KEY POINTS:
A notorious drug linked to date rape is being used by paramedics because it is a better painkiller than morphine in some emergencies.
The decision to use ketamine, which is also known as a party drug, follows a study by Auckland's Westpac rescue helicopter paramedics on 44 patients
between January 2005 and October last year.
Advanced paramedics from St John Ambulance are also now using the drug, and have trained about 160 staff nationwide to administer it.
Auckland Rescue Helicopter Trust medical director Dr John Orton told the Herald that ketamine superseded morphine in many situations.
"Certain pains are fairly easily manageable with morphine-type drugs, but the excruciating acute pain of acute injury is extremely hard to get on top of with morphine," Dr Orton said.
"We're talking about 10 tonne tractors rolled on top of people ... or typical quad bike idiots on Muriwai Beach. They flip it and they've got two broken legs below the knee pointing at right angles but otherwise they're uninjured.
"You've got to straighten these limbs out and splint them. If you try to do that without this sort of agent, it's horrible - you cause excruciating discomfort. So to be able to do this in the field is a major bonus."
Mr Orton said ketamine had been used in medicine for 50 years, but its use in the field, outside a hospital environment, was new.
"Certainly in New Zealand this is the first time it was done," he said.
"What's unique for New Zealand and virtually unprecedented in Australia is to get advanced paramedics to use it in a pre-hospital setting."
Dr Orton said ketamine had some risks, but there were also risks with morphine, including the fact it slowed a patient's breathing, blood pressure and circulation.
Morphine was also not suitable for some head injuries.
"Ketamine has a very, very low risk profile in all those regards and you cannot say that about morphine," he said.
"The risks and the downside are practically nil and the advantages are enormous."
Auckland University associate professor of clinical pharmacology Dr Peter Black said the use of ketamine posed a small risk of medical complications, such as an irregular heart beat, and was also unsuitable for people with epilepsy.
But "there would seem to be no reason paramedics shouldn't use it provided the patient is appropriately monitored," Dr Black said.
St John Ambulance medical director Dr Tony Smith said advanced paramedics had used ketamine on about 100 patients in five months.
Reported side effects included hallucinations or bad dreams, but there had been no epilepsy or heart-related complications.
KETAMINE
* Can be snorted, injected, smoked or put in liquid and drunk.
* Used as a party drug.
* Used by vets and doctors as an anaesthetic.
* Has been associated with date rape cases.
HOW IT HELPS
* Emergency services say it is ideal for rescues where patients:
* Are trapped in or under a vehicle, or in machinery.
* Where "angulated fractures" have occurred and broken bones must be straightened while a patient is conscious.