Prevention of postischemic hypoperfusion after canine cardiac arrest by nicardipine.

We studied the effect of nicardipine (NC) on canine cerebral blood flow (CBF) after cerebral ischemia induced by cardiac arrest. Cerebral ischemia was produced by 10 min of electrically mediated ventricular fibrillation. An iv injection of NC (10 micrograms/kg) bolus was followed by continuous NC infusion (0.33 micrograms/kg X min) immediately after the circulation re-established itself. Local CBF was measured using the hydrogen-gas clearance method. The administration of NC maintained CBF at the pre-arrest level during postischemia, thus preventing the hypoperfusion observed in the control group with no NC. However, in the controls, CBF, reduced at 180 min after re-circulation, was not improved by NC infusion. Consequently, administering NC immediately after re-establishment of circulation may help maintain CBF during the postresuscitation period.