Critical hematocrit and oxygen partial pressure in the beating heart of pigs

Microvascular Research
B HieblF Jung

Abstract

In cardiac surgery the substitution of lost blood volume by plasma substitutes is a common therapeutical approach. None of the currently available blood substitutes has a sufficient oxygen transport capacity. This can limit the functional integrity of the myocardium known as highly oxygen consumptive. The study was aimed to get information about the minimal hematocrit, also known as critical hematocrit (cHct), which guarantees a stable and adequate oxygen partial pressure in the myocardium (pO2). In adult female pigs (n=7) the hematocrit was reduced by isovolemic blood dilution with an intravenous infusion of isotonic 4% gelatine polysuccinate solution, The substituted blood volume ranged between 3000ml and 7780ml (mean: 5254±1672ml). In all animals the pO2 of the myocardium of the beating heart and of the resting skeletal muscle increased until blood dilution resulted in a Hct decrease down to 15%. Further blood dilution resulted in a decrease of the pO2. Only after the Hct was <10% the pO2 was lower than before blood dilution and accompanied by a lethal ischemia of the myocardium. These data indicate a cHct of about 10% in the pig animal model.

Citations

Feb 19, 2016·Clinical Hemorheology and Microcirculation·Aurélien P PichonPaul Robach
Sep 29, 2019·Clinical Hemorheology and Microcirculation·A NiesB Hiebl
Jul 20, 2019·Clinical Hemorheology and Microcirculation·P LambyL Prantl
Feb 14, 2021·Clinical Hemorheology and Microcirculation·Junyuan WuChunsheng Li
Feb 2, 2021·Frontiers in Veterinary Science·Rosalind S Chow

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