The effect of hypervolemic hemodilution and hyperoncotic infusions on the immediate reperfusion impairment in skeletal muscle of the rat after prolonged total ischemia.
The effect of hypervolemic hemodilution and hyperoncotic infusions on the reactive hyperemic volume flow rates during the initial minutes of post-ischemic reperfusion in the rat's tibialis anterior muscle after 1, 2 and 3 hours of tourniquet ischemia was studied using the 133Xenon clearance technique. Median maximal hyperemic peak reflow rates in muscle of non-infused, control animals upon release of a tourniquet were 56.5, 43.6 and 7.5 ml.min-1 x 100 g-1 respectively, demonstrating the development of a post-ischemic reperfusion impairment, a no-reflow phenomenon, that increased with the duration of the preceding period of ischemia. Rapid infusions of isotonic saline solutions over the last five minutes of tourniquet ischemia, aiming at increasing the circulating blood volume of the animals at start of the ischemic leg reperfusion by 2.0, 4.5, and 9.5 ml respectively, or by approximately 10%, 25% and 50%, gave no significant improvement in post-ischemic reperfusion, except in that following 3 hours of leg ischemia and after the two largest volumes. Rapid infusions of solutions of human albumin in a concentration of 200 mg.ml-1 to an amount approximately equalling 0.15, 0.40 and 0.75 g.kg-1 bodyweight till the moment the reperfusion was started, aiming to increase circulating albumin until the start of reperfusion by about 10%, 20% and 40%, significantly improved immediate peak hyperemic reperfusion in proportion to dose and more than doubled post-ischemic peak hyperemic reperfusion rates after the largest dose to 129.6, 102.6 and 39.1 ml.min-1 x 100 g-1 respectively. This improvement in initial post-ischemic hyperemia by hyperoncotic reperfusion may be of importance for achieving a rapid post-ischemic tissue oxygenation and for preventing tissue edema.
Clinical Research Center, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
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Gidlöf
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DH
Lewis
D000418:Albumins / Q000494:pharmacology; D000818:Animals; D005260:Female; D006438:Hemodilution; D006982:Hypertonic Solutions / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007511:Ischemia / Q000503:physiopathology*; D009132:Muscles / Q000098:blood supply*; D051381:Rats; D011919:Rats, Inbred Strains; D015424:Reperfusion; D013997:Time Factors
D000418:Albumins; D006982:Hypertonic Solutions