Special precautions seem indicated to reduce the risk of reoperation for bleeding in particularly elderly patients undergoing combined coronary surgery and other intracardiac repair.

Three cerebral biochemical markers, adenylate kinase (AK), neuron-specific enolase (NSE) and protein S-100, were determined in the cerebrospinal fluid (CSF) of male patients 24 h after coronary artery bypass grafting to investigate the extent of possible center nervous system (CNS) damage and relation to the type of oxygenator and the use of an arterial line filter. The patients were randomized into three groups for extracorporeal circulation (ECC); bubble oxygenator without an arterial line filter (Group I, n = 30), bubble oxygenator with a filter (Group II, n = 29) and a flat-sheet membrane oxygenator without a filter (Group III, n = 33). Pathologically high CSF levels of AK and NSE were found 24 h after ECC in respectively 93% and 95% of the patients. All protein S-100 concentrations were within the normal range. Isolated high CSF concentrations of AK, NSE and protein S-100 were observed in group I. Levels of AK and NSE were the lowest in group III, although there was no statistical difference between the groups. In conclusion, our study suggested that CNS damage caused by ECC involved neurons rather than glial cells. AK and NSE in the CSF seemed to be markers of ischaemic neuronal damage. Postoperative levels of biochemical markers in the CSF tended to be the lowest in the flat-sheet membrane oxygenator group.

A pulsed Doppler ultrasound system was used to analyse microbubble intensity and size in the arterial line during extracorporeal circulation (ECC). Thirty male patients, younger than 70 (range 28-69) years, underwent isolated coronary artery bypass grafting with either a bubble oxygenator (Shiley S-100) without (group 1, n = 10) or with (group 2, n = 10) a depth adsorption arterial line filter (Swank High Flow 6000); or with a membrane oxygenator (Shiley M-2000) without a filter (group 3, n = 10). Mean ECC and aortic crossclamp times were similar in the three groups. Measurements were performed during the initial five minutes of cooling, after 30-40 minutes of ECC and after 10 minutes of rewarming. Microbubble intensity and size did not differ significantly in the three groups at the different intervals. Significantly more and larger bubbles were detected in group 1 (15-150μm) compared to group 2 (< 35μm) (p< 0.001). In group 3 only a minimal number of small bubbles (< 65μm) were observed. An arterial line filter significantly reduced the number and size of microbubbles detected in the arterial line during ECC. A membrane oxygenator was associated with a further reduction of microbubble intensity.

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