A system for psychomotor evaluation; design, implementation and practice effects in volunteers.

This paper describes the design, implementation and assessment of PsychE, 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.

An assessment of portable carbon dioxide monitors during interhospital transfer.

Four 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 well in terms of accuracy but problems with size and battery life made some less suitable for use outside hospital.

The Riyadh Intensive Care Program mortality prediction algorithm assessed in 617 intensive care patients in Glasgow.

The hospital mortality prediction algorithm from the Riyadh Intensive Care Program was assessed in 617 general intensive care unit patients and the results were compared with APACHE II admission scoring. Of the 119 patients predicted to die by the Riyadh Intensive Care Program, 24 (20.2%) recovered sufficiently to be discharged home. The overall false-positive rate was 5.2%, the false predictions mostly occurring in the trended component, the admission component having similar performance to admission APACHE II. For equivalent specificity the Riyadh Intensive Care Program was more sensitive than admission APACHE II risk of death figures, but the very high false-positive rate in those predicted to die precludes the algorithm's use in patient management decisions. In our view, the Riyadh Intensive Care Program does not justify the considerable extra work involved in data collection and processing over current admission scoring systems.

Influence of serum concentrations of catecholamines and i.v. or volatile anaesthesia on evoked electromyography in the hand.

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.