Enhanced oxygen delivery induced by perfluorocarbon emulsions in capillary tube oxygenators.
Previous studies showed that a new generation of perfluorocarbon (PFC) emulsions increased tissue PO2 in the cat retina to a degree that could not be explained by the small increase in arterial O2 content seen after the infusion of low doses of 1 g PFC/kg body weight. It seems that increased O2 delivery at the tissue level after PFC infusion is caused by a local effect in the microcirculation. The authors studies this effect in vitro at steady state in a closed loop circuit, consisting of one of two types of capillary tube oxygenators, deoxygenator(s), a reservoir bag filled with anticoagulated bovine blood or saline (control), and a roller pump, to see if the addition of PFC would have an effect on the PO2 difference (delta PO2) across the capillary tube membrane oxygenator at a blood flow rate of 3 l/min. Perfluorocarbon was added in three incremental doses, each giving about 0.7 vol% of PFC. The delta PO2 across the oxygenator was measured before and after each dose. The mean percent increases in delta PO2 in blood for two types of oxygenators were 19.2 +/- 8% (mean +/- SD, n = 6, P = 0.002) and 9.9 +/- 4% (n = 3, P = 0.05), respectively, whereas the mean percent change in delta PO2 in saline was -4.9 +/- 2% (n = 2, P = 0.2). Inlet PO2s to the oxygenator were only minimally increased. The authors conclude that O2 delivery was significantly enhanced after injection of PFC in blood in this capillary tube model. A near wall excess of PFC particles may account for the augmentation of O2 diffusion in this model.
Vaslef
S N
SN
Department of Surgery, Evanston Hospital, IL 60201, USA.
Goldstick
T K
TK
D000818:Animals; D001802:Blood Substitutes; D002415:Cats; D002417:Cattle; D004058:Diffusion; D004655:Emulsions; D005069:Evaluation Studies as Topic; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; D066298:In Vitro Techniques; D008833:Microcirculation; D008954:Models, Biological; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D010106:Oxygenators
D001802:Blood Substitutes; D004655:Emulsions; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; C003072:perflubron; D010100:Oxygen