MBBS UM (malaya) EXTENDERS

The second short note question would be about blood transfusion. Safe blood products, used correctly, can be life-saving. However, even where quality standards are very high, transfusion carries some risks. If standards are poor or inconsistent, transfusion may be extremely risky. No blood or blood product should be administered unless all nationally required tests have been carried out.


Blood component:
1 A constituent of blood, separated from whole blood, such as:

• Red cell concentrate
• Red cell suspension
• Plasma
• Platelet concentrates

2 Plasma or platelets
3 Cryoprecipitate, prepared from fresh frozen plasma: rich in Factor VIII and fibrinogen

Plasma derivative
Human plasma proteins prepared under pharmaceutical manufacturing conditions, such as:

• Albumin
• Coagulation factor concentrates
• Immunoglobulins

WHOLE BLOOD

• 450 ml donor blood
• 63 ml anticoagulant-preservative solution
• Haemoglobin approximately 12 g/ml
• Haematocrit 35%–45%
• No functional platelets
• No labile coagulation factors (V and VIII)

Indication

• Red cell replacement in acute blood loss with hypovolaemia
• Exchange transfusion
• Patients needing red cell transfusions where red cell concentrates or suspensions are not available

RED CELL CONCENTRATE

• 150–200 ml red cells from which most of the plasma has been removed
• Haemoglobin approximately 20 g/100 ml (not less than 45 g per unit)
• Haematocrit 55%–75%

Indication

• Replacement of red cells in anaemic patients
• Use with crystalloid replacement fluids or colloid solution in acute blood loss

LEUCOCYTE-DEPLETED RED CELLS

• A red cell suspension or concentrate containing <5>
• Haemoglobin concentration and haematocrit depend on whether the product is whole blood, red cell concentrate or red cell suspension
• Leucocyte depletion significantly reduces the risk of transmission of cytomegalovirus (CMV)

Indication

• Minimizes white cell immunization in patients receiving repeated transfusions but, to achieve this, all blood components given to the patient must be leucocyte-depleted
• Reduces risk of CMV transmission in special situations
• Patients who have experienced two or more previous febrile reactions to red cell transfusion

PLATELET CONCENTRATES
Single donor unit in a volume of 50–60 ml of plasma should contain:

• At least 55 x 109 platelets
• <1.2>
• <0.12>

Indications

• Treatment of bleeding due to:
• — Thrombocytopenia
• — Platelet function defects
• Prevention of bleeding due to thrombocytopenia, suchas in bone marrow failure

FRESH FROZEN PLASMA

• Pack containing the plasma separated from one whole blood donation within 6 hours of collection and then rapidly frozen to –25°C or colder
• Contains normal plasma levels of stable clotting factors, albumin and immunoglobulin
• Factor VIII level at least 70% of normal fresh plasma level

Indications

• Replacement of multiple coagulation factor deficiencies: e.g.
• — Liver disease
• — Warfarin (anticoagulant) overdose
• — Depletion of coagulation factors in patients receiving large volume transfusions
• Disseminated intravascular coagulation (DIC)
• Thrombotic thrombocytopenic purpura (TTP)

CRYOPRECIPITATE

• Prepared from fresh frozen plasma by collecting the precipitate formed during controlled thawing at +4°C and resuspending it in 10–20 ml plasma
• Contains about half of the Factor VIII and fibrinogen in the donated whole blood: e.g. Factor VIII: 80–100 iu/ pack; fibrinogen: 150–300 mg/pack

Indication
* As an alternative to Factor VIII concentrate in the treatment of inherited deficiencies of:
— von Willebrand Factor (von Willebrand’s disease)
— Factor VIII (haemophilia A)
— Factor XIII
* As a source of fibrinogen in acquired coagulopathies:
e.g. disseminated intravascular coagulation (DIC)


HUMAN ALBUMIN SOLUTIONS
Prepared by fractionation of large pools of donated plasma

Indication

• Replacement fluid in therapeutic plasma exchange: use albumin 5%
• Treatment of diuretic-resistant oedema in hypoproteinaemic patients: e.g. nephrotic syndrome
• or ascites. Use albumin 20% with a diuretic
• Although 5% human albumin is currently licensed for a wide range of indications (e.g. volume replacement, burns and hypoalbuminaemia), there is no evidence that it is superior to saline solution or other crystalloid replacement fluids for acute plasma volume replacement

COAGULATION FACTORS

Factor VIII concentrate

• Treatment of haemophilia A
• Treatment of von Willebrand’s disease: use only preparations that contain von Willebrand Factor

PLASMA DERIVATIVES CONTAINING FACTOR IX
Prothrombin complex concentrate (PCC)
Factor IX concentrate

• Treatment of haemophilia B (Christmas disease)
• Immediate correction of prolonged prothrombin time