Department of Anaesthesiology, University Hospital Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. freitag@uke.uni-hamburg.de
Standl
Thomas G
TG
Gottschalk
André
A
Burmeister
Marc A
MA
Rempf
Christian
C
Horn
Ernst P
EP
Strate
Tim
T
Schulte Am Esch
Jochen
J
D000818:Animals; D001802:Blood Substitutes / Q000494:pharmacology*; D001810:Blood Volume / Q000502:physiology; D002417:Cattle; D004285:Dogs; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006438:Hemodilution; D006439:Hemodynamics / Q000502:physiology; D006454:Hemoglobins / Q000494:pharmacology*; D008099:Liver / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood*
D001802:Blood Substitutes; D006454:Hemoglobins; C096798:HBOC 201; D010100:Oxygen