SummaryThe use of the Association of Anaesthetists of Great Britain and Ireland checklist for anaesthetic machines, based on an oxygen analyser, was surveyed over a 5-week period in a teaching hospital. Fifiy f v e completed checklists were analysed; no problems developed during anaesthesia which were missed by the checklist. The mean time taken to complete the checklist for one machine was 8.9 min with a range of 5 to 19 min; for two consecutive machines it was 18.25 min with a range of 10 to 30 min. The most frequent faults detected were the poor reliability of some oxygen analysers, absent ventilator disconnection alarms, and absent oxygen supply failure alarms on some older machines. Faults were found in 60% of the machines checked; 18% of these were deemed to be serious.

SummaryThis study set out to examine the nerve stimulators available in one trust hospital. Six different models were identified (Braun Stimuplex, Braun Stimuplex DIG, Digistim 3, Digistim 3 Plus, Regional Master Corporation Nerve Finder, Bard 750 Digital) and the output characteristics were measured for each stimulator using a twin beam calibrated storage oscilloscope. Target current output values from 0.3 mA to 3 mA and load resistances from 560 Q to 10 kQ were selected to model the normal ranges of operating current and skin electrode -needle impedance when performing regional anaesthesia. Only half of the stimulators tested were able to complete the test and deliver a target current to Ϯ20% accuracy. The variation in performance of nerve stimulators means that for a safe and successful nerve block it is important for the operator to be aware of the design and functional limitations of any stimulator being used in clinical practice.

SummaryA revised edition of the guidelines of the Association of Anaesthetists of Great Britain and Ireland, for the pre-operative check of anaesthetic machines, was published in March 1997. A checklist based on the revised guidelines was used for the routine pre-operative checks of anaesthetic machines over a 6-week period in a district general hospital. One hundred and thirty-two checklists were completed. These were analysed for the time taken to complete the check and for the faults found in the anaesthetic machines. The mean time taken to complete a check was 6.8 min and the mean time taken to complete two consecutive checks, in the anaesthetic room and operating theatre, was 12.7 min. Carbon dioxide cylinders were present on the machines in 99 checks (75%), contrary to Association guidelines. Other faults were found in 40 checks (30.3%). The most frequent cause of faults was the oxygen analyser, faults being found in 15 checks. Other frequent faults were due to empty vaporisers or spare gas cylinders and the emergency oxygen bypass control.

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SummaryWe describe a low cost, easy to construct monitoring and teaching aid for thp oesophageal and precordial stethoscopes. It is constructed from two readily available 'state of the art' integrated circuits. The aid allows more than one observer simultaneously to hear heart and breath sounds, without being acoustically isolated from the other monitoring. In addition it is possible to record from the device to audiotape.