Experts who think blood transfusions could be HARMFUL

More are being given than ever. But with potentially deadly side-effects, is it now time to limit their use?

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 around two 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 per cent more likely to die within hours of an operation if the blood had been donated by a woman who’d ever 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 inflame within six hours of blood being given. The lungs become starved of oxygen, leading to a 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 4c.

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. A NOTHEr 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.

Stored red blood cells can also lose their smooth, disc-like 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 on 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 due to surgeons using ‘precautionary’ transfusions, for added security of the patient making a full recovery, even if there has been no or minimal blood loss.

The main sign that donor blood may be needed is anaemia — a drop in haemoglobin, the oxygencarrying substance in red blood cells. Controlling anaemia is crucial, as patients with low haemoglobin levels are 42 per cent more likely to die in the 30 days after an operation than those with normal levels.

A healthy man usually has haemoglobin of 13.5 to 17.5 grams per 100ml of blood and a woman 11.5 to 15.5g.

If levels drop below 5g — typically as a result of blood loss during surgery — the risk to a patient dramatically increases.

But studies show most surgeons transfuse blood at the first hint of anaemia, when haemoglobin readings are still 10g or higher. Some experts fear this is putting patients at risk.

‘Britain’s blood transfusion service is fantastic and, in some ways, it has been a victim of its own success,’ says Professor Toby richards, a vascular surgeon at University College Hospital London and one of the country’s leading experts on donated blood. ‘I can take a blood sample from a patient and receive matched blood for transfusion quicker than I could order a pizza.

‘But transfusions do kill people. The current data shows transfusion is not the most appropriate solution to the management of anaemia.’ The main risk is transfusionassociated circulatory overload (TACO), where too much blood is pumped into the circulatory system too quickly, putting the heart under strain as it tries to pump the additional fluid round the body.

Figures collated by Serious Hazards of Transfusion (SHOT) — a body funded by blood and transplant services from all four parts of the UK — found that in 2016, there were 26 reported deaths where transfusions were implicated. At least 14 were due to TACO.

Another problem is mistakes, such as patients being given the wrong blood type. Around 10 per cent of 1,027 adverse events reported to SHOT last year were due to human error from heavy workload or inadequate staffing.

Now, there is a major drive to improve patient safety and cut costs by curbing excessive use of donated blood.

NICE (the National Institute for Health and Care Excellence) has issued guidance calling for better treatment of anaemia before patients go to theatre — reducing the need for transfusions.

It wants doctors to give more surgery patients with anaemia a medicine called tranexamic acid, a relatively cheap and effective drug that reduces blood loss by at least a third; NICE estimates the drug is currently used in as few as 10 per cent of surgery cases where anaemia is present.

Professor richards, meanwhile, is spearheading a major trial across 40 hospitals in the UK involving a different approach. It is recruiting around 400 patients due for major elective surgery and identified in advance as having irondeficiency anaemia, the most common reason for a low red blood cell count.

Anaemic patients are often advised to take iron tablets or eat iron-rich foods such as red meat and green, leafy vegetables before surgery to bump up their levels.

But Professor richards says dietary iron is absorbed slowly, and it can take six to nine months for it to boost haemoglobin to healthy levels.

In the trial, these patients will be injected with high doses of iron — the equivalent of a year’s iron in the diet — around a week before their operation.

He expects the trial, which finishes in 2018, will reduce NHS use of blood transfusions by at least 15 per cent, saving around £35 million a year. But is restricting the use of blood transfusions really going to be safer? The picture is not clear.

Gavin Murphy, a professor of cardiac surgery at the University of Leicester, recently carried out one of the biggest-ever studies into the safety of transfusions, involving more than 2,000 UK patients. H IS earlier research, in 2007, suggested receiving just one unit of donated blood — roughly a pint — increased the risk of heart attacks and strokes by more than 30 per cent in the month after surgery: the theory is that it triggers severe inflammation inside the arteries around the heart.

But his latest study, published in the New England Journal of Medicine in 2015, seemed to find the opposite. It compared what happened to heart surgery patients if surgeons only gave them blood if their haemoglobin dropped below 7.5g (‘restrictive’ use), compared to others who got it at 9g (‘liberal’ use).

Professor Murphy and his fellow researchers anticipated fewer deaths among the restrictive group — but 4.2 per cent of patients in this group died, compared with just 2.6 per cent in the liberal group.

‘The findings were completely at odds with what we anticipated,’ says Professor Murphy.

‘The culture in the NHS is about restricting the use of blood transfusions. But our study found that when you restrict use in heart surgery, more people die.’

NHS Blood and Transplant told Good Health that it is rolling out a programme of ‘patient blood management’ — or limited use of transfusions — across the health service in England.

It says it will lead to fewer complications, faster recovery and shorter stays in hospital.