BLOOD TRANSFUSION REACTIONS

Some type of reaction will occur in about one to 2% of patients who receive blood transfusion. The antigens of the ABO and Rh systems commonly produce transfusion reactions. In the case of other antigens a number of incompatible transfusions may be required to stimulate sufficient antibodies and cause a reaction. (A) Immunological reactions: (1) Intravascular haemolysis. (2) Extra vascular haemolysis. (3) Sensitivity to white blood cells, platelets and plasma components. (B) Non-immunological reactions: (1) Circulatory overload. (2) Coagulation defects. (3) Hyoerkalaemia. (4) Citrate toxicity. (5) Infections and transmission of syphilis, hepatitis, toxoplasmosis, AIDS, etc. (6) Air embolism. (7) Hypothermia.

The commonest mistakes in blood transfusions are: (1) clerical error, (2) confusing terms, such as “group A serum” instead of “anti-B serum”, (3) failure of the staff to check the reference on the bottle against the laboratory report on compatibility, (4) the presence of similarly named patients in the ward.

After infection with HIV, blood becomes positive after 2 to 18 months. AIDS is usually communicated by sexual intercourse or from blood transfusion. According to guidelines laid by the Government of India, the states of HIV should not be disclosed to blood donor. The intention is to spare him of the agony of knowing the helplessness of his situation. If the blood drawn is positive, it should be discarded. Once blood sample is drawn, the register of patient-identities should be kept quite separate and samples identified only with a code number. If the donor wants to know the result of HIV test, he should be referred to an accessible HIV testing centre where supplemental tests with counseling will be offered to him.

The Centre of Disease Control (CDC), estimates that 5.5% of all HIV positive persons are employed in the health care field. According to the guidelines issued by CDC, with the exception of health care workers and personal service workers who use instruments that pierce the skin, no testing or restriction is indicated for workers known to be infected with HIV but otherwise able to perform their jobs.

A person testing positive for HIV cannot be removed from service, if he is physically fit to discharge his duties.

If a person suffering from AIDS, knowingly marries or has sexual intercourse with a normal person and thereby transmits the infection to other person, he would be guilty of offences

Investgations:

1. Haematological Examination: In case of intravascular haemolysis, the serum of a  post-transfusion sample of blood will show the presence of haemoglobin and methaemaglobi,n Haptoglobins will be reduced. In extra-vascular haemolysis, there is an increase in the quantity of unconjugated bilirubin.
2. Urine: In intravascular haemolysis, haemoglobin will be found in urine. Urobilin, urobilinogen, and red cell casts may be found.
3. Serological Examination: A two percent red cell suspension in saline of the patient’s blood may show agglutinates. Coomb’s test is positive. Ig A specific antibodies will be found in the patient’s blood in sensitivity reaction to donor leucocytes, platelets and plasma factors. There may be eosinophilia.
4. Bacteriological Examination: Residual donor blood may show microorganisms, which can be confirmed by culture.

Autopsy:

spaIn acute intravascular hemolytic reactions, haemoglobinuric nephrosis is seen.The tubules will show acute necrosis and casts of hemoglobin. Lungs will be edematous in cases of circulatory overload. Air in the right ventricle indicates death due to air embolism.