Transfusion of stored blood can cause health problems
transfusion of stored blood is unsafe. It not only carries infections, but also invites serious problems such as heart attack. The process of extracting blood from a donor and storing it before transfusion could severely handicap the capabilities of extracted blood to provide oxygen to a recipient.
A new study shows that just after being taken out of the body blood loses the gas nitric oxide. This is present in haemoglobin and is responsible for opening up blood vessels for passing oxygen to tissues. The absence of nitric oxide could even lead to the death of the recipient.
Two separate studies were carried out by researchers at the Duke University Medical Center (dumc), usa. The findings were published in the Proceedings of the National Academy of Science in October 2007. Timothy McMahon, who led one of the research teams, says nitric oxide levels fall soon after collection. This shows even fresh blood may have adverse biological characteristics. "We were surprised at how quickly the blood changes. We saw clear indications of nitric oxide depletion within the first three hours,' says McMahon.
Jonathan Stamler, a microbiologist at dumc and a member of the second research team, says patients with trauma, heart surgery, heart disease and other critical illness go through many complications after a blood transfusion, including heart attacks, heart failures, and strokes. He suggests that it is the absence of nitric oxide in blood which causes the problems.
The researchers say this problem can be fixed by adding nitric oxide to the blood. Experiments conducted in dogs have shown that this oxygen-carrying capability was increased by 100 per cent.
Indira Dhall, a senior consultant of transfusion medicine at the Batra Hospital in Delhi, says the findings, if proven right in humans, can help cut down the number of units of blood which is needed per patient by increasing the capacity of the blood to carry oxygen. This will also reduce blood related infections.