ABSTRACT
The effects of protamine sulphate on several cardiorespiratory variables were studied under clinical situations in twenty patients following cardiopulmonary bypass. Because recent reports suggest that there may be advantages of intra-aortic versus intra-venous administration we prospectively evaluated cardiorespiratory features 1 and 10 minutes after rapid administering of protamine sulphate either into the aortic arch (through a catheter percutaneously inserted via the radial artery for monitoring purposes) or into the right atrium. Significant variations in some parameters were found in the patients receiving the drug via the aorta, such as a drop of systemic vascular resistances (p less than 0.05), of coronary perfusion pressure (p less than 0.05), of aortic systolic pressure (p less than 0.01), of diastolic (p less than 0.01) and mean blood pressure (p less than 0.05) and a rise in the respiratory quotient (p less than 0.05). It is concluded that the results do not confirm the superior safety of intra-aortic administration of protamine particularly when replenishment of intravascular volume is not provided.
