Transfusions in childrenMedical editor Marit Hellebostad MD
Oslo University Hospital
In most cases, transfusions are a necessity in order for the child to complete treatment. The child receives blood transfusions for low hemoglobin (Hb) and low thrombocytes (trc).
Values vary with age. Generally, normal values for Hb in children are lower than in most adults and reach adult values around puberty.
- Acute blood loss > 15% of total blood volume
- Hb < 8.0 g/dl and symptom-causing chronic anemia
- Hb < 8.0 g/dl and reduced bone marrow function, Hb decreasing and without sign of regeneration
- Hb < 8.0 g/dl in perioperative period
- Hb < 7.0 g/dl in child without sign of other illness
- Ongoing bleeding and thrombocytopenia (trc. < 50 x 109)
- Decision is otherwise based on the degree of thrombocytopenia and its cause (production loss or increase of use)
Thrombocyte transfusion as prophylaxis:
- For counts < 5 x 109/l if the child does not have an increased tendency for bleeding from other cause or significant increase in use. The lower limit can be raised to < 10 x 109/l or < 20 x 109/l if a fall is still expected and thrombocytes cannot be obtained on short notice.
- For thrombocytes < 20 x 109/l after bone marrow transplantation or high febrile infection.
- Before invasive procedures:
- For spinal tap, thrombocytes should be > 20 x 109/l and
- Puncture biopsies (liver/kidney/tumor) > 50 x 109/l
- For surgery, thrombocytes should be > 50–100 x 109/l (insertion of central venous catheter etc.) depending on the character of the procedure and whether there is a tendency for bleeding from other causes. After surgery, thrombocytes should be checked and transfusion should be repeated the same day if needed.
- The child is able to complete treatment
- Maintain intravascular fluid volume to ensure blood flow to all vital organs
- Maintain sufficient oxygen transport to peripheral tissue
For a blood transfusion, SAGMAN erythrocytes are used. One unit is made from 450 ml of pure blood. Most of the plasma is removed and replaced with 100 ml SAGMAN solution (saltwater-adenine-Glucose-mannitol). Hematocrit is about 0.60 %.
One unit of thrombocytes contains 240–300 x 109 thrombocytes and is made from donors with types O and A. In acute situations, the recipient's blood group is insignificant.
Two platelet products are available:
- apheresis platelets that are produced by thrombopheresis from one donor
- buffy coat platelets produced from buffy coats from 4 donors
It is preferable to give apheresis platelets to children to limit the number of donors they are exposed to. The lifetime of apheresis platelets is longer than buffy coat platelets. Apharesis platelets are therefore used for prophylactic transfusions. For acute bleeding, the effect of the two products is the same.
All cellular blood products for children should be filtered. Leukocyte filtration is done to remove cells with antigens and viruses. In the unit, 99.99% of leukocytes are removed.
In some cases, irradiated blood products are necessary. The blood and thrombocytes are irradiated with a minimum of 25 Gy at the blood bank to kill T lympocytes and hematopoietic stem cells.
Thrombocyte transfusions are given:
- For bone marrow transplantation or stem cell transplantation (1 month before or 6 months after the treatment)
- For children with SCID and other serious cellular immune defects
- For intrauterine transfusions and small premature infants (< 1500 gram)
- For exchange transfusion for premature infants
- For use of HLA-compatible platelet concentrations
- For all transfusions from blood relatives
- For use of newly drawn blood
Before the first transfusion, the following is taken:
- MCV, MCH, MCHC
- viral antibodies
Before each transfusion:
- hemoglobin, hematocrit, erythrocytes, white with differential counts, smear, thrombocytes, and reticulocytes
- pre-transfusion test to determine ABO Rh(D) type and antibody screening. (The test is valid for 3 days.)
- Erythrocyte concentration – Rh(D) negative products can usually be given to all, but Rh(D) positive products can only be given to Rh(D) positive acceptors.
- Thrombocyte concentration – Rh(D) negative girls and women in fertile ages who receive Rh(D) positive thrombocyte products should be given prophylaxis for Rh immunization. Boys/men of fertile ages may receive thrombocytes regardless of Rh(D) type.
The child is assessed for a blood transfusion based on:
- symptoms/signs/function level
- underlying illness (heart/lung, serious infection)
- expected development of anemia (marrow function, ongoing bleeding)
The child is assessed for thrombocyte transfusion based on:
- clinical status (bleeding, bleeding tendency, or fever/infection
Blood should never be given simultaneously with medications.
- Premedication is given if the child has reacted to previous transfusions.
- Venous access is checked.
- The donor blood is checked.
- Blood set with filter is used.
- SAGMAN is given over 2-3 hours and thrombocytes over 1-2 hours.
- The set is rinsed with NaCl mg/ml at the end of the infusion.
- The blood bag is stored for 24 hours before disposal.
The child should be observed during the transfusion for reactions. Most serious transfusion reactions occur within the first 20 minutes.
Symptoms of a reaction to a transfusion:
- hot feeling in the face
- shortness of breath
- fall in blood pressure
Suspect/manifest blood transfusion reaction
- The transfusion should be stopped immediately.
- Treatment is started if necessary (fluids, adrenaline, antihistamine, steroids, oxygen, respirator)
- The blood bag and compatibility chart should be checked.
Hemoglobin and thrombocytes are checked.
For poor effect of thrombocyte transfusion, the platelet count should be checked after about 1 hour. The count should have increased by about 30 x 109/l or more after a standard dose.
If the increase is significantly less, the cause may be:
- Abnormally high consumption in the patient. This may indicate more frequent transfusions.
- Antibodies against HLA or platelet-specific antigens. The child must then have a work-up with the blood bank to find a compatible donor.