Increased vascular resistance with hemoglobin-based oxygen carriers.
OBJECTIVE
To compare the effects of resuscitation with hemoglobin-based oxygen-carriers and conventional resuscitation fluids on hemodynamics, oxygen transport, and oxygen consumption in an animal model of the use of these fluids in the treatment of hemorrhagic shock.


METHODS
Twenty-eight immature swine were surgically prepared, allowed to recover five days, water deprived for 48 hours, hemorrhaged of 25 ml/kg over one hour, resuscitated promptly with 1) Ringer's lactate, 75 ml/kg, 2) 7% albumin in Ringer's acetate, 25 ml/kg, 3) 9% unmodified hemoglobin in Ringer's acetate, 25 ml/kg, or 4) 9% alpha alpha-crosslinked hemoglobin in Ringer's acetate, 25 ml/kg, and observed with three hours of hemodynamic and oxygen transport measurements.


RESULTS
Systemic and pulmonary vascular resistance were increased in hemoglobin-treated animals to more than twice the levels seen in crystalloid- or colloid-treated controls. Oxygen consumption and the rate of correction of lactic acidosis were not increased in hemoglobin-treated animals.


CONCLUSIONS
Increased vascular resistance limits the oxygen transport benefit of cell-free-hemoglobin-based oxygen carriers. Cell-free-hemoglobin-induced increases in vascular resistance may place animals' hearts on an unfavorable portion of the Frank-Starling curve as well as complicate further medical treatment by reducing the animals' tolerance to increases in blood viscosity.
Hess
J R
JR
Division of Blood Research, Letterman Army Institute of Research, Presidio of San Francisco, CA 94129-6800.
Macdonald
V W
VW
Gomez
C S
CS
Coppes
V
V
D000818:Animals; D001693:Biological Transport, Active; D001794:Blood Pressure / Q000187:drug effects; D001802:Blood Substitutes / Q000009:adverse effects / Q000633:toxicity*; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects; D011652:Pulmonary Circulation / Q000187:drug effects; D011654:Pulmonary Edema / Q000209:etiology; D012079:Renal Circulation / Q000187:drug effects; D012151:Resuscitation / Q000009:adverse effects; D012449:Safety; D012771:Shock, Hemorrhagic / Q000097:blood / Q000503:physiopathology / Q000628:therapy; D012996:Solutions; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
D001802:Blood Substitutes; D012996:Solutions; D010100:Oxygen