A device that dates back to Roman times was used to save lives in the bloody aftermath of the Boston Marathon bombings about two weeks ago.
Rescuers reportedly whipped out belts, shirts and even neck lanyards to create tourniquets, using these to wrap around bleeding limbs to prevent major blood loss, shock and death.
It was a resounding endorsement of a first-aid tool that had been doubted in recent times.
But experts say the use of a tourniquet is still best left to medical professionals as it may cause more harm than good.
WHAT A TOURNIQUET IS
A tourniquet is basically a tight band placed around an arm or leg to constrict blood flow to the wound, according to the Singapore Red Cross.
The purpose is "to stop blood flow through an artery to prevent further blood loss", said Dr Steven Lim Hoon Chin, a consultant at Changi General Hospital's Accident & Emergency department.
The Romans started to use the tourniquet to stem bleeding during amputations.
Since then, surgeons and military personnel have used it, though its effectiveness came into doubt in the early 2000s.
The best tourniquets are the ones made by medical companies.
"There are commercial examples - some used in military settings - and there are improvised examples, such as the use of a belt, an electrical cord or a piece of clothing that is strong enough," said Dr Lim.
"The efficiency and safety of improvised devices is uncertain, but as long as bleeding can be stopped, lives can be saved."
If a makeshift one has to be used, make sure it is broad, said Dr Lim.
A wider tourniquet will distribute pressure more evenly and is less painful than narrow straps and bands.
"To stop arterial bleeding, a certain amount of pressure is needed to compress soft tissues such as skin, fat and muscles against the wall of the artery, which usually reside deeper," he said.
Use a rod or a stick to turn the makeshift tourniquet and increase the pressure, he said.
But bleeding will stop only if it is applied correctly.
How long a tourniquet should stay on is debatable and even controversial, said Dr Lim.
As a rule, it should be applied for as short a time as possible and the person should be rushed to the hospital immediately.
"Trained personnel should assess to see if it can be taken off during the ride to the hospital if the transport time is more than onehour," Dr Lim added.
WHEN TO USE A TOURNIQUET
In 2003, when solo climber Aron Ralston found his arm pinned under a 360kg boulder in a remote Utah canyon and had to amputate it to free himself, he used a makeshift tourniquet on his upper arm to prevent massive blood loss.
He had fashioned the tourniquet out of a rubber hose that he used to suck water out of his hydration pack.
For MrRalston, it was to make sure he would not bleed to death after the amputation.
In any case, a tourniquet is not something to be used freely and only in situations such as the following, said Dr Lim.
- When direct pressure does not stop the bleeding.
- In emergencies when medical care may be delayed, such as a mass casualty situation that overwhelms hospitals and proper medical care cannot be given to the injured immediately.
- In situations where it is not possible to apply direct pressure, such as a case of multiple bleeding sites or amputation.
THE LAST RESORT
While the tourniquet may look simple to use, it is definitely not for a layman to apply and is best left to medical staff or trained health-care providers, warned Dr Lim.
This is because if the tourniquet is not applied properly, it can increase bleeding, he said.
The use of a tourniquet is not included in the standard first aid course taught by the Singapore Red Cross Academy.
"Tourniquets are complex procedures that should ideally only be done by trained medical professionals, because someone who does not know how to perform one could end up causing more harm than good," said the academy's senior training instructor, Mr Stephen De Souza.
"While it helps to constrict blood flow to the wound, the tourniquet can also cause more bleeding from below it as it prevents the flow of blood back to the heart.
"Eventually, the tissues below the tourniquet are starved of blood and die from lack of nutrients and oxygen."
Dr Lim said there is always the risk of damage to underlying tissues such as muscles, blood vessels and nerves. There is also a possibility of a decrease in the blood supply to a body organ, tissue or part caused by constriction of the blood vessels, as well as a loss of limb.
Said Mr De Souza: "In a situation such as the Boston Marathon blast, if medical personnel are around, a bystander should leave any care to the medical professional.
"Even a trained medic would not apply a tourniquet unless it is the last resort."
This story was first published in The Straits Times on May 2, 2013
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