Half of all hospital drug injections are wrong

00:01 28 March 03 NewScientist.com news service

Half of all drug injections given intravenously in hospitals are done wrongly, a new study reveals, with third of these being potentially dangerous.

British researchers uncovered the disturbing level of errors when they examined drugs given intravenously by nurses in two hospitals in the UK. They believe the rate of mistakes they found is likely to be representative of practice across Europe and the US.

Nick Barber and Katja Taxis, at the School of Pharmacy, London, tracked the preparation and administration of over 400 intravenous (IV) doses given to patients on 10 different wards in the hospitals. "We were surprised about how commonly errors occurred," say Barber. "But not all of these were serious."

However, the error rate they calculated from their data predicts one serious error every day in every hospital in the UK, which is a concern, he says.

The most common mistakes were injecting doses of concentrated drugs too rapidly and preparing drugs incorrectly, by either using the wrong dose or dissolving them in the wrong solution. All could be fatal in certain circumstances.

Speed kills

For some drugs, the speed at which it enters the body is crucial, Barber explains. If they are injected too fast, they can induce anaphylaxis - a life-threatening allergic reaction.

"This is because there is a load of potent foreign chemical shooting around your body - if it hits the brain or heart it can have a marked effect," he said. But injecting a drug slowly, for example, over three minutes can be physically difficult for health care staff.

One of the three "potentially severe" errors Barber and Taxis in their study was of this type - with the antibiotic vancomycin being given too quickly. However, a pharmacist observer for the study intervened before any harm was done.

The second severe error occurred when a patient was nearly injected with an IV preparation containing five times the correct dose of heparin - which stops the blood clotting. "Wrong dose errors are the ones most likely to cause harm," notes Barber.

The third potentially lethal error was when an intensive care team infusing a patient with adrenalin ran out of the drug and had not prepared a second infusion in time.

Barber says the key to tackling such errors was to improve nurse training. He says there would also be a role for companies to develop a simple pump to help nurses administer drugs slowly.

Journal reference: British Medical Journal (vol 326, p 684)

Shaoni Bhattacharya