Goal
Ultimate goal of blood management is to AVOID allogenic blood transfusion
Problems
Increased infection rate
- demonstrated in THR
- decreased killer T cells
Increased risk disease transmission
Increased risk transfusion reaction
Increased post-op fever and antibiotic requirements
Increased cost
Increased hospital stay
Transfusion Recommendations
American Society of Anaesthetists
1. Hb < 6gm/dL
2. Hb > 6 if
- cardiorespiratory disease
- artherosclerotic disease (heart / kidney / legs)
- condition requiring higher oxygen carrying capacity
- symptoms attributed to anaemia
Allogenic Blood Products
1. Whole Blood
- single donation or Unit
- citrate as anticoagulant (binds Ca which is required by the clotting pathway)
- stored < 5/52 at 4°C
2. Packed Red Cells
- 2/3 of plasma removed
- volume 300ml
- haematocrit = 70% (double that of blood)
- can removed WCC if wish (decrease antigen load)
- Hb rise of 1g/dL / Unit
3. Fresh Frozen Plasma / FFP
- platelets removed
- frozen to preserve labile coagulation factors
- should be ABO compatible
Indications
- massive transfusion
- coagulopathy / DIC
- warfarin reversal
4. Cryoprecipitate
- prepared from FFP by slow thawing at 5°C
- contains F VIII / Fibrinogen / VWF
- usual dose is 10-30 U
Indications
- VWD
- CRF
- Advanced Liver Disease
5. Factor VIII Concentrate
Freeze-dried powder
- pooled product -> high risk disease transmission
- recombinate product
Indications
- gold Standard Haemophilia A
- preferred in VWD
6. Factor IX Concentrate
Prothrombin complex concentrate
- contains IX, X & II
- also high disease risk
Indication
- haemophilia B
7. Platelets
Harvested from fresh blood
- may be pooled or unpooled
- store at room temperature for 5/7
- ABO & Rh specific
Indication
- platelet count < 20 000/mm3 with bleeding
- 1 unit of platelets raises the platelet count of a 70 kg patient by about 7,500x109 / litre
Transfusion Risk
|
METABOLIC |
INFECTIVE |
TRANSFUSION REACTION |
|
Hypothermia |
Viral – HIV. B. C. |
Non Haemolytic |
|
Hyperkalaemia |
Bacterial |
Haemolytic |
|
Hypocalcaemia |
Fungal |
|
|
Pumonary oedema |
Prion CJD |
|
|
Coags/DIC/ARDS |
|
|
1. Non Haemolytic Transfusion Reactions
Most common
- 2% to 5% of all transfusions
A. Febrile reactions
Most common
- result from the recipient's antibody response to leukocyte Ag in the donor blood
Symptoms
- chills, fever, headache, myalgia, nausea, and, occasionally, severe rigors
Treatment
- supportive
- rarely requires cessation of the transfusion
Leukocyte-removal filters
- diminish the likelihood of febrile reactions
- use of such filters is expensive and retards blood flow
- should be reserved for those patients who have had at least two adverse reactions
B. Allergic reactions
Most are mild, consisting only of slight urticaria
Laryngeal oedema and bronchospasm (anaphylaxis)
- much less frequent
- occurring in less than 1% of such reactions
Treatment is supportive
- subsides spontaneously within several hours of the transfusion
- if multiple severe allergic reactions to transfusions are at high risk of developing further reactions
- ameliorated by using washed components
2. Haemolytic Transfusion Reactions
Risk range from 1:4,000 to 1:25,000
Death
- 1: 100 000
Almost always from mislabelling
- ABO incompatibility
- destruction of the donor RBC
A. Acute
Clinical features
- chills, fever, chest pain, and flank pain
- nausea, hemoglobinuria, shock, a sense of impending death
- tachycardic and hypotensive
Consequences may be fatal
- effects of intravascular hemolysis on the renal and coagulation systems
Management
- immediately stop the transfusion
- return the unused blood and a sample of the patient's own blood to the blood bank for re-crossmatching
Check
- haemoglobin concentration
- platelet count
- partial thromboplastin time
- serum fibrinogen level
- serum potassium levels
Treatment Hyperkalemia
- diagnose on ECG (depressed ST segment, inverted T waves, U wave)
- hydration with generous administration of fluids and diuretics
- monitor urinary output - maintain out put at 75–100 ml/hour
- IV lasix may be necessary to maintain adequate renal perfusion
- consider transferring the patient to an ICU
B. Delayed
Less dramatic
Initial survival of transfused erythrocytes, followed by hemolysis within 1 to 7 days
Continued occult blood loss from a traumatic or surgical source
- rule out delayed hemolytic transfusion reaction as a possibility
3. Metabolic
A. Circulatory overload
B. Coagulopathy
Dilution of platelets and coagulation factors
- no platelet function at 2/7 in packed cells
- F VIII at 30% after 5/7
- F V at 50% after 14/7
Need to give FFP and Platelets with massive transfusion
- > 1 whole blood volume
- > 6 Units Packed Cells
C. DIC
D. Metabolic disturbances
Hypocalcaemia
- excess citrate forms complexes with serum citrate
Hyperkalaemia
Citrate toxicity
- metabolic alkalosis
- acidosis
E. Hypothermia
- warm bags of blood in massive transfusion
F. TRALI
Transfusion related acute lung injury
- respiratory distress seen after 1 / 2000 transfusions
- development within 6 hours
- may progress to ARDS - like picture
Mechanism
- caused by anti - granulocyte antibodies
- react to donor granulocytes in plasma
Higher incidence in pregnancy
- may be best to use plasma only from men in this situation
D. Infective
A. Bacterial
- rare
- 1 : 500 000 RBC (Yersinia, Serratia)
- 1 : 50 000 platelets (Staph, E coli)
B. HIV
- risk 1 in 2 million
C. Hep B
- risk 1 in 250 000
D. Hep C
- risk 1 in 2 million
Minimising Transfusion Requirement
Options
1. Minimise intraoperative blood loss
2. Cell saver
3. Reinfusion drain
4. Haemodilution
5. Antifibrinolytics
6. EPO
7. Allogenic blood transfusion
1. Minimizing Intraoperative Blood Loss
Surgeon
- careful operative exposure through avascular tissue planes
- good hemostasis using an electrocautery and ligatures
- short operating time
- judicious use of collagen pads
- sterile bone wax
- tourniquets
- use of topical agents
e.g. thrombin packs, thrombin powder, Gelfoam, adrenaline soaked gauze, fibrin glue
Hypotensive Anaesthesia
A series of 24 Jehovah's Witness patients had a 30% reduction in intraoperative blood loss with the use of hypotensive anaesthesia
- combined use of narcotic and inhalant anaesthesia
- epidural / spinal
- positioning the patient to reduce engorgement of blood vessels
2. Cell Saver
Method
- lost blood is collected by aspiration or drainage
- filtered / Washed / Centrifuged
- transfused back to patient
Advantage
- intra-op salvage can return up to 60% of lost red blood cells
- good in spine / acetabular fracture / revision hip
- any surgery where large quantities of blood loss expected
Disadvantage
- expensive equipment
- need technical expertise to run
- may not be cost effective
Complications
- cell hemolysis
- air embolism
Contraindication
- malignancy
- sepsis
Results
Elawad Acta Orthop Scand 1991
- RCT of cell saver in THR
- 75% reduction in allogenic blood transfusion
3. Reinfusion Drain
Principle
- blood collected in closed system drain
- filtered but unwashed
- re-infused within 4 - 6 hours
Results
Cheng et al J Orthop Surg 2005
- RCT of reinfusion drain
- significantly reduced allogenic blood transfusion rates
4. Haemodilution
Technique
- pre-operative or intraoperative venesection of 1-2 units
- blood volume replaced by crystalloid or colloid
- post-op reinfusion
Advantage
- intra-operative blood loss is diluted
Contra-indications
- hypovolaemia
- anaemia
- cardiovascular disease
5. Antifibrinolytics
Options
- Aprotinin / E-aminocaproic acid / Tranexemic acid
Results
Wong et al JBJS Am 2010
- RCT of topical application of tranexemic acid
- injected into the TKR at end of procedure
- reduced postoperative bleeding by 25%
6. Recombinant human erythropoetin
Natural erythropoietin
Secretory glycoprotein of 165 amino acids
- secreted by the kidney
- in response to hypoxemia and hemorrhagic stress
- binds to receptors in the bone marrow
- stimulating the production of red blood cells
Advantage
Pre-operative EPO shown to
- increase hemoglobin
- facilitate pre-op autologous blood
- markedly decreased allogenic blood needs
Disadvantages
Expensive
- approximately $500 for each half point of Hb raised
Results
Krackow et al Orthopedics 2002
- EPO in total joint patients
- 3 doses pre-operatively
- matched to control group of patients
- Hb average 1 point higher
- transfusion rate halved
7. Autologous Blood Donation
Technique
- multiple serial autologous donations may be obtained
- donor's hemoglobin level must be at least 11 g/dl
Contra-indications
- pre-existing medical conditions
- advanced age
- low pre-op Haematocrit or Hb
- poor erythropoetic response to phlebotomy
Problems
- 60% inadequate erythropoetic response post phlebotomy
- patients who donate blood pre-op are more likely to need transfusion earlier and more frequently
- high cost
- logistical obstacles of storage, collection and transfusion
- high number of bags never used approx 50%
Decision Making Jehova's Witness
Issues
Doctor must act with a proper duty of care
Must act in patient's best interests
Really an informed consent issue
Scenarios
Patient confused with shock
- crying out that he is a JW and doesn’t want blood
- doctor can override if he feels patient not in sound state of mind
- unless patient or family has an advanced health directive
Adult patient fully mentally alert
- doesn’t want blood
- can’t give blood
Child presents needing blood to survive
- parents refuse saying child is JW
- doctor can override if he feels that child not old enough to fully appreciate consequences
Unconscious patient with bracelet saying JW and no blood
- doctor may override if condition life threatening
- only advanced health directive which is carried on person stating refusal for blood will be accepted