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Editorial Intravenous conscious sedation for dental treatment: am I my brother’s keeper? Before 2002, both dentists and doctors administered general anaesthetics for dental treatment to large numbers of patients [1] outside a hospital setting. Many of these practitioners had an almost magical belief that somehow this type of anaesthesia was different from that in hospital and was without harm [2]. Unfortunately this was not the case [1, 3]. There was a small but regular litany of deaths, some almost certainly precipitated by the arrhythmogenic property of halothane [4] and then compounded by failure to follow any recognisable resuscitation protocol. In addition, considerable morbidity went unreported. Much of this morbidity reflected general anaesthesia techniques well outside recognised practice [2]. In 1990, the report by Professor Poswillo [5] led to the Department of Health providing funds for monitoring equipment, defibrillators and resuscitation drugs for all dental practices. The report also urged practitioners to reduce the use of general anaesthesia and consider conscious sedation instead. However, the deaths and morbidity continued [6]. ‘A Conscious Decision’, published by The Department of Health in July 2000 [7], noted that ‘standards aimed at protecting patients from the effects of serious complications of general anaesthesia or conscious sedation administered during dental treatment are not rigorously applied or enforced’; and ‘despite a large number of expert reports which have been aimed at improving standards, it seems that patients are still vulnerable to unexpected death or nonfatal complications occurring outside hospital which seem to be avoidable’. By early 2002, general anaesthesia for dental treatment in the United Kingdom was confined to a hospital setting. Thus conscious sedation and the use of local anaesthesia are now the only

therapies approved of by the General Dental Council (GDC) for dental treatment outside hospital [8, 9]. Conscious sedation was defined by the GDC [8] as: ‘A technique in which the use of a drug or drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained throughout the period of sedation. The drugs and techniques used to provide conscious sedation should carry a margin of safety wide enough to render loss of consciousness unlikely’. In the past 5 years there has been a proliferation of centres outside the hospital setting hospital offering sedation for dental treatment to both adults and children. Some centres advertise on the internet and often proclaim that their sedation is given by a consultant anaesthetist. There is rarely any mention of the principles of conscious sedation or the use of local anaesthesia. The impression is given that patients will not remember their treatment. Patients may interpret this as a general anaesthetic and it seems unlikely that many understand the concept of conscious sedation. Since 2001, in addition to the published Standards of the GDC [8, 9], other bodies have issued guidelines on conscious sedation for dental treatment [10–13]. The guidelines are all agreed on conscious sedation as defined and on the principle of minimal intervention, and give guidance on intravenous drug usage. In addition, there is also guidance on the management of any complication [11, 14] which requires the whole dental team to be: ‘fully trained in the appropriate procedure to take in the event of the patient losing consciousness, aware of complications, appropriately trained and regularly rehearsed in emergency procedures including defibrillation when advanced conscious sedation

Ó 2007 The Author Journal compilation Ó 2007 The Association of Anaesthetists of Great Britain and Ireland

techniques are used, fully equipped with appropriate means of airway protection, oxygen delivery and drugs for emergency use. It is essential that these are carefully checked, that the oxygen supply is secure and adequate and that the drugs are in-date with all requisite means for immediate administration at all times. It is vitally important for the whole team to be prepared and that it rehearses the routine regularly’ [11]. For adults, the standard technique for intravenous conscious sedation [11, 13] is the use of a titrated dose of a single drug, for example the current use of the benzodiazepine, midazolam. Drugs used in combination (sometimes called ‘alternative techniques’) are said to be appropriate in specially selected circumstances, although these have never been defined in any standard or guideline. Do the special circumstances reflect the needs of the patient or that the administration of drug combinations must be restricted to an experienced practitioner and team fully trained in their use working in an appropriate environment? In any event, the use of fixed doses or bolus techniques is unacceptable as success is directly related to titration of the dose according to the individual patient’s needs [11, 13]. The UK National Clinical Guidelines in Paediatric Dentistry 2002 [10], from The Faculty of Dental Surgery, Royal College of Surgeons, specifically addresses the use of conscious sedation in children. The only form of conscious sedation recommended without reserve for children, outside hospital, is titrated nitrous oxide inhalation. The guidelines caution that the use of intravenous midazolam in children may cause disinhibition rather than sedation. The guidelines also state that ‘intravenous sedation for children below the age of 14 should be carried out in a hospital facility’. The guidelines are also clear that potent opioids such as fentanyl and alfentanil, and drugs such as propofol 645

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and ketamine ‘should only be administered by a qualified anaesthetist in a hospital environment’. It is noted further that ‘the use of multiple drugs increases the risk of complication and is not recommended’. The Scottish Intercollegiate Guidelines Network (SIGN 58) document [12] states: ‘There is insufficient scientific evidence to support the routine use of intravenous (IV) sedation for dentistry in children under the age of 16 years. General anaesthetic agents such as propofol and potent opioids such as fentanyl, alfentanil and remifentanil should only be administered by an appropriately trained anaesthetist in a hospital setting with full back up facilities’. It seems clear therefore that intravenous conscious sedation in children is not recommended, except on rare occasions, and that it should preferably be carried out in hospital. Has this plethora of advice created a safe environment, outside hospital, for patients undergoing conscious sedation for dental treatment? Unfortunately not. Cases adjudicated recently by the Professional Conduct Committee (PCC) of the GDC and others (both adults and children) which are still sub judice indicate that there are considerable problems. In one case that came before the GDC, a female adult patient weighing 50 kg, received 4 mg midazolam, 50 lg fentanyl, 10 mg ketamine and 5 mg propofol given by a staff grade anaesthetist, for a 15-min procedure to remove two teeth. This was followed by a period of unconsciousness in the recovery area, accompanied by vomiting and several days for the patient to recover fully. The judgement (April 2007) of the PCC of the GDC was that ‘the care provided to Mrs A in the recovery period was poor’. The dentist was found not guilty of serious professional misconduct. However, he did volunteer, while under oath giving evidence, that he would not be undertaking any dentistry in the future under conscious sedation. The pharmacological rationale and the concept of titrating a mixture of a benzodiazepine, a potent opioid and two intravenous anaesthetics is difficult to interpret. For example, should the

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drugs be mixed together, and if so in what doses or which drug should be given first; in addition, how are the patient’s requirements determined? At present there are no peer-reviewed publications to provide guidance on these matters. A further difficulty is whether the concept of conscious sedation applies if patients are sedated in a hospital setting. A review of sedation provided in hospital [15], for a variety of procedures, makes it clear that, if patients are not in a state of conscious sedation, then all the safeguards for general anaesthesia should apply. The mode of sedation used in these circumstances will not be applicable outside hospital for dental treatment under current GDC Standards. In another case, a 6-year-old boy, weighing 17 kg, received in bolus fashion 2 mg midazolam, 4 mg ketamine and 250 lg alfentanil intravenously, given by a consultant anaesthetist. Local anaesthesia was injected by the dentist, who then removed six teeth. The procedure lasted 10 min. When the nasal oxygen was discontinued after the extractions, the oxygen saturation fell. By the time the patient reached the recovery area in a head-up position, he was unconscious, cyanosed and his oxygen saturation and pulse rate were extremely low; blood pressure was not measured. Ventilation with 100% oxygen could not be carried out in the recovery area as the equipment was not available. The patient was returned to the treatment area, his trachea was intubated and he was ventilated with 100% oxygen. An ambulance was called and the patient was transferred to hospital. Although the patient survived, he now has brain damage and may require considerable care in the future. The dental and anaesthetic management of this child did not conform to any of the published guidelines. The judgement of the PCC of the GDC (October 2006) was to find the dentist guilty of serious professional misconduct and his name has been removed from the GDC Register. The GDC has no jurisdiction over doctors and it will be up to the General Medical Council (GMC) to assess the liability of the anaesthetists in cases like this. Why

then did the GDC strike off the dentist even though he did not administer the sedation? The answer lies firstly in the GDC Standards [8] at the time this case occurred, which state: ‘where a second dental or medical practitioner is providing conscious sedation for a patient, the treating dentist must ensure that the person acting as the sedationist has undertaken a relevant postgraduate education and training, accepts the definition of conscious sedation given and the principle of minimum intervention, and has specific experience of the use of conscious sedation in dentistry’. Second, it was by no means clear that informed consent for intravenous conscious sedation had been obtained from the patient’s parents. No apparent consideration was given to any alternative and nitrous oxide was allegedly not available. Third, the dental record was deemed to be unacceptable. The PCC of the GDC took the view that what occurred was part of the dentist’s responsibility. The mixture of drugs used in this case was presented to a meeting of The Dental Sedation Teachers Group (DSTG) and published without comment in their Autumn 2005 newsletter [16]. The article describes a review of 6000 sedated children, a remarkably large number for something (intravenous sedation) which every guideline describes as a rare event. There is some confusion in the article over titration vs bolus intravenous injections and potency vs length of action of the drugs used. Onset time of the drugs is not mentioned. Although having eschewed titration as ‘theoretically illogical’ based on this confusion, the article concludes that, ‘titration of midazolam alone or the entire mixture gives an added safety margin against the tendency towards deep sedation’. Deep sedation is deemed to be general anaesthesia by the GDC and therefore not acceptable outside a hospital setting [8]. It is interesting that, in the DTSG Autumn 2006 newsletter, the following appears: ‘The opinions expressed in this and previous Newsletters are those of the authors and are not necessarily those of the Editor or of the Dental Sedation Teachers Group’ – hardly a vote of confidence.

Ó 2007 The Author Journal compilation Ó 2007 The Association of Anaesthetists of Great Britain and Ireland

Anaesthesia, 2007, 62, pages 645–647 Editorial . ....................................................................................................................................................................................................................

Anaesthetists and dentists involved in conscious sedation for dental treatment outside hospital should not perpetuate the magical belief, as occurred with general anaesthesia, that sedative techniques as described above are risk-free. Common sense would indicate that they are not. Why then are they given? One wonders whether financial expediency plays a part. Only some 20 min were scheduled for each case described above. This allegedly included patient assessment by both the dentist and the sedationist, discussing the options for conscious sedation and obtaining informed consent as well as the dental treatment required. Titration of midazolam in adults or titrating nitrous oxide in children may be time-consuming, requires an appropriate ambience and is not always successful as a first option. It may therefore seem easier to take a chance and administer by bolus a mixture of intravenous drugs. Although the risk of something going wrong is low, this increases the possibility that when it does occur, the people present have not trained as a team in dealing with complications [11] and do not know what to do. Under these circumstances, as the cases above illustrate, tragedy may not be far away. Patients attending for dental treatment outside hospital are unlikely to have serious co-morbidities and their dental problems are not life-threatening. Therefore, we should do everything we can to avoid adverse outcomes. It is worth emphasising that conscious sedation alone, as defined, regardless of which drug or drugs are used to achieve the state, is unlikely to provide the necessary analgesia for most dental treatment. Therefore, the purpose of conscious sedation is to provide sufficient pain and anxiety control to encourage the patient to accept a properly administered local anaesthetic. Regrettably, this prime concept is hardly mentioned by some of those engaged in teaching conscious sedation for dental treatment [17]. A simple step, in future, would be that all those involved in conscious

sedation for dental treatment follow the published guidelines [7–14]. The cases described here should remind anaesthetists, acting as sedationists, that if they deviate from the guidelines not only are they putting their patients at risk, but also the professional standing of themselves and their dental colleagues. In this instance the anaesthetist is indeed his brother’s keeper. L. Strunin Emeritus Professor of Anaesthesia Barts and The London Queen Mary’s School of Medicine and Dentistry University of London, UK The Grange, Firsby, Spilsby Lincolnshire PE23 5QL, UK E-mail: [email protected]

References 1 Coplans MP, Curson I. Deaths associated with dentistry. British Dental Journal 1982; 153: 357–63. 2 The Royal College of Anaesthetists. Standards and Guidelines for General Anaesthesia for Dentistry, February. London: The Royal College of Anaesthetists, 1999. 3 Coplans MP, Curson I. Deaths associated with dentistry and dental disease. Anaesthesia 1993; 48: 435–8. 4 Worthington LM, Flynn PJ, Strunin L. Death in the dental chair: an avoidable catastrophe? British Journal of Anaesthesia 1998; 80: 131–2. 5 Poswillo D. General Anaesthesia, Sedation and Resuscitation in Dentistry. Report of an Expert Working Party for the Standing Dental Advisory Committee. London: Department of Health, 1990. 6 Seel D. Dental General Anaesthesia. Report of a Clinical Standards Advisory Group Committee on General Anaesthesia for Dentistry. London: Department of Health, 1995. 7 Department of Health. A Conscious Decision. A Review of the Use of General Anaesthesia and Conscious Sedation in Primary Dental Care, July. London: Department of Health, 2000. 8 The General. Dental Council. Maintaining Standards. Guidance to Dentists on Professional and Personal Conduct

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November 1998 with amendments up to November 2001. London: The General. Dental Council, 2001. General Dental Council. Standards for Dental Professionals, May. London: The General. Dental Council, 2005. Hosey MT. UK National Clinical Guidelines in Paediatric Dentistry. Managing anxious children: the use of conscious sedation in paediatric dentistry. International Journal of Paediatric Dentistry 2002; 12: 359–72. Standing Dental Advisory Committee. Conscious Sedation in the Provision of Dental Care. Report of an Expert Group on Sedation for Dentistry. Commissioned by the Department of Health. London: Department of Health, 2003. Scottish Intercollegiate Guidelines Network (SIGN 58). Safe Sedation of Children Undergoing Diagnostic and Therapeutic Procedures. A National Clinical Guideline, May, 2004. Scottish Dental Clinical Effectiveness Programme. Conscious Sedation in Dentistry: Dental Clinical Guidance. May 2006. Resuscitation Council. Medical Emergencies and Resuscitation Standards for Clinical Practice and Training for Dental Practitioners and Dental Care Professionals in General Dental Practice, July. London: Resuscitation Council (UK), 2006. UK Academy of Medical Royal Colleges and their Faculties. Implementing and Ensuring Safe Sedation Practice for Healthcare Procedures in Adults. Report of an Intercollegiate Working Party chaired by the Royal College of Anaesthetists. London: Royal College of Anaesthetists, 2001. Mikhael M. Conscious sedation in children; a review of 6000 cases. Dental Sedation Teachers Group (DSTG) Newletter 2005; 5: 5. Training in Conscious Sedation for Dentistry. The Dental Sedation Teachers Group, 2005.

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