Hemolytic reactions can be:
- Acute Hemolytic reactions
- Delayed Hemolytic reactions: The Delayed Hemolytic reactions are seen after a few days of blood transfusion.
Acute hemolytic reactions
It is usually due to ABO incompatibility (mismatch reaction). The most common cause of these transfusion reactions is clerical error. There is intravascular hemolysis. Incidence is 1 in 6,000 (fatal hemolytic reaction incidence is I in 1 lakh).
Clinical manifestations of Acute hemolytic reactions :
As low as 10 ml of blood can produce a hemolytic reaction.
The awake patient presents with pain & burning in vein (earliest), fever with chills and rigors, nausea and vomiting, flushing, chest and flank pain, dyspnoea.
In anaesthetized individual it is manifested as tachycardia, hypotension (so minute to minute blood pressure monitoring during early transfusion is necessary) and oozing from surgical site (more specific).
It is confirmed by hemoglobinuria. The haemoglobin crystals block the renal tubules leading to acute renal failure.
Management of Acute Hemolytic reactions :
i. Stop infusion.
ii. Recheck the details of blood slip.
iii. Send the remaining blood back to blood bank.
iv. Maintain the urine output (1 to 2 mi/kg/br) by mannitol and fluid administration.
v. Dopamine in renal doses (2 to 5 .tg/kg/min) improves renal blood flow.
vi. Alkalinize the urine.
viii. Assay urine haemoglobin, platelet count, fibrinogen level and PTT (to diagnose DIC) and replace with blood components accordingly.
Delayed hemolytic reactions
These are extravascular hemolytic reactions. These are usually due to Rh system or other systems like Kelly, Duff, etc. These reactions are mild and seen after 2 to21 days.
The Delayed hemolytic reactions are diagnosed by Coombs’ test.
Treatment: Only supportive.