Joan Fahy is a senior nurse at Mater Private Hospital, Cork. One of her specialties is haemovigilance.
The World Health Organisation describes haemovigilance as a “set of surveillance procedures covering the entire blood transfusion chain, from the donation and processing of blood and its components, through to their provision and transfusion to patients”.
This makes it a vital practice in health care.
Nurse Fahy says it is very important to donate blood particularly as she sees every day the huge benefits of donated blood and blood products.
Blood is a specialised fluid which has four main components: plasma, red blood cells, white blood cells, and platelets.
It has many different functions, including transporting oxygen and nutrients, forming blood clots to prevent and stop bleeding, transporting around cells and antibodies that help fight infection and bringing waste products to the kidneys and liver.
Generally, about 7% of your total body weight is blood. An average-sized person has 4.5 to 5.5 litres of blood. The liquid component of blood is called plasma which is a mixture of water, sugar, fat, protein, and salts.
Known for their bright red colour, red blood cells (erythrocytes) are the major component, accounting for about 40% of blood volume. The production of red blood cells is controlled by erythropoietin, a hormone produced mainly by the kidneys.
Red blood cells begin as immature cells in the bone marrow from where, after a period of growth they are released into the bloodstream. The red blood cell survives, on average, four months hence they are always in production.
Red blood cells contain a special protein called haemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled.
Blood appears red because of the large number of red blood cells, which get their colour from the haemoglobin.
White blood cells (leucocytes) protect the body from infection. They are much fewer in number than red blood cells, accounting for about 1% of your blood.
Platelets help the blood clotting process by gathering at the site of an injury, sticking to the lining of the damaged blood vessel, and forming a platform on which blood clotting can occur.
This results in clot formation, which covers the wound and prevents bleeding. Lower than normal platelet counts can lead to bleeding.
The Irish Blood Transfusion Service has a difficult and ongoing task of collecting enough blood to meet the needs of patients all over the country.
It requires up to 3,000 donations every week for people, who have suffered injury, had surgery, have a blood disorder or cancer, among many other reasons. In Ireland every week more than 1,000 people receive blood transfusions.
However, just 3% give blood. It is so important to donate because a person who has a bleeding stomach ulcer or has suffered trauma due to a car crash may require 30 units of blood.
Visit www.giveblood.ie or phone locall 1850 731 137 and enquire if you are suitable to donate or discuss it with your family doctor.
There are several reasons people cannot give blood and these are explained on the Irish Blood Transfusion Service website. On a given day there can be just four days’ supply remaining.
If you meet the criteria to give blood then do. Allow an hour or so for the whole process, make sure you eat before you go. Giving the blood itself only takes a few minutes.
Tea and a biscuit afterwards allows you time to rest. You will have donated about 470ml, less that a pint and you will have saved a life.
Telephone 021-601 3200
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