ONE of the most difficult decisions I face as a consultant in special care dentistry is deciding how best to provide dental care for patients with learning disabilities who are referred to me for treatment. They can often have complicated medical histories or a physical or mental disability which makes it difficult for them to cooperate with dental care. In addition to their disabilities, they may also be anxious about dental care.
Traditionally, general anaesthesia (GA) was the first choice to manage pain and anxiety for people with special needs. But, following a number of deaths of children under anaesthesia in the 1990s, the use of GA was limited to a hospital setting in 1999. Current provision of dental care under GA varies around the UK and in some areas only oral surgery is available, while other centres are limited to day-case GA.
An alternative method of managing behaviour in special care patients is conscious sedation. It gives the option of providing more complex dental treatment over a number of visits rather than a ‘one-hit GA’. It also allows examination and preventative care on a regular basis.
Sedative drugs may be administered by a variety of routes: Inhalational sedation (IS) uses a mixture of nitrous oxide and oxygen delivered in varying concentrations by a dedicated machine via a nasal mask. It works well for people with mild learning disabilities who are able to understand the semihypnotic suggestions, which are important for the success of the technique. It is less successful in those with more severe disabilities who may not be able to cooperate with placement of the mask or breathe only through their nose.
Intravenous sedation (IVS) can be used for people with learning difficulties but requires cooperation with cannulation. The main difficulty once sedated is determining the level of sedation in someone with little or no verbal communication. The dental team must rely on observations: non-verbal signs of sedation and acceptance of dental care.
Oral sedation offers a significant advantage in that it avoids the need for intravenous access and requires little patient cooperation to administer. Midazolam provides safe and effective sedation with a rapid onset and can be added to any drink: tea, coffee, soft drinks etc. The usual adult dose is 20mg and peak plasma levels are generally achieved in 30 minutes so that dental treatment can usually start 15 to 20 minutes after administration. One difficulty we have found is acceptability: a patient may drink the midazolam on their first appointment but the second time they attend may be reluctant to take the funny tasting drink again.
Oral sedation can be unpredictable and unusual reactions are even more likely in someone with a learning disability. The sedationist must be able to cannulate and staffing and equipment must be of the same standard as that required for IVS.
Intranasal sedation (IN) has changed the way I manage patients with learning disabilities. It requires little cooperation from the patient and has a rapid onset. The standard adult dose is 10mg and using concentrated midazolam (40mg/ml midazolam with 20mg/ml lignocaine) requires only 0.25ml delivered by a mucosal atomisation device. IN midazolam is very easy to administer but it is not titrated against the patient’s response and requires venous access once the patient is sedated for administration of additional midazolam or reversal with flumazenil. It is an appropriate technique for the experienced sedationist and provides a safe effective way of administering dental care to people with special needs.
There are no set rules for providing care under GA or sedation and patients need to be assessed individually. The following factors need to be considered in making the decision:
● Is the patient in pain?
● Amount of treatment required
● Are intraoral examination and radiographs possible?
● Level of care available post treatment
● How far do the patient and carers travel? Are they willing to attend for a number of visits under sedation?
● Complexity of medical history – suitable for treatment in an outpatient setting or better managed in hospital?
● How long are GA and sedation waiting lists?
Assuming both sedation and general anaesthesia are available then patients fall into three categories:
1: Those who will not allow even an examination when awake and who present in pain. In this group, it can be difficult for carers to ascertain whether the person is suffering dental pain. GA is probably better than sedation for most cases to ensure treatment can be carried out to deal with the source of pain at the first appointment. This provides particular challenges for the dental team who must devise a treatment plan in theatre and ensure the availability of all necessary dental equipment and materials. In addition, consent must be obtained for all necessary treatment including extractions.
2: Those for whom sedation is partially successful: examination and cleaning are possible but not operative dentistry. This group can have sedation on a regular basis for recalls and oral hygiene measures but will require GA for more advanced care.
3: Those for whom sedation does allow examination but this reveals either a great deal of treatment or more complex dentistry is required, e.g. removal of wisdom teeth. For these patients the initial examination under sedation will help the team plan treatment and allow them to discuss this with the carers when obtaining consent. It allows efficient use of theatre time.
Consent should be obtained at the assessment visit. In England and Wales, an adult, even a parent, cannot give consent for another adult and treatment can only be carried out if it is in the patient’s best interest. However, those who care for the patient should be involved in the decision-making process. ‘Best interests meetings’ can be organised to decide if the treatment proposed is appropriate. The Department of Health produce Consent Form 4 for adults who are unable to consent to investigation or treatment. It includes details of an assessment of the patient’s capacity and best interests. There is space for those close to the patient and for two healthcare professionals to sign the form. For those without relatives or friends the Mental Capacity Act (2005) allows for appointment of an independent mental capacity advocate (IMCA).
In Scotland there are specific procedures and regulations to follow, governed by the Mental Health (Scotland) Act 2003, which involves issuing a certificate of incapacity.
It is reasonable that the risks of general anaesthesia are discussed with the patients and carers. It is not necessary to tell patients that they might die under GA but you can explain that current mortality rates in the UK are about 1 in 100,000 anaesthetics. This risk is considerably less than being seriously injured in a road accident. The limitations in the scope of dental care that can be provided under GA should be discussed and that teeth with extensive caries will be extracted and not restored.
Deciding on GA or sedation requires weighing up a host of factors and requires experience. There is a need for all means of controlling pain and anxiety to be available for people requiring special care dentistry. Sedation extends the range of dentistry possible for these patients and a move away from GA can only lead to an improvement in oral health for this group. However, there are still a significant number for whom GA will be the only option.
Dr Carole Boyle is a consultant in special care dentistry at King’s College London Dental Institute at Guy’s, King’s College and St Thomas’ Hospitals. Email: firstname.lastname@example.org