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Cerebral injury is a well-known complication of cardiac surgery. Investigations of both injury mechanisms and neuroprotective strategies have partially been limited by the lack of an adequate preclinical model of small animal cardiopulmonary bypass (CPB). We sought to determine if neurological injury could be demonstrated in a recovery model of complete CPB in the rat. Rats ( n = 5) underwent 45 min of normothermic CPB followed by 24 h of recovery. Compared to sham-operated rats ( n = 5), the CPB group showed a worse neurological outcome score (median, 25-75th percentile) compared to controls (5, 4-7 vs 9, 8-9, p = 0.016). This rat model of CPB may allow for the study of CPB-associated neurological injury.

Transcranial doppler (TCD) is used during cardiopulmonary bypass (CPB) to assess cerebral emboli and to estimate cerebral perfusion. We sought to compare TCD middle cerebral artery blood flow velocity (Vmca) to 133Xe clearance cerebral blood flow (CBF) measurements during mild hypothermic CPB thus determining its utility in cerebral perfusion assessment.Thirty-four patients undergoing mild hypothermic CPB (35 degrees C) were studied and had comparisons of Vmca and 133Xe CBF at three time intervals, 10, 30 and 60 min after the institution of CPB. Linear regression analysis was performed on data from each of the 3 intervals as well as for pooled data from all 3 periods.The correlation coefficients for the 3 time periods were, r = 0.32 (p = 0.12), r = 0.32 (p = 0.11), r = 0.48 (p = (0.02), respectively. The pooled data correlation had a coefficient of 0.34 (p = 0.003).These findings suggest that TCD Vmca is a relatively poor correlate of CBF during mild hypothermic CPB.