Acute Hemolytic Transfusion Reaction AHTR

Summary

This video covers Acute Hemolytic Transfusion Reactions (AHTR), a serious and potentially life-threatening condition caused by transfusing incompatible blood. Symptoms can appear within 10-15 minutes, ranging from fever and pain to severe complications like shock and kidney injury. The video explains the pathophysiology behind the reaction, including immune responses and clotting mechanisms, as well as treatment protocols such as stopping the transfusion and providing supportive care. Emphasizing prevention, the video stresses the importance of accurate patient and blood identification during transfusions.

Takeaways

• 😀 Acute Hemolytic Transfusion Reaction (AHTR) is a life-threatening complication that occurs when donor red blood cells are incompatible with the recipient's plasma due to identification errors.
• 😀 Only **10 milliliters** of incompatible blood can trigger severe symptoms in AHTR, highlighting the importance of careful transfusion management.
• 😀 Early signs of AHTR within the first 10-15 minutes include fever, tachycardia, mild abdominal pain, and back pain, which can progress to more severe symptoms like hypotension and shock.
• 😀 The complement system (C3a, C5a) plays a key role in AHTR by causing mast cell degranulation, which leads to vasodilation, hypotension, and shock.
• 😀 Histamine release from mast cells causes **bronchoconstriction** (difficulty breathing), **diarrhea**, **abdominal pain**, and allergic reactions such as rashes and flushing.
• 😀 The activation of coagulation pathways in AHTR leads to **disseminated intravascular coagulation (DIC)**, small blood clot formation, ischemia, and bleeding at injury sites.
• 😀 Free hemoglobin released from ruptured red blood cells causes kidney damage, **flank pain**, and **dark red urine** due to renal inflammation.
• 😀 Immediate treatment of AHTR involves stopping the transfusion, flushing the IV line with normal saline, and administering supportive care for vital functions.
• 😀 It is critical not to give any more donor blood if AHTR is suspected. Disconnect and flush the transfusion line immediately.
• 😀 Prevention of AHTR requires strict attention to **patient and blood unit identification**, slow transfusion initiation, and careful monitoring during the first 15 minutes to detect early reactions.

Q & A

What is an acute hemolytic transfusion reaction (AHTR)?

An acute hemolytic transfusion reaction (AHTR) is a serious, potentially life-threatening reaction that occurs when the donor's red blood cells are incompatible with the recipient's plasma. It often results from errors in blood identification during the transfusion process.

How much incompatible blood can trigger an acute hemolytic transfusion reaction?

As little as 10 milliliters of incompatible blood can trigger an acute hemolytic transfusion reaction.

What are the initial symptoms of an acute hemolytic transfusion reaction?

The initial symptoms of an acute hemolytic transfusion reaction include fever, tachycardia, mild abdominal pain, chest pain, flank pain, and back pain.

What are the severe symptoms of AHTR if left untreated?

If left untreated, symptoms can progress to high fever, chills, hypotension, dyspnea, shock, oliguria, abnormal bleeding, and dark red urine. The reaction can also lead to disseminated intravascular coagulation (DIC).

What causes the symptoms of an acute hemolytic transfusion reaction?

The symptoms are caused by recipient antibodies attacking the donor's red blood cells. This activates complement proteins like C3a, C5a, which can lead to mast cell degranulation, histamine release, vasodilation, hypotension, bronchoconstriction, and other effects that cause inflammation and tissue damage.

How do complement proteins contribute to the reaction in AHTR?

Complement proteins like C3a and C5a play a crucial role in the reaction by binding to mast cells and triggering their degranulation. This leads to the release of histamine, causing vasodilation, hypotension, and increased vascular permeability, which contributes to shock and other symptoms.

What role does histamine play in an acute hemolytic transfusion reaction?

Histamine causes vasodilation and increased permeability of blood vessels, leading to hypotension. It also causes smooth muscle contraction in the lungs, leading to bronchoconstriction, wheezing, and difficulty breathing.

What is disseminated intravascular coagulation (DIC), and how is it related to AHTR?

Disseminated intravascular coagulation (DIC) is a condition in which small fibrin clots form throughout the body, leading to small vessel obstruction, ischemia, necrosis, and eventual depletion of platelets and clotting factors, which causes bleeding. It can be triggered by AHTR when complement proteins activate the coagulation cascade.

What is the treatment for acute hemolytic transfusion reaction?

The treatment for AHTR includes immediately stopping the transfusion, disconnecting the blood line, flushing the line with saline, and preparing to infuse fresh saline. Supportive measures may include fluid resuscitation, monitoring vital signs, possible ventilatory support, and medications like dopamine or furosemide to support kidney function.

What are the prevention methods for acute hemolytic transfusion reactions?

Prevention involves extreme care during the blood identification process, including proper patient and blood unit identification to avoid clerical and human errors. Transfusions should be started slowly, and patients should be monitored for early signs of reaction, particularly in the first 15 minutes.