COVERS for anaesthetic machines: an audit and standard

Abstract

pre-use checklist) re-audit of 102 completed checklists showed 20 tests revealing faults on 59 occasions All the anaesthetic machines in one District General (range 1.0-11.6%), 16 (27%) day to day and 43 (73%) Hospital were tested for faults on three occasions for non-recurring. COVERS supported by scheduled both audit and re-audit using an extended checklist regular comprehensive checking delegated to another based on that devised by the Association of Antime and performer is recommended as the mandatory aesthetists of Great Britain and Ireland. Ninety compre-use checklist. pleted checklists were analysed for the audit and 24 tests revealed 236 individual faults (range 1.1-64%). Sixty-five (27.5%) could have occurred on a day-today basis and 171 (72.5%) of the faults were non-

Revised checklist for anaesthetic machines

“…This may have been considered unnecessary in a machine check that is based on the use of an oxygen analyser. However, this study found faults in the oxygen analyser in 11.3% of machine checks and other studies found the oxygen analyser to be absent or faulty in 25.4% and 55% of machine checks [7, 8]. In the light of these results, failure to check the oxygen failure warning alarm is difficult to justify.…”

“…Even when the presence of a carbon dioxide cylinder is not counted as a fault, faults were found in 30.3% of the machine checks in this study and the majority of these were potentially serious. Other studies have found the occurrence of faults to be at least as frequent as this [7, 8].…”

“…The major change introduced in the revised guidelines is the use of the ‘tug‐test’ to replace the disconnection of pipeline supplies. It has been suggested that regular disconnection of the pipelines is time‐consuming and unnecessary [6, 7] and that it may also damage the pipeline terminals. An important consequence of this change is that Checklist 2 does not test the oxygen failure warning alarm in machines connected to pipeline oxygen.…”

“…Several authors have suggested that the most important reason for failure to follow the guidelines is that they are perceived as being too time consuming [2, 3, 5]. Other authors have questioned the necessity of such a comprehensive checklist and in particular have suggested that the practice of disconnecting the pipeline supplies is unnecessary [6, 7]. Barthram and McClymont [8] found that the average time to check a machine according to the original guidelines was 8.9 min and that the average time to perform two consecutive checks, in the anaesthetic room and operating theatre, was 18.25 min.…”

Basal oxygen flow

“…min −1 maintained as an attempt to meet the requirements for minimal oxygen consumption of the patient’ with ‘minimum oxygen flow incorporated into safe anaesthesia machines’[1]. This setting was promoted as the minimum for adults first by Ohmeda then Dräger and became, effectively, a standard though none was formally created [2], and we incorporated it into our departmental comprehensive machine check [3]. The latest edition of Ward's Anaesthetic Equipment [4] considering Anti‐hypoxia Devices includes details of minimum standing flow of 175–250 ml.min −1 for Ohmeda and basal flow of 200–300 ml.min −1 for M & IE.…”