Experts raise transfusions fear

Doctors’ ‘love of blood’ gone too far, risks lives

LIKE antibiotics, X-rays and vaccines, blood transfusions are widely considered to be among the greatest breakthroughs in medicine.

Since World War II, when they were first used large-scale, they have saved countless lives across the world.

But now, with about 2 million transfusions a year performed on the NHS, there are fears that what some experts call doctors’ “love of blood” has gone too far, potentially endangering patients with transfusions that are unnecessary – an estimated one in five cases.

Concerns over the safety of blood from strangers were highlighted recently by a Dutch study that suggested men given transfusions during surgery were 50% more likely to die within hours of an operation if the blood had been donated by a woman who’d been pregnant.

The most common cause of death was transfusion-related lung injury, a rare condition where an abnormal immune response makes the recipients’ lungs severely inflamed within six hours of blood being given. The lungs become starved of oxygen, leading to cardiac arrest.

The findings of the Dutch study, published in the Journal of the American Medical Association, were based on the outcomes of more than 30 000 adults given transfusions of blood between 2005 and 2015 – there was no risk to other women from the once-pregnant women’s blood, while men were generally safe with blood from any other donor.

The results are potentially alarming because – other than blood type – donor details are never disclosed at the time of a transfusion.

Scientists think one explanation may be that infection-fighting cells called antibodies, acquired by women during pregnancy to protect their baby in the womb, may trigger a fatal immune system reaction in some men.

And there are other safety concerns to do with the use of stored blood.

Studies show an increased risk of infections, including pneumonia, among patients given a stranger’s blood stored in bags for a month or more at 4ºC.

One theory behind why this occurs is that red blood cells this old may be less resilient than those in fresh blood and get broken down more quickly when pumped into the body.

When this happens, they release large amounts of iron – a major source of energy for bacteria.

Another concern is that storing blood may trigger biochemical changes that are potentially harmful. Some studies suggest that red blood cells release toxic enzymes that would normally be flushed out of the body through waste products, but instead accumulate in stored blood.

Bloodstream

Stored red blood cells can also lose their smooth, disclike shape and become more pointed and spiky – making it harder for them to move through the bloodstream, depriving vital organs of their oxygen payload.

But using fresh blood may not be the answer. A 2015 University of Edinburgh study looked at deaths among 2 500 anaemic patients in intensive care wards who were either given blood a week old or blood almost a month old.

The results, published in the journal Blood, found no difference in deaths in the three months after treatment.

Blood is made up of four main elements: red blood cells, white blood cells, platelets and plasma.

Most transfusions involve red blood cells, which carry oxygen around the body. Without red blood cells, organs start to fail and shut down.

But, over the years, the use of donated red blood cells has increasingly been extended from treating catastrophic bleeding into routine surgery. Some experts say this is because of surgeons using “precautionary” transfusions, for added security of the patient making a full recovery, even if there has been no or minimal blood loss.

Figures collated by Serious Hazards of Transfusion (SHOT) – a body funded by UK blood and transplant services – found that last year, there were 26 reported deaths where transfusions were implicated. Another problem is mistakes, such as patients being given the wrong blood type.

About 10% of 1 027 adverse events reported to SHOT last year were caused by human error from heavy workload or inadequate staffing.

There is a major drive to improve patient safety and cut costs by curbing excessive use of donated blood in Britain. – Daily Mail