ER ketamine
Aggressive ER patients that do not respond to sedatives could be given ketamine.Tetra Images/Getty Images

Party drug ketamine has been found effective to sedate difficult and aggressive ER patients.

A small study, published in the Annals of Emergency Medicine, shows that a minority of patients do not respond to the usual sedatives. They could safely be given ketamine instead, allowing doctors to treat them without fear for their own security.

Ketamine is an anaesthetic and analgesic drug. It is mostly used in veterinary medicine as an animal tranquilizer but can also put humans to sleep before an operation. An increasing number of studies have also showed it can treat many different psychiatric diseases, including severe depression.

However, in recent year, health authorities have also warned of the potential risks of ketamine, since it is used illicitly as a party drug and a hallucinogen. It can lead to extreme dizziness, drowsiness and confusion, and is sometimes referred to as a "date rape drug". It has no particular smell or taste, and has sometimes in the past been put in the drinks of unsuspecting women.

Sedated in 20 minutes

The study investigated the effect of a small dose of ketamine on 49 emergency patients, in two hospitals of Newcastle, Australia. Over half (57%) of them were male and all displayed acute behavioural disturbance and signs of aggressiveness. The average age was 37 years old.

The first sedative drug that was given was droperidol. If this didn't work after the second attempt, patients were then given ketamine. Out of those 49 people, only about 10% (five patients) did not achieve sedation within two hours or required additional sedation within an hour.

They were then given ketamine, and sedation was successful in all these cases, after an average time of 20 minutes.

Few adverse effects

Demographic characteristics and drug doses were recorded at the time of the study, and only three of patients encountered minor adverse effects with ketamine, including vomiting and transient oxygen desaturation ( a drop in the blood's oxygen levels). Therefore, according to scientists, ketamine can be used on a small number of patients at small doses of 4 to 5 mg/kg without too much risk for the patient.

"Difficult to sedate patients with behavioural disturbances (...) cause significant disruption and danger to emergency department staff, and consume time and resources required for other patients." says study author Geoff Isbister, MD at the University of Newcastle in Australia.

"Although such patients are uncommon, they cause significant disruption and danger to emergency department staff, and consume time and resources required for other patients. Ketamine is a reasonable third-line agent to use on these patients once other sedation options have been exhausted", he concluded.