Acute Hemolytic Anemia

What is a hemolytic transfusion reaction?

A hemolytic transfusion reaction is a reaction that occurs after a patient receives a transfusion of "incompatible" blood. The red blood cells that were given to the patient are destroyed by the patient's immune system. Blood that you receive in a transfusion must be compatible with your own blood. Being compatible means that the body will not form antibodies against the blood that is received by it.

At what point does a reaction normally occur?

Symptoms of a hemolytic transfusion reaction usually appear during or right after the transfusion.  In most cases it occurs very soon after the transfusion often within 24 hrs post-transfusion. It can also occur quickly upon transfusing a few milliliters, or up to 1-2 hours post-transfusion. This is generally referred to as "immediate". Sometimes, they may develop after several days in which case it is a delayed reaction.

Delayed hemolytic reactions commonly occurs about 4-8 days after blood transfusion, but may develop up to one month later. Unfortunately, many delayed hemolytic reactions will go undetected because the red cell destruction occurs slowly. Delayed hemolytic reactions can also occur in patients who have developed antibodies from previous transfusion or pregnancy but, at the time of pretransfusion testing, the antibody in question is too weak to be detected by standard procedures. Subsequent transfusion with red cells having the corresponding antigen results in an anamnestic antibody response and hemolysis of transfused red cells.

What are the symptoms?

Flushing: An acute hemolytic transfusion reaction may cause almost immediate flushing of the skin. The skin turns bright pink. This is mostly observed in the face, although flushing may be widely distributed.

Pain at the Infusion Site: Transfusion of incompatible blood typically causes burning or aching pain at the IV site where the blood is entering the body. Pain may extend along the blood vessel into which the transfused blood is flowing. The skin over the infusion site and along the blood vessel path may be warm to the touch.

Anxiety: People experiencing an acute hemolytic transfusion reaction often report sudden, extreme anxiety as the transfused blood enters the body. Feelings of danger or looming disaster are commonly experienced.

Back and Chest Pain: A transfusion with incompatible blood frequently causes low back or flank pain (the region between the hipbone and the ribs). Chest pain and tightness are also common symptoms.

Fever and Chills: The immune system response in an acute hemolytic transfusion reaction causes a rapid spike in body temperature. Shaking chills commonly accompany the fever.

Cold, Clammy Skin: An acute hemolytic transfusion reaction commonly causes shock. With shock, the blood pressure drops precipitously causing cold, clammy skin. These skin effects are due to a release of a hormone called epinephrine.

Shortness of Breath and Pounding Heartbeat: The symptoms of an acute hemolytic transfusion reaction typically begin within the first five to 60 minutes of beginning the transfusion. Shortness of breath and a pounding, rapid heartbeat develop as the body goes into shock. In very severe cases, it can turn out to be a life-threatening condition where certain body parts is not getting enough blood flow thereby causing organ damage.

Blood Urine: Usually, the destroyed red cells are flushed from the body through the kidneys (via urination). The urnie becomes bloody and turns reddish brown. If sever, this can cause a renal failure leading to very severe complications. The kidneys lose their ability to remove waste and help balance fluids and  electrolytes in the body. 

Others: Jaundice and disseminated intravascular coagulation (DIC) may also occur.

How can such a condition be diagnosed?

Although in many cases, the effects of a wrong transfusion maybe seen quite directly (due to the physical and/or mental torture being suffered by the patient), laboratory confirmatory tests may also be carried out to nail the issue. A hemolytic reaction significantly alters the test results of the following tests

  • CBC
  • Coombs' test, direct
  • Coombs' test, indirect
  • Fibrin degradation products
  • Haptoglobin
  • Partial thromboplastin time
  • Prothrombin time
  • Serum bilirubin
  • Serum creatinine
  • Serum hemoglobin
  • Urinalysis
  • Urine hemoglobin

Note: In an unconscious or anesthe-tized patient: Uncontrollable bleeding due to disseminated intravascular coagulation may be the only sign of a hemolytic transfusion reaction
Is there any treatment that can be offered to such patients?

Immediately, the following needs to be done

  1. Immediately discontinue the transfusion while maintaining venous access for emergency management.
  2. Adopt measures to reduce the risk of renal failure by administering low-dose dopamine, vigorous hydration with crystalloid solutions, and osmotic diuresis with mannitol. Care must be taken to ensure that the body does not go into a shock.
  3. A pain reliever can be given to  reduce fever and discomfort.
  4. Later,  blood samples from the person getting the transfusion and from the donor may be tested to tell whether symptoms are being caused by a transfusion reaction.

How do we avoid such conditions?

It has been well proved that the most common cause for such a situation is a clerical error from the blood storage center that issued the blood unit for transfusion.Preventing hemolytic transfusion reactions depends on proper patient identification and labelling of samples and blood components in each and every step, from sample collection to blood administration. Before a transfusion, patient and donor blood must be tested (crossmatched) to see if they are compatible with each other. A small amount of donor blood is mixed with a small amount of patient blood. The mixture is checked under a microscope for signs of antibody reaction.

One point to note is that the incidence of such reactions varies with the  type of component, its preparation method, and its storage age. Diagnostic criteria and the level of surveillance are 2 other factors as well. 
Studies have shown that there is a pronounced difference in frequency for reactions to red cells versus platelets. Although there is no real data for India on the rate and occurance of such reactions, it is believed that generally, the reported incidence of such reactions to red cells is about one per cent in the general hospital population and higher in patients with hematologic malignancy, thalassemia, or sickle cell anemia. Such incidence with prestorage leukoreduced platelets has been reported to be approximately six to eight per cent. Severe reactions characterized by chills and rigors occurred in only one to two per cent of transfusions with WBC-reduced platelets.

Reference: 
http://www.livestrong.com/article/111626-hemolytic-reaction-blood-trans…
http://www.nlm.nih.gov/medlineplus/
http://emedicine.medscape.com/article/206885-treatment
http://en.wikipedia.org/wiki/Acute_hemolytic_transfusion_reaction
http://www.transfusionmedicine.ca/resources/books/vein-vein/complicatio…