Viva - Transfusion

Question 1

What is patient blood management

Answer 1

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

Question 2

Why is peri op anaemia bad

Answer 2

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

Question 3

Patient blood management pillars

Answer 3

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

Question 4

Cross matching

G&S

Answer 4

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

Question 5

Universal donor

Answer 5

O-

Question 6

Universal recipient

Answer 6

Rh+

Question 7

Commonest blood

Rarest

Answer 7

O+

AB-

Question 8

What do we test blood for

Answer 8

HIV ab
HCV ab
HBC surface antigen
Syphillis

Question 9

Blood storage and shelf life

Answer 9

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)

Question 10

Contents of RBC

Preparation

Shelf life

Answer 10

Hct 0.6-0.7

Centrifuged whole blood and leucodepleted

35 days

Question 11

FFP

Contents

Preparation

Shelf life

Answer 11

Clotting factors and albumin

What remains after centrifuging then frozen to maintain V, VIII

Stored at -30C - 1 year
Use within 24 hours thaw

Question 12

Platelets -
Contents
Preparation

Shelf life

Answer 12

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)

Question 13

Cryo

Content
Prepare

Answer 13

One unit - 300mg fibrinogen
70IU factor VIII
vWF

FFP is thawed to 1-6C
Stored at -24
Ten units - one pack

Question 14

Octaplas

Content
Prepare

Answer 14

Solvent detergent treated FFP - concentrates the factors

From 1500 donors

Question 15

What is a storage lesion

Answer 15

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

Question 16

Define massive transfusion

Answer 16

Whole circulating volume in 24 hours
50 circulating volume in 3-4 hours

Ten units

Question 17

Complications of massive transfusion

Answer 17

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)

Question 18

Transfusion thresholds

Answer 18

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

Question 19

Critical care transfusion guidance

Answer 19

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

Question 20

Adverse effects of transfusion, in particular age of cells

Answer 20

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
/

Question 21

Describe transfusion related haemolytic reactions

Answer 21

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)

Question 22

Non haemolytic reaction

Answer 22

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.

Question 23

Describe iron overload in transfusion

Answer 23

Chronic transfusion - SCD

Iron Exceeds transferrin binding capacity, and deposits in organs.

Free radicals - cirrhosis, cardiomyopathy

Tx - venesection, chelation - desferioxamine

Question 24

Infection risks

Answer 24

HIV 1 in 5 mil
Hep B 1:450,000
C - 1, 32mil

Risk reduced by screening and leucodepletion

Question 25

Describe TACO

Answer 25

LVF, CCF within 24 hours

Pre-transfusion assessment, look for cardiac and renal impairment.

Treat as failure - sit up, o2, inotropes, furosemide, GTN

Question 26

TRALI

Answer 26

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