Cerebral venous congestion during cardio-pulmonary bypass: role of bispectral index monitoring.

A 58-year-old male patient was posted for double valve replacement under hypothermic cardiopulmonary bypass (CPB). During aortic cross-clamp (AXC), the central venous pressure (CVP) was found to have increased to 22 mmHg. After 4 minutes of sustained increase in CVP, burst suppression (SR) started increasing. After 5 min of increase in SR, bispectral index (BIS) declined rapidly to 17. Propofol infusion was stopped and re-evaluation of signs of facial congestion showed changes to that effect. The perfusionist noted steadily decreasing venous return. As soon as the superior vena cava (SVC) cannula was withdrawn by 3 cm, CVP immediately declined to 6 mmHg. The venous return in the CPB reservoir normalized and BIS returned to 42 after a transient rise to a maximum of 58 and SR decreased to 0 within 2 min of repositioning of the venous cannula. The patient was successfully extubated after 7 hours without any sequelae.