Neurocognitive Changes After Coronary Bypass Surgery

Abstract

In this issue of Circulation , Djaiani and associates report that the processing of shed blood with a cell saver resulted in a significant reduction in postoperative neurocognitive dysfunction after coronary artery bypass surgery (CABG) in elderly patients.1 The authors further implied that this significant improvement in neurocognition was a result of less lipid embolization in those patients in whom a cell saver was used. The study was a randomized double-blinded trial that compared the use of a cell saver with cardiotomy suction (defined as control). Cardiotomy suction is a standard component of cardiopulmonary bypass (CPB), in which shed blood in the mediastinum is suctioned to a venous reservoir, where it is collected and then periodically reinfused through the arterial circuit to the patient. This technique was not used in patients in the cell saver group, but rather shed blood was suctioned via the cell saver system and processed, and red blood cells alone were infused to the patient through a similar arterial circuit. A standard 32-μm filter was used in the arterial pressure line in both groups. Article p 1888 Elderly patients who underwent CABG were chosen because it has been documented that these individuals are at increased risk to develop neurological dysfunction after cardiac surgery. The study was powered (n=209) to see a 50% reduction in cognitive dysfunction with additional patients added (for a total of 226 patients) to compensate for potential drop out, which turned out to be similar in both groups. The primary end point of neurocognitive evaluation was based on a battery of standardized and validated tests used to assess neuropsychological outcome. Evaluation was done at baseline and on follow-up at 6 weeks. In addition to neurocognitive decline, Figure 1 in Djaiani et al also demonstrates improvement in the battery of 12 tests documenting …