Report - Cerebral electrical impedance value reflects brain edema caused by cardiopulmonary bypass in infants.

The study aimed to investigate if the dynamic changes in cerebral electrical impedance (CEI) values could be used to monitor brain edema during cardiopulmonary bypass (CPB) in infants. Forty infants (mean age: 1.4±0.38y) with acyanotic congenital heart disease who underwent CPB open-heart surgery between September 2009 and March 2010 were prospectively enrolled, and divided into 2 groups based on aortic cross-clamping (ACC) time: CPB-A (ACC<50 min) and CPB-B (ACC<50 min). During the same period, twenty infants (aged 1-3y) who underwent surgery for indirect inguinal hernias were selected as controls. Serum astrocyte S100 protein (S100) and neuron-specific enolase (NSE) levels were determined before and after CPB. Changes in CEI were detected using the BORN-BE system. No intraoperative death occurred. Compared with controls, left and right side CEI values, serum S100 and NSE levels in the CPB groups significantly increased from surgery beginning to end (P<0.05). After surgery, these levels decreased (P<0.05). Detection rates of cerebral edema in the CPB-B group 24h post-operative were significantly higher than in the CPB-A group (P<0.05). CEI value can be used to dynamically monitor brain edema in infants undergoing CPB, and is an index reflecting brain damage during CPB in infants.