Transfusion Protocol: Paediatric Appendix
Please refer to Trust guidelines for general protocols regarding
cross matching, collection of blood, administration, and potential
complications of blood transfusions.
Volume of blood to be transfused to children:
The calculation of blood to be transfused in to children is given by the
following equation:
Volume to be
transfused (mls)
=
Weight of the
patient (kg)
X
Aimed for increment
of Hb (g/dl)
X
5
This formula is based on two recent population studies1,2, both based in the
Intensive Care Unit setting. One study calculated a multiplier of 4.8, the other
of 5.02. Although most of our patients are not as unwell as these patients,
these are the only studies with an evidence base for transfusion volumes.
Some other messages from these studies:
o The age of the patient does not affect the transfusion formula.
o Measuring the haemoglobin 7 hours after the transfusion gives the
same result as measuring the haemoglobin straight after the
transfusion.
o The speed of transfusion does not affect final haemoglobin.
Time to give transfusion over
Give transfusions over 3-4 hours (but not more than 4). If a definite end point
haemoglobin concentration is to be achieved, then give over 3 hours, check
the Hb on a blood gas at 3 hours, and give more if needed before the blood
expires.
Cannula size to be used in children
A red blood cell is about 8 m in diameter. A yellow cannula (24G) has in
internal diameter of 0.70mm, which theoretically would allow 7500 red blood
cells to go through at once. Maximum flow rate through a 24G cannula is
20ml/min, which could theoretically enable transfusion of up to 4800ml in 4
hours. Studies have not found increased haemolysis with using smaller
cannulas3,4.
We recommend using a cannula which is suitable for the patient’s age,
condition, and veins. There is no need to change any cannula which is
already in situ.
Transfusion of platelets and FFP
Volume of platelets and FFP to be given is a standard 15ml/kg. Give platelets
as soon as possible after getting them from the lab: make sure that your IV
access is working prior to fetching them. Give them from the bottom of the
bag, as there may be some settling of the platelets and you want to give as
many of them as you can.
Use of Iron Binding Agents
A significant proportion of patients needing blood transfusions will have
conditions needing regular transfusions, for which iron chelation is necessary.
These are likely to be patients with thallassaemia or sickle cell disease. This
will be clearly documented in the notes.
Use of Irradiated blood
This is indicated in patients who have had a bone marrow transplant, have
Severe Combined Immune Deficiency (SCID), and certain other oncological
conditions. This will be clearly marked on the patient’s notes, with clarification
in the Oncology guidelines.
1. K P Morris, N Naqvi, P Davies, M Smith, and P W Lee. A new formula
for blood transfusion volume in the critically ill. Arch. Dis. Child, Jul
2005; 90: 724 - 728.
2. P Davies, S Robertson, S Hegde, E Massey, and P Davis. Calculating
the required transfusion volume in children. In Press, Transfusion (Due
March 2007)
3. De la Roche, M.R., & Gauther, L. (1993). Rapid transfusion of
packed red blood cells: Effects of dilution, pressure, and
catheter size. Annals of Emergency Medicine, 22(10), 15511555.
4. Frelich, R., & Ellis, M.H. (2001). The effect of external
pressure, catheter gauge, and storage time on hemolysis in
RBC transfusion. Transfusion, 41,799-802.
Conflict of Interest.
PD is the first author of reference 2. He is unrelated to the PD in reference 1.
Patrick Davies November 2006
(reviewed by Kate Forman 6th December 2006)