Difficult Airway Society guidelines

We thank Chambers for the many positive comments in his editorial (Anaesthesia 2004; 59: 631–3) that accompanied publication of the Difficult Airway Society (DAS) guidelines on management of the unanticipated difficult intubation (Anaesthesia 2004; 59: 675–94). We believe that these guidelines help to integrate the training syllabus with clinical practice and conform to the recommendation by the Royal College of Anaesthetists that each department displays failed ventilation and failed intubation wall-charts. We would like to respond to a number of points in the editorial. The national airway management guidelines already published and those to be published soon by various European countries are all consensus-based. The great difference between a guideline for management of anaphylaxis and one for failed intubation is that in the latter, adherence to the guidelines will depend on the user having certain skills. The consensus group was particularly aware of the need to ensure that the guidelines contained a small number of airway techniques to facilitate training and provision of desirable equipment in each hospital. We stress the need for good training in basic and advanced airway management. This does not seem to be provided in the UK [1]. We believe that readers of Anaesthesia will judge the guidelines (and the editorial) by the application of common sense. Our indications for cricothyroidotomy are misquoted. We did not state that ‘immediate’ recourse to cricothyroidotomy should be made in the ‘can’t intubate, can't ventilate' (CICV) situation, and this statement should not be attributed to us. In the text we state: ‘Before resorting to invasive rescue techniques, it is essential that a maximum effort has been made to achieve oxygenation and ventilation with non-invasive techniques.’ We then present a risk–benefit analysis of the decision to proceed to a surgical airway and state: ‘Rapid development of severe hypoxaemia, particularly associated with bradycardia, is an indication for imminent intervention with an invasive procedure.’ The flow-chart indicates recourse to cricothyroidotomy in ‘CICV situation with increasing hypoxaemia’, without defining levels of saturation at which intervention should take place. The top of this chart lists in detail the non-invasive steps that should be taken to improve oxygenation before recourse to a surgical airway. We put much thought into all sections of the paper and believe that our recommendations for intervention in CICV are appropriate. It is not possible to define the exact point at which cricothyroidotomy should be performed, but the degree of hypoxaemia and the speed of desaturation are important. Preparations for cricothyroidotomy should be made whenever management of CICV proves unusually difficult, so that surgical intervention can be performed speedily when the difficult decision to proceed to an invasive technique is taken. Should emergency cricothyroidotomy be a core skill? Any suggestion otherwise implies that some avoidable deaths are acceptable because it is too much trouble to arrange proper training. Emergency cricothyrotomy is a core skill and all anaesthetists should know how to perform one and work in an environment in which the necessary equipment is immediately available. Manikin practice is essential and is conveniently carried out in a skills-room. Case presentations on the lost airway are an important and popular component of DAS meetings, and the techniques are taught in our workshops. The DAS (http://www.das.uk.com) is keen to hear from anyone undertaking emergency cricothyroidotomy in the UK. How safe is airway management in the UK? The DAS has tried to initiate national data collection on airway related mortality and morbidity but has not been able to interest the relevant anaesthetic bodies in the project. As ‘enthusiasts’ we have confidential knowledge of a substantial number of unreported airway deaths, many involving consultant anaesthetists and some occurring in the private sector. The cases of which we have heard must be the tip of the iceberg and, in the absence of accurate figures, we guess that not fewer than 20 patients per year die as a result of loss of the airway in anaesthetic and ITU practice in the UK. These tragedies often involve anaesthetists of good standing with a ‘standard’ range of skills, so this problem must be regarded as a ‘system’ problem that can only be solved by collection of comprehensive data, methodical analysis, and subsequent publication of recommendations. We do not agree that this is too much effort. In the UK there are at present two sources of information on complications of airway management. These are the records of cases that have resulted in litigation and the reports of National Confidential Enquiry into Patient Outcome and Death (NCEPOD) in England and Wales and Scottish Audit of Surgical Mortality (SASM) in Scotland. We believe that they fail to give an accurate picture of problems with airway management. The cases that result in litigation are probably only a small proportion of the total number of patients who suffer serious complications. Despite this limitation and their retrospective nature the Closed Claims Project, run by the American Society of Anaesthesiologists since 1985, has produced many important recommendations [2]. In the UK no effort has been made in recent years to learn from airway tragedies which result in litigation. There are certainly unpublished data available in the offices of the Medical Defence societies and the Legal Departments of the NHS. There seems to be a conspiracy of silence but we believe that a closed claims analysis system is needed in the UK. The forms used for data collection by NCEPOD and SASM are not designed to collect information about airway management and deal only with deaths. Information from ‘near misses’ is often more valuable than that from incidents [3–5]. There is a need for an effective incident reporting system [3–10]. Key features of confidential systems for reporting infrequent events are that they should be national [11] and not be organised by any body that is involved in licensure, certification or accreditation. Analysis should be performed by those with a special interest in the subject. These aims could be accomplished by creating a Web-based system for reporting complications and near misses in airway management in anaesthesia and in ITU practice in the UK. DAS would like to help with the design of such a system and with analysis of the data generated. We believe that reports from such a system could lead to a reduction in the number of avoidable airway deaths in the UK.