Blood Transfusion

Dr. Tanuj Paul Bhatia

Indications

1. Elective transfusion - Correction of anemia before surgery - In preparation for major surgery2. Emergency transfusion - Hemorrhage

• Post Traumatic• Operative/Post operative• Spontaneous

Blood Grouping

• More than 400 antigen systems have been identified.

• Expressed on red cell membranes.• Such antigens capable of interacting with

serum antibodies in recipient.• HOWEVER, only a small proportion have

potential to cause clinically significant hemolysis.

ABO system

• System of sugar residue antigens.• MOST IMPORTANT ANTIGEN SYSTEM

WHY?

IgMPresence of naturally occuring IgM antibodies in the serum

• They occur spontaneously.• Are directed against A and/or B antigens that

the individual’s own red cells do not carry.• Can cause fatal reactions by causing lysis of

incompatible red cells within intravascular compartment.

Blood Group

Antigen(s) present on the red cells

Antibodies present in the serum

A A antigen Anti-B

B B antigen Anti-A

AB A antigen andB antigen

None

O None Anti-A and Anti-B

Rhesus system

• Antibodies are IgG type.• These are induced antibodies and not

naturally occuring.• Require a past exposure to cause reactions e.g. Previous blood transfusions or exposure

to fetal red cells during pregnancy.

• Mainly cause red cell destruction in RE system i.e. Extra vascular hemolysis.

• Consists of 47 antigens.• c, C, D, e and E are most important. • Rh positive = D antigen present• Rh negative = Absent D antigen

Other blood group systems

• Many other systems• Most likely to be implicated in

hemolytic transfusion reactions are Kell,Kidd, andDuffy.

Cross-matching

• Blood routinely grouped according to ABO and Rhesus systems.

• After matching donor and recipient blood groups, cross matching is done.

• Donor RBC are incubated with recipient’s serum to look for evidence of hemolysis

Macroscopic evidenceMicroscopic evidence

Physiology of stored blood

• Several metabolic and functional changes occur.

• Easily compensated by an individual with moderate hepatic, renal or bone marrow function.

• Blood is stored at 4-8 C mixed with anticoagulant, most commonly CPD-A (citrate-phosphate-dextrose-adenine).

• Red cell changes• Depletion of ATP and 2,3 DPG.• RBC become rigid and less effective in oxygen delivery

to tissues.

• White cell and platelet changes• No useful function in blood stored for more than 24 hrs.

• Coagulation factors• V, VIII and XI fall in 24 hrs• IX and X become ineffective in 7 days.

• Biochemical changes– Becomes acidotic– Becomes hyperkalemic– Due to spontaneous red cell lysis– Readily compensated except in seriously

compromised patients and massive transfusion.• Microaggregates

– Granulocyte –platelet aggregates start to form within 24 hrs of storage.

– Can form pulmonary microemboli .– Thus BT set should have an appropriate filter.

Whole blood and component therapy

Whole blood

Platelet rich plasma

Platelet concentrate

Fresh frozen plasma

Cryoprecipitate

Red blood cells

Red blood cell concentrate

Whole blood

• Fresh whole blood– Rich in all blood elements

including coagulating factors.

• Stored whole blood– Looses many properties as

explained.– CPD-A blood can be stored

at 4-8 C for 35 days– CPD blood for 21 days

Whole blood(contd.)

Indication - Acute , active blood loss with hypovolaemia - Exchange transfusion

Contraindication - Risk of volume overload : Chronic anaemia Incipient cardiac

failure

1 unit increases Hb by about 1.4 g/dl

Packed red cells• Units with red blood cells and some

plasma• With anticoagulant like CPD-A• Hematocrit is 75% to 80%• Indication - Replacement of red cells in anaemic patients. - Use with crystalloid or colloid solution in acute blood loss.

Dosage 10 - 15 ml / kg

Fresh frozen plasma

• Contains approx. 200 ml of plasma.• Frozen within hours to preserve the level of

coagulation factors.• Stored at -40 C, has a shelf life of 6 months.• Should be thawed for 30 minutes in waterbath

before admi.• To be given within 30 min after thawing.

FFP(contd.)

• Indications– Coagulopathies eg. Due to liver disease.– DIC

Cryoprecipitate

• Prepared from FFP by thawing and separating and refreezing jelly like precipitate.

• Enriched with factor VIII, Fibronectin and Fibrinogen.

• Volume is about 20 ml. • Indicated in patients with Hemophillia,

uncontrollable hemmorhage and DIC.

Platelet concentrates

• Each unit of platelets are suspended in 30-50 ml of plasma .

• 5 to 6 such units are combined to make a ‘Pool of platelets’ to raise platelet count by atleast 30 x 10⁹/l in a 70 kg man.

• The only blood product not kept refrigerated, stored at 22 C under gentle agitation.

• Shelf life is less than 5 days.• Indicated in DIC, Dengue fever, Bone marrow failure.

Transfusion reactions(Hazards of transfusion)

• ‘Reaction’ = ‘Any unwanted effect of blood transfusion’

• Doctor should always be sure that transfusion is absolutely necessary and consider alternatives.

• Upto 1 L of blood loss can safely be restored with crystalloids alone if bleeding has

stopped .

1. Immediate and life threatening

• Profound intravascular haemolysis,• Air embolism,• Circulatory overload,• Complications of massive blood transfusion.

2. Immediate but not life threatening

• Severe extravascular hemolysis,• Febrile reactions,• Atopic reactions.

3. Late reactions

• Delayed immune mediated hemolysis• Local reactions• Transmission of infection

Hemolytic reactions

• Fortunately rare• Cause = transfusion of mismatched blood due to clerical

or technical error.• Always check labels on blood bags as well as patients

blood group before starting transfusion.• Signs and symptoms

– Pain at infusion site– Shortness of breath– Chest pain– Facial flushing, vomiting– Fever and rigors

Hemolytic reactions(contd.)

• Patient may go for shock, renal failure, DIC and jaundice.

• Rx– Stop transfusion immediately– Maintain venous access and saline infusion– Inj chlorpheniramine 10 mg iv given stat– Steroids– Insert urinary catheter– Management of complications

Febrile reactions and minor allergic reactions

• Nonhemolytic febrile reactions and minor allergic reactions are the most common transfusion reactions.

• Each occurring in 3-4% of all transfusions.• Nonspecific symptoms of fever, chills, and malaise.• Rx

– Stop transfusion– Inj CPM 10 mg iv – Send to lab for re-crossmatching

Complications of massive blood transfusion

• Massive transfusion is defined as the replacement of more than one-half of the blood volume within a 24-hour period .

• Or replacement of 10 units of blood over the course of a few hours .

Complications are…

1. Volume overload,2. Hypothermia,3. Coagulopathy,4. Hyperkalemia,5. Metabolic acidosis,

Transmission of infection

• HIV• HBV• HCV• Syphilis

• All donors and all of donated blood is to be screened for the above.

THANK YOU