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Re: Barriers to fibreoptic intubation. - A reply
- Nicholas M Woodall, Barker G, Harwood R (24 October 2008)
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Re: A comment from outside the square. A reply
- Michael B. Hooper (27 August 2008)
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A comment from outside the square. A reply
- N M Woodall, RG Harwood, GL Barker (20 July 2008)
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Barriers to fibreoptic intubation
- Andrew F Smith, Kenichi Ode (15 July 2008)
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Sedation and airway local anaesthesia for awake fibreoptic tracheal intubation. Response to Drs Xue,
- Nicholas M Woodall, Robert J Harwood, Graham L Barker. (10 July 2008)
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Complications of awake fibreoptic intubation - a comment from outside the square.
- Michael B. Hooper (1 July 2008)
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An anaesthetic school’s interest in awake fibreoptic intubation training
- Ben W Howes, Gareth Gibbon, Mark Porter, Jonathan Gatward, David Barnes, Fiona Kelly, Andrea Doodson, Simon Webster, Nick Wharton (16 June 2008)
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Sedation and airway local anaesthesia for awake fibreoptic tracheal intubation
- Fu-Shan Xue, Qian-Jin Liu, Ya-Chao Xu (9 June 2008)
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Nicholas M Woodall , Barker G, Harwood R
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We apologise to the correspondents for this tardy response. We will deal with their comments and questions but not necessarily in the same order. Clearly other readers including some e-correspondents share the unfavourable view of the discomfort associated with awake fibreoptic intubation that you refer to. It should also be said that the experiences of the subjects in our paper may not be representative of a group of patients. Although our group of anaesthetists found the procedure acceptable and in some cases enjoyable they differ from patients in a number of ways. They are very well informed about what to expect, what is involved and they are all volunteers who may leave at any time. They are a self selected group who conceivably may have a personality that finds this type of process acceptable; they might also be enthusiasts. Furthermore as participants they receive benefits in the form of training and experience which in part may make the overall experience more pleasant. Many patients may not have these options or benefits which may mak the procedure less agreable. Lidocaine does have a bactericidal effect and it is possible that his may reduce the likelyhood of bacteraemeia after multiple endoscopies and tracheal intubation. We observed nasal abrasions during repeated endoscopies but overt bleeding was very rare. We have not performed endoscopy after nasotracheal intubation attempts but bleeding was most commonly seen after intubation attempts or on extubation. This suggests that muscosal damage or breach is more severe and more common after intubation than after endoscopy and perhaps would be most likely to cause bacteraemia. For reasons of brevity subtle aspects of the anaesthetic technique may have been omitted as Dr Smith and Dr Ode correctly assert. Below we offer observations and opinions on aspects of the anaesthetic technique employed and emphasise factors which we consider to offer a favourable benefit and contribute to the comfort and safety of our subjects. 1/ Preparation. All endoscopitsts are very well prepared and are made familiar with their equipment. All aspects of the motor skills required for fibreoptic endoscopy and intubation have been demonstrated, practised and rehearsed using several types of models. The endoscopists are covertly(to reduce performance anxiety) evaluated and problem areas corrected before the procedure. This is also done in the workshop beforehand. 2/ The working environment is optimal, all facilities and equipment likely to be needed are at directly at hand along with very well organised and efficient ODP support. 3/ Communication between the instructors and the trainee endoscopists is established and practised in the preparatory workshops to ensure delegates fully understand the instructions the instructors will be giving. 4/ There is a clear non-verbal system of communication. The subject can indicate any distress and the cause will be dealt with. We have a low threshold to abandon the procedure since it is not clinically important to persist if pain or nasal obstruction prevent intubation. 5/ Excellent preparation reduces the anxiety of the subject, the endoscopists and the trainers resulting in optimal performance. 6/ Anticholinergic drugs are very important, they increase the effectiveness of topical local anaesthetics applied to the airway and they control secretions thus improving the view. To be effective they need time to work, IV glycopyrrolate is maximally effective after 15 mins. And nebulisation of lidocaine gives the glycopyrrolate time to become effective. 7/ Ten percent lidocaine causes pain when applied to mucous membranes. We avoid 10% lidocaine where possible. We never apply this to the nose and always administer some weaker topical local anaesthetic to the mouth before giving 10% lidocaine. 8/ Nebulisation is an important step, though nebulised 4% lidocaine alone is inadequate for fibreoptic intubation, nebulisation prior to applying supplementary supplementary topical local anaesthetic makes it more acceptable to the subject, since it reduces coughing and obtunds pain caused by application of concentrated local anaesthestic (10% lidocaine). 9/ The nasal route is preferred for endoscopy since it can be performed without artificial airways or aids, in addition this route avoids the need for the subject to widely open their mouth. If the nasal route is selected pressure on the back of the tongue can be avoided reducing the tendency to produce gagging. The main disadvantage of the nasal route is discomfort or obstruction as the tracheal tube is passed through the nose. 10/ After nebulisation the nose requires supplementary topical local anaesthetic. First a superficial nasendoscopy is performed to select the easiest and largest nostril/nasal passage. Only one side is topicalised, thus allowing more local anaesthetic to be delivered to the route of endoscopy. This avoids wasting any of the local anaesthetic allowance on the side not intended for intubation. Topical vasoconstictors such as Xylometazoline [Otrivine] increase space within the nasal passages and therefore reduce discomfort when passing tubes through them. When the topical local anaesthetic(4 or 5% lidocaine) is applied the subject is encouraged to tilt their head back and to inhale deeply as the nose is sprayed. They are then encouraged to take maximum benefit of the local anaesthetic solution and swill it around their mouth and around the back of the tongue. 11/ Next 10% spray is directed at the base of one tonsillar pillar then the other during inspiration. This takes place only after nebulisation and topicalisation of the nose. This prior application of local anaestetic reduces the pain associated with administering this very effective spray. 12/ Water based lubricant jelly is used only for the tracheal tube insertion as wide application throughout the airway makes manipulation of the endoscope clumsy and may provide a barrier for the action of the topical local anaesthetic. 13/ The lower airway is anaesthetised with a fine spray via an epidural catheter inserted through the working port of the endoscope as described previously. 14/ Care must be used when spraying, hasty administration or no flow of gas produces droplets of a large volume and mass which stimulate coughing and gaging. 15/ Spray should first be delivered first to the back of the tongue then the epiglottis followed by the larynx and later to trachea. It is possible to view the larynx and epiglottis from the posterior nasopharynx. Where pharyngolaryngeal structures can be sprayed from a position of safety. If coughing is provoked the endoscope will not then hit the larynx as it rises and falls during coughing. 16/ When laryngeal reactivity decreases the endoscope is advanced along posterior pharyngeal wall 17/ If spray is delivered to a supine subject a pool of local anaesthetic forms on the posterior pharyngeal wall, the endoscope is advanced along this numb surface. 18/ We monitor laryngeal reactivity, if the vocal cords move in response to the LA spray more is needed. 19/ When the vocal cords cease to react approach more closely and direct spray between the vocal cords into the trachea, still looking for reaction of the subject and vocal cord movement. 20/ Great emphasis is placed on using very small gentle movements of the endoscope. There is no need for speed. 21/ The endoscope is only advanced when a view of the lumen is available. 22/ A white out or pink out is an absolute indication to withdraw the instrument until the lumen is visible. If not, pain or discomfort is inevitable. 23/ when the subject ceases to react to further local anaesthetic administration to the larynx and trachea insert the endoscope to mid- trachea and ask an assistant to hold it in that position fixed position. This is important, over insertion and stimulation of the carina can cause coughing, alternatively accidental withdrawal leads to failure. Optimal positioning of the endoscope can be aided by the assistant fixing the endoscope and monitoring the view on the screen to confirm the tip of the endoscope remains static. 23/ Use small(6.0), well lubricated, tubes for tracheal intubation. 24/ During the railroading of tracheal tubes ask the subject to protrude their tongue and take slow deep breaths. These actions will increase the size of the airway and make snagging of the tracheal tube less likely. 26/ Sometimes the passage of the tracheal tube will become obstructed, slow gentle forward pressure may overcome this. The bevel should face any suspected obstacle thus if the obstruction is at the back of the nose on the posterior nasopharyngeal wall the bevel should face cephallo-posteriorly and if the obstruction is at the level of the larynx it should face caudo-posteriorly. Soft tubes become distorted on insertion and therefore the direction of the bevel is uncertain therefore continuous gentle rotation during insertion is helpful to overcome obstruction. 27/ Subject should be discouraged from trying to view their own endoscopy but encouraged to relax and breathe deeply. Emphasis on slow deep breathing during intubation acts as a distraction for the subject but also produces vocal cord abduction and opens the airway more widely. Many of these observations and tips or not our own but have been gleaned from the teachings of others such as Ian Calder and John Smith. Conflict of Interest:None declared |
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Michael B. Hooper, Specialist Anaesthetist
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Editor,- A recent reply by Woodall et al, published on this site, in response to an E-letter by me (1), contained serious misunderstandings and consequently inappropriate accusations, to which I feel I should respond. The main point of my letter was to introduce the concept of totalitarianism in a socio-biological sense. It is relevant in a socio- biological sense because humans are both social and biological, and though it may be uncomfortable to view human activities as purely biological phenomena, contemporary science has no problem with it. The use of the term, in this sense, may be unconventional but is merely an interpretation of authoratative, published biological science philosophy (2) which could well be taken as the evidence Woodall et al claim to be unavailable to "this debate". It would be a shame if clinical medicine were above accepting or assessing pertinent views from other science-based disciplines. That perhaps all complex and organized activities within human society possess a (socio-biological) totalitarian structure was the only general 'view' I offered and is one which surely requires only a minor lateral step to appreciate. It should be possible to accept that paranoid or conspiratorial overtones are not implied. In a socio-biological sense 'totalitarianism' is meant to describe both the way in which many individuals benefit through social cooperation, and the way in which some individuals may suffer; the latter may be a cost of the former and entire systems are inherently susceptible to manipulation by influential individuals or groups. Just as contemporary societies in general may be required to sacrifice liberty for security (or vice versa) more specialized cooperative organizations must decide upon appropriate, analogous balances. If an organization is comprised of intelligent and highly educated individuals, what is wrong with pointing out that they should be careful in determining the point of balance? Drs Woodall, Harwood and Barker justify their study by pointing out that they expected all participants to have made "...an assessment of the risks and benefits to them as individuals". Not all of their subjects of course could logically have benefitted from the results of the study in which they participated, but even where possible, one should be prepared to recognise the way in which individuals are influenced by the system, to which they commit themselves. This in fact is the whole point: it is not sufficient to say that subjects had a 'free choice' when any choice is potentially influenced and limited by the system. Distorted senses of 'free choice' 'altruism' or 'individual selfishness' occur if assessments are influenced by fear of legal action or peer criticism for example. Both are clearly instruments of socio-biological totalitarianism and subject to ever-changing trends. I accept the point that there is more to fibreoptic intubation than manipulation skills, but Woodall et al are wrong to claim that the reference I used to support model and manikin training (3) necessarily endorses training on human volunteers, - except for the purposes of validating model and manikin training. The authors of this reference may, for all I know, accept that 'live subject' training is even more effective, but the fact remains that the model and manikin training is not ineffective and could be judged as having a better balance between benefits and risk as far as participants are concerned. There was no intention to question the honesty of responses by participants to some parts of the questionnaire. Honesty and truthfulness are not quite the same if the question you think you are answering is not the same as the one you were asked. It is very probable that all responses were utterly genuine, but that they confused perhaps a retrospective assessment of their experiences with the actual experience itself. By way of analogy one can, taking into account the effort made in revising for and the nervous tension experienced in sitting an exam, retrospectively assess the elation and pride of passing the exam and claim honestly that one enjoyed it all. This does not equate with a truthfulness that one literally enjoyed the actual exam, only that one enjoys the experience of looking back on an ordeal that is over and has resulted in some kind of tangible gain. What elates one depends on what one hopes to achieve and this can be strongly influenced by peer pressure and system doctrine. It is not a matter of whether Woodall et al themselves were capable of using "charismatic indoctrination" in order to compel participants to lie, but one of whether long-term exposure to shifting system doctrine can influence the content of honest beliefs and goals. The degree to which statements of enjoyment about (normally) non-enjoyable reactions were ridiculous, seemed to reveal the nature of the interaction between system and individuals, rather than the deceitfulness of the subjects. Woodall et al finally object to my use of the word "masochistic" in relation to the apparently paradoxical responses to parts of their questionnaire by a very few participants. As far as I am aware no other word describes the paradoxical experience of enjoyment in response to an event which a large majority of individuals would not find enjoyable. In addition, as far as I am able to understand, no other kind of pleasurable experience other than sexual may occur in response to normally unpleasant circumstances. The word "masochistic" therefore was used in a vernacular sense and because there was no perceived alternative. In fact I did not in any case actually define any response as masochistic, but as only "apparently masochistic" clearly indicating that I felt it highly unlikely that any subject actually did enjoy coughing or gagging for example. Again, I will make the point that this is not the same as suggesting any subject was guilty of deceit, so much as of a desire to conform whole- heartedly with the system, - as merely represented in subjects' eyes at the time, by the authors and other course supervisors. Indeed the authors' decision to include this part of their letter is disappointingly petty and confused. It seems bent on making lewd fun of an honest point of view and ignores the paradox of why, if they expected no-one to enjoy certain experiences, they included these as available responses in the first place. Otherwise their inclusion seems only to jeeringly obscure the acknowledged fact that fibreoptic intubation training on volunteers is associated with a high incidence of complications, even if some choose to consider them as entirely minor. Until something goes wrong. M. Hooper Townsville, Queensland, Australia. 1.Hooper M. A comment from outside the square. http://bja.oxfordjournals.org/cgi/eletters/100/6/850#3097 2.The Origins of Virtue. Ridley M. 1996; Viking, London. 3.Martin KM, Larsen PD, Segal R, Marsland CP. Effective non- anatomical endoscopy training produces clinical airway endoscopy proficiency. Anesth. Analg. 2004; 99: 938-44 Conflict of Interest:None declared |
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N M Woodall , RG Harwood, GL Barker
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“From outside of the square” Dr Hooper offers views on philosophy, society, medicine, religion and medical training. He describes a totalitarian system within medicine which allows individuals to place themselves at risk and he expresses concern that those outside of this system may be “branded a dissenter, heretic, activist, or plain old trouble maker”. This interpretation could be true, but, if the totalitarian hypothesis he describes does not exist those same dissenters might reasonably be regarded as misguided, deluded or mad. We are not expert philosophers or psychiatrists and do not feel able to contribute positively to a debate of this kind. Accepting this caveat there are some aspects on which we are able to comment. Dr Hooper states “The real question was why highly educated individuals would want to subject themselves to such a procedure, in the full knowledge of a wide range of possible, established complications, and that unforeseen, unusual and even possibly fatal complications could occur as a result of most medical interventions?” On application for this training all delegates are asked to indicate what they hope to achieve on the training course, most report in some form that they wish to acquire or enhance their skills in local anaesthesia of the airway and fibreoptically assisted intubation. Feedback collected after training suggests that this objective is met in the overwhelming majority of delegates. We assume that the doctors who seek training make an assessment of the risks and benefits to them as individuals. If they perceive the risk to be high and the benefit low they do not apply. If the benefits are high and the risks low perhaps they will. He may be right to suggest that anaesthetists volunteer for this type of training because they are altruistic and that the benefits are wholly received by patients, alternatively anaesthetists may volunteer for purely selfish reasons. Many regard awake fibreoptic intubation as an important skill they need in order to perform their job safely and with confidence (1). When dealing with airway problems anaesthetists have been shown to adopt familiar but higher risk strategies with serious adverse results (2). Although the patient pays the highest price for this approach with sometimes very poor or fatal outcome the anaesthetist may also suffer if they feel they have failed, become involved in lengthy protracted litigation or incur criticism of their fitness to practice. Possession of advanced airway skills such as the ability to perform an awake fibreoptic intubation gives an anaesthetist a low risk method of managing many difficult airways thus providing the anaesthetist with a positive long- term personal benefit by reducing the stress and anxiety associated with managing many anticipated airway problems. Dr Hooper seems to suggest that awake fibreoptic intubation skills can be maintained on plastic models, the reference he cites (3) relates only to mechanical skills of endoscope manipulation; competent and safe fibreoptic airway endoscopy must embrace much more than just these skills. Furthermore the same reference he uses endorses training on human volunteers with the following statement “The experience of performing clinical bronchoscopy and in turn being topicalized and bronchoscoped was both well tolerated and highly valued by participants in this study.” Dr Hooper also expressed concerns about the truthfulness of the responses to the questionnaire he states “I think there is a high chance that they were made because the individual demonstration of enthusiasm for perceived doctrine is a pillar of totalitarian belief systems, and some individuals will take this to extremes. Discomfort, anxiety and coughing or gagging are not enjoyable experiences and the few extreme responses are ridiculous in themselves, but important indicators of the nature of the system from which they came.” From his comment he fosters the notion that by our charismatic indoctrination we have created an environment where anaesthetists subject themselves to a horrendous ordeal then feel compelled tell us they have enjoyed it. We did not ask delegates why they had made the responses he disbelieves. When performing this evaluation we must accept those data that our research produces and try to interpret these where possible. It is possible that individuals completing feedback forms after an educational event develop a degree of momentum and a satisfied delegate might award very favourable responses widely. We would agree that it is very surprising that some delegates rated the coughing and gagging during awake FOI as enjoyable. Many have witnessed unpleasant demonstrations of awake intubation elsewhere, but it may be, that if delegates find the whole procedure unexpectedly acceptable and experienced little or no coughing or gagging it would be a plausible response to rate this as enjoyable. All parties must accept, however, that there is no further evidence available to inform this debate: we did not ask subjects to describe why they had made the responses they indicated as this was not possible using anonymous questionnaires and since the only other reports of this type appear to support our findings (3) it is inappropriate to suggest or imply that there has been any attempt to deceive. Furthermore we felt that the use of the word “masochistic” was inadvisable. Masochism is defined as “a form of sexual gratification by the endurance of physical or mental pain”.(Collins Dictionary) We are not certain that this is what Dr Hooper intended to imply. It is true that we made no enquiries about the sexual preferences of delegates attending the course. It is, however, also true that we did not expect that this information would ever be needed. Like any educator we hope that these courses are enjoyable and rewarding but not in the way that Dr Hooper seems to suggest. 1. Howes B, Gibbon G, Porter M, Gatward J, Barnes D, Kelly F, Doodson A, Webster S, Wharton N. An anaesthetic school’s interest in awake fibreoptic intubation training. http://bja.oxfordjournals.org/cgi/eletters/100/6/850 2. Kluger MT, Tham EJ, Coleman NA, Runciman WB, Bullock MF. Inadequate pre -operative evaluation and preparation: a review of 197 reports from the Australian incident monitoring study.Anaesthesia 2000;55: 1173–8. 3. Martin KM, Larsen PD, Segal R, Marsland CP. Effective non- anatomical endoscopy training produces clinical airway endoscopy proficiency. Anesth. Analg. 2004; 99: 938-44 Conflict of Interest:None declared |
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Andrew F Smith University Hospitals of Morecambe Bay, Kenichi Ode
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Dear Editor We read with interest the paper by Dr Woodall and colleagues on the complications of awake fibreoptic intubation (1). As enthusiasts for this technique ourselves, we were pleased to see our belief that this procedure can be not only well tolerated but also enjoyable for subjects, even after multiple attempts, without sedation. However, our view is not universal; a survey in the Oxford region showed that in the scenario of a patient being woken after a failed rapid sequence induction by an SHO, only 43% of consultants would use an awake fibreoptic intubation initially. Of those who would not use fibreoptic intubation, 76% felt it was an unpleasant experience (2). We do believe that awake fibreoptic intubation is an under-utilised technique in managing difficult airways, but the perception that it is uncomfortable or distressing procedure seems to be a barrier to its wider use (3). As the subtle details of such successful anaesthetic practice are not always fully described in such reports, we would invite the authors to comment on what aspects of local anaesthetic technique, maybe not described explicitly in the article, which they feel were most crucial which they feel were most crucial to making the technique so acceptable to their subjects. We would also like to explore the issue of bacteraemia in relation to awake fibreoptic intubation. We suggest Woodall and colleagues are correct in attributing rigors and flu-like symptoms to the bacteraemia from nasal endoscopy and intubation. Several other investigations have made this link (4-6). These authors recommended either prophylactic antibiotic administration, or the preferential use of the orotracheal route in at- risk patients. The evidence for this recommendation remains inconsistent however, as other studies (7-9) have found no difference in the risk of bacteraemia between the two routes. We believe it is thus fair to state that there is no clear evidence that bacteraemia is worse in nasotracheal than orotracheal intubation. The conflicting findings of the different studies should prompt us to investigate the factors which might affect bacteraemia. One which does not appear to have been considered is the effect of topical lidocaine, either by direct physical cleansing of the nasal mucosa, or potentially by an antibacterial action of lidocaine itself (10, 11). The other apparently unexamined point in respect to fibreoptic intubation is the relative contributions of the passage of the scope and the tube to systemic bacteraemia. We would be interested to know the authors’ opinion on these points. 1. Woodall NM, Harwood RJ and Barker GL. Complications of awake fibreoptic intubation without sedation in 200 healthy anaesthetists attending a training course. Br J Anaesth 2008: 850-5 2. Allan AGL. Reluctance of anaesthetists to perform awake intubation. Anaesthesia 2004: 78-82 3. Walker K, Smith AF. Promoting awake fibreoptic intubation. Royal College of Anaesthetists’ Bulletin 2007: 2329-33 4. Dinner M, Tjeuw M, Artusio JF. Bacteremia as a complication of nasotracheal intubation. Anaes Analg 1987: 460-2 5. Oncag O, Cokmez B, Aydemir S, Balcioglu T. Investigation of bacteremia following nasotracheal intubation. Paediatr Anaes, 2005: 194-8 6. Berry FA, Blankenbaker WL, Ball CG. Comparison of bacteremia occurring with nasotracheal and orotracheal intubation. Anaes Analg 1973: 873-6 7. Gerber MA, Gastanaduy AS, Buckly JJ, Kaplan EL. Risk of bacteremia after endotracheal intubation for general anestehsia. South Med J 1980: 1478-80 8. Ali MT, Tremewen DR, Hay AJ, Wilkinson DJ. The occurrence of bacteremia associated with the use of oral and nasopharyngeal airways. Anaesthesia 1992: 153-155 9. Valdes C, Tomas I, Alvarez M, Limeres J, Medina J, Diz P. The incidence of bacteraemia associated with tracheal intubation. Anaesthesia 2008: 588-592 10. Aydin ON, Eyigor M, Aydin N. Antimicrobial activity of ropivacaine and other local anaesthetics. Eur J Anaesthesiol 2001: 687-694 11. Olsen KM, Peddicord TE, Campbell GD, Rupp ME. Antimicrobial effects of lidocaine in bronchoalveolar lavage fluid. J Antimircobial Chemotherapy 2000: 217-219 Conflict of Interest:None declared |
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Nicholas M Woodall , Robert J Harwood, Graham L Barker.
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We would like to thank Drs Xue, Liu and Xu for their interest in our paper. We entirely agree that sedation is useful in clinical practice; in common with Dr Xue, our objective is to produce a calm and comfortable patient. We discussed some of the advantages of using sedation within the paper. Although awake inubation is often easier when performed with supplementary sedation, ineffective analgesia and oversedation may lead to failure or serious complications (1). Sedation should therefore not be used as an alternative to the provision of effective local analgesia. It is unfortunate Dr Xue and colleagues feel they are unable to translate our findings into clinical practice. We feel a technique which is effective and acceptable to unsedated volunteers is likely to be made even more acceptable when supplemented with cautious sedation. Furthermore, the absence of sedation allowed the assessment and evaluation of symptoms subjects attributed to the local anaesthetic. Details of the local anaesthetic technique employed have been described previously (2) as referenced within this paper and shown in a text box 2. It is true that the incidence of local anaesthetic side effects was higher than reported in our previous paper (2); that study group was small and subjects consented to serial blood sampling for plasma lidocaine concentration measurement. It is possible that the additional attention this required may have altered their perception or reporting of symptoms attributed to lidocaine. Dr Xue and colleagues state “The maximum safe dosage of lidocaine for airway local anaesthesia has generally been considered to be 4 mg/kg” and they provide a reference for this(3). Unfortunately their source gives no evidence to support the selection of the 4mg kg-1 dose limit. Moreover, Dr Xue and colleagues mistakenly give the impression that the 4mg kg-1 limit is recommended by the British Thoracic Society which actually recommends an upper limit of 8.2mg kg-1 (4) on its website. Dr Xue’s statements on the rapid absorption of lidocaine and toxicity need to be considered very carefully. Lidocaine may produce symptoms or side effects at plasma concentrations below 5mg l-1, but toxicity is usually taken to represent illness or damage produced by a drug. We are unable to find evidence to support the statement Dr Xue makes that “lidocaine toxicity has occasionally occurred in the patients with a safe plasma level of < 5ìg/ml”. It is true to state that a death has occurred due to presumed lidocaine toxicity(5) but the dose of lidocaine administered was not known (6). Dr Xue and colleagues consider absorption of lidocaine from the oropharynx and trachea together but these routes are, in reality, quite different. Drugs absorbed from the lower airway may pass directly into the systemic circulation, whereas drugs delivered to the oral mucosa are diluted with saliva and are swallowed and absorbed from the stomach and gut where lidocaine enters the portal circulation and undergoes extensive first pass metabolism(7) by the liver. It is for this reason that liver disease is very significant when using lidocaine for topical analgesia. When performing awake intubation most of the local anaesthetic is delivered to the upper airway – the nose mouth pharynx and larynx where it is diluted with saliva and swallowed. Drugs delivered to the trachea may directly enter the systemic circulation but evidence shows that in conscious subjects topical lidocaine tends to be coughed-up and swallowed too (8). This situation differs from studies of lidocaine absorption following direct intra-tracheal administration in intubated subjects (9) where no expectoration occurs and the drug may directly enter the systemic circulation. References 1/ Peterson.G, Domino. K, Caplan. R, Posner, K. Lee. L, Cheney. F. Management of the Difficult Airway A Closed Claims Analysis. Anesthesiology 2005; 103:33–9 2/ Williams K.A., Barker G.L., Harwood R.J., and Woodall N.M. Combined nebulization and spray-as-you¬-go topical local anaesthesia of the airway. Br J Anaesth 2005; 95: 549-53 3/ Simmons ST, Schleich AR. Airway regional anesthesia for awake fiberoptic intubation. Reg Anesth Pain Med 2002; 27:180-92. 4/ British Thoracic Society Bronchoscopy Guidelines Committee, a Subcommittee of Standards of Care Committee of British Thoracic Society. British Thoracic Society Guidelines on diagnostic flexible bronchoscopy. Thorax 2001; 56: 11–21 5/ Day RO, Chalmers DR, Williams KM, Campbell TJ. The death of a healthy volunteer in a human research project: implications for Australian clinical research. Med J Aust 1998; 168: 449-51 6/ Department of Health, New York State. Report on death of University of Rochester student issued. http://www.health.state.ny.us/press/releases/1996/wan.htm accessed 10/12/07 7/ Neal M,J. Medical Pharmacology at a Glance Wiley Blackwell; 3Rev Ed edition 1997. 8/ Kinnear WJM, Reynolds L, Gaskin D, MacFarlane JT. Comparison of transcricoid and bronchoscopic routes for administration of local anaesthesia before fibreoptic bronchoscopy. Thorax 1988; 43: 805p 9/ Bromage P. Concentrations of lignocaine in the blood after intravenous, intramuscular epidural and endotracheal administration. Anaesthesia 1961; 6:461-78 Conflict of Interest:None declared |
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Michael B. Hooper, Specialist Anaesthetist
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Editor, - I recently wrote a letter (1), which briefly referred to the view that totalitarianism is not merely a type of political system, but can be considered, in a socio-biological sense, as a hallmark behavioural and cultural phenomenon inherent to all levels of human society. I use the term to indicate any formalized system of instruction or regulation of humans, in which the relevant target population not only accepts, but desires such interventions. Participation in a totalitarian system means effectively that target populations actively cooperate with, or even seek out instruction, and regulation. They may come to accept wide-ranging opinions and beliefs which people external to the system might find quite ludicrous. Categories of totalitarian systems include families, clans, clubs, polite society, political parties, religions, as well as learned academic and professional societies. In each case, enthusiastic adoption by individuals, of the behaviours and beliefs which define the particular system, is necessary for the survival of the system. Of course human societies could not function without totalitarianism in its generic sense, for it is the way we cooperate with each other; medical training for example depends upon it, as does the maintenance of law and order. There are however degrees of totalitarian control and suggestibility which transgress boundaries of commonsense, - at least as judged from outside the system. The trouble is that these same conclusions might possibly not be reached from within, either because the same conclusions are conceptually impossible from within, or because anyone expressing them is branded a ‘dissenter’, ‘heretic’, ‘activist’ or plain old ‘troublemaker’. Everyone can think of political or perhaps religious totalitarian systems which are (externally) unacceptable, but relatively few perceive the role of socio-biological totalitarianism within other arenas of human interaction, and therefore the potential for developing other kinds of belief systems, which become increasingly extreme as a result of their insulation from the main body of human society. The recent report by Woodall et al of complications in anaesthetist participants in an awake fiberoptic training course (2) disturbed me. The paper revealed what I felt was an unacceptably high rate of immediate and delayed respiratory tract complications, as well as significant alterations in heart rate and blood pressure, and symptoms of local anaesthetic toxicity (37% of participants as 63% experienced no symptoms). One participant even required the advice of a neurologist, a CT brain scan and a lumbar puncture. Of course the results do not relate directly to the safety of the technique as applied to patients, as participants were not sedated and were each intubated many times, - but this is actually beside the point. The real question was why highly educated individuals would want to subject themselves to such a procedure, in the full knowledge of a wide range of possible, established complications, and that unforseen, unusual and even possibly fatal complications could occur as a result of most medical interventions? I rarely perform fiberoptic intubations, but I agree that there is a need to maintain one’s skills in this area. To that end I recently attended a workshop in which manikins and non-anatomical devices were used to improve dexterity with fiberoptic endoscopes. There is evidence that such devices enable individuals to maintain their skills in this area and to be able to transfer these to clinical situations (3). None of the participants on my workshop suffered any complication. Woodall’s paper concludes: “The use of volunteers… carries risks and needs further evaluation”. Surely the use of volunteers simply needs to be stopped rather than encouraged, and instead it is the structure of the totalitarian system, which allows individuals to place themselves at risk, for the sake of the system’s beliefs in 'altruism' or 'duty', which needs evaluation. When asked to assess the distress they experienced during fiberoptic intubation, few apparently suffered badly and most found the experience acceptable. More worryingly though, out of the 200, 2, 5 and 2, apparently were not merely unperturbed but (actively) enjoyed being uncomfortable, anxious or being made to cough or gag, respectively. 25 found the overall experience of being intubated enjoyable, but 4 found it very enjoyable. These responses are astounding; why would anyone say that? My interpretation of these apparently masochistic responses is that perhaps they were not strictly truthful. I think there is a high chance that they were made because the individual demonstration of enthusiasm for perceived doctrine is a pillar of totalitarian belief systems, and some individuals will take this to extremes. Discomfort, anxiety and coughing or gagging are not enjoyable experiences and the few extreme responses are ridiculous in themselves, but important indicators of the nature of the system from which they came. The medical profession could, if it wanted, be one of the first totalitarian systems which encourages a health-promoting awareness of, and caution in submitting to totalitarian doctrinal attitudes and so ensure that it itself remains a benign form. Sacrifice of individual physical and psychological safety of healthcare providers should not routinely be expected or volunteered in the name of duty or altruism to the receivers, especially as the definition of duty is usually directly, or indirectly manipulated by politicians. M. Hooper Townsville, Queensland, Australia *Email: michaelhooper@westnet.com.au 1. Hooper M. The PLG debates. Bulletin of The Royal College of Anaesthetists 2008; 48: 2472 2. Woodall NM, Harwood RJ, Barker GL. Complications of awake fiberoptic intubation without sedation in 200 healthy anaesthetists attending a training course. Br. J Anaesth 2008; 100: 850-55 3. Martin KM, Larsen PD, Segal R, Marsland CP. Effective non- anatomical endoscopy training produces clinical airway endoscopy proficiency. Anesth. Analg. 2004; 99: 938-44 Conflict of Interest:None declared |
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Ben W Howes Severn Airway Training Society, Gareth Gibbon, Mark Porter, Jonathan Gatward, David Barnes, Fiona Kelly, Andrea Doodson, Simon Webster, Nick Wharton
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Dear Editor We read with interest Dr Woodall’s excellent paper summarising complications of awake fibreoptic intubation (AFOI) on volunteers learning the technique by practicing on each other (1). We are currently proposing to run a similar free local course for all trainee anaesthetists at the Bristol School of Anaesthesia. To gauge interest we surveyed all anaesthetic trainees within the school about their attitudes to AFOI. We used an online survey tool (http://www.surveymonkey.com/) and emailed all trainees from a list supplied by the anaesthetic school programme director. There was a 92% response rate (146/158) during December 2007 and January 2008. We asked four questions: How important do you consider skills in awake fibreoptic intubation to be for a senior responsible anaesthetist? 85% (123/146) felt that AFOI was an “essential skill.” 15% (23/146) felt it a “useful skill.” No trainees felt it “not particularly useful” or “useless.” How confident are you at performing awake fibreoptic intubation as a solo anaesthetist with an experienced assistant? 0.7% (1/146) professed to have expert skill. 8% (11/146) claimed to be confident to proceed. 21% (30/146) claimed not to be as confident as they should be but would be willing to proceed. 34% (49/146) would need expert help but would like to perform AFOI. 32% (46/146) had never had a go but seen it done and 6% (9/146) were uncertain as to what AFOI was. The Severn Airway Training Society is putting together a day to train you to perform AFOI aiming to provide hands on experience of both intubating and being intubated by your colleagues after training. It would be held in theatres with due consideration for safety. What would be your opinion of this proposal? 74% (107/146) felt that this is a great idea and were keen to participate. 21% (30/146) of respondents were interested but unsure about taking part. 1.4% (2/146) felt more training was needed but there were better ways of doing it. 1.4% (2/146) felt it to be a bad idea. 3.4% (5/146) were uncertain of how they felt about it. Our results show that a large majority of trainees consider AFOI an essential skill for the competent anaesthetist. They also demonstrate a spectrum of confidence levels that would reflect a spectrum of experience. Very few claimed to have full confidence in their ability to perform AFOI independently (12/146, 8%). There was an impressive amount of interest in our course (137/146, 95%), the majority feeling it a great idea and keen to take part. The strength of our survey is that it is representative and provides evidence of current opinion amongst trainees. We believe we have identified a real demand to improve training opportunities in order to achieve competence in what is believed to be an essential skill by the majority of trainees. The findings of Dr Woodall et al suggest that there is a real but unevaluated risk of complications from nasoendoscopy. The majority of reported side effects were inconsequential or trivial, but this does not remove the need for scrupulous screening of candidates and an emphasis on safety. Risk to trainees has to be balanced by the potential benefit to our patients from the adoption of these learned skills. There is also the issue of potential of harm to our patients resulting from AFOI. Developing expertise requires that we perform this technique as often as possible. Would AFOI be truly in our patients’ best interests in weaker indications for AFOI, such as active gastro-oesophageal reflux disease, as suggested by other experienced practitioners(2)? These are decisions to be made in conjunction with our patients. With this new, valid information on the risk of nasoendoscopy and endotracheal intubation from subjects practicing on each other it would be interesting to find out how trainees’ opinions might change. We suspect that, like ourselves, the majority of trainees enthusiastic about the course would still altruistically perceive that the benefit of this training significantly outweighs this risk. References: 1) Woodall NM, Harwood RJ and Barker GL. Complications of awake fibreoptic intubation without sedation in 200 healthy anaesthetists attending a training course. Br J Anaesth 2008; 100: 850-5 2) Walker K and Smith A. Awake fibreoptic intubation – Summary of responses. Bulletin of Royal College of Anaesthetists 2008 49; 2524-24 Conflict of Interest:We are planning a local training course in awake fibreoptic intubation |
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Fu-Shan Xue, Anesthesiologist Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Qian-Jin Liu, Ya-Chao Xu
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Sedation and airway local anaesthesia for awake fibreoptic tracheal intubation Editor—We read with interest the paper of Woodall et al.1 They observed the complications of awake fibreoptic intubation (FOI) without sedation in 200 anaesthetists attending a training course. We would like to make a few comments and suggestions on the relative management and airway local anaesthetic technique for awake FOI . In this study, awake FOI was performed without any sedation. In preparing the patient for the awake intubation, in addition to the airway local anaesthesia, IV opioids combined with benzodiazepines are commonly used to provide sedation and analgesia because a calm and comfortable patient is much more likely to cooperate with the anaesthetist during the airway procedures. Also, the benzodiazepines produce significant amnesia and can help prevent seizure activity in the event of local anaesthetic toxicity.2 It is evident that lack of sedation makes it difficult to translate the findings of this paper to the clinical practice. The authors did not state clearly the volume, concentration and number of the supplementary spray-as-you-go topical lidocaine, and time from the first application of lidocaine to intubating the trachea. As compared to the findings of their previous study,3 side-effects and symptoms of lidocaine absorption were more common in this study [4/25 (16%) vs. 71/200 (36%)], though the same maximum lidocaine dose (9 mg/kg) was used. It may be helpful to consider the possible reasons of this difference. The maximum safe dosage of lidocaine for airway local anaesthesia has generally been considered to be 4 mg/kg.2 According to British Thoracic Society Guidelines on diagnostic flexible bronchoscopy, a maximum lidocaine dose of up to 9 mg/kg was selected in their studies.1,3 Because the safety of patients is of paramount importance, we do not agree that such large doses of lidocaine are recommended as safe dosages in routine clinical practice due to the following factors. First, lidocaine pharmacokinetics are complex and may be affected by many factors.3 This means that the plasma lidocaine level achieved in a particular patient is often unpredictable, even though a safe dosage has been used. It has been shown that when maximum safe dosage of lidocaine has been used or exceeded, in the vast majority of cases the plasma lidocaine concentration is within a safe therapeutic range, but an occasional patient has developed an unexpectedly high level.4 Martin et al.5 noted that after administration of 2% lidocaine 7.1-14.8 mg/kg by a spray-as-you-go technique, 92% (36 of 39) of subjects reported subjective cerebral side effects of lidocaine and 3 subjects experienced tremulousness which was taken to be a sign of early toxicity. In addition, the death of a healthy volunteer as a result of lidocaine toxicity due to large dose application has occurred after fibreoptic bronchoscopy for research purposes.6 Second, lidocaine toxicity has occasionally occurred in the patients with a safe plasma level of < 5μg/ml.3 Third, the spray-as-you-go airway anaesthesia technique by thoracic surgeons during fibreoptic bronchoscopy may make more wastage of local anaesthetics due to repeated airway suction and lavage compared to that by the anaesthetists during awake FOI.2 Fourth, endotracheal injection of lidocaine can result in blood levels similar to IV injection with the peak level occurring at about 5-6 min.4 Therefore, we consider that the dosage of lidocaine administered in the airway must strictly be limited, especially for patients with increased risk of systemic toxicity, such as the gerontal patients and those with hepatic dysfunction and airway mucosal inflammation or damage. Monitoring dosage and limiting to minimum amounts required for patient comfort will assure continued safe outcomes. F. S. Xue* Q. J. Liu§ Y. C. Xu* *Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing, China. §Washington University School of Medicine, St. Louis, MO, USA. E-mail: fruitxue@yahoo.com.cn References 1. Woodall NM, Harwood RJ, Barker GL. Complications of awake fibreoptic intubation without sedation in 200 healthy anaesthetists attending a training course. Br J Anaesth. 2008; 100:850-5. 2. Simmons ST, Schleich AR. Airway regional anesthesia for awake fiberoptic intubation. Reg Anesth Pain Med 2002; 27:180-92. 3. Williams KA, Barker GL, Harwood RJ, Woodall NM. Combined nebulization and spray-as-you-go topical local anaesthesia of the airway. Br J Anaesth 2005; 95:549-53. 4. Perry LB: Topical anesthesia for bronchoscopy. Chest 1978; 73(Suppl. 5):691-3. 5. Martin KM, Larsen PD, Segal R, Marsland CP. Effective nonanatomical endoscopy training produces clinical airway endoscopy proficiency. Anesth Analg 2004; 99:938-44. 6. Day RO, Chalmers DRC, Williams KM, Campbell TJ. Death of a healthy volunteer in a human research project: implications for Australian clinical research. Med J Aust 1998; 168:449-51. Conflict of Interest:None declared |
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