Transfusion Medicine Flashcards
What are the four main blood components?
Red blood cells
Platelets
Plasma
Cryoprecipitate
What’s in the bag of red cells that can be administered at room temperature to patients?
Optimal additive solution containing sugars and chemicals that are friendly for the red cells and enable them to last between 28-35 days before they expire as long as refrigerated
Red cells
When should red cells be administered?
To top up people who don’t have enough red cells, including anaemic or major bleeding
What does ‘restrictive thresholds’ mean in clinical settings with regard to red cells administration?
If a patient can tolerate a lower haemoglobin/haematocrit, we won’t transfuse them provided there isn’t another reason to transfuse them before that threshold
Which trial proved that a restrictive transfusion strategy for ill patients in ICU was not inferior to a liberal transfusion strategy?
TRICC Trial 1999
What’s in the bag of platelets?
Platelet additive solution
Platelet pool
When are platelets transfused?
When platelets are low in the patient
Especially when the platelets are low and they are bleeding
According to the recent British Society of Haematology Guidelines (2016), what is the platelet threshold for non-severe bleeding procedures?
30 x 10 ^ 9 /L
According to the recent British Society of Haematology Guidelines (2016), what is the platelet threshold for severe/life-threatening bleeding procedures?
50 x 10 ^ 9 /L
What’s in the bag of fresh frozen plasma (FFP)?
Plasma
When is FFP used/administered?
To correct factor deficiencies in patients who might need a procedure or who are bleeding/haemorrhage
Given alongside red cells to replace blood that’s lost due to massive haemorrhage/major bleeding
How long does it take for FFP to be thawed?
15 minutes to half an hour
What is the average volume of a unit of FFP?
250 ml
What is the therapeutic dose of FFP for an adult?
4 units
What is the volume of fluid of the therapeutic dose of 4 units of FFP for an adult?
1 litre (needs consideration in patients who don’t tolerate volume very well)
What is a cryoprecipitate?
Concentrated fibrinogen product with clotting factors
When is cryoprecipitate used?
When patients have low fibrinogen
Protocolised for major haemorrhage
What are the special considerations for using cryoprecipitate?
Has to be thawed
Should be thought of early in major haemorrhage
What is the term used to describe the legal obligation we have to understand where the blood used for transfusion came from (donor) and where it went?
Vein-to-vein traceability
What percentage of vein-to-vein traceability should we aim for during transfusion?
100% (most hospitals achieve 90-99%; unusual to get 100%)
What needs to be checked or followed to ensure that the right blood is going to the right patient during the transfusion process?
Positive patient identification
Bedside labelling of samples
Electronic patient ID (expensive so not all hospitals have it)
Two sample rule
Electronic issue/lab IT rules
Final bedside check (minimum 4 points - first name, last name, DOB, MRN)
Consent
What is one of the biggest/likeliest risks to patients undergoing transfusion?
Human error (ABO-incompatible transfusions)
Apart from human error, what are some other risks of transfusion?
Immunological: febrile, allergy, alloimmunisation, transfusion-related acute lung injury (TRALI)
Circulatory: transfusion-associated circulatory overload (TACO)
Infection: bacterial, viral eg HEV, variant Creutzfeldt-Jakob disease (vCJD), the unknown
What types of disease in patients should we be concerned about and consider transfusion medicine for in dentistry?
Patients with bleeding disorders or haematological oncology (especially if they have cytopenia or received bisphosphonates)
What are some issues in transfusion with regards to thrombocytopenia in dentistry?
Platelet count needed for extraction is unclear
In the prospective cohort study in 2012 in liver pre-transplant patients with thrombocytopenia, it was found that there was no significant difference in time to haemostasis. What were the range of platelet count and INR for those patients?
Plts >30
INR <3
What conclusion was made from the retrospective cohort study in haematological patients (thrombocytopenic) in 2013 with regards to transfusing patients with platelet count of <50 and their bleeding outcome?
Transfusion had no impact on bleeding outcome
According to the retrospective analysis in 2017, what were the predisposing criteria of severe bleeding post-surgery, especially when combined together?
INR >2.5
Platelet count <40
