Pii: s0966-6532(98)00041-9

Office-based anaesthesia: the UK perspective1 Directorate of Anaesthesia, Keele Uni6ersity, North Staffordshire Hospital, Stoke-on-Trent, Staffordshire ST4 6QG, UK Abstract
Although office-based anaesthesia is not prevalent in the United Kingdom, anaesthesia has long been provided in community dental surgeries. Because of concerns over the safety of providing anaesthesia in hazardous remote locations, several expertworking parties have examined UK dental anaesthesia and made numerous recommendations for safe practice. Concerningtraining, general anaesthesia, sedation, equipment, monitoring, resuscitation and building layout, these recommendations providean excellent basis for local, regional or national guidelines for many forms of office-based anaesthesia. Putting the recommenda-tions into practice, however, has had a fundamental impact on the provision of UK dental anaesthetic services and may havesignificant cost implications. These aspects should be carefully considered by anyone involved with planning or deliveringoffice-based anaesthesia. 1998 Elsevier Science B.V. All rights reserved.
Keywords: Office-based anaesthesia; United Kingdom; Dental surgeries; Guidelines 1. Introduction
ministered has been declining for many years. In 1967there were approximately 2 million dental general The current enthusiasm for office-based anaesthesia anaesthetics administered, compared to about 370000 in the United States has yet to reach the United King- in 1988 [1]. This decrease is due partly to overall dom. No doubt this latest trend will make the Atlantic improvements in dental health, as well as to increased crossing sooner or later, just as so many fashions have promotion of the use of local anaesthesia. Nevertheless, done in the past, but currently the phenomenon re- it is recognised that there will continue to be a public mains an American one. Given the pioneering status of demand for general anaesthesia for dental procedures, the United States in office-based anaesthesia, can especially amongst children, and that this is better Americans really hope to learn anything from their conducted in the familiar and friendly atmosphere of British colleagues? I believe that they can, for although the dental surgery than in a hospital unit. This desire to Britain does not yet conduct office-based anaesthesia distance minor procedures from the hospital environ- for general surgery, we have a long history in the ment is also one of the factors which is driving the related field of community-based dental anaesthesia.
development of office-based anaesthesia in the USA.
For many years, patients have been receiving sedation Overall, dental anaesthesia has a good safety record, and general anaesthesia in their dental practitioner’s with a mortality rate which compares very favourably surgery for a variety of procedures, especially simple with that for hospital-based general anaesthesia. Never- tooth extractions. This was once a very common proce- theless, a number of deaths have occurred (Fig. 1) and dure, although the number of general anaesthetics ad- while the overall number is comparatively small, anydeath resulting from a simple dental procedure in anotherwise healthy patient is a cause for serious concern.
* Tel.: + 44 1782 553054; fax: + 44 1782 719754.
1 For this reason, several expert working parties have Based on a lecture presented at the SAMBA mid-year meeting, reviewed the practice of dental anaesthesia and have 0966-6532/98/$19.00 1998 Elsevier Science B.V. All rights reserved.
PII S0966-6532(98)00041-9 I. Smith / Ambulatory Surgery 6 (1998) 69 – 74 Fig. 1. Annual deaths resulting from dental practice involving general anaesthesia (hatched bars) or sedation (solid bars) in the years 1963 – 1968and 1979 – 1988. Data from Tomlin (1974) [7] and The Poswillo report (1990) [1].
produced a number of recommendations aimed at 1990, the Poswillo report recommended that dental greatly improving its safety. While some of these rec- anaesthesia should be regarded as a postgraduate sub- ommendations are specific to dental practice and the ject, that all anaesthetics should be administered by UK environment, the majority are equally applicable to accredited anaesthetists and that anaesthetic training other forms of office-based anaesthesia and should be should include specific experience in dental anaesthesia considered by anyone attempting to establish local (or [1]. All of these suggestions are equally applicable to preferably national) guidelines for such a service.
office-based anaesthesia. Just as dental anaesthesia pre-sents its own unique problems and challenges, so toodoes office-based anaesthesia. Office-based anaesthesia 2. General anaesthesia
should be recognised as a subspecialty, just as ambula-tory anaesthesia has been in the past, and specific Perhaps because of their pioneering role in the devel- training should be provided. There is also a strong opment of general anaesthesia, the administration of safety case for insisting that general anaesthetics should anaesthetics has always been a part of British under- only be administered in offices (and other remote loca- graduate dental training. Previously, the majority of tions) by accredited (or Board-certified) anaesthetists.
dental anaesthetics were administered by dentists, often Trainee anaesthetists, who frequently work unsuper- working as both operator and anaesthetist. As long ago vised in British hospitals, are rarely permitted to work as 1967, the Joint Subcommittee of the Standing Medi- alone in dental practices in the United Kingdom (where cal and Dental Advisory Committee recommended that Nurse anaesthetists are not recognised at all).
‘‘all general anaesthetics should be administered byspecialist anaesthetists trained in dental anaesthesia’’.
The Poswillo report also considered the need to In practice, very little changed as a result of this report continue to provide general anaesthesia in dental and in 1978 a further working party was set up, which offices. The authors advocated the use of local anaes- published its findings in 1981 [2]. Usually referred to by thesia with sedation wherever possible, but recognised a the name of its chairman, the Wylie report called for a continuing need for general anaesthesia. Local anaes- register of recognised dental anaesthetists, although it thesia ( 9 sedation) should probably be the preferred allowed dentists to be included on this list, provided choice for all forms of office-based surgery, although they had received adequate training at both undergrad- with a far wider range of procedures than are encoun- uate and postgraduate level. The practice of a single tered in dentistry, this will not always be possible.
person acting as both operator and anaesthetist was Taking the recommendations of the British expert deplored, however. The requirement for specialist train- working parties and extrapolating from them to the ing was taken a step further by a more recent working wider arena of office-based anaesthesia would produce party which was set up in 1989. When published in I. Smith / Ambulatory Surgery 6 (1998) 69 – 74 3. Anaesthetic equipment
have anaesthetic equipment (and scavenging apparatus)installed as part of their infrastructure.
Traditional dental anaesthetic apparatus has adopted a different design to that used elsewhere and has in-volved intermittent (on-demand) gas flows and fre- 4. Sedation
quently incorporated the ability to administer hypoxicgas mixtures to patients. Although such equipment has The expert working parties on dental anaesthesia not been manufactured for many years, older apparatus considered the use of sedation, with local anaesthesia, has often been retained for long periods, especially in to be safer than general anaesthesia. ‘Sedation’ is a infrequently used locations. It is common practice in nebulous term which can describe a spectrum of con- hospitals (and elsewhere) that new equipment is sited in sciousness ranging from almost fully alert to comatose.
‘front-line’ areas and older apparatus is displaced to Ideally, the needs of the individual patient should be less frequently used locations. The Wylie report recom- assessed and specific drugs should be used to treat pain, mended that equipment for the delivery of anaesthesia discomfort and anxiety, with each drug separately ti- should conform to similar standards to those in hospi- trated to effect [3,4]. Because of their familiarity with tal practice, in particular with regard to the inability to potent sedative-hypnotic drugs and managing uncon- deliver hypoxic mixtures and the provision of oxygen scious patients, anaesthetists are ideally suited for failure alarms [2]. It is imperative that offices which providing sedation and monitoring its effects. In dental propose to offer an anaesthetic service be equipped and office-based practice, however, it may be impracti- with modern anaesthetic equipment and are not fur- cal to have anaesthetists available whenever sedatives nished with old or ‘second hand’ apparatus. Not only are used. At present, British surgeons frequently admin- should the equipment be inherently safe, but it should ister sedative drugs (e.g. for endoscopy) for this reason.
also be sufficiently similar to that which the anaesthetist The provision of simple sedation by non-anaesthetists is familiar with using in other locations. Arrangements may be reasonably safe, provided that there is a low must also be made for servicing such equipment and risk of unconsciousness or respiratory depression. This maintaining it to the accepted standard, with provision will depend upon the technique, with certain drugs (e.g.
for its eventual replacement in due course. In the olden propofol) being more likely to produce loss of con- days, anaesthetists frequently carried their equipment sciousness [5] and some combinations (especially opi- with them as they moved from location to location.
oids and benzodiazepines) producing severe respiratory With the development of more sophisticated equip- ment, which was larger and heavier, it became neces- The Poswillo report [1] defined the term ‘simple sary to fix apparatus at its site of use. Manufacturers sedation’ as ‘‘a carefully controlled technique in which are beginning to develop more transportable anaes- a single intravenous drug (or a combination of oxygen thetic delivery equipment, but the effect of frequent and nitrous oxide) is used to reinforce hypnotic sugges- movement and handling on the accuracy and safety of tion and reassurance…’’ . In addition, the technique such apparatus needs to be considered. Offices which ‘‘allows verbal contact with the patient to be main- intend to provide an anaesthetic service should ideally tained at all times’’. Furthermore, ‘‘the technique mustcarry a margin of safety wide enough to render unin-tended loss of consciousness unlikely’’. Any techniqueof sedation not coming within the above definition was considered to be general anaesthesia and therefore un- Recommendations concerning the use of general anaesthesia in office- suitable for non-anaesthetists to perform. On this basis, based practice, modified from Poswillo (1990) [1] the Poswillo report suggested that dentists could safelyadminister sedatives to their patients, provided that (1) The use of general anaesthesia should be avoided wherever they also received training in practical aspects of seda- tion and were able to adequately monitor their patients (2) The same general standards in respect of personnel, premises and respond to any likely problems. The routine use of and equipment must apply irrespective of where the generalanaesthetic is administered flumazenil was also disallowed, both because it wouldencourage the development of excessive sedation and (3) Office-based anaesthesia must be regarded as a postgraduate because its short duration of effect permits resedation to occur after the patient is discharged. Once more, (4) All anaesthetics should be administered by accredited many of the recommendations concerning sedation may anaesthetists who must recognise their responsibility forproviding office-based anaesthetic services be adapted to office-based anaesthesia, as illustrated inTable 2. Where sedation is managed by adequately- (5)Anaesthetic training should include specific experience in trained anaesthetists, these guidelines need not all be I. Smith / Ambulatory Surgery 6 (1998) 69 – 74 trained nurse or operating department assistant. In an Recommendations concerning the use of sedation (by non-anaes- isolated environment, where additional help may be far thetists) in office-based practice, modified from Poswillo (1990) [1] away, the provision of skilled assistance is even more (1) Sedation be used in preference to general anaesthesia essential. The assistant should be dedicated to helping the anaesthetist in caring for the patient and not also (2) Intravenous sedation should be restricted to the use of a responsible for aiding the surgeon or performing other single titrated dose of one drug with an end point remote from duties [2]. This assistant should be adequately trained in order to be capable of looking after and monitoring an (3) The use of flumazenil should be reserved for emergencies unconscious patient, assisting with the anaesthetic andmonitoring equipment, helping with venous access and (4) Additional caution should be exercised when administering airway management and should also be trained inresuscitation [2].
(5) Practical training in office-based sedation should be provided (6) More emphasis should be given to (surgical) undergraduate 6. Resuscitation
(7) Surgeons wishing to administer simple sedation should Patients may collapse in a surgeon’s office at any time. This may be due to a variety of reasons, and may (8) All surgical undergraduates should be proficient in not necessarily involve general anaesthesia or sedation.
venepuncture and the use of indwelling cannulae For this reason, resuscitation facilities should always be (9) Surgeons must be aware of the significance of pulse oximeter available and staff should be adequately trained. Where general anaesthesia and sedation are practiced, these (10) Patients receiving sedation should be accompanied by a provisions are of even greater importance. Fortunately, the need for resuscitation occurs relatively infrequently,even in quite busy units. For this reason, it is essentialthat all necessary equipment is regularly checked and 5. Facilities, monitoring and support staff
maintained and that procedures are rehearsed fre-quently. Effective resuscitation cannot be provided by a Offices which provide sedation and, especially, gen- single person so it is important that all members of the eral anaesthesia for minor surgery will require more team are adequately trained. In order to ensure effec- equipment and facilities compared to those which are tive resuscitation, the team must work well together used only for consultations. The additional require- and training and practice should therefore be a group ments for resuscitation will be considered later. Patients event. Awareness of the patient’s underlying medical who have received general anaesthesia should be al- condition(s) and chronic medication may help in identi- lowed to recover in a separate room and be cared for fying the likely cause of collapse and guide successful by a dedicated and adequately trained member of staff.
resuscitation, and so a thorough medical history should Supervision of patients recovering from sedation is also always be obtained (and documented) prior to begin- required, although it has been suggested that additionalpersonnel may not be required because of the shorter recovery period [1]. Other recommendations concerning Recommendations concerning facilities for office-based anaesthesia basic facilities are listed in Table 3.
and minimal monitoring standards (for general anaesthesia), modified American anaesthesiologists are familiar with mini- mal monitoring standards, although these have been The same general standards in respect of premises must apply less strictly applied in the UK. The level of monitoring irrespective of where the general anaesthetic is administered suggested for dental surgeries providing general anaes- Offices delivering general anaesthesia should be registered and thesia are listed in Table 3, and these recommendations would also be suitable for other forms of office-based Adequate recovery facilities (and personnel) should be available anaesthesia. Capnography was only considered neces-sary in association with tracheal intubation because At no time should the recovering patient be left unattended readings obtained from the alternative, a dental nasal Minimal monitoring should include the following: mask, are often unhelpful. In the wider office-based Pulse oximeter (also recommended for sedation)ECG setting, capnography should be used with laryngeal masks and probably also with face masks.
Capnography (whenever the trachea is intubated) Skilled assistance for the anaesthetist has always been Appropriate training must be provided for those assisting the a cornerstone of UK. anaesthetic practice and hospital- based anaesthetists always work with a specifically- I. Smith / Ambulatory Surgery 6 (1998) 69 – 74 Recommendations concerning resuscitation in office-based anaesthe- Essential resuscitation equipment, modified from Poswillo (1990) [1] (1) Every member of the office team should be trained in resuscitation. Training should be a team activity pocket mask)Self-inflating bag, valve and (2) Every member of the office team should have their proficiency in cardiopulmonary resuscitation tested and (3) Resuscitation procedures should be regularly practiced in the (4) A history of preexisting medical conditions and regular medications should be taken from the patient prior to starting (5) Surgeons must be proficient in the use of airway adjuncts.
Surgical students should be taught basic life support at an early stage and be proficient in airway management (6) All anaesthetists practicing office-based anaesthesia must have (7) All surgeons must be proficient at establishing access to the (8) All surgeons should examine their offices critically with regard to their suitability for resuscitation and access for paramedics (9) Suitable equipment (Table 5) and drugs (Table 6) should be available for resuscitation. Equipment must be regularly serviced and maintained, while drugs must be checked regularly ning treatment. Many of these points were highlighted Because outside help will never be immediately avail- by the Poswillo report, and their recommendations able, the office should be self-sufficient in basic equip- concerning resuscitation are especially pertinent to ment (Table 5) and drugs (Table 6) for resuscitation other forms of office-based practice (Table 4).
and life support. Emergency equipment should be regu- In addition to training staff and providing equip- larly inspected and serviced to ensure that it remains ment, consideration should be given to resuscitation functional on those rare occasions when it is actually when planning new offices (or adapting old ones) todeliver anaesthesia. The operating surface must be suffi- ciently firm to permit closed chest compression and the Drugs for emergency use, modified from Poswillo (1990) [1] operating table should also be able to be tilted head-down quickly. There should be sufficient space around the patient to allow several people to perform the tasks which will be necessary during resuscitation, including cardiac massage, airway management and establishing additional venous access. Consideration should be given to how long it will take for an ambulance to Glyceryl trinitrate (tablets or sublingual spray) arrive and what will be the additional journey time to the nearest hospital. Once the ambulance has arrived, it would be unfortunate for additional time to be wasted trying to gain access to the office via stairways or narrow corridors and doorways. Ideally, offices provid- ing an anaesthetic service should be located on the ground floor with an unimpeded approach for emer- Midazolam or diazepamSuxamethonium (succinylcholine) gency services [2]. The workload implications for a hospital supplying emergency care to patients receiving office-based anaesthesia should also be considered.
I. Smith / Ambulatory Surgery 6 (1998) 69 – 74 required. Drug supplies should be stored under appro- has demonstrated that this standard of care is not priate conditions and stock should be replaced when it necessarily cheap. Apart from the improvements in approaches its expiration date. Since many of these safety which have resulted from the British expert drugs will (with luck) never be used, arrangements may working parties’ reports, one of the major changes to be made with more frequent users to exchange supplies have occurred is a substantial reduction in the number of older stock, rather than having to discard out of date of dental surgeries providing anaesthetic services. The drugs. The decision on whether or not to stock dantro- main reason being the high cost required to equip such lene (for treatment of malignant hyperpyrexia) is a locations to an adequate standard. Ironically, many difficult one (because of the short shelf-life and signifi- healthcare regions have now established fully equipped cant cost), and may depend on the rapidity with which and staffed dental surgeries within the hospital, and supplies can be obtained from another source. Sharing closed community clinics! If office-based anaesthesia is arrangements may be possible where several offices (or to succeed in the USA, it must be for the correct office and hospital) are located nearby.
reasons and not simply to save money.
7. Summary
References
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all staff are adequately and appropriately trained. The [4] Smith I. Monitored anesthesia care: how much sedation, how possibility of complications must be recognised and much analgesia? J Clin Anesth 1996;8:76S – 80S.
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these should be considered before moving further for- [7] Tomlin PJ. Death in outpatient dental anaesthetic practice.
ward. Safe practice is possible, but the UK experience

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