Conscious sedation in general dental practice

23 April 2021
4 min read
Published:

Ben Goode discusses the use of intravenous midazolam.

Dental anxiety affects almost half of the population and as a profession we have a duty to do all we can to ensure that these patients can access good quality dental care. With the help of a well-trained dental team, many of these patients overcome their fears by non-pharmacological methods. There are, however, a significant number of patients whose fear is so severe that they avoid dental care in all but extreme occasions and attend the dental practice for emergency care only. These patients often have neglected dentition with high treatment need, often set in a backdrop of previous painful experiences.

It is this group of patients that will benefit greatly from pharmacological intervention to help them establish good oral health.

Conscious sedation
In 2015, the Dental Faculties of the Royal Colleges of Surgeons and the Royal College of Anaesthetists produced a guidance document for members of the dental team who provide conscious sedation. This is considered to be current best practice in the provision of dental sedation. They define conscious sedation 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 for dental treatment should carry a margin of safety wide enough to render loss of consciousness unlikely.”

Conscious sedation is not a replacement for local anaesthesia or good behavioural management but can help patients who experience:

  • Dental phobia
  • Severe gag reflex
  • Anxiety about a particular dental procedure (such as extraction)
  • Special needs

Intravenous (IV) conscious sedation can be carried out with a number of drugs but in this article we will deal specifically with midazolam, as it is the most commonly used in general dental practice.

It can be provided by a suitably trained dental team and is most commonly given to adult patients.

As a member of the benzodiazepine group of drugs, it works on the GABA receptors in the central nervous system. This results in reduced anxiety, an amnesic effect, and generalised relaxation. However, it also causes respiratory suppression, therefore careful assessment and monitoring of the patient is required.

Assessment of the patient
As with any dental procedure, a full oral health examination is required which includes:

  • Presenting complaint
  • Medical history
  • Previous dental history
  • Extraoral examination
  • Intraoral examination
  • Special tests (radiographs and so on)

Specific to dental sedation:

  • Blood pressure
  • Oxygen saturation
  • BMI
  • Pulse
  • Social history (for example, do they have a suitable escort who can care for them as well as any of their dependents?)
  • ASA grading – this is a grading of a patients general health from the American Society of Anaesthesiologists (see table below)
ASA Grade  
I Fit and healthy
II Mild systemic disease
III Severe systemic disease
IV Incapacitation disease that is a constant threat to life
V Moribund patient who is not expected to live 24 hours with
or without surgery

Following the assessment, a diagnosis and treatment plan is devised. A written treatment plan, consent, preoperative instructions and medical history form is completed by the patient prior to booking the sedation appointment.

Training
Current guidelines recommend that all conscious sedation training courses must be externally quality assured and assessed. They should also incorporate supervised clinical practice.

In practice this requires dentists to have completed a recognised diploma in conscious sedation, such as that provided by Newcastle Dental School or King's College London.

Dental nurses should have completed the certificate in dental sedation nursing provided by the National Examining Board for Dental Nurses.

For revalidation all members of the team must undergo a minimum of 12 hours of continuing professional development every five years that are relevant to the techniques practised. They must also complete immediate life support and airway management training annually.

Equipment required

  • A pulse oximeter to monitor the patient’s oxygenation and pulse rate
  • A blood pressure monitor
  • Flumanezil (the reversal agent for midazolam), administered in the case of over-sedation
  • Full dental emergency drugs kit, including portable oxygen
  • Defibrillator

On the day of their appointment
The patient attends with their escort and following confirmation of their consent for treatment, an indwelling cannula (for example, venflon) is placed in a vein. This is usually in their antecubital fossa or dorsum of their hand. It is secured into position for the duration of the procedure, along with the blood pressure cuff and pulse oximeter finger probe.

Midazolam of strength 1mg/ml is titrated at a rate of 1mg per minute until the appropriate level of sedation is achieved that allows the patient to accept treatment. This is usually within the range of 1mg-10mg midazolam.

Throughout the procedure, both the dentist/sedationist and dental nurse continue to monitor not only the pulse oximeter but more importantly the patient. Observations such as breathing rate and pallor give an indication as to the quality of sedation and health of the patient. At all times patients must be able to respond to verbal commands and should be comfortable and relaxed.

After treatment
After treatment has been completed and at least one hour after the last increment of midazolam has been administered, the patient can be assessed for discharge into the care of their escort.

This will include:

  • Are the patient’s vital signs stable and within a normal range for them?
  • Can the patient walk unaided?
  • Can they complete Eve’s test?
  • Have written and verbal postoperative instructions been given to both the patient and escort?

The cannula and pulse oximeter can then be removed and the patient discharged. The complete assessment and treatment of a patient with IV midazolam cannot be covered by one article but this is intended to provide all members of the dental and wider healthcare team with an overview of the procedure. It is an exciting field to be involved in and makes dental care possible for many patients who otherwise would be unable to accept it.