Gas Anaesthesia in Dentistry: Past Bans, New Practices and the Introduction of Relative Analgesia

The Historical Context

In the United Kingdom, the use of chair dental general anaesthesia was never 'banned.' However, the Royal College of Anaesthetists and the General Dental Council jointly recommended in the late 1990s and early 2000s that general anaesthesia for dental extraction should only be offered in a hospital setting. This change aimed to improve safety and discourage the use of general anaesthesia for simple extractions, where local anaesthesia is often sufficient.

This recommendation was made to address the perceived significant risks associated with administration of general anaesthesia in dental surgeries. Concerns were raised about the lack of dedicated anaesthetists and resuscitation equipment, which could be inadequate in a dental office.

Around 90% of dental surgeries in the UK had never experienced a critical or fatal incident, compared to a small number of such events in hospitals. Nonetheless, the joint recommendation was made to ensure a consistent standard of care and patient safety.

Why the Recommendation?

The primary reasons behind this recommendation were two-fold:

Improving safety by ensuring that only qualified personnel with appropriate equipment and skills deliver general anaesthesia in a controlled environment (hospital). Encouraging the use of local anaesthesia for minor procedures where it is more appropriate and safe.

While this recommendation has been in place for over a decade, it is not currently being reversed in the UK.

Relative Analgesia: A Different Approach

While the recommendation discouraged the use of general anaesthesia for simpler extractions, it did not rule out the use of analgesics or sedatives. One such alternative is relative analgesia, a technique that uses low concentrations of nitrous oxide, commonly known as 'laughing gas,' to provide some sedation and pain relief.

Relative analgesia is administered through a dedicated machine that resembles an anaesthetic machine, but it is designed to deliver sub-anaesthetic concentrations of nitrous oxide. This ensures that the patient remains conscious and responsive to verbal commands, thus making it a safer option for patients who may be too anxious for a local anaesthetic alone.

How Relative Analgesia Works

During relative analgesia, a patient inhales a mixture of nitrous oxide and oxygen through a small mask. The nitrous oxide concentration is kept below the level that would render the patient unconscious, ensuring that the patient remains in control and can communicate with the dentist.

This technique is particularly useful for patients who have a significant fear of needles or require more complex procedures. Patients who receive relative analgesia often report feeling more at ease and relieved of pain and anxiety during the dental procedure.

Conscious Sedation: An Evolving Practice

Conscious sedation is another sedation technique used in dentistry today. This method involves the use of sedative drugs, typically administered orally, to reduce anxiety and induce a state of mild sedation. With conscious sedation, the patient remains fully conscious but experiences a heightened sense of relaxation and reduced anxiety.

Conscious sedation techniques are particularly beneficial for patients who have moderate to severe anxiety or who have had negative previous dental experiences. Dentists carefully titrate the dosage of sedatives to maintain the patient's level of consciousness, ensuring that the patient can still respond to verbal commands and assist in the procedure if needed.

Conclusion

The introduction of relative analgesia and the evolving practice of conscious sedation represent advancements in dental care. These techniques provide safer and more comfortable alternatives to general anaesthesia for certain dental procedures, allowing more patients to receive the care they need with increased comfort and lower risks.

As technology and safety standards continue to improve, it is likely that dental practices will increasingly adopt these innovative methods to meet the diverse needs of their patients.