In search of consensus on ethics in airway research

In their recent editorial, Dr Ward and Professor Irwin proposed a set of ‘CARE’ (Consensus on Airway Research Ethics) guidelines 1. In this editorial, we offer a counter-opinion. Anaesthesia has a strong record of publishing airway research and has also been prominent in promoting research ethics and combatting research fraud 2-6. Its parent organisation, the Association of Anaesthetists of Great Britain and Ireland (AAGBI), has published high quality consensus guidelines on consent 7. For clinicians involved in any field of research, the ethical principles, reiterated by Ward and Irwin, will be familiar and they apply equally to clinical practice and airway research, notably: patient respect; patient autonomy; an emphasis on informed patient-centred consent; clinician transparency; and honesty in general and particularly when things go wrong. Most clinicians will therefore agree with many statements in the editorial. Nonetheless, we take issue with several points. The authors contend that “airway-related research in anaesthesia is, arguably, dominated by manikin-based studies”. However, in an EMBASE and Medline search (performed by a medical librarian), manikin studies make up a very small proportion of such studies, (< 3.5% per annum) in the last decade (Fig. 1). Although the authors state “Accordingly, it is comparatively rare for investigators in this field to undertake patient-based research” the published literature does not support is view. Publications in Anaesthesia have championed a change from manikin–to patient-based studies by emphasising the need for evaluation of new airway devices 8, illustrating the lack of fidelity of some manikins 9-12 and explicitly stating the need for patient-based studies 13: this latter editorial stating “…… it is time for serious researchers to move on to study patients rather than manikins. Call a halt to these prolific manikin-based studies and anaesthesia will be the better for it”. However, before abandoning manikin research altogether, there are further considerations. One area of research would be evaluation of available manikins to determine their fidelity as ‘research surrogates’, building on previous work 9-12, 14. We also may need to study with manikins to better understand how they might capture enough of the critical elements of reality 15, 16 or because real-life modelling is simply impractical, such as during crisis management research 17. Importantly, manikins have a critical role in part-task and crisis management training 18 and in these areas further manikin-based airway research is still required and appropriate. Rather more importantly, the CARE proposals have the potential to negatively impact on airway research. While we completely agree with statements such as ‘the patient comes first’, a basic tenet of medicine that is embedded in the centuries-old adage ‘primum non nocere’ 19, airway research is not a notably high-risk area of practice and it is not clear why this area merits singling out. The same applies to several other aspects of the proposed guidelines – researchers should be trained, competent, not expose patients to avoidable risk, explain processes and risks to patients and should declare interests. There is nothing specific to the airway here – remove the word ‘airway’ and substitute in ‘cardiovascular’, ‘regional’ or ‘TIVA’ etc. and they are equally applicable. Although the title, text and table describes the proposals as ‘consensus’ principles, it is not at all clear from where this consensus arises. The two authors appear to write as individuals and do not declare that they write on behalf of any airway (or other) organisation. On this matter, we agree with Dr Grocott who addressed this matter in a recent letter 20. Regarding the specifics, we are concerned that the ‘principles’ state that only patients who are ASA 1–2 and with a low risk airway should be routinely recruited to airway studies, with patients outside these groups included ‘only in exceptional circumstances’. First, it is not immediately apparent why it is automatically necessary to routinely exclude ASA 3 patients from airway-related research. On a practical level, in many tertiary centres, including some of the currently most research-active globally, such a ‘rule’ might exclude the majority of patients from research. This is a more general problem in the intensive care unit (ICU) and emergency department (ED), where rates of failed intubation and airway-related mortality dwarf those in routine anaesthesia 21, but almost all patients would be considered ASA ≥ 3. In these locations, current issues such as the use of videolaryngoscopy (see below), optimal oxygenation techniques and the most appropriate airway rescue techniques (likely to be applied by clinicians with limited airway skills) are areas of particular concern, currently bedevilled by poor quality and irrelevant research. Second, Ward and Irwin state: ‘Patient participants with a history of airway-related problems or features suggestive of a potential difficult airway should be excluded’. Accepting that patients must not be put at any undue risk by research and their involvement in research should include a consent process which is explicit, open and leading to ‘shared decision making’ (as in other parts of medicine) 7, it is also important that research is relevant and appropriately generalisable. At present, evidence supporting the use of ‘advanced airway techniques’ in patients with difficult airways and in difficult environments is often extrapolated from use of these techniques in patients with easy airways in elective settings. The suggested restriction would lead to research that does not represent the patients cared for in clinical practice and this is particularly relevant to research into difficult airway management and in ICU, ED and out of hospital. Exclusion of such patients risks ignoring the real difficulties that we face in an age when videolaryngoscopy and advanced supraglottic airway devices (SADs) have improved airway management: namely patients with abnormal and pathological airways, in whom airway management may fail 22 and in whom patient harm may occur. These differ from airways that can be simulated by simply restricting access to a normal airway. Analogous to the use of manikin studies being generalised to humans, research findings in ASA 1–2 patients with reassuring airways cannot be generalised to other populations. If we continue to exclude patients with any markers of predicted or known difficulty we ignore the most relevant patients and this will lead to, at best, potentially irrelevant research and at worst either a lack of applicable evidence or evidence that is misleading 23. Airway research in difficult patients or higher risk environments is demanding and requires the highest ethical standards, but it can be argued that there is an ethical necessity for it. Enrolment of patients in any research that is irrelevant and/or not applicable is itself unethical 24. The World Medical Association Helsinki Declaration, quoted also by Ward and Irwin, states “Every biomedical research project involving human subjects should be preceded by careful assessment of predictable risks, in comparison with foreseeable benefits to the subject or others”. 25. If there is no foreseeable benefit to the subject or others, it is unethical. As an example, Mihai's videolaryngoscopy review in 2008 noted that more than 90% of patients recruited to these studies were likely to have easy airways, meaning that the value of the devices in an important target population (patients with difficult laryngoscopy) was impossible to determine 26. Patients who consented to participation in these studies probably were not aware of their limited relevance. It has taken another eight years to adequately explore that question further 27. We know from several sources that airway management pre-hospital 28, in ED 21, 29, ICU 21, 30 and in other remote areas is higher risk than in a theatre setting. These are areas where there is avoidable patient harm, a particular need for research and a current lack of high quality data. Staying with the videolaryngoscopy example – a recent systematic review of videolaryngoscopy which included 64 randomised controlled trials, was only able to include one study in ICU and one in ED and therefore unable to explore whether videolaryngoscopy is of specific benefit in these locations 27. Similarly, much current research into SADs is performed in low-risk patients, in low-risk settings, and in small studies 31. This tells us little about safety or about efficacy in the plethora of advanced settings in which SADs are now used in everyday clinical practice. Specific research in these advanced settings in appropriate patient populations is needed. The proposed CARE guidelines state that ‘multiple attempts at securing the airway should be avoided’, with which we agree, but go on to state that this is ‘a maximum of two failed attempts’. While in many cases this may be appropriate, this will not always be the case and it does not reflect guidance in most recent airway management guidelines 32, 33. The proposed CARE guidelines also state that only experts should evaluate new airway devices and techniques. There are numerous problems here. How does one define an ‘airway expert’? Is a ‘clinical expert’ also a ‘research expert’? Is an expert in one technique or field of practice also an expert in others? How do we manage the lack of agreement between experts in airway management 34? An expert, by definition, is likely to think and act differently from a non-expert, and certainly from a novice or near novice. If research is restricted to experts, it is unlikely that the outcomes will be generalisable and this will limit its relevance. In practice, most airway management is not undertaken by experts and for research to be generalisable it should be performed in a clinically relevant context. It is reasonable to state that a senior experienced clinician should be involved in the design, supervision and conduct of research. It is certainly necessary to ensure that those performing research are sufficiently trained and familiar with the device being investigated, such that the study is an examination of the device rather than the clinician's learning curve 35 (except where that is the explicit intent of the study). But this all stops short of restricting research to experts. Further, if only experts perform research this will prevent development and training of the next generation of airway researchers, which is likely to be counter-productive. For all these reasons restricting airway research to experts is not only impractical but will not be of benefit to patients or future research. So, while we agree wholeheartedly that airway research must be conducted in an ethical manner and therefore with some of the points made in Ward and Irwin's editorial, we fear that their proposals risks encouraging some irrelevant, poorly generalisable, or even inappropriate research. We fear their proposals inhibit addressing important questions around patient safety in clinically relevant populations. Our patients are becoming increasingly co-morbid and complex, and our research must seek to include such patients to be relevant. We hope Anaesthesia will reconsider whether the CARE guidelines should be adopted. To paraphrase the quotation in the editorial 35, ‘airway research in ASA 1–2 patients with easy airways managed by experts, is all well and good, if all your patients are ASA 1–2, have easy airways and are managed by those experts’. This debate is timely as the UK Difficult Airway Society is in the process of establishing a working party to explore ethics in airway research. After relevant literature review, and expert and stakeholder discussion, we hope a consensus will be reached. Important comments and contributions in support of this editorial were also received from Dr. P. Baker (Auckland City Hospital, Auckland, New Zealand), Dr. R. Cooper (Toronto General Hospital, Toronto, Canada), Prof. R. T. Greif (Inselspital, Bern University Hospital, Bern, Switzerland), Dr. B. McGrath (University Hospital of South Manchester, Manchester, UK), Prof. S. N. Myatra (Tata Memorial Hospital, Mumbai, India), Dr. E. O'Sullivan (St James Hospital, Dublin, Ireland), Dr. A. Patel (University College Hospital, London, UK). No external funding or competing interests declared.

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