Prophylaxis of cerebro-vascular complications while performance of aorto-coronary shunting in conditions of artificial blood circulation

Abstract

Objective. To estimate the efficacy of application of vasodilator nitroglycerine on background of high volumic speed of perfusion for prophylaxis of the cerebral vessels microembolism while performance of the aorto-coronary shunting (ACSH) operations in conditions of artificial blood circulation. Маterials and methods. The investigation was conducted in 72 patients, suffering the ischemic heart disease, to whom aorto-coronary shunting operation was accomplished in conditions of artificial blood circulation in the Odessa Regional Clinical Hospital. Median age of the patients have constituted (67.3 ± 5.2) yrs old, median body mass index - (27.4 ± 5.2) kg/m2, average duration of the operation - (269.4 ± 7.8) min, including the artificial blood circulation stage - (145 ± 4.5) min. General statistical sampling of the patients examined was randomized in accordance to the comparison group (n=34) and the investigated (n=38) group. For prophylaxis of the air microembolism in patients of the comparison group before the artificial blood circulation apparatus switching on during 9 - 10 min nitroglycerine was infused in the dose 8 - 10 mcg/kg × min on background of high (120 - 130% from the calculated one) volumic speed of perfusion with support of median index of arterial pressure on the level 50 - 60 mm Hg. Іntraoperative monitoring of cerebral blood flow was done, using transtemporal access in accordance to standard procedure. Cognitive status of the patients was estimated with the help of verbal and nonverbal tests (day before and on the fifth postoperative day). Results. The investigation accomplished have revealed, that in all the patient the ACSH operation in conditions of artificial blood circulation was accompanied by microembolism in the system of cerebral blood flow of the discrete character. Іntraoperative creation in cerebral blood flow of more than 750 microemboli causes occurrence of a clinically significant lowering of the brain cognitive functions in early postoperative period. Application of nitroglycerine as a kind of peripheral vasodilator in the dose 8 - 10 mcg/kg × min on background of high (120 - 130% of the calculated) volumic speed of perfusion have caused the reduction of the cognitive dysfunction severity by 15 - 20%.