IPD_379.fm Page 359 Friday, August 16, 2002 9:35 AM International Journal of Paediatric Dentistry 2002; 12: 359–372 UBlackwell ScienKce, Ltd National Clinical Guidelines in Paediatric Dentistry* Introduction The twelfth National Clinical Guideline in Paediatric Dentistry is published here. The process of guideline production began in 1994, resulting in first publication in 1997. Each guideline has a nominated main author but the content is not a personal view; it represents rather a consensus of opinion of current best clinical practice. Each guideline has been circulated to all consultants in paediatric dentistry in the UK, to the Council of the BSPD, and to people of related specialities recognized to have expertise in the subject. The final version of the guideline is produced from a combination of this input and thorough review of published literature. The intention is to encourage improvement in clinical practice and to stimulate research and clinical audit in areas where scientific evidence is inadequate. Evidence underlying recommendations is scored according to the SIGN classification and guidelines should be read in this context. For those wishing further detail, the process of guideline production in the UK is described in International Journal of Paediatric Dentistry 1997; 7: 267–268. Managing anxious children: the use of conscious sedation in paediatric dentistry M. T. HOSEY management of anxious children within paediatric Introduction dental care in the UK. Indeed, even in parts of the All children should be able to expect painless, high world where deep sedation techniques are more quality dental care. The following guideline is common, their use is often limited to hospitals [1]. intended to assist dentists in the management of Nitrous oxide inhalation sedation remains the pre- healthy anxious children; discussion of the sedation ferred technique for the pharmacological manage- of medically compromised children or those with a ment of anxious paediatric dental patients. learning disability is not included. It is hoped that this guideline will be an adjunct Behavioural management and prevention, coupled to clinical judgement and careful treatment planning with local anaesthesia when required, form the within both primary dental care and specialist foundation of the delivery of pain-free dentistry to paediatric dentistry practice. It is therefore generally children. Although behavioural management may need assumed that the dentist is also the sedationist. to be augmented with conscious sedation for some Restraining devices (such as the papoose board) and anxious children, pharmacological agents are not deep sedation techniques (where the patient is more substitutes for effective communication and the per- deeply sedated than the General Dental Council suasive ability of the operator. There is certainly no definition of conscious sedation [2]) are not accept- place for invasive and high-risk sedative techniques able in UK dental practice. Where there is evidence such as deep sedation or polypharmacy in the dental or a substantive body of opinion relating to a specific drug or route indicating that deep sedation might occur, or where research is meagre, referral to a Correspondence: Marie Therese Hosey, University of Glasgow, Glasgow, UK. E-mail: [email protected] hospital-based paediatric dental service and, where © 2002 Faculty of Dental Surgery, Royal College of Surgeons 359 IPD_379.fm Page 360 Friday, August 16, 2002 9:35 AM 360 M. T. Hosey Table 1. ASA Classification. Class I No organic, physiological, biochemical or psychiatric disturbance. Class II Mild to moderate systemic disturbance, e.g. mild diabetes, moderate anaemia, well-controlled asthma, not disabling. Class III Severe systemic disease, e.g. severe diabetes with vascular complications, severe pulmonary insufficiency, disabling. Class IV Severe systemic disorders that are already life-threatening, e.g. signs of cardiac insufficiency. Class V The moribund patient who has little chance of survival without operative intervention. appropriate, the assistance of a qualified anaesthetist 1.2 Goals of paediatric conscious sedation are to: has been recommended. As such, not all drugs reported in this guideline are recommended for use Grade C in primary care dentistry in the UK, but are included 1 Promote patient welfare and safety. because the author is aware that the diversity of pub- 2 Facilitate the provision of quality care. lished literature might lead some dental practitioners 3 Minimize the extremes of disruptive behaviour. to consider using them in an effort to find an alter- 4 Promote a positive psychological response to native to general anaesthesia. treatment. These guidelines should be read in the context of 5 Return the child to a physiological state in which the contemporary recommendations of the GDC safe discharge is possible [4]. and the UK national and regional government and other respected authorities, particularly in respect 1.3 Patient assessment of appropriate qualifications, staffing level, training, equipment and facilities. Grade C This guideline is based on the evidence currently • This must include a full medical and dental history available but even although the paediatric dental and must be performed before the decision to pro- sedation literature is extensive, there are relatively vide treatment under conscious sedation is made. few randomised controlled trials. Furthermore, the evaluation of the efficacy of an individual drug is often 1.4 Fitness for conscious sedation confounded by the use of polypharmacy, restraining devices and diverse methodology. The Poswillo Report Grade C [3] clearly stated that conscious sedation should • Children who are ASA I or II (Table 1) can be involve the administration of a single drug. In the deemed fit to undergo conscious sedation in gen- light of the paucity of evidence to the converse, and eral, community or specialist (paediatric) practice. in the interest of the safety and well-being of child • Those who are not in these categories requiring dental patients, this guideline will apply this prin- conscious sedation should be treated in a hospital ciple to children’s dentistry in the UK. environment with due consideration to their indi- vidual needs and medical condition, involving the assistance of medical colleagues where appropriate. 1.0 Conscious sedation 1.1 General Dental Council definition 1.5 Patient information and consent [2] A technique in which the use of a drug or drugs Grade C produces a state of depression of the central nervous • Informed consent for a course of dental treatment system enabling treatment to be carried out, but during under conscious sedation must be obtained from each which verbal contact with the patient is maintained parent/guardian, and the child, where appropriate, throughout the period of sedation. The drugs and tech- prior to the conscious sedation appointment. niques used to provide conscious sedation for dental • An explanation of the sedation technique proposed treatment should carry a margin of safety wide enough and of appropriate alternative methods of pain and to render unintended loss of consciousness unlikely. anxiety control must be given. The level of sedation must be such that the patient • In advance of the procedure, the child and their remains conscious, retains protective reflexes, and parent or guardian must be given clear and com- is able to understand and to respond to verbal prehensive pre- and postoperative instructions in commands [2]. writing. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 361 Friday, August 16, 2002 9:35 AM Use of conscious sedation in anxious children 361 • It is essential that primary care dentists who 1.6 Escort sedate children undergo training that is recognized Grade C by appropriate authorities and that their clinical • A parent, legal guardian or other responsible adult skill and knowledge relating to paediatric conscious must accompany the child to and from the treat- sedation, including local anaesthesia, behavioural ment facility. management and the provision of operative dental • A sedated child must always be attended by a care for children, is regularly updated. suitably qualified member of the dental team. • The dental nurse should be appropriately trained • The sedationist should be chaperoned at all times in sedation techniques. Attainment of the Certifi- by another member of staff. cate in Dental Sedation Nursing (CDSN) from the National Examining Board for Dental Nurses (NEBDN) is encouraged. 1.7 Fasting • Specialist paediatric dentists are expected to have Grade C acquired the necessary skills and competency for- • Fasting is not required for children undergoing nitrous oxide inhalation conscious sedation, but such inhalation sedation using nitrous oxide but dentists individuals are still obliged to update themselves might recommend that a light meal only is consumed regularly and to adhere to national and regional in the two hours prior to the appointment. policy and procedure. Grade C 2.0 Choice of sedative agent for children • Children who undergo all other forms of seda- undergoing dental treatment tion should be fasted prior to the procedure as follows: The drug groups used for paediatric dental sedation • No solid food within 6 h include inhalational agents, benzodiazepines, other • No milk within 4 h sedative hypnotics and psychosedatives. • No clear fluid within 2 h 2.1 Nitrous oxide 1.8 Documentation Grade C 2.1.1 Indications The notes must: Grade A • Include the name and signature of the operator Nitrous oxide inhalation sedation: together with the name(s) of the assistants. • Should be offered to children with mild to moderate • Contain a clear treatment plan, completed medical anxiety to enable them to accept dental treatment history and consent form, appropriate radiographs better and to facilitate coping across sequential visits. and briefly give an account of the reason for the • Should not be used in isolation from the support need for sedation. given to the child by the dentist. • Document the operative treatment that was performed, the name of the drug, concentration Grade B and batch number (if appropriate), dosage, route • Can be used to facilitate dental extractions in children. and duration of sedation. • Is preferred to general anaesthesia for anxious • State which monitors were used (as appropriate) children undergoing elective orthodontic (premolar) together with their readings. extractions. • Include a time-based record where appropriate. • Is a cost effective alternative to general anaesthesia. • Is a weak analgesic, although this effect can be influenced by the psychological preparation of the 1.9 Staff training requirements patient. Grade C • The dental team must undergo appropriate training Grade C on a regular basis as determined by competent • Has a minimal effect on cardiovascular and res- authorities. piratory function. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 362 Friday, August 16, 2002 9:35 AM 362 M. T. Hosey 2.1.2 Contra-indications 2.3 Midazolam Nitrous oxide inhalation sedation: 2.3.1 Grade B • Midazolam is generally reserved for anxious ado- Grade B lescent or adult dental patients. • Is of less value in those who require multiple extra- • It can cause disinhibition rather than sedation in ctions, poor attenders and very young children. children. Grade C 2.3.2 Grade C Contra-indications to nitrous oxide inhalation Oral midazolam: sedation include: • May have a potential value as a pre-medication • Common cold, tonsillitis, nasal blockage and and sedative agent. bleomycin chemotherapy [5]. • Is not recommended for use outwith a hospital • Pre-co-operative children. environment. • First trimester of pregnancy. 2.3.3 2.1.3 Nitrous oxide pollution Intra-nasal midazolam: Grade B Grade C • Is not recommended in children who have copious • Dental operators should ensure that they comply nasal secretions or who suffer from an upper res- with COSHH [6] in respect of N O pollution and 2 piratory tract infection. gas safety. • Is not recommended for use outwith a hospital environment. 2.1.4 Other inhalational agents 2.3.4 Grade C • Although isoflurane and other inhalational agents Rectal midazolam: such as sevoflurane have been reported, their use Grade A in children should be limited until further research • Can facilitate restorative treatment in uncoopera- emerges. tive children. Grade C 2.2 Diazepam and temazepam • Should only be attempted in a hospital facility with the assistance of a qualified anaesthetist. 2.2.1 2.3.5 Grade C Grade B Intramuscular midazolam: • Oral benzodiazepines can be used to relax anxious • Is not recommended for conscious sedation in patients prior to dental treatment but their effects paediatric dentistry. can be unpredictable in children. 2.4 Flumazenil (Anexate) 2.2.2 Rectal diazepam Grade B Grade B • Reversal with Flumazenil should not be used as • The anterograde amnesia produced might be of value a routine part of the conscious sedation procedure. to those children who have to undergo traumatic • Flumazenil may induce convulsions [7]. dental procedures. 2.5 Opioids and other miscellaneous agents with sedative properties (chloral hydrate, hydroxyzine, 2.2.3 Intravenous diazepam promethyaine hydrochloride, fentanyl & pethidine) Grade C 2.5.1 Grade C • There is no role for intravenous diazepam sedation • The efficacy of these drugs is questionable and the in paediatric dentistry. associated risks may outweigh their benefit. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 363 Friday, August 16, 2002 9:35 AM Use of conscious sedation in anxious children 363 • Repeated administration of chloral hydrate carries • Children who are given an oral sedative should a theoretical risk of carcinogenesis. be placed in a quiet room facility together with • These drugs are not recommended outwith a hos- their escort and a competent member of staff. pital environment. • Sedated children should be monitored clinically and electronically. 2.5.2 Grade C • The use of narcotics such as pethidine is not rec- ommended in the UK. 3.3 Intravenous conscious sedation • Fentanyl and other potent opioids should only be Grade C used by a qualified anaesthetist in a hospital setting. • Intravenous sedation is not recommended in pre- cooperative children. Dentists should consider 2.6 Common anaesthetic agents that are used as whether the provision of an elective general sedatives anaesthetic might be preferable in such circum- 2.6.1 Propofol stances. • Single drug intravenous sedation, e.g. midazolam, Grade C is recommended for adolescents who are psycho- • The use of propofol in paediatric dentistry is still logically and emotionally suitable. experimental and requires the assistance of a qual- • Intravenous sedation should only be administered ified anaesthetist in a hospital environment. by an experienced dental sedationist with a trained dental nurse in an appropriate facility. 2.6.2 Ketamine • A pulse oximeter, at least, should be used to aug- Grade C ment alert clinical observation. • Ketamine should only be administered by a qual- • Intravenous sedation for children below the age of ified anaesthetist in a hospital environment. 14 years should be carried out in a hospital facility. • Patient-controlled sedation may be of value for anxious adolescents. 3.0 Routes of administration 3.1 Inhalation 3.4 Rectal Grade C • This is the recommended route for conscious Grade C sedation for paediatric dentistry • Rectal administration is not socially acceptable in the UK. Grade B • It is currently not recommended outwith a hospital • The inhalational route is the most reliable in terms facility and requires the assistance of a qualified of onset and recovery. anaesthetist. • Efficacy is reduced when children object to the nasal hood or have difficulty breathing through the nose. 3.5 Intramuscular sedation Grade C • Only dedicated dental nitrous oxide inhalation Grade C sedation delivery systems must be used. • This is not recommended. • The operator should use a close-fitting scavenging • Operators should consider whether the alternative nasal hood. An air-entrainment valve is not required. provision of a general anaesthetic might carry a • The use of a rubber dam improves the effect of lower risk and give greater long-term psycholog- the sedation and reduces atmospheric pollution. ical benefit to the child. 3.2 Oral 4.0 Polypharmacy Grade C • The oral sedative agent should only be prescribed Grade B and administered by the operating dentist within the • The use of multiple drugs increases the risk of facility where the dental procedure is to take place. complication and is not recommended. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 364 Friday, August 16, 2002 9:35 AM 364 M. T. Hosey undergoing dental extractions, especially elective 5.0 Complications during paediatric dental premolar orthodontic extractions, with the exception conscious sedation of very young children, those who require multiple Grade C extractions and irregular attenders [10–20]. • Complications can include respiratory depression, nausea, hypoxia, hyperactivity and unintentional 2.1.2 loss of consciousness. Nitrous oxide sedation has minimal effect on car- diovascular and respiratory function and the laryn- 6.0 Monitoring geal reflex [10,21,22]. However, using nitrous oxide Grade C inhalation sedation in conjunction with other sedat- Monitoring is the continuous observation of data ives may rapidly produce a state of deep sedation from specific organ systems to evaluate the status or general anaesthesia. Nitrous oxide should be used of physiological function [8]. with caution on ASA 3 and ASA 4 status patients, for whom it would be more appropriate to admin- • Alert clinical monitoring is essential at all times. ister sedation in a hospital environment supported • It is vital that adequately trained staff and the by a consultant anaesthetist [23]. appropriate monitoring facilities are available to alert the operator if the patient undergoes desaturation. • Electronic monitoring is not required in nitrous 2.1.3 Nitrous oxide pollution oxide inhalation sedation. Exposure to nitrous oxide can result in depression of • A minimum of pulse oximetry is an essential vitamin B12 activity resulting in impaired synthesis of requirement for all other types of sedation. RNA. Dental surgeons and their staff are particularly at risk as they are exposed to high concentrations 7.0 General anaesthesia in the confined space of a dental surgery, especially if scavenging is inadequate [6,24–32]. Grade C • For pre-cooperative children, general anaesthesia remains the preferred method of providing dental 2.1.4 Other inhalational agents treatment and may carry less risk and psycholog- Isoflurane ical trauma than inadequate or over-sedation. Isoflurane is more potent than nitrous oxide. It has an ethereal odour and subanaesthetic concentrations Explanatory notes reportedly produce rapid induction and amnesia without any significant cardiac or respiratory 2.1 Nitrous oxide inhalation sedation impairment [33–35] but its use as a sedative has not Nitrous oxide gas has a sweet odour, which is been thoroughly investigated in children. Isoflurane pleasant to inhale and non-irritant. It has low tissue may irritate infant airways. solubility and a minimum alveolar concentration (MAC) value in excess of one atmosphere, rendering Sevoflurane full anaesthesia without hypoxaemia impossible at Sevoflurane has been reported as a sedative in children normal atmospheric air pressure. Poor tissue solubility undergoing dental treatment [36] and as a deep sedative ensures its effect is characterized by rapid onset and for wisdom teeth extraction [37]. There may be a fast recovery [9]. theoretical risk of nephrotoxicity [38]. The technique is still experimental and should not be used in primary 2.1.1 care dental practice until further research emerges. Nitrous oxide inhalation sedation offsets the increase 2.2 Diazepam & temazepam in pulse and blood pressure that is related to increased anxiety and facilitates coping across sequential visits, The benzodiazepines have been extensively used by although some extremely anxious children may refuse both the medical and dental professions on account to accept the nasal mask. It is a viable and cost- of their characteristic ability to act as anxiolytic, effective alternative to general anaesthesia for children hypnotic, anticonvulsant and muscle relaxant drugs © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 365 Friday, August 16, 2002 9:35 AM Use of conscious sedation in anxious children 365 which produce an anterograde amnesia [39,40]. 2.3.1 IV midazolam Whilst the drugs are valued for pre-medication, their Whilst the use of IV midazolam has been widely sedative effect in children is more variable. reported in adults, there are few studies to support its routine use in the dental management of anxious 2.2.1 Oral temazepam children. Mixing midazolam and fentanyl for intravenous Oral temazepam, administered as an elixir or use has led to respiratory arrest in a child [55]. gelatinous capsule has been reported to provide successful sedation for both anxious adults [42,43] 2.3.2 Oral midazolam and children [44,45]. Unfortunately, drug addicts Studies have produced conflicting results and are further who extracted the drug from the ‘jellies’ to inject confounded by the use of restraints and cosedatives intravenously abused the use of the gelatinous [56–61]. Oral midazolam reaches the systemic capsule, which is no longer available. circulation via the portal circulation, this decreases the drug’s bioavailability, necessitating a higher oral 2.2.2 Rectal diazepam dosage compared to intravenous administration [52]. Rectal administration of a solution of diazepam Midazolam is now available in hospitals in a reaches peak serum levels in approximately 10 min blackcurrant flavoured solution. Previously, ‘crucial [46]. Flaitz et al. (1985) using this technique to problems arose with administration of (IV formulation) facilitate restorative care on 2–6-year-old children, oral midazolam due to its unpleasant taste’ despite reported it to be effective, predictable and safe [47]. it having been ‘dissolved in a favourite beverage’ Whilst Jensen and Schroder (1998) suggested that [60], such as a cherry elixir [52,57,62]. the resultant amnesia facilitated better behaviour and acceptance of dental care in 4–6-year-old children 2.3.3 Intranasal midazolam who had undergone local anaesthetic extraction of Intranasal administration of midazolam produces a traumatized primary incisor teeth [48]. sedative effect within 5 min of administration [63]. Studies using intranasal midazolam in paediatric 2.2.3 Intravenous diazepam dental patients are few in number and have involved Healy and Hamilton (1971) reported that the few subjects but have shown that amnesia can be protective laryngeal reflex was lost when IV induced [61,64]. The administered dose is limited by diazepam was used to sedate anxious children [49]. the volume of the solution, as large volumes can cause The use of IV diazepam has been superseded by the coughing, sneezing and expulsion of part of the drug introduction of midazolam. [52,62]. There have been reports of occasional respiratory depression and transient burning discomfort effecting the nasal mucosa [59,65]. 2.3 Midazolam Pharmacological agents such as erythromycin, some 2.3.4 Rectal midazolam calcium channel blockers and antifungals can inhibit Krafft et al. (1993) reported that rectal midazolam midazolam metabolism, resulting in a more profound had a short duration of onset, required a low dosage or lengthier sedative effect [7]. Midazolam, known and was easily administered [60]. However, adverse generically as imidazobenzodiazepine, has a high reactions such as agitation, excitement, restlessness affinity for the benzodiazepine receptor (almost double and disorientation together with significantly reduced that of diazepam). Unlike diazepam, the basicity of blood oxygen levels, nausea and vomiting have been the molecule allows stable water-soluble salts to be reported and ‘advanced airway management formulated. High lipophilicity at physiological pH proficiency is recommended’ [66–69]. Indeed, the and very high metabolic clearance and elimination use of this technique is likely to result in a level of allow rapidity of onset and speedy recovery. Termina- sedation that is unacceptable in the United Kingdom. tion of action is by redistribution to peripheral tis- sues and by biotransformation [50,51]. Midazolam 2.3.5 Intramuscular midazolam has a more rapid onset and recovery and produces Downs et al. (1997) reported that children sedated a greater degree of amnesia than diazepam in dental using IM midazolam cried continuously throughout patients [50–53] although it can cause hallucinations the procedure, despite the addition of nitrous oxide, in children [54]. and did not even benefit from amnesia [70]. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 366 Friday, August 16, 2002 9:35 AM 366 M. T. Hosey or in combination with chloral hydrate. Avelos-Arenas 2.4 Flumazenil et al. (1998) reported high rates of oxygen desatura- Flumazenil reverses all the effects of benzodi- tion when chloral hydrate-hydroxyzine hydrochloride azepines. The duration of action of Flumazenil is combinations were used and suggested that the com- 15–140 min and is dose dependent. The half-life of bination was most effective when deep sedation was the antagonist is shorter than midazolam, which may produced [84]. Indeed, the addition of hydroxyzine lead to resedation, and post-op anxiety can occur resulted in 21% of children experiencing at least one unless it is carefully titrated. Therefore, whilst episode of oxygen desaturation below 95% [85]. Flumazenil renders midazolam a safer agent for Promethazine hydrochloride is a phenothiazine induction of anaesthesia, conscious sedation and derivative and as such is a potent tranquillising agent IV infusion [71–78], routine reversal is not recom- that will potentiate the respiratory depressant effect mended as part of the conscious sedation technique. of narcotics, barbiturates and other antihistamines. 2.5.3 Pethidine 2.5 Chloral hydrate, hydroxyzine and promethazine Pethidine has been reported to cause nausea, hydrochlorate and pethidine vomiting and oxygen desaturation [86]. 2.5.1 Chloral hydrate Evidence to support the single use of Hydroxyzine Chloral hydrate is a chlorinated derivative of ethyl Hydrochlorate, Promethazine Hydrochlorate or alcohol that can act as an anaesthetic when Pethidine is poor. Their use should be restricted to administered in high doses. It is a weak analgesic the hospital environment. and psychosedative with an elimination half-life of approximately 8 h. In small doses, mild sedation 2.6 Common anaesthetic agents that can also be occurs and, in intermediate doses, natural sleep is used as sedatives produced. Although chloral hydrate has enjoyed widespread use as a paediatric sedative agent for 2.6.1 Propofol many years it can be ineffective in the management Propofol (Diprivan: 2,6 di-isopropophenol) is a fast of the refractory child due to variable absorption and acting sedative with a narrower margin of safety partial inactivation in the hepatic portal circulation than some other agents, i.e. the dose required to [79]. Moreover, chloral hydrate depresses blood produce a sedative effect is close to that used to pressure and respiratory rate and may cause oxygen induce anaesthesia. Infusion pumps are used to control desaturation [80] and prolonged drowsiness [81]. the dose, and patient controlled systems are currently Nausea and vomiting are also common complications, in development, which have been used with some attributable to gastric irritation. In larger doses, success in adult patients [87–93]. Veerkamp et al. myocardial depression and arrhythmia can occur. (1997) published an account of an exploratory study The addition of nitrous oxide resulted in 27% of where children, mainly with nursing bottle caries, children losing control of their airway [82]. Chloral had teeth removed using propofol administered by hydrate is contraindicated in children with heart an anaesthetist. The authors reported that conscious disease as well as those with renal or hepatic sedation was difficult to achieve in this age group and impairment. Recently there has been concern that recommended further investigation [94]. Furthermore, there is a risk of carcinogenesis, especially when the use of propofol to sedate children in intensive used repeatedly [83]. It is rapidly becoming obsolete care units has lead to severe adverse reactions, as a sedative agent in paediatric dentistry. related to hyperlipidaemia [95]. It is therefore recommended that the use of propofol in children 2.5.2 Hydroxyzine hydrochloride and promethazine should be regarded as experimental and as such hydrochloride confined to hospital facilities with the assistance Hydroxyzine hydrochloride and Promethazine of a qualified anaesthetist until further research hydrochloride are psychosedatives with an evidence emerges in this population. antihistaminic, antiemetic and antispasmodic effect. Common side-effects are dry mouth, fever and skin rash. 2.6.2 Ketamine Hydroxyzine hydrochloride is a diphenylmethane Ketamine is a powerful analgesic, which, in small which is usually given orally or intramuscularly, singly dosages, can produce a state of dissociation whilst © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 367 Friday, August 16, 2002 9:35 AM Use of conscious sedation in anxious children 367 maintaining the protective reflexes. Side-effects dose administered. Some sedationists prefer to use a include hypertension, vivid hallucinations and (needleless) syringe placed in the buccal sulcus behind physical movement although these are less prevalent the teeth or to mix the drug with a flavoured elixir. in children [9]. Ketamine is also known to increase secretions, including salivation, increasing the risk 3.3 Intravenous sedation of laryngospasm [23,54,68,96]. Reinemer et al. (1996) found that the combination of a benzodiazepine with The majority of studies where intravenous seda- ketamine resulted in a statistically significant increase tion was performed have used adults, many of whom in blood pressure, heart rate and a fall in oxygen were undergoing third molar surgery, as the study saturation [97]. As such, advanced airway proficiency sample. The very few studies that reported the use of was recommended [54]. This drug is not recommended intravenous sedation in children have used multiple for use in paediatric dental sedation. drugs and have produced a deeper level of sedation than is acceptable in the UK, and they have therefore been excluded from this paper. Indeed, even paedi- 3.0 Routes of administration atric dentists in the USA, who have deep sedation techniques available, may prefer general anaesthesia 3.1 Inhalation over parenteral sedation in their private (non-hospital) The inhalation sedation technique that is com- practices [1,99–101]. monly used in dentistry refers to the administration of a titrated dose of nitrous oxide in oxygen. In this 3.4 Rectal route respect, the technique is different from the Entonox (50 : 50 oxygen and nitrous oxide mixture) that is Although the rectal route has been reported to be administered in maternity or medical A & E units. effective, predictable and safe, especially in relation Only dedicated dental nitrous oxide inhalation seda- to diazepam [40,47], this route has not found wide- tion delivery systems must be used. The standard spread acceptance in paediatric dental practice in the delivery system is designed to prevent administra- UK, probably because an enema is required. tion of nitrous oxide gas concentrations in excess of 70%, i.e. there is an assured minimum oxygen con- 3.5 Intramuscular centration of 30%. There should be a fail-safe device which shuts down nitrous oxide delivery should the Intramuscular administration of sedative agents is oxygen supply fail. The dentist sets the flow depend- reliable but painful and was mainly used in the UK ing on the calculated tidal volume of the patient and prior to induction of general anaesthesia. It is not then uses a single valve to vary the percentage delivery recommended for paediatric dental management of nitrous oxide against oxygen. Meanwhile, the [23,102]. dentist should encourage relaxation through semi- hypnotic suggestion and reassurance as the psycho- 4.0 Polypharmacy logical preparation by the operator exerts a beneficial influence on the analgesic effect of the gas [98]. The use of drug combinations or premixed drug cocktails is generally best avoided because of the increased risk of side-effects [23,103–105]. 3.2 Oral Respiratory depression is more likely to occur Oral agents have a slower and more variable onset when more that one sedative agent is administered. of action and depth of sedation than sedatives Milgrom et al. reported that 63% of their anxious administered by other routes. Compared to other young adult study group, sedated with a midazolam- routes, onset of sedation is prolonged and duration fentanyl combination, suffered from apnoea (cessation of action is unpredictable due to variable gastric of breathing) [106]. Barr and Wynn (1992) reported absorption. Despite this, Nathan (1989), in a survey that 37% of children sedated with ketamine and of USA pedodontists, reported that this was the fentanyl had either nausea or vomiting [107]. In a preferred route even for difficult paediatric dental more recent study, almost 40% of children sedated patients [1], even although children may spit out the with a combination of chloral hydrate, hydroxyzine dose [59], leaving the clinician uncertain of the exact and pethidine suffered from apnoea [108]. © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372 IPD_379.fm Page 368 Friday, August 16, 2002 9:35 AM 368 M. T. Hosey mucosal colour are detectable and symptoms may 5.0 Complications during paediatric conscious not become clinically evident until dangerously low sedation levels of oxygen tension develop [113]. The main complications related to paediatric conscious sedation are hypoxia, nausea and vomiting and 6.1 Pulse oximetry inadvertent general anaesthesia (over sedation). Morbidity and mortality increases in the extremes of Pulse oximetry has revolutionized modern moni- age and with worsening ASA classification [109]. toring procedures. It is a non-invasive method of Sams et al. (1992), in a retrospective review of case measuring arterial oxygen saturation using a sensor notes, reported that 48% of children had oxygen probe, placed on the patient’s finger or ear-lobe, desaturation while sedated for dental treatment which has a red light source to detect the relative [110]. Even although relatively few papers report difference in the absorption of light between saturated over-sedation or other adverse effects in paediatric and desaturated haemoglobin during arterial pulsation. dentistry, such complications are not uncommon Adequate oxygenation of the tissues occurs above [104,111]. Indeed, even the use of a mouth prop can 95%, whereas oxygen saturations lower than this misguide the sedationist leading to over-sedation. are considered to be hypoxaemic. Under normal cir- The interpretation of the level of sedation in cumstances, a child’s oxygen saturation (SaO ) is 2 literature published outside the UK, especially in 97–100%. relation to the GDC definition, is often difficult. The probe is sensitive to patient movement, In the USA, the different levels of sedation are relative hypothermia, ambient light and abnormal linked to mandatory levels of monitoring, facilities haemoglobinaemias, which means that false read- and expertise [112]. However, despite this, a critical ings can occur. Indeed, the role of carbon dioxide incident analysis of paediatric (medical and dental) monitoring (capnography), as an adjunct to pulse sedation suggested that permanent neurological oximetry and alert clinical observation, is under injury or death occurred most frequently in non-hos- increasing scrutiny [8,114–116]. pital-based facilities [104]. 7.0 General anaesthesia 6.0 Monitoring Whenever the level of sedation is found to be Although the principal functions monitored are the inadequate the planned procedure should be central nervous, cardiovascular and respiratory abandoned. An elective general anaesthetic is safer systems, hypoxaemia is the major complication in than topping up the sedative dose, even when this the sedation of paediatric dental patients. is done with extreme care [23]. Hypoxaemia is defined as a low partial pressure of oxygen in the blood, which may be caused by Author’s note conditions such as failure of oxygen supply, pulmo- nary disease, cardiovascular collapse, hyperventila- Reference to the dosage of the various drugs tion, apnoea or airway obstruction. Traditional mentioned, with the exception of nitrous oxide, has methods of monitoring sedated paediatric patients been deliberately excluded, as it was not my include visual observation of skin colour, depth intention to have this guideline used as a ‘recipe and rate of respiration, measuring pulse and blood book’ for conscious sedation of children. I am happy pressure and listening to heart and breath sounds to give further advice or information on request. using a pre-cordial stethoscope. Moore et al. (1984) described a method of determining the level of Acknowledgements consciousness in a sedated child in which the head was allowed to drop forward onto the chest while I’d like to express my sincere thanks to Dr Helen an observer listened for breath sounds [82]. Marlborough, Senior Assistant Librarian, at the Trained personnel skilled in conscious sedation University of Glasgow Library, for her invaluable are vital to monitor the safety and well-being of the contribution to the arduous task of systematically sedated child dental patient. However, hypoxaemia searching the wealth of published literature in this can occur before changes in vital signs or skin and and related subject areas. Without her help the © 2002 Faculty of Dental Surgery, Royal College of Surgeons, International Journal of Paediatric Dentistry 12: 359–372