Current priming solutions for cardiopulmonary bypass contain a potent coronary vasodilator.
We studied the effects of acetate (Ac), the buffer in crystalloids used during cardiopulmonary bypass (CPB) (e.g. Normosol-R and Plasma-Lyte, Ac = 27mEq/l), on coronary resistance (R) for the empty beating heart, and on vascular resistance (SVR) of 19 dogs on CPB. Control R with Ac = O (R c) was obtained by adjusting flow to give a pressure of 90 +/- 10mmHg (R = 532 +/- 32 dynes sec/cm 5g, other Rs are given as a percentage of their respective R c).  Continuous addition of Ac = 1.6 or 7.1mEq/L of blood resulted in a rapid decrease in R to 34 +/- 3 and 17 +/- 2% of R c, followed by a recovery to higher steady values of 53 +/- 3 and 27 +/- 2% respectively (p less than 0.008). A bolus administration of 2mEq and 6mEq into the coronary circuit resulted in R dropping to 30 +/- 5 and 17 +/- 6% respectively.  Rs obtained with Ac were compared to the Rs obtained for control 20sec reactive hyperaemia (35 +/- 1%), after 30 minutes global ischaemia (14 +/- 1%), and with the addition of bicarbonate (98 +/- 2%). Ac did not change heart rate, but caused an increase in O 2 consumption from 3.4 +/- 0.4 to 4.8 +/- 0.7 ml/min/100g, (p less than 0.038).  Systemically, a bolus of 6mEq of Ac caused an immediate drop in SVR to 45 +/- 5% of control.  The property of Ac as a potent coronary and vascular dilator may need to be considered when Ac is used during cardiac surgery.  Statistical comparisons were made with the paired t-test.
Tamari
Y
Y
Department of Surgery, North Shore University Hospital, New York.
Tortolani
J A
JA
Maguine
M
M
Czegledy
F
F
D000085:Acetates / Q000494:pharmacology*; D000818:Animals; D002314:Cardioplegic Solutions / Q000737:chemistry / Q000494:pharmacology*; D002315:Cardiopulmonary Bypass; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption; D014655:Vascular Resistance / Q000187:drug effects*; D014664:Vasodilation