Blood transfusions Flashcards
What is the difference between blood components and blood products?
Components - therapeutic constituent of blood, not covered by the medicines act
Products - produced by pharmaceutical processes, classed as medicines so covered by medicines act
How long can it take to get fully crossmatched red cells?
30-40 mins
How long can it take to get group specific red cells?
10-15 mins
How long can it take to get group O red cells?
< 5 mins
How long can it take to get plasma components?
30 mins as required thawing
How long can it take to get platelets?
Immediately
What is Transfusion Associated Circulatory Overload?
TACO
How do you know how much blood to give to someone?
Identify appropriate Hb threshold and target for patient
Non-bleeding adults - single unit transfusion, then reassess after one unit
What are the risk factors for TACO?
Low body weight
Patients > 50
Patients with pre-existing conditions
How much will 4ml/kg of red cells increase Hb by in adults?
10g/L
How do you work out the volume to transfuse?
(Desired Hb g/L - actual Hb g/L x weight kg x factor)/10
What are irradiated components used for?
Prevention of Transfusion Associated Graft-Versus-Host Disease (TA-GvHD) in severely immunocompromised patients
Prevents donor T cells causing tissue and organ damage
Not required for all immunocompromised patients
Not required for plasma components due to absence of destruction of T cells
What is CMV screened blood used for?
Virus lies latent in white blood cells (UK blood components leucodepleted so risk significantly reduced)
For elective transfusions in pregnancy (not in emergency or at time of delivery)
Intrauterine transfusions
Neonates (up to 28 days post expected date of delivery)
Granulocytes to patients
What are washed cells used for?
Indicated for patients with recurrent or severe allergic reactions to red cells
Discuss with haem
What is HLA and HPA matched blood used for?
Considered where lower than expected improvement in platelet count following platelet transfusions
What are monoclonal antibody treatments for? What is the issue with them in terms of transfusions?
Used in treatment of patients with haematological malignancies
May interfere with serological testing in transfusion laboratory
Induced reactivity can persist for up to 6 months after last treatment
Inform lab if patient is on or due to start monoclonal therapy
When is extended phenotyping of blood required?
Patients with haemoglobinopathies
How are red cells stored?
2-6 degrees
Shelf life 35 days
How quickly does a red cell transfusion need to occur?
Within 4 hours of removal from the fridge
What happens if red blood cells are not transfused?
Can be returned to lab with clear documentation confirming length of time out of fridge
If not started within 30 mins can be transfused as long as transfusion rate allows completion within 4 hours of removal from fridge
How are platelets stored?
20-24 degrees in agitation
Shelf life 5-7 days
How is FFP and cryoprecipitate stored?
-25 degrees
Shelf life 3 years
Thawed upon request
What antibodies does group O blood have?
A and B
What antibodies does group AB blood have?
None
What antibodies does group A blood have?
B
What antibodies does group B blood have?
A
What is the universal donor blood group for red cells?
O
What is the importance of RhD?
85% population D positive
If D negative or of childbearing potential and unknown blood group = D negative components
If exposed to positive D red cells, may produce anti-D which can cause haemolytic disease of the newborn in future pregnancies
In an emergency can use D positive if D negative. Doesn’t cause acute problem but will require D negative for all future transfusions
What is the compatibility of platelets?
ABO antibodies in donor plasma within platelet component can cause haemolysis of patient’s red cells
AB or A universal group
What is the universal group for FFP/cryoprecipitate?
AB or A
How quickly should red cells be transfused?
90-120 mins per unit
If at risk of TACO slower, careful haemodynamic monitoring
Rapid transfusion in major haemorrhage
How quickly should platelets be transfused?
30-60 mins
Rapid if major haemorrhage
How quickly should FFP/cryoprecipitate be transfused?
10-20 mls/kg/hr
What are the S&S of a transfusion reaction?
Fever, chills, rigors
Angioedema, anaphylaxis
New hypo- or hypertension tachycardia
Dyspnoea, stridor, wheeze, hypoxia
Fall in urine output, haemoglobinuria
New pain, myalgia
Nausea
Urticaria, rash, pruritis, flushing
Severe anxiety
Feeling of impending doom
What is the emergency management of a transfusion reaction?
Stop transfusion
Require medical advice immediately
Assess and maintain ABC
Maintain IV access
Check component compatibility
Treat
How are transfusion reactions treated?
Antipyretic/antihistamine
Pause and restart infusion under close supervision after treatment depending on reaction and patient response
Discontinue if patient doesn’t respond to treatment or symptoms worsen
What is a delayed haemolytic transfusion reaction?
Rare type of reaction usually seen in patients with undetected red cell antibodies which may have developed following previous transfusion or pregnancy
Occurs days after infusion suggesting red cells being destroyed too quickly
What are the S&S of a delayed haemolytic transfusion reaction?
Jaundice
Fever
Falling Hb or lower than expected rise
Haemoglobinuria
What is an acute transfusion reaction?
Occurs up to 24 hours following transfusion
Name 3 acute transfusion reactions
Febrile, allergic, and hypotensive
Acute haemolytic transfusion reaction
Transfusion Associated Circulatory Overload
Transfusion related acute lung injury
Transfusion associated dypnoea
Transfusion transmitted infection
What are the S&S of febrile, allergic, and hypotensive reactions?
Increased temp 1-2 above baseline or >38 in isolation = mild febrile reaction
Increased temp > 39 or rise >2 from baseline = moderate reaction
Chill/rigors
Hypotension as isolated Sx
Isolated rash (mild) or angioedema, dyspnoea, hypoxia and/or urticaria (moderate)
Allergic features and airway compromised or haemodynamic instability (anaphylaxis)
What is an acute haemolytic transfusion reaction?
Evidence of haemolysis with falling Hb in presence of a red cell antibody
What occurs acutely with an acute haemolytic transfusion reaction?
Rise in temp
Pain at infusion site
Anxiety
What can occur in a severe acute haemolytic transfusion reaction?
Hypotension
Fall in urine output
Spontaneous bleeding (DIC)
How can a TACO be diagnosed?
Unexpected changes in cardiovascular status -> hypertension, tachycardia, raised JVP/MAP, enlarged cardiac silhouette of CXR, peripheral oedema
Pulmonary oedema
LA hypertension signs -> new/worsening cardiac failure on ECG, NT-proBNP on pre- and post-transfusion sample
How is a TACO treated?
Diuretics
What is a transfusion related acute lung injury?
Can occur in absence of circulatory overload, suspected if patient develops acute dyspnoea with hypoxia and bilateral pulmonary infiltrates during or within 6 hours of transfusion
Due to HLA antibodies in donor
What is transfusion related dyspnoea?
Respiratory distress not due to patients underlying condition with 24 hours of transfusion and doesn’t mean criteria of TRALI, TACO, or allergic reaction
What is a transfusion transmitted infection?
Rare and bacterial contamination
Sx occur shortly after starting the transfusions
What are the symptoms of a transfusion transmitted infection?
Rise in temp
Rigors
Hypotension
Tachycardia
What is a delayed transfusion reaction?
Occurs > 24 hours post blood transfusion
Name a delayed transfusion reaction
Delayed haemolytic transfusion reaction
Post transfusion purpura
Transfusion associated graft vs host disease
What is a delayed haemolytic transfusion reaction?
Evidence of haemolysis in presence of a red cell antibody
How does a delayed haemolytic transfusion reaction present?
Fever
Minimal rise/subsequent rapid fall in Hb
Otherwise unexplained increased in bilirubin
What is post transfusion purpura?
Severe but rare immune mediated complication occurring 5-12 days post transfusion
How is a post transfusion purpura diagnosed?
Unexplained platelet drop > 50% following transfusion
What is TA-GvHD?
In people with impaired T cell function, lymphocytes from transfused blood can engraft mounting an immune response against the recipients cells
>95% mortality
Multi-organ failure
How do you manage a mild transfusion reaction?
Mild pyrexia -> PO paracetamol
Mild allergic reaction -> antihistamines
What should you do after a patient has had a mild transfusion reaction?
Can restart transfusion at lower rate following clinical review and close observation
Not necessary to give pre-medication if one previous single mild allergic reaction
If Sx persist after transfusion stopped consider alternative causes for the reaction
How do you manage a moderate reaction to a blood product?
Manage symptomatically according to severity
Paracetamol, antihistamines
Inhaled short-acting beta-2 agonists and O2 if required for resp symptoms
What should you do following after a patient has had a moderate transfusion reaction?
Can restart after full clinical review by medical staff and either patient recovers with only symptomatic interventions or there is an obvious alternative explanation for S&S
Closely monitor
How do you manage a severe haemolytic reaction?
ABC
How do you manage an ABO incompatible transfusion?
Fluid resuscitation
Send sample -> FBC, PT/APTT/fibrinogen, renal function, G&S
Monitor urine output
ITU for early review - inotropic, renal, and/or respiratory support
How do you manage a suspected bacterial contamination?
Blood cultures
Broad spectrum Abx
Notify transfusion lab and haematologist immediately to arrange culture of implicated units
When should you give red cells?
Improve O2 to tissues by increasing circulating haemoglobin
Main indications -> bleeding, anaemia, haemoglobinopathies
Name 3 clinically significant antibodies
Anti-K
Anti-D
Anti-c
Anti-JK
What is the role of platelets?
Preventing and stopping bleeding
What should one adult therapeutic dose of platelets increase the platelet by?
At least 20 x 10^9/L
What is the prophylactic dose of platelets?
One therapeutic adult dose
Post-transfusion increment check 10 minutes after transfusion finished to ensure desired platelet count reached
How much FFP/cryoprecipitate can you use per unit of red cells?
1:1
How much FFP should you give?
15-20ml/kg body weight
How much cryoprecipitate should you use?
2 units equivalent to 10 individual pooled donations
How much will 2 units of cryoprecipitate increase fibrinogen by?
1g/L
What should you give in major haemorrhage?
Likely to need more than 4 units of red cells within an hour
Plasma if >4 units red cells transfused
Order FFP
1 FFP to every 1-2 units of red cells transfused
What is an allogenic blood transfusion?
Donated by another person
What are the 3 pillars of patient blood management?
1st = optimise red cell mass
2nd = minimise blood loss and bleeding
3rd = harness and optimise physiological reserve of anaemia
What are the 3 points at which you can minimise blood loss and bleeding and what can you do within these?
Preoperative -> management of anaemia, manage bleeding risk, pre-operative autologous donation
Intraoperative -> meticulous homeostasis, anaesthetic blood conserving strategies, autologous blood techniques, pharmacological/haemostatic agents
Postoperative -> monitoring and managing post-operative bleeding, maintaining normothermia, autologous blood salvage, managing homeostasis/anticoagulation
What are the 2 types of cell salvage?
ICS
PCS
What is ICS?
Used during surgery to collect blood from the site of surgery which would otherwise be lost
Concentrated and washed before reinfusion
More robust and function better than allogenic RBC
Only contains RBC
What is PCS?
When whole blood lost from wound following surgery and evacuated via wound drain can be collected and processed for reinfusion
Recovered blood processed and washed with same cell salvage devices used intraoperatively or specialised PCS wound drains where filtered before reinfusion
What can cell salvage be indicated in?
Cardiac surgery
Aortic surgery
Revision joint surgery
Spinal surgery
Total hip replacement
Traumatic liver/spleen injury not associated with perforated bowel
Urological surgery
Obstetric surgery
What patient specific factors can indicate the need for cell salvage?
Increased risk of bleeding
Low tolerance for blood loss
Rare blood group/multiple antibodies where it may be difficult to obtain allogenic blood for the patient
Religious or other objections to receiving allogenic blood
When is cell salvage not indicated?
Surgical field grossly contaminated with bacteria eg bowel contents, gross infection
Sickle cell disease as low O2 conc in reservoir can cause them to sickle
Substances not intended for IV use in surgical field
Concerns in malignancy as possibility of reinfusing malignant cells -> giving risk to metastases
What is the purpose of anti-D in pregnancy?
Preventing formation of immune anti-D antibodies
What happens in screening for pregnant women for blood groups?
Group and antibody screen at booking and 28 weeks
When is anti-D used?
For pregnant D negative women carrying a D positive foetus
Pregnant women where foetal D type is unknown
Not given if already formed anti-D antibodies
Routine antenatal anti-D prophylaxis given to all non-sensitised D negative women from 28 weeks to prevent sensitisation from silent FMH
Within 72 hours of the experience of potentially sensitising events after 12 weeks
What are potentially sensitising events?
Where small amounts of foetal blood can enter maternal circulation
Name 3 potentially sensitising events
Antepartum haemorrhage
Abdominal trauma
External cephalic version
In utero therapeutic interventions
Invasive antenatal testing
Miscarriage/threatened miscarriage
Intrauterine death
Ectopic pregnancy
Evacuation of molar pregnancy
TOP
Delivery
For what potentially sensitising events is anti-D indicated before 12 weeks?
Ectopic pregnancy
Molar pregnancy
Surgical TOP
Uterine bleeding where this is repeated, heavy, or associated with abdominal pain
