Faculty of Health Sciences
School of Medicine
Department of Anaesthesiology
Selected Highlights from Research Findings
Children suffering from congenital cardiac lesions have to undergo cardiac catheterisation in order to make an accurate diagnosis before surgical repair is undertaken. The anaesthetic technique may influence the findings. The effect of two anaesthetic agents, sevoflurane and ketamine, on haemodynamic changes during the procedure were compared. It was found that ketamine caused a significantly higher blood pressure and heart rate, but otherwise the techniques can be regarded as equivalent. The type of cardiac lesion had no influence on haemodynamic changes nor on arterial oxygen saturation.
Contact person: Dr FJ Smith.
Clinicians are confronted by different clinical parameters. When treating patients, they must decide when the treatment has had some significant effect, or that a particular parameter has changed to such an extent that treatment is warranted. A questionnaire was compiled in which clinicians were exposed to 18 different series of parameters, e.g. blood pressure rising, haematocrit decreasing, etc. The doctors were requested to mark the number where they thought a significant change has occurred. It was found that more than 50% of doctors regarded a change of 20% as clinically significant.
Contact person: Dr FJ Smith.
Patients undergoing cardiac operations are exposed to cardiopulmonary bypass during which they may sustain brain injury. The injury may vary from frank stroke to subtle neuropsychological changes. The aim of this study was to determine whether the anaesthetic technique (midazolam plus ketamine (MK) or sufentanil (S)) has any impact on the neuropsychological outcome. Quantitative EEG (QEEG), reaction time, serum S-100b and serum neuronspecific enolase (NSE) were used as markers of brain damage. The most noticable EEG finding was an increase in slow wave activity. The EEG outcome did not differ among groups MK and S, but was significantly worse after valve replacement than after coronary artery bypass surgery. The reaction time outcome was significantly better with MK than with S but did not differ between valve replacement and coronary artery bypass surgery. The rise in S-100b did not differ between groups or operations but NSE was significantly higher after than after. This study has shown that the outcome was probably better with MK than with S, and the outcome of the coronary artery bypass surgery was better than after valve replacement.
Contact person: Dr FJ Smith.
Blood pressure and heart rate have been used to estimate the level of anaesthesia: too deep or too light. Hyper- or hypotension and tachy- or bradycardia may however be caused by factors other than the level of anaesthesia. EEG-entropy measures the predictability of the EEG at different levels of anaesthesia. A very good correlation was found between entropy and the sedation scale, whereas a poor correlation was found between the level of anaesthesia and haemodynamic changes.
Contact person: Dr FJ Smith.
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