SummaryThis paper describes the design, implementation and assessment of PsychE, a psychomotor evaluation system. Six standard tests are included: numeric vigilance, a dual task, probed memory recall, simple reaction time, choice reaction time and semantic long-term memory. The test presentations are described in detail. Practice effects were assessed in 10 healthy volunteers and were only evident in the performance measures for the simple reaction time test. For the remaining five tests, stable performance was reached within a single test session. The volunteers were healthy and most were regular users of computers. Therefore, the lack of practice effects cannot be assumed for the general population. A control group is essential for all studies using these tests. The system is implemented on an IBM-compatible personal computer and includes a database shell for the convenient collection, storage and analysis of performance data. Assessment of psychomotor and cognitive function is widely performed in anaesthetic research. Formal testing uses tasks and methodologies, derived largely from research in experimental psychology and ergonomics, that assess the three main components of cognition: memory, perception and attention. The tasks have been used to assess the adverse effects of drugs and other stressors on an individual's cognitive state and to assess the recovery of function after anaesthesia [1]. Recent reviews [1][2][3][4] have identified features of such tasks that may have significant effects upon their sensitivity. One of these is practice, which generally results in an improvement of performance at each successive presentation of the test. The resulting learning curve can cause difficulties in determining when performance has returned to baseline after a drug effect unless suitable control measures are taken [1]. For this reason, it is important to establish how much practice is necessary to reach a stable level of performance on any given task so that treatment effects are not confounded.Practice is particularly relevant to computer assessment packages, which are often composed of the tasks that are the most likely to show learning effects. The developers of some existing systems have provided exemplary normative data [5]. The aim of this study was to develop an integrated suite of computerised cognitive and psychomotor tasks and to establish the learning curve profile for each task. Methods

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SummaryFour portable carbon dioxide monitors were assessed by a mobile intensive therapy team during interhospital transfer of critically ill patients. Particular attention was paid to practical considerations such as size, battery life and ease of use. All the monitors performed wdl in terms of accuracy but problems with size and battery life made some less suitable for use outside hospital.

We have examined the correlation between serum concentrations of catecholamines and the evoked electromyographic (EEMG) response from the first dorsal interosseous muscle of the hand in 20 patients during minor surgery under propofol or enflurane anaesthesia without neuromuscular blocking drugs. The supinated forearm, with the wrist fully extended, was strapped firmly to an armboard and immobilized with adhesive tape. In the propofol group, the mean EEMG response to the first stimulus in the train-of-four (T1) decreased to 83.0% (95% confidence intervals (CI) 78.7-87.3%) of baseline, while in the enflurane group the mean EEMG T1 response decreased to 84.0% (95% CI 81.6-86.4%) of baseline. The decrease in the EEMG response occurred over 20 min and did not correlate with plasma concentrations of adrenaline or noradrenaline (correlation coefficients all < 0.26). We conclude that the decrease in EEMG response during the first 30 min of anaesthesia occurred during both i.v. and inhalation anaesthesia, and that changes in plasma concentrations of catecholamines did not cause the decrease in the EEMG response.

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