Astudillo R, van der Linden J, Ekroth R, Wesslén O, Hallhagen S, Scallan M, Shore D, Lincoln C
Department of Anesthesia and Intensive Care, University Hospital, Uppsala, Sweden.
Ann Thorac Surg. 1993 Sep;56(3):515-9. doi: 10.1016/0003-4975(93)90891-k.
It is controversial whether profound hypothermia (15 degrees C) provides adequate cerebral protection during a limited period of total circulatory arrest during pediatric cardiac surgery. In the present study, transcranial Doppler echography was used to monitor the blood flow velocity (BFV) pattern in the middle cerebral artery (MCA). The purpose of the study was to investigate the influence of a period of circulatory arrest on MCA BFV, as judged from the reperfusion flow velocity pattern. The MCA BFV was studied in 22 small children undergoing profound hypothermic cardiac operations after induction of anesthesia. Twelve of the children had a period of profound hypothermic circulatory arrest (15 to 74 minutes; arrest group). Circulation was maintained in the remaining 10 children (nonarrest group). Time-averaged MCA BFV was decreased and diastolic BFV was absent immediately after cardiopulmonary bypass in 10 of 12 children in the arrest group. In contrast, only 1 of 10 patients in the nonarrest group (p < 0.05) showed this pattern. Diastolic BFV normalized 54 to 328 minutes after the arrest in the arrest group. Circulatory arrest during profound hypothermia is followed by a period of low cerebral perfusion, whereby time-averaged MCA BFV is decreased and MCA BFV is absent during diastole. We speculate that this can be explained by an increase in intracranial pressure after brain edema.
在小儿心脏手术的有限全循环停搏期间，深度低温（15摄氏度）是否能提供足够的脑保护存在争议。在本研究中，经颅多普勒超声用于监测大脑中动脉（MCA）的血流速度（BFV）模式。本研究的目的是根据再灌注血流速度模式，探讨循环停搏期对MCA BFV的影响。对22例麻醉诱导后接受深度低温心脏手术的小儿进行了MCA BFV研究。其中12例患儿经历了深度低温循环停搏期（15至74分钟；停搏组）。其余10例患儿维持循环（非停搏组）。停搏组12例患儿中有10例在体外循环后即刻平均MCA BFV降低且舒张期BFV消失。相比之下，非停搏组10例患者中只有1例出现这种模式（p<0.05）。停搏组停搏后54至328分钟舒张期BFV恢复正常。深度低温期间的循环停搏后会出现一段脑灌注降低的时期，在此期间平均MCA BFV降低且舒张期MCA BFV消失。我们推测这可以用脑水肿后颅内压升高来解释。
