Could a Blood Transfusion Give You a Heart Attack?

Article excerpt


EVERY week, more than 1,000 people receive blood transfusions in Ireland to help them cope with everything from having their appendix removed to openheart surgery.

Since the mid-20th century, blood transfusions have been regarded as essential for patients undergoing surgery.

But now there are concerns that, while blood transfusions have indeed saved lives, they may have also claimed them.

Recent studies suggest that undergoing a blood transfusion during surgery subsequently increases the patient's risk of death -- particularly from heart attacks or strokes -- and of serious illnesses, such as septicaemia, pneumonia and cancer of the lymph glands.

Experts fear surgeons are unaware of the risks of using transfusions except where they are absolutely vital.

The exact reason why being given a stranger's blood may have such a devastating effect is a mystery. But it is not linked to contaminated blood infecting them with deadly viruses.

Instead, scientists are investigating two possible causes. One is that donated blood, instead of boosting a sick person's ability to ward off infection, might leave their immune system unable to resist attacks by bacteria and viruses.

The other is that transfusions may trigger inflammation in the blood vessels, increasing the risk of heart attacks and strokes following surgery.

This is because during its 30-day shelf-life, stored blood undergoes key changes that can make it toxic for some recipients.

It is thought that toxic enzymes that are released by red blood cells and flushed out of the body through waste products instead accumulate in stored blood and attack the immune system.

Researchers at the University of Kentucky found that having a small blood transfusion of just one unit -- roughly a pint -- increased the risk of dying within 30 days by 32 per cent.

A pint is the lowest amount patients usually receive. Most need about three pints to help them cope with surgery.

The study, published in the Journal of the American College of Surgeons, looked at 125,000 patients undergoing surgery for a range of conditions, such as a hernia or appendix removal.

As well as the greater risk of death, it found the chances of developing blood poisoning, pneumonia or wound infections rose by 23 per cent, compared to those who did not get blood.

PATIENTS who got two units were at greater risk, with death rates in this group up 38 per cent and sickness 40 per cent.

'I was surprised that one unit [could have such a risk],' said researcher Dr Andrew Bernard, of the University of Kentucky's College of Medicine.

'But I believe that surgeons, anaesthetists and medical professionals under-appreciate the negative impacts of transfusion.

'Transfusion is a life-saving therapy that has made complex surgical treatment possible. But it also has undesirable effects on the immune system.'

One study, published in Anaesthesia and Analgesia, looked at 9,000 heart surgery patients and found the risk of dying within six months of having one or two pints of blood transfused increased by 67 per cent. Blood is made up of four main elements: red blood cells, white blood cells, platelets and plasma.

Most transfusions involve red blood cells that have been separated from the other components in blood, as they are responsible for carrying oxygen around the body.

When a patient loses blood during an operation, they lack sufficient red blood cells to keep the body in the position to make a full recovery. Without red blood cells, organs start to fail and can shut down.

Over the past 50 years, the use of donated red blood cells has extended from catastrophic bleeding into routine surgery. …