A shot in the leg bone to save cardiac arrest victims

A paramedic demonstrates how a small drill-needle can be inserted into the leg bone below a patient’s knee cap. This will be used to inject a shot of adrenaline to save a person who has suffered cardiac arrest.
PHOTO: A shot in the leg bone to save cardiac arrest victims

Paramedics here are testing a new way to get adrenaline to the heart of cardiac arrest victims - by drilling below the knee.

The Singapore Civil Defence Force (SCDF) and the Singapore General Hospital hope this could raise survival rates.

During a cardiac arrest, adrenaline, in addition to cardiopulmonary resuscitation (CPR) or an electric shock, is used to stimulate the heart and make it pump again, said Associate Professor Marcus Ong, senior consultant at SGH's Department of Emergency Medicine.

The adrenaline is usually delivered through an intravenous line in a vein in the arm. However, this is a challenge, explained SCDF's chief medical officer Ng Yih Yng.

"It's hard for paramedics to find the vein. It is flat during a cardiac arrest since there is no blood pumping through," he said.

Now, if intravenous insertion is not possible, paramedics will insert a 25mm-long needle into the leg bone below the patient's knee cap. This will be used to drill a small hole in the bone, which allows access to the bone marrow underneath, which connects to the body's circulatory system.

A shot of adrenaline, which is meant to constrict veins and restore blood flow, is then delivered into the bone marrow using a syringe.

This method could work more than 90 per cent of the time, compared to 50 per cent for the intravenous line, said Colonel Dr Ng. "The patient does not feel any pain because he would be unconscious during a cardiac arrest."

Paramedics will use the drill only if they fail to insert an intravenous line after two attempts, Prof Ong said.

The drill method is more expensive as each of these one-time-use drill-needles costs about S$200, while intravenous lines cost less than S$2.

From this month, SCDF and SGH will evaluate the effectiveness of the drill method on 400 cardiac arrest patients, and test if the benefits outweigh the cost.

Over 160 SCDF paramedics have been trained to use the medical drill, which is already used in public hospitals here.

Every year, about 1,800 people here collapse from cardiac arrest outside the hospital. About 3 per cent survive.

"Hopefully, we can bring up survival rates if we are able to get the life-saving adrenaline to them in a more effective way," said Prof Ong. "The public also has an important role in saving a life, by starting CPR as soon as possible."

This article was first published on August 4, 2014. Get a copy of The Straits Times or go to straitstimes.com for more stories.