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E F Bruggemans

Publications and source records attributed to E F Bruggemans.

5 recordsLinked to original sources
PubMed2003

Feasibility and reliability of on-line automated microemboli detection after carotid endarterectomy. A transcranial Doppler study.

OBJECTIVES: recently, a new algorithm for transcranial Doppler (TCD) ultrasound detection of microembolic signals (MES) was developed. In the present study, we investigated its on-line performance in TCD monitoring after carotid endarterectomy (CEA) and assessed off-line its accuracy in detecting MES. MATERIALS AND METHODS: first, the feasibility of MES detection in TCD monitoring after CEA in a routine clinical setting was evaluated in 50 patients. Second, to test the reliability of the software a 2-h digital audio study tape was made and analysed by the algorithm and five human experts. The "gold standard" was defined as the agreement between human experts: a MES was considered to be present if at least three human observers agreed. RESULTS: TCD monitoring for emboli detection after CEA was well tolerated by the patients and could be performed reliably. In the study tape, the human gold standard detected 107 MES, with 93 MES having an intensity of > or =7 dB. The software detected 81 and 77 MES, respectively. Using the 7 dB intensity threshold, the software had no false positives and 16 false negatives. The kappa value between the human gold standard and the software was 0.91, the proportion of specific agreement was 0.83. CONCLUSIONS: the tested algorithm provides a reliable method for automated on-line microemboli detection after CEA. This makes monitoring of the effectiveness of antiplatelet agents in the prevention of stroke after CEA more practicable.

Algorithms↗
PubMed1997

Assessment of cognitive deterioration in individual patients following cardiac surgery: correcting for measurement error and practice effects.

Assessment of cognitive change in individual patients may be confounded by unreliability of test scores and effects of repeated testing. An index correcting for both problems is proposed and compared with change indices that do not or do not adequately deal with measurement error and practice effects. These indices were used to examine cognitive deterioration in a sample of 63 patients undergoing cardiac surgery. It was demonstrated that for test measures with a low reliability, failure to correct for measurement error resulted in overestimation of deterioration rates. For test measures with a high reliability, but showing substantial practice effects, failure to correct for practice effects resulted in underestimation of deterioration rates. With the proposed index, cognitive deterioration shortly after cardiac surgery was most frequently observed for attention and psychomotor speed, less frequently for verbal fluency, and only occasionally for learning and memory.

Aged↗
PubMed1995

Residual cognitive dysfunctioning at 6 months following coronary artery bypass graft surgery.

Neuropsychological testing is a sensitive method for quantitative assessment of cognitive dysfunctioning following cardiopulmonary bypass (CPB). However, the methodological problems associated with this method, such as learning effects due to repeated testing and the effects of distress on test performance, have often been underestimated. In this study, these confounding effects were controlled for by including the spouses of patients, exposed to the same potential stress effects associated with the operation, as a nonsurgical control group. The experimental group consisted of 63 patients (40-75 years) undergoing elective coronary artery bypass graft (CABG) surgery. A battery of standardized neuropsychological tests was administered to both groups 2 weeks preoperatively and 1 week, 1 month, and 6 months postoperatively. Statistical testing of inter-group differences in preoperative to postoperative changes in test performance revealed the following results: (1) For immediate memory and learning, in general test scores showed the same time course for both groups. (2) For recent memory, patients' scores showed a significant deterioration at 1 month after CABG surgery compared with the scores of spouses. This effect had not completely disappeared at 6 months postoperatively. (3) For attention and psychomotor speed as well as verbal fluency, patients' scores had deteriorated significantly at 1 week after surgery, with incomplete recovery at 6 months. These negative cognitive effects were not related to the patients' ages or CPB parameters (duration of CPB, aortic cross-clamp time, mean flow and arterial pressure during CPB and aortic cross-clamping, and minimum nasopharyngeal temperature). No differences in self-ratings of mood over time were found between the patients and spouses. The results indicate that, when adequately controlling for the effects of learning and distress, some cognitive functions are still impaired at 6 months after CABG surgery.

Adult↗