A proposal for updating the classification of SADs and a new scoring system

The scoring and classification of supraglottic airways (SADs) is an interesting topic and currently the subject of much debate.

In 2011, a paper by Cook and Howes entitled, Recent developments in efficacy and safety of supraglottic airway devices, published in Continuing Education in Anaesthesia, Critical Care and Pain, described a classification of SADs into 1st and 2nd generation devices. The simplicity of this classification had immediate appeal and it quickly became established as the most widely used method for classifying SADs.

In A critique of elective pediatric supraglottic airway devices by White, Cook and Stoddart, a 1st generation device was described as asimple airway tube’ and 2nd generation as a device that ‘incorporates specific design features to improve safety by protecting against regurgitation and aspiration’.

Numerous publications, presentations and reviews subsequently utilised this classification, including the seminal  NAP4 report, the 4th National Audit Project of the Royal College of Anaesthetists (RCoA) and the Difficult Airway Society (DAS) on ‘Major Complications of Airway Management in the United Kingdom’, which made a number of recommendations regarding the use of SADs, and in particular the use of 2nd generation devices.

Its use has not been confined to the UK. The term is widely understood, accepted and used internationally. However, the classification of SADs as either 1st or 2nd generation was not the first classification.

In 2004, A Proposed Classification and Scoring System for Supraglottic Sealing Airways: A Brief Review by Miller was published in Anesthesia & Analgesia. This categorised SADs by the sealing mechanism. Three primary groups were identified:

  • Cuffed perilaryngeal sealers – such as the laryngeal mask airway
  • Cuffed pharyngeal sealers – such as the Cuffed Oropharyngeal Airway (COPA™)
  • Uncuffed anatomically preshaped sealers – such as i-gel®

This classification was further subdivided, so cuffless perilaryngeal sealers could be either ‘directional’ or ‘non-directional’, and cuffed pharyngeal sealers could be designated as ‘with’ or ‘without’ oesophageal sealing. The sealing mechanisms were described in detail, in conjunction with force vectors, frictional force and whether a device was reusable or single-use; or incorporated a mechanism to provide additional protection against aspiration.

In 2009, five years after Miller’s paper, the International standard, ISO 11712:2009(E) Anaesthetic and respiratory equipment – Supralaryngeal airways and connectors was published. This standard included five classifications of supralaryngeal designs. Further details can be obtained from my 2012 blog post on the classification of SADs.

Whatever their merits or limitations, neither the classification in the international standard or Miller’s classification from 2004 ever enjoyed the same measure of popularity or widespread use currently evident for the categorisation in to 1st and 2nd generation. It is therefore particularly interesting to note a proposal by the originator of the 1st/2nd generation classification, Professor Cook, for an update in correspondence to the editor of the British Journal of Anaesthesia (BJA).

The proposal is to add the suffix ‘i’ to 1st or 2nd generation to indicate those devices which enable intubation (eg with success >50%) and then include ‘d’ for direct intubation and ‘g’ for guided intubation. The correspondence provides three examples of SADs classified in this manner, as follows:

  • cLMA – 1st generation ‘ig’
  • Intubating LMA – 1st generation ‘id, ig’
  • i-gel® – 2nd generation ‘ig’

Further discussion regarding an updated classification can be seen on the BJA Out of the blue E-letters archive. Alternative classifications have been proposed, including one by Michalek and Miller in, ‘Airway Management Evolution – In a search for an ideal extraglottic airway device.

The scoring, as opposed to the classification of SADs, also has an interesting history. Miller proposed a ‘provisional scoring of airways’ in his 2003 paper already discussed above. This identified desirable features of airways for routine use and then for each variable (easy insertion, seal for IPPV etc) assigned a score to each device. An updated version, also by Miller, along similar lines, appeared in the second chapter of the book, The i-gel supraglottic airway, edited by Michalek and Donaldson.

The most recent scoring of SADs appeared in a particularly interesting editorial entitled, ‘Time to abandon the ‘vintage’ laryngeal mask airway and adopt second-generation supraglottic devices as first choice’ by Cook and Kelly.

This editorial notes that SADs now have important roles beyond airway maintenance during routine low-risk surgery, including airway maintenance in obese and higher risk patients and airway management outside the operating theatre by experts and novices, most especially during cardiac arrest. Other examples are also provided.

As a result, the authors state it is worth considering ‘whether one device can be the best device for all such functions and perhaps considering whether some devices might no longer be needed. This discussion raises the question as to whether the cLMA (and equivalent SADs) have any role in modern airway practice or whether it is time to move on.’

The editorial discusses a number of interesting and important issues related to the use of SADs, including the question of safety and efficacy, what sort of evidence should be sought when deciding which SAD to select – particularly if safety is the major concern – and the value and limitations of randomised controlled trials in answering safety related questions. Other issues of importance are also discussed, so it is critical the editorial is read in its entirety to fully appreciate the context in which the scoring system included in the paper is provided.

The scoring system itself lists the desirable features of a SAD (airway seal, overall insertion success, aspiration protection, avoiding sore throat etc) for a specific application (routine use during elective anaesthesia, use by a novice at a cardiac arrest etc), provides a maximal score for each parameter according to its importance and then allocates a score for each parameter for each device.

The authors confirm the ranking and allocated scores are based on their judgement, clinical experience and knowledge of the literature and also acknowledge that others may allocate maximal and relative scores differently.

I will not spoil your enjoyment of this editorial by revealing the results here, except to say the authors comment that, in the tables provided, it is notable that different circumstances lead to different SADs ranking highest and that ‘the cLMA rarely ranks highly in such analyses.’

The four scoring tables provided are as follows:

  • Table One: Choice of airway for routine use during elective anaesthesia
  • Table Two: Choice of airway for use by a novice at a cardiac arrest
  • Table Three: Choice of airway for expert rescue after failed intubation during rapid sequence induction
  • Table Four: Choice of airway for rescue after failed intubation followed by intubation through the SAD

In summary, a number of methods for classifying and scoring SADs have been proposed over the years. The most popular and widely used classification remains the categorisation of SADs as either 1st or 2nd generation. An update to this classification has been proposed to indicate those devices which enable intubation and a new scoring system has been published as part of an editorial in the BJA.

i-gel is a registered trademark of Intersurgical Ltd. cLMA is an abbreviation for the LMA Classic. LMA and LMA Classic are registered trademarks of Teleflex Incorporated or its affiliates. COPA is a trademark of Mallinckrodt Medical, Inc.

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The Macintosh laryngoscope – is there a pretender to the crown?

Over 70 years after Sir R R Macintosh first described it in his landmark study published in The Lancet in 1943, the Macintosh laryngoscope remains universally popular.

Intersurgical plastic single use Macintosh laryngoscope blade, InterForm stylet and InTube ET tube

The dominant position of the Macintosh cannot be attributed to a lack of alternatives. Dorsch and Dorsch, in their huge 1,000+ page book, Understanding anesthesia equipment, list over 45 types of laryngoscope blade. Although some of these are described as modifications of the Macintosh, including the Oxiport Macintosh, Polio, Fink, Tull Macintosh, Bizarri-Giuffrida, Upsher Low Profile, Upsher ULX Macintosh, Improved vision Macintosh and the Left handed Macintosh, the list of alternatives also includes a significant number of other designs, including the Wisconsin, Schapira, Soper, Guedel, Bennett, Seward, Phillips, Alberts, Robertshaw and the Bainton. This list is not exhaustive. If you don’t have easy access to a copy of Dorsch & Dorsch, an extract is included in Annex D of the international standard, ISO 7376:2009: Anaesthetic and respiratory equipment – Laryngoscopes for tracheal intubation.

 In current practice, the two major types of Macintosh blade are generally considered to be the American, also called the ‘standard’, and the English, sometimes known as the ‘classic’ or ‘e-type’. The latter description is a particular favourite, conjuring up the image of the classic E-Type Jaguar, once described by Enzo Ferrari as, ‘The most beautiful car ever made’. Such a comparison may seem a little tenuous, but surely they can both be considered design classics?

The primary differences between the English or German and the American Macintosh are the shape, height and length of the proximal flange and the distance from the light to blade tip. The performance of both types was compared in a 2003 study by Asai et al, published in the British Journal of Anaesthesia, entitled ‘Comparison of two Macintosh laryngoscope blades in 300 patients.’ There was a difference in the view of the glottis in 80 patients. Among these patients, the view was better for the English blade for 63 patients and the standard blade was better for 17 patients. The authors concluded, ‘In patients in whom laryngoscopy was unexpectedly difficult, the English blade provided a better glottic view significantly more frequently than the standard blade.’

Probably the closest rival to the Macintosh in terms of popularity is the Miller blade. Described two years earlier than the Macintosh, the 1941 paper by Miller in Anesthesiology and simply entitled, ‘A new laryngoscope’, described a straight blade which when compared to an ‘old style medium sized blade’, was ’rounded on the bottom, smaller at the tip, and has an extra curve beginning about two inches from the end. The internal diameter of the base is shallow, but adequate to permit the passage of a 38 catheter.’ This landmark study is free to access on the Anesthesiology web-site. Miller also described a modification of his adult laryngoscope for children in 1946, ‘A new laryngoscope for intubation of infants’, Anesthesiology. 7(2):205, March 1946. This paper is also free to access.

The Miller blade remains popular for children, with straight blades in general having been described as ‘superior in elevating the tongue, removing it from the field of view to facilitate a better visualization of the infant larynx than the curved blade laryngoscope’. Doherty JS et al, 2009. Pediatric Anesthesia, 19: 30–37.

 In 2009, The UK NHS Purchasing & Supply Agency’s Centre for Evidence-based Purchasing (CEP) produced a  Buyer’s Guide for Laryngoscopes (CEP08048). The scope of this guide only extended to Macintosh blades sizes 3 and 4. No Miller or other alternative blades were included, perhaps reflecting the fact that ‘The Macintosh is the most popular [blade] for use with adults in the United Kingdom…’

 In the UK 4th National Audit Project (NAP4) – Major complications of airway management in the UK, it is confirmed in relation to tracheal intubation that, ‘Direct laryngoscopy with a Macintosh blade remains the technique of first choice if not actively contraindicated when difficulty is not anticipated.’

 Intersurgical single use plastic Macintosh laryngoscope blade

Given the huge variety of options available, why is the popularity of the Macintosh so enduring?

 Scott and Baker provide some answers in their 2009 review article, How did the Macintosh laryngoscope become so popular? In a very informative and entertaining article, the authors, New Zealanders like Macintosh, suggest that poor straight blade laryngoscopy technique prior to the widespread use of muscle relaxants, commercial availability, Macintosh’s connections in the industrial sector and unprecedented influence on the development of anaesthesia, as key factors in the success of the Macintosh blade that can be traced back to ‘prevailing circumstances’ in the 1940s. They conclude that, ‘Despite being able to achieve superior laryngoscopy with paraglossal straight blade technique and the multiple alternatives available, the Macintosh laryngoscope remains ubiquitous and is regarded as the gold standard of direct laryngoscopy’.

 In 1984, over 40 years after publication of the original description of the Macintosh laryngoscope and 25 years before the review article published by Scott and Baker, Jephcott published  A historical note on its clinical and commercial development. It was estimated by Jephcott that well over 1 million Macintosh blades had been made and sold in the previous 40 years. With regard to the origin of the design, Jephcott confirmed Macintosh’s own account from a letter he received from him:

 “I had a bit of luck and the nous to take advantage of it. On opening a patient’s mouth with a Boyle-Davis gag I found the cords perfectly displayed. Richard Salt (a really excellent chap) was in the theatre with me: before the morning had finished he had gone out and soldered a Davis blade on to a laryngoscope handle and this functioned quite adequately as a laryngoscope. The important point being that the tip finishes up proximal to the epiglottis.” Interestingly, he continued by noting that, ‘The curve, although convenient when intubating with naturally curved tubes, is not of primary importance as I emphasised subsequently.’

 Jephcott confirms the Macintosh laryngoscope was originally produced by Medical and Industrial Equipment Ltd (MIE), quickly followed by The Longworth Scientific Instrument Company Ltd. In the USA, Foregger of New York started to make the device in 1943. Jephcott concluded his article by noting that, ‘Today the Macintosh laryngoscope is known throughout the world and is made by many firms in many countries. The technique discovered by Macintosh and the instrument he designed for its achievement has survived translation into plastic and the adoption of the fibre-light. No doubt they will endure other developments in years to come.’

 Jephcott’s prediction was correct. Since his article in 1984, the Macintosh blade has also survived translation in to single use metal blades and is incorporated in to the design of a number of video laryngoscopes. The Macintosh blade remains the dominant blade for direct laryngoscopy in the 21st century, with no obvious pretender to the crown.

NAP4 – two years on

NAP4, the 4th National Audit Project of the Royal College of Anaesthetists (RCoA) and the Difficult Airway Society (DAS) on ‘Major Complications of Airway Management in the United Kingdom’, was published in March 2011.

Two years on, the key findings of the report continue to resonate. These include:

  • A high failure rate of emergency cannula cricothyroidotomy
  • Failure to correctly interpret a capnograph trace leading to several oesophageal intubations going unrecognised in anaesthesia.
  • Numerous cases where awake fibreoptic intubation (AFOI) was indicated but was not used.
  • Problems arising when difficult intubation was managed by multiple repeat attempts at intubation.

Poor airway assessment, a failure to plan for failure and poor judgement were also identified as key clinical themes in a number of the cases reported. Such is the breadth of NAP4, that the above represent little more than a highly selective short-list.

Interestingly, when the report was launched, one of the authors highlighted in a presentation on ‘Aspiration of gastric contents and of blood‘, which can be seen as a podcast on the RCoA web-site, that ‘there’s nothing new in NAP4’, referring to the fact that one of the major findings of the report (perhaps the major finding?), that aspiration of gastric contents was the single commonest cause of death in anaesthesia events, was also the finding of a report published in Anaesthesia way back in 1956 entitled, ‘Deaths associated with anaesthesia: A report on 1,000 cases‘. So, despite all the advances in airway management and anaesthesia over the last 50 years, aspiration remains a major concern.

For many, I am sure NAP4 did highlight a lot that was new, or at the very least, NAP4 probably provided evidence to support what logic and personal experience had suggested might be true. The ultimate judgement on the success of the report may only become evident in the years ahead, when it can be assessed what practical changes have been made in light of the many recommendations of the report.

A number of posters and abstracts at national and international conferences have already assessed or reported on changes implemented in their departments in the light of NAP4. At the annual DAS meeting in 2011, these included the following:

Audit comparing supraglottic airway (SAD) device use at a DGH to NAP4 guidelines. Thomas S – This poster reported on SAD use in obese patients, use in procedures with risk of reflux or previous difficult intubation and supraglottic training and awareness of NAP4.

Post NAP4 – Implications for intensive care nursing. Lamb RG et al – A report on a project looking at basic awareness of ICU nursing staff regarding Rapid Sequence Induction (RSI) and their familiarity with difficult airway equipment. The results were used to assess the need for further education of nursing staff who may be expected to assist with RSI.

Capnography use in ICU. Measuring up to NAP4. Cole S et al – A poster reporting on the results of a survey to measure capnography use in ICUs across Scotland and to describe factors influencing use.

Capnography use outside of theatres in the Northern Deanery before and after publication of NAP4. Metcalfe SE et al – An audit on use of capnography in the UK for patients undergoing anaesthesia and being intubated irrespective of location.

Some of the recommendations of NAP4, such as each department of anaesthesia having a ‘Departmental Airway Lead’, have long been advocated by the UK Difficult Airway Society. Many hospitals already have an airway lead, but following discussions between DAS and the RCoA, the college council has endorsed a strong recommendation that all anaesthesia departments should conform with this NAP4 recommendation. The responsibilities of the position should include, the overseeing of local airway training, ensuring local policies exist and are disseminated for predictable airway emergencies, liasing specifically with ICU and emergency departments to ensure consistency, and ensuring that difficult airway equipment is appropriate to the local guidelines and standardised within the organisation.

Further potential responsibilities have also been outlined. The RCoA intends to maintain a database of departmental airway leads. DAS also plans two follow-up surveys to study the impact of NAP4. A National survey of institutional responses to NAP4 and a national ‘sprint audit’ to collect national data on practice and activity over a short period. We await the results with interest. See the DAS Newsletter – Projects Edition December 2012 pp6-7 for further details

NAP5 – Accidental Awareness during General Anaesthesia in the United Kingdom, has just been published, but two years on from publication, its predecessor remains essential reading.

Classification of supraglottic airways

Early classification and scoring systems for supraglottic airways
In recent years, a number of attempts have been made to categorise supraglottic airways (SADs). In 2004, A Proposed Classification and Scoring System for Supraglottic Sealing Airways: A Brief Review by Miller was published in Anesthesia & Analgesia. This categorised SADs by the sealing mechanism. Three primary groups were identified:

  • Cuffed perilaryngeal sealers – such as the Laryngeal Mask Airway®
  • Cuffed pharyngeal sealers – such as the Cuffed Oropharyngeal Airway (COPA®)
  • Uncuffed anatomically preshaped sealers – such as i-gel®

This classification was further subdivided, so cuffless perilaryngeal sealers could be either ‘directional’ or ‘non-directional’, and cuffed pharyngeal sealers could be designated as ‘with’ or ‘without’ oesophageal sealing. The sealing mechanisms were described in detail, in conjunction with force vectors, frictional force and whether a device was reusable or single-use; or incorporated a mechanism to provide additional protection against aspiration. Whatever the merits of this system, it now appears unnecessarily complex, although to be fair, Miller’s objective was limited to providing a consistent method for evaluating and understanding the mechanisms of action of any given SAD.

In the same paper, Miller provided a provisional scoring of airways, which suggested a number of desirable features appropriate for a SAD for routine use in anaesthesia. This included easy insertion by a non-specialist, stable airway once positioned, sufficient sealing quality to apply positive pressure ventilation, a good first-time insertion success rate, minimal associated risk of aspiration, and minimal risk of cross-infection and serious side effects. These attributes remain valid today, although to this list we could probably now add latex free and atraumatic, requiring minimal training for safe and effective use, incorporation of a bite block, MRI compatibility, and perhaps suitability for use as a conduit for intubation.

International standard for supralaryngeal airways
In 2009, five years after Miller’s paper, the International standard, ISO 11712:2009(E) Anaesthetic and respiratory equipment – Supralaryngeal airways and connectors was published. This standard included five classifications of supralaryngeal designs as follows:

  • Cuffed oropharyngeal airway, where the ventilatory opening is located at the base of the tongue and a sealing surface is located in the oropharynx.
  • Laryngeal masks, where the ventilatory opening is surrounded by the cuff, which forms a seal with the periglottic tissues. The ventilatory opening and the cuff seal usually represent the most distal portion of the device.
  • Pharyngeal or pharyngeal-esophageal tube, where a cuff surrounds the ventilatory tube in a circumferential fashion and is located proximal to the ventilatory opening. This design compartmentalizes the pharynx, with the cuff serving as a sealing divider between the proximal and distal pharyngeal compartments, and the ventilatory opening(s) are located in the distal pharyngeal compartment.
  • Pharyngeal airway liner, which is represented by the streamlined liner pharyngeal airway (SLIPATM). This is a shell-like device that, upon insertion, expands the soft tissues of the neck. The tension of the elastic neck soft tissues that surround the device provides the sealing mechanism. The ventilatory opening is located within the shell in the periglottic area.
  • Device with a soft, gel-like, non-inflatable cuff and widened, concaved buccal cavity stabiliser. The sealing mechanism is created by the soft non-inflatable cuff accurately mirroring the anatomy of the laryngeal inlet to create an impression fit, without the need for cuff inflation.

 This classification did little to reduce complexity.

 1st and 2nd generation devices
In the same year as ISO 11712 was published,  White, Cook and Stoddart, in a review article published in  ‘Pediatric Anesthesia’, entitled, A critique of elective pediatric supraglottic airway devices categorised SADs into 1st and 2nd generation devices. A 1st generation device was described as a ‘simple airway tube’ and 2nd generation as a device that ‘incorporates specific design features to improve safety by protecting against regurgitation and aspiration’. I am not sure if this was the first published description of this method of classification, but its simplicity had immediate appeal, and it quickly became established as the most popular method for classifying SADs.

 It has since been used in numerous published clinical studies, review articles and conference lectures and a number of recommendations regarding use of 2nd generation devices were made in the 4th National Audit Project of the Royal College of Anaesthetists (RCoA) and The Difficult Airway Society (DAS) report, Major complications of airway management in the United Kingdom.

Of course, 2nd generation devices are not all the same, so the clinical evidence for each device regarding safety and efficacy still needs to be reviewed and assessed individually. Designation as a 2nd generation device does not in itself confirm superiority of performance, but the classification does provide useful information about basic product design characteristics, such as whether the device incorporates a mechanism for the management of regurgitant fluid.

In conclusion, although initial classifications of SADs provided some useful information, they were also complex, and as a result never really obtained widespread use or acceptance. The more recent classification of SADs into 1st or 2nd generation devices has proved popular, is widely used and provides valuable information regarding basic product design. Safety and efficacy of individual devices still needs to be reviewed and assessed individually.

A basic diagram highlighting the differences between 1st and 2nd generation devices is shown below (Fig 1). An Infographic, with additional background information, is also available (Fig 2). Please contact me if you would like a pdf copy of the infographic.

Fig 1

Fig 2 – Infographic

Cricoid pressure – new data from the USA

As a postscript to my previous post on the use of cricoid pressure during RSI, I have just seen this abstract of a survey conducted in the United States regarding a modified RSII, entitled, Modified Rapid Sequence Induction and Intubation: A Survey of United States Current Practice. I have not seen the complete article yet, but the abstract seems to confirm cricoid pressure as one of three key components of a modified RSII, along with oxygen administration before induction and an attempt to ventilate the patient’s lungs before securing the airway. As the authors comment themselves, ‘Although this definition seems intuitively obvious, no previous work has tested whether it is commonly accepted’.

490 surveys were received from 58 institutions. 93% of respondents reported using a modified RSII. A majority of respondents (71%, CL: 63%-77%) reported administering oxygen before anesthesia induction, applying cricoid pressure, and attempting to ventilate the lungs via a facemask before securing the airway.

Staying with the United States, albeit via a UK report, it was noted in the UK 4th National Audit Project (NAP4) that the American Society of Anesthesiologists (ASA) Closed Claims Practice Group reported that cricoid force was ‘used’ in half of claims relating to aspiration. Claims for aspiration in which cricoid pressure was applied were settled for lower awards than those where it was omitted.

Interestingly, one of the recommendations in NAP4 related to RSI was as follows, ‘On balance, rapid sequence induction should continue to be taught as a standard technique for protection of the airway. Further focused research might usefully be performed to explore its efficacy, limitations and also explore the consequences of its omission.’

No doubt the debate about RSI and cricoid pressure will continue…

UK National Audit Projects – past, present and future

National Audit Project Four, or NAP4 as it is commonly known, which examined major complications of airway management in anaesthesia, emergency departments and intensive care, has been widely acknowledged as a milestone in airway management research. A seminal work, it was designed to determine what type and how often airway devices are used, how often major complications occur, what do they consist of and what can be learnt from them to reduce their frequency and consequences. In the opinion of many, this was an objective largely achieved.

Its legacy is not yet clear, but I would suggest it is not only the content of the report that has determined its success to date, but also the ease with which it can be accessed and how easy it is to navigate through it and find the information you need. Each of the main chapters has a quick summary, a review of what is already known, a case review, data analysis, discussion, and finally, clear learning points and recommendations. It has quickly become a constant and valued source of reference. In addition, those organisations involved with NAP4 are to be commended, not only for making the report itself easy to find and free to download, but also making available all the presentations from launch day, as well as podcasts of the lectures, available on the Royal College of Anaesthetists web-site.

It might be tempting to dismiss NAP4 as being of local UK interest only, but this would be a mistake, since many of the themes, results and conclusions, are likely to have a much wider, if not universal, interest and significance. Encouragingly, NAP4 has been the subject of international, as well as domestic lectures at key conferences since its publication. Notably, one of the authors of NAP4 was invited to give a presentation at the Society of Airway Management (SAM) annual conference in the USA in 2011. A challenge was issued to the audience, ‘dismiss the findings of NAP4 as not relevant to your (local, institutional, national) practice if you like……but please do not do so until you have collected robust data to show it is not relevant to your practice’.

With the high profile and success of NAP4, I was curious to know more about its predecessors and what the future might hold for the next series of reports. I was aware of NAP3, ‘Major Complications of Central Neuraxial Block in the UK’, but I was not aware of NAPs one and two. NAP1 examined the supervisory role of consultant anaesthetists, and NAP2, the place of mortality and morbidity review meetings. The report and findings for both can be downloaded from the Royal College of Anaesthetists web-site.

We already know NAP5 will report on ‘Accidental Awareness during General Anaesthesia’. The project was officially launched on 1st June, seeking notification of all reports of accidental awareness during general anaesthesia (AAGA) reported between 1st June 2012 and 31st May 2013. As with NAP4, every UK hospital has agreed to participate. The Clinical Lead for NAP5 is Prof Jaideep Pandit, who will work closely with Dr Tim Cook, the College Advisor for National Audit Projects.

The process of selecting the subject for NAP5 may have provided us with some clues as to the possible subjects for NAP6 and beyond. Among the topics proposed for NAP5 were ‘Anaphylaxis’, ‘Dental damage’, ‘Obesity – incidence and complications’, ‘Recovery Room complications’, ‘Tracheostomy: complications’ and ‘Post-operative nausea and vomiting’. All worthy subjects, but with the request for re-submissions for NAP6 unlikely for another 12 months, perhaps a new subject might come to prominence and prove irresistible. Time will tell.