blood_transfusion
blood product transfusions
consent
Jehovah's Witnesses
early involvement of the hospital's Haematology team should be sought if likely to need blood products
most carry a Medical Directive that clearly states the person’s view on the non-use of blood products
BUT the existence of a medical directive does not automatically mean the patient carrying it will refuse treatment.
clinicians have an obligation to be satisfied that the patient is fully informed prior to the patient making a decision to refuse treatment
inability to consent:
if the patient is unconscious or not competent to make an informed decision the staff should make every effort to notify next of kin or other representatives to discuss treatment options
only an agent under the Medical Treatment Act or a guardian under the Guardianship and Administration Act can refuse medical treatment
other persons responsible can merely withhold consent to treatment, they cannot refuse treatment
Jehovah’s Witnesses have set up a number of Hospital Liaison Committees with representatives who are available to advise or assist in individual cases - there is a 24hr emergency contact number
refusal should be documented as per hospital's Refusal of Treatment procedure
children:
Section 24 of the Human Tissue Act 1982 enacts that a medical practitioner who gives a child a blood transfusion against the express wishes of the parent is not committing a criminal offence.
the blood transfusion must be treatment for a condition the child has and without the transfusion the child is likely to die.
where there is a dispute or disagreement, contact the Office of the Public Advocate
most will usually NOT accept:
whole blood transfusions
transfusion of major blood components - red blood cells, platelets, plasma and white blood cells
preoperative autologous blood collection and storage for later re-infusion
on an individual basis, may accept:
blood fractions such as albumin, clotting factors, etc
autotransfusion (intra/postop blood salvage & re-infusion)
heart bypass –when primed with non-blood products
haemofiltration/haemodilution
haemodialysis -when no blood prime is used
renal dialysis
see the following documents distributed by JW in 2019 to assist doctors in management to avoid transfusions:
indications for RBC transfusion in patients
consider:
signs and symptoms of hypoxia
ongoing blood loss
risk to the patient of the anaemia
risk to the patient of the transfusion
level of anaemia:
Hb < 70 g/L (although if asymptomatic and specific therapy available may consider no transfusion)
Hb 70-100 g/L AND EITHER:
likely to have blood loss in surgery, or,
signs or symptoms of impaired oxygen transport, or
anaemia-related symptoms in a patient on a chronic transfusion regime, or,
during marrow suppressive therapy
NB. Hb > 100 g/L unlikely to need blood transfusion unless significant acute blood loss
usage of RBCs
-
complete transfusion bag within 4 hours of commencement of that bag
1 unit of RBCs ~240ml and will raise Hb level in an adult by ~10g/L (paediatric unit is ~50ml)
NB. see your hospital's policy and procedure for the administration of blood products - the following is only a guide!
administer through a new IV blood giving set incorporating a 170-200 micron filter (large particle filter which only removes aggregates and other large particles)
usually give over 2-4hrs but faster if acute bleeding
start transfusion within 30 minutes of removing blood from fridge, otherwise, return blood to fridge
use a blood warmer if massive transfusion
transfuse one unit at a time
avoid transfusing overnight unless an emergency
check patient vital signs (pulse rate, respiration rate, blood pressure and temperature) at the start of transfusion AND at least after 15 minutes, at the end of the transfusion
special requirements:
irradiated RBC's:
to reduce Transfusion Associated Graft-Versus Host Disease (TA-GVHD) thus examples of when to use irradiated RBCs are:
infants under 3 months age
patients treated with ECMO or LVAD
immunocompromised patients (eg. transplant recipients, malignancies, haem/onc patients)
intrauterine and exchange transfusions
directed donations
timing of irradiation is important for neonatal and paediatric patients.
irradiation reduces the storage-life of red cells and whole blood
Packs irradiated within 14 days of collection expire 28 days after collection.
Packs irradiated more than 14 days after collection expire either 5 days after irradiation OR at original expiry of pack, whichever comes first.
in patients where hyperkalaemia is a concern, red cells should be transfused within 24 hours of irradiation eg:
-
renal patients
CMV neg
indications for fresh frozen plasma (FFP)
usage of FFP
indications for platelet transfusion
bone marrow failure:
no risk factors ⇒ administer if platelet count less than or equal to 10×109/L
risk factors such as fever, antibiotics, etc ⇒ administer if platelet count less than or equal to 20×109/L
surgery in patients with thrombocytopenia:
aim to maintain platelets > 50×109/L
high risk of bleeding surgery (eg. neuro/ocular), aim to maintain platelet count > 100×109/L
maybe appropriate in other patients with thrombocytopenia
platelet function disorders:
massive blood transfusion or haemorrhage:
usage of platelets
most platelets arrive as a single pooled unit suspended in T-sol and reduced plasma
DO NOT refrigerate - platelets are stored for up to five days at 20 - 24°C with gentle agitation on a platelet shaker.
volume: pooled > 160ml; apheresis 100-400ml; apheresis paeds 40-60ml
give 1 bag as fast as is tolerated (but not faster than 5mls/minute for first 15 minutes unless acute bleeding) and complete within 4 hours of start
-
indications for cryoprecipitate
usage of cryoprecipitate
blood / RBC transfusion reactions
most often due to presence of WBC Abs formed by recipient as a result of previous transfusions or pregnancies, (rarely now due to Gram -ve endotoxin in blood or apparatus) usually not severe & last only few hrs;
occur in 3-4% of blood transfusions
Always Ix as fever is sign of haemolytic reactions as well!
Rx: panadol;
allergic reactions:
Urticaria usually due to sensitising Abs in recipient reacting with exogenous Ag such as milk or egg protein in donor serum - esp. if recipient atopic. Rx antihistamine;
Generalised anaphylaxis rare (1 in 20,000 units transfused) due to this cause;
Immediate HS reactions may be severe due to donor proteins such as IgA which recipient either lacks or has different IgA subclass.
In addition, allergic reactions may occur if donor has Hx of striking HS & thus has much Ab, therefore of recipient comes in contact with that Ag, a HS reaction may occur but only via donor Ab (ie. passive transfer of a HS state).
haemolytic reactions:
occur in 1 in 40,000 units transfused and result in death in 1 in 100,000 units transfused
intravascular haemolysis:
Usually due to rapid destruction of donor RBCs - usually due to incompatible ABO gps mainly result from labelling errors rather than technical error in failing to detect incompat.
Soon after Tx begins → heat/pain along transfused vein → facial flushing, rigors, fever, severe loin pains, constriction feeling in chest, hypotension/shock/death may follow;If severe, Hbaemia, Hburia, decr. [haptoglobin], methaemalbuminaemia appears; DIC;
Jaundice may take several hrs to develop;
Oliguria due to intense renal vasoconstriction & acute renal failure may develop;
extravascular haemolysis in MP system (esp. spleen):
Usually due to other blood gp incompatibilities (Rh, etc) & is slower & less dramatic with milder symptoms although Hbaemia may occur to same degree but renal failure/death rare.
May also result from faulty storage of blood (freezing or heating), over-long storage or bacterial contamination;
circulatory overload:
XS or too rapid administration may → CCF/APO esp. heart dis/severe anaemia;
Thus if susceptible then limit to 2 units packed cells/24hrs each unit <4hrs Tx time;
Consider exchange transfusion or intraperitoneal (irradiated) Tx if severe anaemia;
bacterial contamination:
Esp. Pseudomonas & coliforms (cold-growing Gram -ves);
After brief latent period, → profound shock, fever, abdo. pain → death in hrs!
Thus don't use blood kept @ room temp > 4hrs;
biochemical derangements in massive transfusions:
hyperkalaemia esp. old cells or irradiated cells, or if renal impairment & potentiated by citrate induced hypocalcaemia;
-
increased citrate
hypothermia; XS 2,3 DPG → shifts Hb-O2 curve;
coagulopathy due to dilutional effect and lack of platelets and clotting factors in packed red cells
air embolism:
may be caused by transfusing any plasma-containing blood product
it is caused by the interaction between the recipient's leukocytes and preexisting donor antileukocyte antibodies
this results in complement activation and increased pulmonary vascular permeability
complicates 0.1-0.2% of all transfusions
delayed reactions:
sensitisation:
delayed haemolytic transfusion reactions:
In pts. sensitised by previous preg/Tx, alloAb titre may be undetectable & thus apparent compatible blood when transfused may restimulate Ab production → sudden destruction of donor cells usually within 3-7 days → jaundice or failure of Hb to rise as expected or falls;
May then find the irregular Ab when re-Xmatch or if Direct Coombs test pts blood;
donor blood-borne infection:
EB virus
CMV probably the most common;
Hep A/B/C/D/E
⇒ screen all for HBsAg as 50% will develop hepatitis if +ve;
risk of hep C is ~1 per 3000-4000 units transfused
risk of hep B is ~1 per 50,000 units transfused
HIV screened blood risk ~1 per 150,000 units transfused
Malaria
Syphilis now rare as survives poorly in storage & many recipients on penicillin;
Brucellosis
Toxoplasma
Filariasis
Trypanosoma
Kala-azar
multiple microemboli:
toxic substances in plastic leached out from plastic bag/tubing by blood:
transfusional haemosiderosis:
thrombophlebitis:
esp. if: > 12hrs Tx (different units though)
rubber tubing not plastic;
adminis. autoclave glucose soln → decr. pH, esp. if post-Tx → ?lyse RBCs;
indwelling catheters > 8hrs;
graft-vs-host reaction (TA-GVHD):
now reduced to 0.15% of transfusions due to improved preventive measures
TA-GVHD occurs when donor lymphocytes from transfused blood engraft in the recipient and cause disease.
typically TA-GVHD occurs 10-14 days post transfusion with clinical features of fever, skin rash, hepatitis, diarrhoea and pancytopenia.
it is fatal in more than 90% of cases.
at risk patients:
prevent by giving irradiated cells to at risk patients (leukocyte depletion using current technology is inadequate for this purpose)
references and other resources
blood_transfusion.txt · Last modified: 2019/10/18 02:53 by wh