Effect of lidocaine on improving cerebral protection provided by retrograde cerebral perfusion: A neuropathologic study

Objective: To determine whether lidocaine can improve the neuropathologic r esults in canine brains after retrograde cerebral perfusion (RCP). Design: Randomized, blinded, experimental study. Setting: University animal laboratory. Participants: Mongrel dogs. Interventions: Fourteen mongrel dogs were placed on 120 minutes of hypother mic (20 degrees C) RCP. Following the RPC, they then resumed cardiopulmonar y bypass and rewarming for 60 minutes. In the lidocaine group (n = 8), lido caine was administered continuously; in the control group (n = 6), normal s aline was administered. Cerebral perfusion fixation was performed at the en d of the experiment. Measurements and Main Results: The number of ischemic cells in 200 neurons was counted in the parietal cortex, CA1 sector of the hippocampus, CA3 sect or of the hippocampus, ventral posterolateral nucleus of the thalamus, and Purkinje cells of the cerebellar cortex. Those in the parietal cortex, CA1 sector of the hippocampus, and ventral posterolateral nucleus of the thalam us were significantly less in the lidocaine group than in the control group (25.8 +/- 17.3 v 53.7 +/- 12.0; p < 0.01; 17.0 +/- 8.5 v 54.7 +/- 22.1; p < 0.01; and 16.9 +/- 17.8 v 49.7 +/- 28.4; p < 0.05, respectively). The tot al number of ischemic cells in the five examined regions was also significa ntly less in the lidocaine group than in the control group (89.5 +/- 19.4 v 219.5 +/- 45.5; p < 0.01). Conclusion: Continuous lidocaine significantly alleviated the ischemic neur opathologic injury after RCP and thus possibly improved cerebral protection . Copyright (C) 1999 by W.B. Saunders Company.