Tranfusion Flashcards
how long does it take to transfuse 1 unit of RBC
1.3-3 hrs.
what is the time limit within which RBC for transfusion must be used once out of cold storage
4hrs
what conditions and for how many days is RBC for transfusion kept
4 degrees for 35 days.
what is plasma replaced with in a RBC transfusion
solution of electrolytes, glucose and adenine.
How we can determine the ideal Hb concentration for various groups or individual patients
Transfusion threshold- the lowest concentration of Hb that is not associated with symptoms of anaemia.
How does the body adapt to anaemia
increased cardiac output, increased artery blood flow, increased oxygen extraction, increased RBC DPG (diphosphoglycerate), increase production of EPO, increase erythropoeisis, high respiratory rate,
what affects the body’s ability to adapt to anaemia
underlying conditions
age- elderly can adapt less than younger.
how much RBC in transfused in anaemia.
≤70 g/L for patients with mild symptoms of anaemia,
≤80 g/L for patients with cardiovascular disease
alternative treatments for anaemia except RBC transfusion.
correcting the cause of anaemia- iron deficiency, B12 folate deficiency, EPO treatment for patients with renal disease
correction of coagulopathy
discontinuation of anti platelet agents. Administration of anti-fibrinolytic agents
what category of patients are on continuous RBC transfusion
those with myeloid failure syndromes
what are the aims of RBC transfusion of patients with acquired anaemia
Symptomatic relief of anaemia
Improvement of Quality of Life
Prevention of ischemic organ damage
why is the threshold Hb 80-100g/dl
Co-morbidities that affect cardiac, respiratory function
Iron overload
Adaptation to anaemia
what are the aims of RBC transfusion of patients with inherited anaemias (thalassemia)
Suppression of endogenous erythropoiesis- bacsue the RBC are abnormal.
In what conditions and for how many days are platelets stored for
22 degrees for 5 days
define adult therapeutic dose
is platelets from 4 pooled donations
why are patients transfused with platelets
treat- bleeding disorders due to severe thrombocytopenia or platelet dysfunction. Prevention of bleeding Massive haemorrhage bone marrow failure prophylaxis for surgery.
what is the risk of platelet transfusion
infections
what are the contraindications of platelet transfusion
e.g. when should it not be used
Heparin induced thrombocytopenia and thrombosis
Thrombotic thrombocytopenic purpara.
why a patients transfused fresh, frozen plasma
coagulopathy with bleeding
massive haemorrhage
Thrombotic thrombocytopenic purpura.
what are the contraindications of fresh frozen plasma
Warfarin reversal.
Replacement of single factor deficiency
what conditions and for how long is fresh frozen plasma stored for.
30 degrees for up to 24 months
what is the typical dose of fresh frozen plasma
12-15 mL/kg (4-6 units for average adult
what is the transfusion time for fresh frozen plasma
30 mins
where is Prothrombin Complex Concentrate (PCC) derived from.
Plasma-derived
what are the uses for prothrombin complex concentrate
life-threatening warfarin over-anticoagulation
Vit K dependent factors: II VII IX X
what are the requirements of any prothrombin complex concentrate
CMV negative
Irradiated- To prevent transfusion associated graft versus host diseases (rare) in specific t cell immunodeficiency cases
before transfusion what laboratory tests are conducted on the patient
- Determination of ABO and Rh(D) group
* Patient’s plasma “screened” for antibodies against other clinically significant blood group antigens.
what is crossmatching
Donor red cells of the correct ABO and Rh group are selected from blood bank.
Patients plasma is mixed with aliquots of donor red cells to see if a reaction (agglutination or haemolysis) occurs
o No reaction- RBC is compatible and no risk of acute haemolysis
o Reaction- RBC not compatible, risk of acute haemolysis.
risk of transfusion
Acute transfusion reactions
o Immunological- acute haemolytic transfusion reaction, anaphylactic reaction, Transfusion related acute lung injury (TRALI).
o Non immunological- Bacterial contamination, TACO (transfusion associated circulatory overload), Febrile non-haemolytic transfusion reaction
Delayed transfusion reactions
o Immunological- Transfusion associated graft versus host disease (TA- GvHD)- abnormal T cell attack on host.
o Non- immunological- Transfusion Transmitted Infection (TTI) –viral/prion
define acute reactions to transfusion.
define delayed reactions to transfusion.
> 24 hours of transfusion
pathogenesis of acute haemolytic reaction
Deposition of Hb in the distal renal tubule results in acute renal failure.
Stimulation of coagulation results in micro vascular thrombosis
Stimulation of cytokine storm
what molecules causes vasoconstriction in acute haemolytic transfusion
NO
what are the signs and symptoms of acute haemolytic reaction.
fever and chills, back pain, infusion pain, hypotension, haemoglobinuria, increased bleeding chest pain.
what check must be made when administering a blood transfusion
Check patients details on the compatibility label against the patients wristband at the bedside.
how many days after transfusion is a delayed haemolytic reaction
Onset 3-14 days following a transfusion of RBC
what are the clinical features of delayed haemolytic reaction
fatigue, jaundice and fever.
how is the haemoglobin affected in delayed haemolytic reaction
drop in Hb
how is the LDH level affected in delayed haemolytic reaction
increased
what does the direct coagulation test show show is a patient with delayed haemolytic reaction
positive
what does the Coomb’s test show- The Anti-human globulin
used to detect IgG antibodies on red cells
how is the anti human goblin test carried out
- Red cells coated with IgG antibody eg anti-Rh in a Rh Positive patient
- AHG added
- Visible aggulutination
pathogenesis of acute lung injury
activated WBC lodge in pulmonary capillaries
release substances that cause endothelial damage and capillary leak.
diagnosis of TRALI (acute lung injury)
Acute Lung Injury” occurring within 6 hours of a transfusion.
Hypoxemia- abnormally low oxygen.
New bilateral chest X-ray infiltrates
No evidence of volume overload
Treatment of TRALI is supportive. (acute lung injury)
Mild form- oxygen therapy
severe form-mechanical ventilation and ICU support.
within what time frame do patients suffering from TRALI recover within
72 to 96 hours
symptoms of TACO (Transfusion-associated circulatory overload )
sudden dyspnea, orthopnoea (shortness of breath when lying flat), tachycardia, hypertension, hypoxaemia (low oxygen), raised BP and elevated JVP
risk factors for TACO (Transfusion-associated circulatory overload )
- elderly patients
- small children
- patients with compromised left ventricular function
- increased volume of transfusion
- increased rate of transfusion.
common allergic reaction from transfusion results in what 2 symptoms
Urticarial Rash (hives- raised small bumps on skin) ± wheeze
define anaphylaxis
Severe, life-threatening hypersensitivity reaction
what are the symptoms os anaphylaxis
wheeze/asthma, raised pulse, decreased blood pressure, laryngeal and facial odema.
what causes Febrile non-haemolytic transfusion reactions (FNHTR
cytokines or other biologically active molecules that accumulate during storage of blood components
symptoms of Febrile non-haemolytic transfusion reactions (FNHTR
- Fever - rise in temp > 1°C ± shakes/ rigors
* ± increased pulse
