EXCHANGE RED CELL TRANSFUSION POLICY BASILDON AND THURROCK
HOSPITAL GUIDELINES (Revised Feb 2001) INTRODUCTION: Exchange
transfusion is a treatment which permits replacement of the major part of
the patients red cells with transfused red cells.
The main indications for this treatment relate to complications of
sickle cell disease and in the management of haemolytic disease of the
newborn. The following
protocol is intended as a guideline to assist in the management of adult
patients with sickle cell disease.
INDICATIONS
FOR EXCHANGE TRANSFUSION IN SICKLE CELL DISEASE: A)
EMERGENCY: 1. Sickle
cerebrovascular crisis (usually stroke).
3. Sickle liver/spleen
sequestration syndrome. B)
ELECTIVE:
1. Prolonged or recurrent
sickle painful crises. FIRST PRINCIPLES: a) A successful exchange depends on good venous access. Usually the antecubital veins suffice if they are well developed. If not, central venous access is essential and it may be necessary to obtain the help of an anaesthetist if there is a history of difficulties in the past. One should insert a single lumen canula of largest diameter otherwise venous flow will be impeded. b) Exchange transfusion is a process which starts out as being very efficient, (when only HB S containing red cells are removed), but becomes progressively more inefficient as the procedure continues, (when some of the transfused HB A containing red cells are venesected and wasted). For an average adult, one would expect a 4 unit exchange to achieve a HB A:HB S ratio of about 50:50; but a 10 unit exchange may be required to achieve a ratio of 80:20. To improve efficiency, one should therefore remove HB S containing blood at the beginning and transfuse (without venesection) HB A containing blood at the end of the procedure (whenever indicated). One can prevent dehydrating the patient by transfusion 500ml of normal saline before the first unit is venesected. c) It is important to keep the patient well hydrated throughout the procedure as dehydration will worsen the sickling. Each unit of blood removed should have a volume of about 400ml and each unit of blood transfused will have a volume of about 200-250ml. Therefore, in order to stay in balance, it will generally be necessary to transfuse an additional 150-200ml of normal saline with each unit of blood exchanged. Ideally, all the blood venesected and transfused should be weighed and a fluid balance sheet kept to monitor hydration. It is equally important to clinically assess hydration during the procedure by keeping an eye on pulse, BP and urinary output. d) The number of units to be exchanged and transfused can be calculated from the size of the patient, the initial Hb level and the target Hb level (usually 11g/dl). In an average adult, each unit of blood exchanged will cause the Hb to rise by 0.5g/dl and each unit of blood transfused (without venesection) will result in a rise of about 1.25g/dl. An average procedure would involve a 4 unit exchange followed by a further two unit transfusion (6 in, 4 out). e) Remember that exchange transfusion means the administration of large volumes of blood. It is essential to ensure correct identification of donor blood and recipient. Febrile or other allergic reactions may occur and should be treated in the usual manner. A proper record of the transfusion must be made and inserted into the patient’s notes. MATERIALS REQUIRED: Organise yourself as the procedure will take at least two hours to perform. Obtain a trolley and a large yellow plastic bag for waste. You will need: sterile gloves, three way tap, tourniquet, green needles, IV bung with rubber entry port, large syringes (you may need to assist the backflow of blood using a Louer lock 50ml syringe), empty venesection bags (available from blood bank), spring gauge (for weighing blood also available in blood bank), drip stand, normal saline, giving sets, etc. You will probably be provided with a blood giving set from blood bank. If you are not familiar with the priming of these devices, then obtain help from an experienced nurse. PERFORMING THE EXCHANGE:Attach the three way tap directly to the central line or as close as convenient to the IV canula. Attach the IV bung to one port and the 50ml syringe to another. The final port can be used for the transfusion fluid. The venesection bags were designed for single unit venesection and come complete with a large bore needle on the blood line. When required, the needle should be inserted through the rubber bung which can be used repeatedly. The following is the sequence to be followed: 1.Transfuse 500ml normal saline over 20 minutes. 2. Venesect first unit of blood. If the antecubital vein is being used, apply the tourniquet (without causing ischaemia otherwise more sickling will result) and hopefully a unit can be removed under gravity over about 15 minutes. If the flow is sluggish, try slight repositioning of canula or it may be necessary to assist venesection using three way tap and syringe mechanism. A trained member of staff must be present always while blood is flowing from the patient. 3. Transfuse first unit of blood as fast as possible (20 mins). Flow may be sluggish for a number of reasons: the canula is too small; the blood may be to viscous; there may be a blockage in the filter if not properly primed. The situation may improve greatly, if you piggy-back normal saline through a green needle into the rubber bung on the blood line. It will be necessary to transfuse a total of 150-200ml of normal saline with each unit of blood as explained previously. 4. Repeat steps 2 & 3 until planned exchange units administered. 5. Transfuse any remaining units over 2-3 hours each. This can be administered and monitored by the nursing staff. 6. Take an FBC for Hb estimation and Hb electropreresis to assess extent of exchange. 7. Disconnect from patient and clear away any waste. 8. Venesected blood should be sealed by tying a knot in the blood line and needle should be made safe; it can be returned to blood bank for safe disposal. 9.Record what you have done on the drug sheet, fluid balance sheet and medical notes. 10. Well done, have a tea break! You deserve it.
IF YOU
HAVE ANY DOUBTS OR QUESTIONS, DO NOT HESITATE TO CONTACT THE HAEMATOLOGIST
ON-CALL THROUGH THE SWITCHBOARD Consultants: Dr Paul Cervi & Dr Eric Watts |
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