Sedation with 50% nitrous oxide/oxygen for outpatient dental treatment in individuals with intellectual disability

Persons with intellectual disability have difficulty in cooperating with outpatient care, and many are referred for general anaesthesia. Intellectual disability has traditionally been a contraindication for conscious sedation. We evaluated the behavioural impact, effectiveness, and tolerance of sedation in this population using a fixed 50% nitrous oxide/oxygen mixture as a single agent. We used dental treatment as a model of outpatient care; 349 patients (192 males, 157 females; mean age 22y [SD 14]; range 3-81y) were recruited over a 12-month period at seven centres. Sedation was deemed successful if planned dental treatment was completed. Behaviour was scored with the modified Venham scale. Out of 605 sessions, 91.4% were successful. No serious adverse effects occurred. Minor adverse events (such as nausea) occurred in 10.1% of sessions. We conclude that the use of safe and effective conscious sedation may reduce the indications for general anaesthesia.