An improved method of profound hypothermia using a pulsatile cardiopulmonary bypass
Mori, A.; Sono, J.; Nakashima, M.; Minami, K.; Okada, Y.
Nihon Kyobu Geka Gakkai 28(9): 1351-1357
1980
ISSN/ISBN: 0369-4739 PMID: 7430715 Document Number: 155245
Profound hypothermia with core cooling and core rewarming was abandoned because of the high incidence of brain damage. Whether cardiopulmonary bypass with pulsatile blood flow replacing non-pulsatile flow would prove feasible was studied. The recovery time from anoxic damage of the brain due to circulatory arrest was estimated to obtain another arrest period for other intracardiac procedures. Mongrel dogs were cooled down to a brain temperature of 20.degree. C with cardiopulmonary bypass and warmed again with bypass, providing 2 periods of total circulatory arrest at 20.degree. C with a short period of bypass in between. Throughout the course of hypothermia, cerebral excess lactate (.DELTA.XL) (Huckabee) were determined. Throughout the cooling period from 30.degree. C down to 20.degree. C, the mean value of .DELTA.XL in the pulsatile group was significantly lower than that (0.66 .+-. 0.11) in the nonpulsatile group (P < 0.01). After 40 of the 1st total arrest at a brain temperature of 20.degree. C, 30 minutes of pulsatile perfusion is enough to eliminate the anaerobic metabolism of the brain caused by the 1st total circulatory arrest (P < 0.1). Core cooling and core rewarming with pulsatile cardiopulmonary bypass in cardiac surgery can be safely employed for profound hypothermia. When the period of the 1st total circulatory arrest is 40 min at a brain temperature of 20.degree. C, the 2nd total arrest can be obtained for other intracardiac procedures, after 30 min of pulsatile cardiopulmonary bypass.