IV SEDATION INTRODUCTION
Dental professionals are licenced to dispense single drug intravenously for sedation. This is typically Midazolam, a Benzodiazepine.
It is important that all sedation is completed with appropriately trained staff. This includes two people with sedation training acquired through formal training or mentorship. This is generally one clinician trained for sedation who also completes the procedures, one sedation trained dental nurse to aid the sedation and one dental nurse to assist with the procedures. No treatment should be completed without appropriate assessment of the patient and without necessary training. Logbooks are traditionally maintained to keep a record of the number of patients treated and the outcome. This aids maintenance of the skills for treatment alongside appropriate CPD.
A technique in which the use of a drub, or drugs, produce a state of depression of the central nervous system enabling treatment to be carried, out, but during which communication can be maintained and the modification of the patient’s state of mine is such that the patient will respond to command throughout the period of sedation. Techniques used should carry a margin of safety wide enough to render unintended loss of consciousness unlikely. (GDC June 1996)
1950’s: First Synthesised
1960’s: Diazepam used intravenously for anaesthesia induction
1986: Midazolam is developed
Benzodiazepines act on the central nervous system, specifically the gamma-aminobutyric acid (GABA) moderator. Receptors for GABA can be divided into GABAA and GABAB. GABAA receptors inhibit neural transmission causing sedation, amnesia, anxiolysis, muscle relaxation and anti-convulsant activity. GABA act on GABAA receptors to increase the chloride ions released. This reduces the excitability of the neurone giving the changes in the nervous system. Agonists (Lorazepam, Midazolam and Diazepam) increase the potency of GABA on the GABAA receptors to further increase the Chloride ions released, which effectively causes a shift in the GABA concentration-response curve to the left. GABA is still required for the effect. Antagonists (Flumenazenil) have the opposite effect and therefore shift the curve to the right.
Different agonists have a variable affinity to the receptor site which alters potency. This means that Lorazepam is more potent that Midazolam and in turn Midazolam is more potent than Diazepam.
Author: Amelia Reed
Last update: 10/04/2015