Blood is only given if it is really necessary during or after an operation (e.g. in case of a major blood loss and significant decrease in the amount of red blood cells which may be associated with a reduced Oxygen-carrying capacity of blood and decreased blood pressure and increased heart rate or clotting factors when the blood clotting is compromised) 

The following blood products are availabe:

1. Your own blood (can be collected by a cell saver, filtered and re-infused into the vein)
2. Packed red blood cells (1 unit = half a pint of concentrated red cells which carry the oxygen)
3. Plasma (1 unit = half a pint of yellowish blood components, contains clotting factors, immune cells and fluid)
4. Platelets (1 unit is a bit less than half a pint, cells that are responsible for the clotting of the blood)
5. Prothrombin complex concentrate (containing the essential clotting factors 2, 7, 9 and 10).

If you don’t want blood (e.g. Jehova’s Whitnesses) or if you have any concerns please discuss with the nurse, surgeon and anaesthetist. Some patients only refuse human blood and blood components. However, synthetic clotting factors (Factor VII) are available, too. Tranexamic Acid is a drug that can enhance the clotting of your blood in case of ongoing bleeding. There are other measures to build up the number of red cells in your body before the operation (Erythropoetin, Iron). You may also accept cell salvage (the collection, filtration and infusion of your own blood, where the circuit will not be disconnected from your body. An enhanced directive (prepared prior to the hospital admission) can be helpful to meet the requirements of a patient.

Cell salvage (collection and re-infusion of you own red blood cells) is often used for operations with a major blood loss (e.g. open heart surgery, revision of joint replacements, vascular surgery, spinal surgery, liver transplantations, ruptured ectopic pregnancies, Caesarean sections with a high bleeding risk, some neurosurgical procedures) Cell salvage does not apply to every operation and/or patient. Contra-indications are bacterial contamination

Blood transfusions are more likely with larger or more complicated operations (e.g. Laparotomy, Nephrectomy, Bypass operations, larger fractures)

If there is a high possibility that a blood transfusion is required, a blood sample will be taken prior to the operation and blood will be either grouped and saved (blood type dertermined and tested for antibodies) or cross-matched (fully tested against a requested number of blood products) and blood products will be provided by the blood bank when needed.

Blood testing for "Group and Safe" is usually carried out for the following operations: Caesarean sections, hysterectomy, some laparoscopies, Placenta previa or Caesarean sections, Hip and knee replacements, shoulder and elbow replacements, fractured neck of femur, discectomies, spinal deconpression and fusion, cystectomy, nephrectomy, open prostatectomy, Pyeloplasty, TURP, TURBT, aortic aneurysm repair, aorto-femoral bypass, femoral-polpiteal bypass, carotid endarterectomy, liver biopsy, neck dissection, laryngectomy, mandibulectomy, anterior resection, hemicolectomy, laparotomy,  mastectomy, bilateral breast reduction, oesophagectomy, splenectomy, thyroidectomy, Parathyroidectomy, bowel resections (These are examples, it is not a complete list, and practice may vary between different hospitals)