Haem - Viva - Transfusion Flashcards
What is patient blood management
Concept with the idea of reducing / preventing unneeded transfusion to improve pt safety.
Cornerstones
Detect and manage pre-op anaemia
Minimise peri-op blood loss
Manage post op anaemia
Why is peri op anaemia bad
Indie risk factor for increased ICU and hospital LOS
Related to post op complications
Increased mortality
Found in 1/3 of patients at pre-assessment
Increased risk of needing transfusion - not without risk
Patient blood management pillars for surgery
Detect anaemia - (130 M, 120 F)
Use of pre-op clinics
Treat iron deficiency - oral/iv
EPO
Gastro referral??
Minimise blood loss Review anti-platelets/anti coag Surgical haemostasis Cell salvage Regional blocks
Post op - Optimise cardiopulmonary reserve CO and oxygen delivery Avoid further bleed Treat infections Transfusion thresholds
Cross matching
G&S
X-match - process of mixing donor cells with recipient serum and looking for agglutination
G&S - determine ABO group and Rhesus status, then store sample from x-match
Universal donor
O-
Universal recipient
Rh+
Commonest blood
Rarest
O+
AB-
What do we test donated blood for
HIV ab
HCV ab
HBC surface antigen
Syphillis
Blood storage and shelf life
CPDA
35 days
C - Citrate - binds calcium (anti coag)
P - Phospate - ATP substrate
D - Dextrose - energy for glycolysis
A - Adenine - increase ATP
USA - SAGM, saline, adenine, glucose, mannitol (42 days)
Contents of RBC
Preparation
Shelf life
Hct 0.6-0.7
Centrifuged whole blood and leucodepleted
35 days
FFP
Contents
Preparation
Shelf life
Clotting factors and albumin
What remains after centrifuging then frozen to maintain V, VIII
Stored at -30C - 1 year
Use within 24 hours thaw
Platelets -
Contents
Preparation
Shelf life
55x10to9 per 50mls plasma
Pooled from 4-6 FFP donation
Stored at 20-24C, agitated to stop clumping
3-5 days (not cross matched)
(Note 1/3 sequested following transfusion)
Cryo
Content
Prepare
One unit - 300mg fibrinogen
70IU factor VIII
vWF
Cryo is thawed to 1-6C
Stored at -24
Ten units - one pack
Octaplas
Content
Prepare
Solvent detergent treated FFP - concentrates the factors
From 1500 donors
What is a storage lesion
Changes in haem and biochemistry in stored blood
Hyperkalaemia (one unit stored 4 weeks could be 5-30mmol) Acidosis - pH 6.8 Low 2,3, DPG curve to left Platelets to 0 after 48 hours Factor 5 and 8 reduced activity
Define massive transfusion
Whole circulating volume in 24 hours
50 circulating volume in 3-4 hours
Ten units
Complications of massive transfusion
Coagulopathy (dilutional and consumptive)
Hypothermia
Acidosis (impaired oxygen delivery)
High K Low Ca (ca in blood bound to citrate, and consumed in clotting) Low Mg (binds citrate)
Transfusion thresholds
70 with aim for 70-90 is accepted
TRICC study - liberal versus restrictive strategy (70). Trend to reduced mort, and significant in pts with lower APACHE score and under 55.
TRACS - no difference in mortality in cardiac patients
TRISS - no difference in ischaemic events in sepsis
TITRe2 - no difference in ischaemic/infective complications when 75 or 90 BUT increased mortality in restrictive group. CARDIAC PTS
Critical care transfusion guidance
Hb > 90 - NO
Sepsis - early <6 hours - 90-100
Late > 6 hours >70
TBI - 90
SAH 80-100
ACS - 80-90
Stable angina - 70
Otherwise - 70
Beware co-morbid states
Adverse effects of transfusion, in particular age of cells
1) just giving blood is associated with death and MOF (?cause)
2) No difference between fresh (<8 days) and old (42 days) blood
Other risks -
Haemolytic reactions - immediate and delayed
Non-haemolytic reactions - febrile and allergic
Metabolic - High K, low Ca, alkalosis
Iron overload
Infection - bacterial, HIV, Hep B, Hep C, CMV, CJD
TACO
TRALI
/
Describe transfusion related haemolytic reactions
Immediate or delayed
Im: recipient Ab attack donor cells
LDH up, Hb down, +Direct Coombs,
Caused by ABO incompatibility.
Tachy, hypotension, angioedema, bronchospasm, urticaria
Tx - fluid resus plus vasopressors, oxygen, aim u/o 2mls/kg
Send blood for FBC, clotting, Coombs x-match
Delayed - previous alloimmunisation to minor Abs (Rh/Kidd)
Non haemolytic reaction
Febrile or Allergic
Febrile. Common. 2C. Donor leucocytes with recipient WC Abs
(Less common due to leucodepletion now)
Continue if mild, paracetamol. Stop if severe
Allergic - stop blood. Send to bank. Treat as anaphylaxis.
Describe iron overload in transfusion
Chronic transfusion - SCD
Iron Exceeds transferrin binding capacity, and deposits in organs.
Free radicals - cirrhosis, cardiomyopathy
Tx - venesection, chelation - desferioxamine
Infection risks from blood transfusion
HIV 1 in 5 mil
Hep B 1:450,000
C - 1, 32mil
Risk reduced by screening and leucodepletion
Describe TACO
Transfusion-associated circulatory overload
LVF, CCF within 24 hours
Pre-transfusion assessment, look for cardiac and renal impairment.
Treat as failure - sit up, o2, inotropes, furosemide, GTN
What is Transfusion-related acute lung injury (TRALI)
ARDS within 6 hours transfusion
Can be immune/non immune
Prevented by leucodepletion
Pooling donor plasma dilutes antibody conc
Use of male donors for FFP plasma
Aim negative balance and treat as ARDS
