Transfusion medicine Flashcards
What is the usual transfer time of 1 unit RBC?
1.30-3h - 4h limit from removal from cold storage to end of transfusion
How is RBC kept healthy during storage?
plasma is removed to leave concentrated red blood cells
replaced by a solution of electrolytes, glucose and adenine
Why are patients transfused with RBC?
To prevent symptoms of anaemia
To improve quality of life of anaemic patients
To prevent ischemic damage of end organs in anaemic patients
What is the transfusion threshold (trigger)?
lowest concentration of Hb that is not associated with symptoms
varies between different subgroups of patients
How long is the shelf life of platelets?
5 days from collection
What is the adult therapeutic dose of platelets?
platelets from 4 pooled donations
When do you transfuse platelets?
bleeding due to severe thrombocytopenia (low platelets)
platelet dysfunction
prevention of bleeding
When you transfer fresh frozen plasma?
coagulopathy with bleeding/surgery
massive haemorrhage
thrombotic throbocytopenic purpura
What are the contraindications of plasma?
warfarin reversal.
replacement of single factor deficiency
What is used for emergency reversal of life-threatening warfarin over-anticoagulation?
Prothrombin Complex Concentrate (PCC) - Plasma-derived Vit K dependent factors: II VII IX X
What is the group and screen test?
determination of ABO and Rh(D) group
patients plasma screened for antibodies against other clinically significant blood group antigens
What is an anti-globulin test?
testing the patient’s plasma against a panel of red cells containing all the clinically significant blood groups
What is a crossmatching compatibility test?
correct ABO and Rh donor selected
Patients plasma is mixed with aliquots of donor red cells to see if agglutination or haemolysis occurs
What are the immunological acute transfusion
reaction complications/ adverse effects of transfusion?
Acute haemolytic transfusion reaction
ABO incompatibility
Allergic /anaphylactic reaction
TRALI (Transfusion-related acute lung injury)
What are the non immunological acute transfusion
reaction complications/ adverse effects of transfusion?
Bacterial contamination
TACO (transfusion associated circulatory overload)
Febrile non-haemolytic transfusion reaction
What are the immunological delayed transfusion
reaction complications/ adverse effects of transfusion?
Transfusion-associated graft-versus-host disease (TA-GvHD)
Post transfusion purpura
What are the non immunological delayed transfusion
reaction complications/ adverse effects of transfusion?
Transfusion Transmitted Infection (TTI) –viral/prion
Before what time period after transfusion is a acute reaction?
24 hours
After what time period after transfusion is a delayed reaction?
24 hours
What infections come under infective risk of blood transfusions?
Hepatitis B
HIV
Hep C
What is a sign of a transfusion reaction when giving a transfusion?
Oozing from venepuncture sites
What blood group can only receive itself but donate to anyone?
O
What blood group can receive from anyone but donate only to themselves?
AB
What is acute haemolytic reaction?
caused by ABO incompatibility
release of free Bh
deposition of Hb in the distal renal tubule = acute renal failure.
stimulation of coagulation results = microvascular thrombosis
stimulation of cytokine storm
What are the signs and symptoms of acute haemolytic reaction?
Fever and chills Back pain Infusion pain Hypotension /shock Hemoglobinuria (may be the first sign in anesthetized patients) Increased bleeding (DIC) Chest pain Sense of “impending death"
When does acute haemolytic reaction first present?
severe = within the first 15 mins milder = later but usually before the end of transfusion
What are the signs and symptoms of delayed haemolytic reaction?
fatigue, jaundice, and/or fever Drop in Hb Increased LDH Increased indirect bilirubin Positive direct antiglobulin test
When does delayed haemolytic reaction first present?
Onset 3-14 days following a transfusion of RBC
What is delayed haemolytic reaction?
due to immune IgG antibodies against RBC antigens other than ABO after the transfusion
What is transfusion related acute lung injury?
Donor has antibodies to recipient’s leucocytes
Activated WBC lodge in pulmonary capillaries
Release substances that cause endothelial damage and capillary leak
When does transfusion related acute lung injury present?
within 6 hours of transfusion
What are the signs and symptoms of transfusion related acute lung injury?
Hypoxemia
New bilateral chest X-ray infiltrates
No evidence of volume overload
What is the treatment for transfusion related acute lung injury?
Mild forms may respond to supplemental oxygen therapy.
evere forms may require mechanical ventilation and ICU support
What are the signs and symptoms of transfusion-associated circulatory overload (TACO)?
sudden dyspnea orthopnoea - shortness of breath which occurs when lying flat tachycardia hypertension hypoxemia Raised BP elevated jugular venous pulse
What are the risk factors of transfusion-associated circulatory overload (TACO)?
elderly patients small children patients with compromised left ventricular function increased volume of transfusion increased rate of transfusion
What presents in an allergic reaction after a transfusion?
Urticarial Rash
wheeze
What are the symptoms of anaphylaxis after a transfusion?
Severe, life-threatening soon after transfusion started Wheeze/ asthma raised pulse low BP (shock) Laryngeal oedema/ facial oedema
What is febrile non-haemolytic transfusion reactions (FNHTR)?
cytokines or other biologically active molecules that accumulate during storage of blood components
What are the signs and symptoms of febrile non-haemolytic transfusion reactions (FNHTR)?
Fever
shakes/rigors
raised pulse
