| Abstract: | Since ischemic anoxia in experimental animals has been reported to produce areas of cerebral postocclusive nonperfusion, the authors studied the effect of heparin on recovery from tourniquet-produced cerebrovascular injury in 41 barbiturate-anesthetized, ventilated cats (PaCO2 30 +/- 2.5 torr). Twenty-four control animals were subjected to 2-to-12-minute ischemic injuries without further treatment. Seven experimental animals were given heparin (1000 u/kg) 1 minute before 4-to-7-minute ischemic injuries, while 10 animals received heparin (1000 u/kg) immediately after 4-to-7-minute injuries. All animals were monitored with continuous arterial and intracranial pressure (ICP) recordings, EEG, and evoked cortical responses. Ischemia and evoked-response recovery times were linearly related in all groups (r = 0.998 control, r = 0.936 heparin preinjury, r = 0.951 heparin postinjury). Regression-line slope comparison indicated shorter evoked response and EEG recovery times in the heparin-treated groups than in the control group. Heparin administration did not effect elevations of ICP seen 6 and 12 hours postinjury in control versus experimental groups. In cats with injuries lasting 5 minutes or more, all control animals were decerebrate and apneic, while 5/12 heparin-treated animals had lesser neurologic deficits. |
