Hemodynamic, metabolic, and morphological effects of cardiopulmonary bypass with a fluorocarbon priming solution

Systemic perfusion, myocardial contractility, and morphological changes during and after cardiopulmonary bypass (CPB) were investigated in 22 greyhounds; Fluosol-DA 20% (FDA) and normal saline (NaCl) were compared as priming solutions for hypothermic (25 degrees C) CPB. Hemodynamic and oxygenation indices were similar in all groups. Animals with fluorocarbon primes had higher serum lactate concentrations (mean +/- standard error of the mean [SEM]) during CPB (NaCl 1.64 +/- 0.2, FDA 2.39 +/- 0.3, p less than 0.01), representing an increase over the control of 12% and 319% in the NaCl and FDA groups, respectively. After CPB, serum lactate concentration remained elevated in the FDA group, but it returned to the level of the control in the NaCl group (NaCl 1.49 +/- 0.5, FDA 2.29 +/- 1.1, p less than 0.01); increases over the control level were 7% and 302% in the NaCl and FDA groups, respectively. Myocardial contractility after CPB, expressed as dP/dt[40], was similar in the two experimental groups. Three weeks after CPB, a histological examination by light microscopy of multiple organs obtained from a separate group of 12 animals treated similarly was performed, demonstrating no significant morphological differences between animals primed with fluorocarbon or with saline. The results suggest that FDA is a satisfactory priming agent for hypothermic CPB. It adequately preserves myocardial function and causes no adverse morphological changes, but a persistent, as yet unexplained, elevation in serum lactate concentration occurs.