O. Muikku et al., EFFECTS OF ORGANIC NITRATE VASODILATORS ON PLATELET-FUNCTION BEFORE AND AFTER CARDIOPULMONARY BYPASS, Acta anaesthesiologica Scandinavica, 39(5), 1995, pp. 618-623
Various in vitro, ex vivo and in vivo tests have shown that organic ni
trates attenuate platelet function. Because organic nitrates are commo
nly administered to patients undergoing cardiac surgery, the postopera
tive bleeding tendency observed in these patients might be strengthene
d by nitrates. Therefore, we compared the acute effects of nitroglycer
in (0.5 mu g kg(-1) min(-1)) and isosorbide dinitrate (0.5 or 2.5 mu g
kg(-1) min(-1)) with those of placebo on platelet function both befor
e and after cardiopulmonary bypass in 40 patients undergoing coronary
artery bypass grafting (CABG). Bleeding time, platelet retention on gl
ass beads, i.e, platelet adhesiveness, and thromboelastograph tracings
were used as indicators of platelet function. Although nitroglycerin
and isosorbide dinitrate induced significant haemodynamic changes, e.g
. decreases in arterial and pulmonary arterial pressure, they had no s
ignificant effects on the indices of platelet function. We conclude th
at, when given in haemodynamically effective doses, neither nitroglyce
rin nor isosorbide dinitrate have any measurable acute effect on plate
let function as evaluated with on-site tests in patients undergoing CA
BG surgery.