PENTOXIFYLLINE AMELIORATES POSTISCHEMIC DELAYED HYPOPERFUSION OF THE CEREBRAL-CORTEX FOLLOWING CARDIAC-ARREST IN CATS

Two major events occurring in the cerebral hemodynamics after successf ul resuscitation from cardiac arrest are reactive hyperemia and postis chemic hypoperfusion. We examined the effect of pentoxifylline on the feline cerebral hemodynamics following cardiac arrest. Fifteen cats we re anesthetized and artificially ventilated. Using our photoelectric m ethod, the local cerebral blood volume (CBV), mean transit time of blo od (MTT), and cerebral blood flow (CBF) in the parietotemporal region were measured. Thoracotomy was performed, and cardiac arrest (ventricu lar fibrillation) was induced by direct application of a 2-V DC counte rshock. The heart was resuscitated with a DC countershock at 30 sec af ter cardiac arrest. In 9 cats, pentoxifylline (25 mg/kg) was infused i nto the femoral vein at 5 min before cardiac arrest (PTX group). The o ther 6 cats served as controls (control group). In both groups, the CB V, CBF and mean arterial blood pressure (MABP) overshot the control le vels just after resuscitation, whereas the MTT was decreased. In the c ontrol group, postischemic hypoperfusion was detected at 30-180 min af ter resuscitation from cardiac arrest (CBF (ml/100 g/min): 51 +/- 4 (c ontrol), 38 +/- 4 (30 min, p < 0.05), and 23 +/- 3 (180 min, p < 0.05) ). However, the postischemic hypoperfusion was not observed in the PTX group. Pentoxifylline ameliorated postischemic delayed hypoperfusion in the cerebral cortex after a short period of cardiac arrest. Pentoxi fylline may be useful in the emergency situations following cardiac ar rest.