Transfusion Medicine

Policies, procedures and guidelines for arranging blood/ its products and transfusion

Blood transfusion is an essential part of modern healthcare. Used correctly, it can save life and improve health. However, as with any therapeutic intervention, it may result in acute or delayed complications of alloimmunization and carries the risk of transfusion-transmitted infectious agents, such as HIV, hepatitis B and C viruses, syphilis and malaria.

The Department of Transfusion Medicine consistently supplies safe blood and blood components of high quality. Blood is collected from voluntary non-remunerated donors and from low-risk group of relatives and friends of patients. Each unit of donor blood is tested for HIV I and II, hepatitis B surface antigen (HBsAg) and antibody to hepatitis C virus by chemiluminisence and serological tests for syphilis and malaria antigen by rapid antigen detection kits. Each unit of blood is also tested for HIV 1, HBV and HCV by nucleic acid test (NAT) to make blood components safer. The units which are non-reactive on screening tests for the infectious markers both by Chemiluminescence and NAT and non-reactive for syphilis and malaria are supplied for use. Transfusion of blood and its components is not 100% safe; however, the risk from their transfusion is very low

Responsibilities of the physicians who request for the blood and its components

• Exercise informed judgement about clinical needs of blood/its products.
• Ensure that the benefi ts of transfusion outweigh the risks of transfusion like immunization and transmission of transfusion-transmitted infection such as HIV, hepatitis B and C, syphilis and malaria.
• Prior to the decision of elective transfusion, the ordering physician should discuss with the patient/close relative the indications/need for transfusion of blood components, its benefi ts and risks and that there are no alternatives for transfusion.
• Informed consent about transfusion of blood and its products should be taken from the patient or a close family member and be kept in the patient’s case sheet.
• Indicate degree of urgency and provide adequate information to the department of blood transfusion services.
• Transfusion should be prescribed only when its benefi ts to the patient are likely to outweigh the risks of transfusion-transmitted infections and alloimmunization.
• Prescription should also include the correct dose and rate of transfusion especially in paediatric patients.

Responsibilities of residents and nurses of the hospital

Ensure provision of appropriate and properly identifi ed patient’s blood samples with bar code sticker for blood grouping and compatibility tests along with a completely fi lled requisition form to the department of blood transfusion services.

• Requisition form for arranging blood products
  1. Requisition form should be fi lled completely. Bar coded sticker containing the particulars of the patient – Name, Registration no., Ward/Room no., etc. should also be fi xed on the requisition form
  2. Name of father/husband of the patient should be written on the requisition form
  3. In case of a previous history of transfusion, the blood group of the patient should be mentioned. It eliminates human near-miss errors, which may be disastrous.
  4. Check the appropriate box to indicate the priority of transfusion requirement (routine, urgent or immediate). Mention the date and time blood required. The requisition must be signed by the resident doctor.
  5. Counsel the patient’s relatives regarding the number of blood units needed to replace in the blood bank in advance for all routine requests and fi ll the replacement blood donation slip signed by the patient’s attendant and resident in-charge.
  6. All requests along with the replacement donation slip must accompany patient’s relation/friend and they should be advised to donate blood for their patient.
  7. Orders for ABO and Rh grouping, antibody screening and cross-matching for the required units of blood/red cells only should be entered in the computer (HIS).
  8. Timing for blood donation is 9:00 a.m. to 6:00 p.m. on all days except Sundays and holidays. Donors are registered till 5:00 p.m. only.
  9. There is no restriction to the ABO group for blood donors. All blood group donors are welcome. Advance donation for a patient is acceptable under special circumstances.
• Blood sample of the patient
  • The patient’s blood sample should be taken in pre-labelled tubes: The label should have a bar code, patient’s name, registration number, ward/room no. and date of collection of the sample.
  • The patient’s blood samples: 5 ml blood in a plain/gel tube and 2 ml blood in an EDTA tube (blood taken in an EDTA tube mixed properly) should be sent to the blood bank with the requisition form through the relative of the patient.
  • In a newborn baby up to 6 months old, send the mother’s blood sample as well.
  • Sample rejection: Transfusion Medicine department will not accept unlabelled, incorrect, incomplete or illegibly labelled samples or those with any discrepancy in the requisition forms.

Issue of blood components from the Blood Bank

• The blood bank should be asked to supply blood and blood components only when the patient requires and when he/she is medically fi t to receive the transfusion.
• It will be issued on the issue slip having the patient’s name, registration number, ward/room number, name of the product(s) and number of unit(s) required. If the blood is required in the operation theatre, the number of the operation theatre should also be written on the slip.
  1. Routine request : Blood and blood components are not required for at least 8 hours from the time the request is received. In this type, every unit of blood is screened for antibody with Coombs’ test by the standard technique.
  2. Urgent request : Blood or component is made available within one hour from the time the requisition is received. In this type, only immediate spin cross-matching is done, which does not rule out the irregular antibody, cold antibodies.
  3. Immediate request : No cross-matching is performed, only ABO and Rh-matched blood is issued within 15 minutes from the time request is received in the blood bank. Therefore the requisition form sent to the blood bank should mention in writing the issuance of uncross-matched blood being ordered for the patient. After issuing the uncross-matched blood the technician of the blood bank will do cross-matching promptly, if incompatibility is detected the patient’s physician will be informed immediately.

NB : If the direct/indirect anti-human globulin test or both are positive, cross-matching may take more time. If the demand is inevitable the least incompatible or a suitable unit not fully compatible can be supplied if possible, on the written consent of the physician of the patient.

Blood and blood component administration

1. Before transfusing red blood cells/its components the physician/nurse should check and verify the following by two verifi ers and signed in the Transfusion administration record sheet:
   • Unit(s) of blood/red cells/components for transfusion for the signs of deterioration (haemolysis, discolouration and for any clot, etc.).
   • Check particulars of the patient, ABO and Rh(D) group and unit number in the compatibility label on the bag, in the cross-match report and verify them with the unit number and group on the bag. The date of collection and expiry date of the component should also be checked.
2. Check the identity of the patient before transfusion.
3. The I.V. line used for blood transfusion should not be used for any other drug except normal saline and 5% albumin.

Blood components administration

Red blood cells

• Refrigerated blood/red cells can be transfused to the patient within half an hour after issuing of blood bag from blood bank.
• Shake the blood bag gently by inverting several times before transfusion
• Blood/red cells should be transfused with a disposable, sterile blood administration set with a standard in-line fi lter having a pore size of 170– 200 microns.
• Vital signs pulse, respiratory rate, BP and temperature, etc. should be checked before transfusion and recorded in the patient’s transfusion administration record sheet.
• The infusion should be started at a slow rate 2 ml/minute or less for the fi rst 15 minutes. Date and time of starting transfusion should be recorded. Vitals monitoring should be done frequently every 45 minutes and recorded in the same sheet. If no problem is noted, the infusion rate may be increased as directed by the physician depending on the clinical need. A unit of red cells may be infused over 2–3 hours but should not exceed 4 hours. A typical paediatric infusion rate is 2–5 ml/kg/hour.
• If required, blood/red cells can be given as fast as the patient can tolerate. The infusion rate is based on the patient’s blood volume, cardiac status and haemodynamic condition.
• Change the transfusion set after every 6 hours if the patient requires ongoing transfusion support. In an episode of multiple component transfusion use separate blood transfusion sets for different types of components.

Fresh frozen plasma (FFP)

• FFP is issued from the blood bank in the thawed form and should be transfused immediately if it is used as a source of labile coagulation factors. If used for a purpose other than labile coagulation factors replacement, it can be transfused as early as possible or within about 12 hours from the time of issue from the blood bank, if stored at 2–6 °C.
• Transfuse at the rate of 10–15 ml per minute. Transfusion of one unit of FFP should be fi nished within one hour.

Platelets concentrate and platelet apheresis

• Platelet concentrate should be transfused immediately, if required it can be stored at 20–22 °C for not more than half an hour. Do not refrigerate them.
• The rate of transfusion must be slow and should not exceed more than 15 ml per minute.
• Transfusion of platelets must be fi nished within one hour.

Platelets concentrate and platelet apheresis

• Platelet concentrate should be transfused immediately, if required it can be stored at 20–22 °C for not more than half an hour. Do not refrigerate them.
• The rate of transfusion must be slow and should not exceed more than 15 ml per minute.
• Transfusion of platelets must be fi nished within one hour.

Cryoprecipitate

• Same as fresh frozen plasma.

Return of blood/blood components

• The blood cold chain is the system for transporting and storing of blood and its components at the proper temperature till it is transfused into the patient. Nurses are responsible for ensuring that blood products issued from the blood transfusion services are kept at the proper temperature till their infusion into the patient.
• Packed red cells should be transfused within 30 minutes after issuing from the blood bank and if required they can be stored in the ward/operation theater for 30 minutes in a refrigerator at 2–6 °C. If not required, they should be returned to the blood bank immediately or not later than 1 hour after issue.
• Thawed FFP and cryoprecipitate will not be taken back by the department of blood transfusion services.
• Platelets once issued will not be taken back by the department of blood transfusion services.

Transfusion of red blood cells and its components

Packed red blood cells

• Red blood cells (RBC) transfusion may be appropriate to improve oxygencarrying capacity.
• The decision to transfuse should be based on the clinical assessment of the patient, not solely on Hb or HCT value.
• When indicated, a single unit RBC transfusion should be the standard for a non-bleeding, hospitalized patient.
• A restrictive or lower transfusion threshold (Hb 7–8 g/dl) is safe and indicated for most clinical scenarios.
• Red blood cells are preferred over whole blood.
• Red blood cells available are:
  • Pre-storage buffy coat removed red blood cells in ADSOL/SAG-M, prepared from 450 ml of blood Log 1 (80–85%) leukocyte reduced.
  • Pre-storage buffy coat removed and fi ltered leukocyte-reduced red blood cells in additive solution (SAG-M), prepared from 450 ml of blood Log 3 (95–99.9%) leukocyte reduced.
• PRBC has a shelf-life of 35 days without and 42 days with SAGM (saline, adenine, glucose and manitol) at 2–6 °C.
• Volume of one unit of PRBC = 280±50 ml
• Advantages of packed red blood cells:
  • Reduces the risk of circulatory overload.
  • Reduces the incidence of transfusion reactions to donor’s antibodies and plasma proteins.
  • Reduces the volume of anti-coagulants and electrolytes transfused.
  • ABO group antibodies (anti-A and anti-B) are reduced and non-ABO identical cells to the patient’s group but compatible with patient’s serum/ plasma can be given.
• Advantages of pre-storage leukocyte-depleted red blood cells:
  • Eliminates FNHTR
  • Eliminates allergic reactions
  • Reduces HLA immunization
  • Decreases CMV infection
  • Decreases postoperative infection
  • Reduces transfusion-related lung injury (TRALI)
  • Reduces transfusion-associated graft-versus-host disease (TA-GVHD)

Leukocyte reduced red cells should be used for transfusion to make the transfusion safe.

Indications of transfusion of red blood cells

General

• Hb less than 7 g/dl: RBC transfusion usually indicated
• Hb 10 g/dl or higher: RBC transfusion usually not indicated Active bleeding (surgical or traumatic)
• Acute blood loss of 30% or more of blood volume
• Haemodynamic instability and/or signs/symptoms of anaemia or tissue hypoxia (tachycardia, hypotension, or mixed venous oxygen saturation < 55%) unresponsive to other measures and anticipated ongoing bleeding.
• Target Hb concentration:
  • ≥7 g/dl in an otherwise healthy patient
  • >8 g/dl in elderly patients and those with known cardiac or respiratory disease

Non-bleeding, medical or surgical patients

• Critically ill (ICU) patients, including those with septic shock: Hb threshold ≤7 g/dl
• Patient with upper gastrointestinal bleeding without hypovolaemic shock: Hb threshold ≤7 g/dl
• Postoperative general, cardiac and orthopaedic patents who are asymptomatic and not bleeding ≤8 g/dl
• Haemodynamically stable patient with pre-existing cardiovascular disease: Hb threshold ≤8 g/dl
• Patients with coronary syndrome (acute MI, unstable angina) have lower tolerance for anaemia. they may require a higher Hb threshold 9–10 g/dl
• Patients with traumatic brain injury, subarachnoid haemorrhage or evidence of cerebral ischaemia ≤9 g/dl
• Symptomatic anaemia in a normovolaemic patient with Hb < 10 g/dl regardless of Hb level

Special patient situations

• Out patients with bone marrow failure may be prophylactically transfused to maintain a Hb at >7 g/dl. Transfusions are almost never indicated when Hb is >10 g/dl.
• Patient with sickle cell disease prior to undergoing major surgical procedure: ≤10 g/dl.

1. Acute blood loss (surgery, trauma or bleeding)

   Loss of blood	Replacement fl uid
   20% (750 – < 1000 ml) of blood volume	Not required.
   20 to < 30% (1000–1500 ml) of blood	Crystalloids/colloids, No RBCs in volume, young, healthy patients, unless patient has pre-existing anaemia and continuous blood loss.
   30% to < 40% (1500–2000 ml) of blood	Rapid volume replacement with volume crystalloids/colloids, RBC transfusion is probably necessary.
   40% (>2000 ml) or more than blood	Is life-threatening and need volume immediate volume replacement with crystalloids/ FFP and RBC transfusion is necessary.

   Elderly patients, or those with underlying anaemia or other comorbid factors, may be transfused with RBCs following a blood loss of less than 30%.

2. Preoperative transfusion

   Patients with asymptomatic anaemia and haemoglobin ≤10 g/dl may need to be transfused if:

3. Chronic anaemia
   • The cause of the anaemia should be established. RBC transfusion is contraindicated if specifi c replacement therapy is possible (e.g. iron, vitamin B12, folic acid). Transfusion should be used if the situation is life-threatening, such as in case of emergency surgery, acute blood loss, or trauma.
   • Patients with anaemia secondary to aplasia or bone marrow suppression need transfusion
4. Special situations
   • Thalassaemia major The aim of transfusion in thalassaemia cases is to prevent symptoms and to suppress endogenous erythropoiesis by maintaining the haemoglobin level at a minimum of 10–12 g/dl. It is not advisable to exceed an Hb level of 15 g/dl.

Components of choice

• Red blood cells less than 7 days old
• Leucocyte depleted red blood cells
• Rh and kell antigen matched blood
• Cross match with antibody screening and for every positive screen test antibody identifi cation is must and blood provided should be that antigen negative.

Dose

• 10–20 ml/kg body weight every 3–4 weeks
• As the body size increases, 1–2 units every 3 weeks

• Exchange transfusion in newborns
  • The fi rst choice is whole blood. A unit of whole blood is normally having haematocrit of 37–45%, which is more than adequate for neonatal needs. If whole blood is not available then alternatives are:
    • Red blood cells should be as fresh as possible and not more than 5 days old.
    • Red cells and FFP (to adjust the HCT as < 50%) of the same (patients group) unit as that of red cells.
    • Red cells and FFP of another unit of the same group as that of the red cells.
    • Red cells and AB group FFP or red cells and 5% albumin.
• CPD or CPDA-1 is common anti-coagulant preserved red blood cells. SAGM added PRBC are acceptable but should be avoided in neonates due to risk of adenine toxicity.

Choice of blood for neonates

In addition to the above-mentioned points, selection of blood for exchange transfusion in case in which a maternal alloantibody is directed towards the antigen of the infant’s red cells (haemolytic disease of the newborn) should be compatible with the mother’s serum.

ABO groups of donors red cells for exchange transfusion

Choice of donor’s cells is listed in the order of preference.

Contraindications for transfusion of red cells

• Well-compensated anaemic patients such as those with chronic renal failure.
• Nutritional anaemia such as iron defi ciency or megaloblastic anaemia who are responsive to iron and folic acid therapy unless the patient shows signs of decompensation.
• To correct protein and coagulation factor defi ciency.
• Preoperative transfusion to raise Hb above 10 g/dl.
• To enhance general well-being, to promote wound healing, to prevent infection and to expand blood volume when the oxygen-carrying capacity is adequate.

Doses and effect of red cells in additive solution (Adsol/ SAG-M) prepared from 450 ml of blood

• In an adult (60–70 kg) patient, who is not bleeding, 1 unit of red cells will increase Hb by 1 g/dl or HCT 3%
• In children, 8 ml red cells/kg body weight will increase Hb by 1 g/dl or HCT 3%
• In infants, 3–5 ml red cells/kg body weight will increase Hb by 1 g/dl or HCT 3%
• A unit of red cells prepared from 350 ml of blood will increase Hb about 0.75 g/dl.
• In non-actively bleeding patients, assessment of post-transfusion Hb may be done as early as 15 minutes after completion of transfusion and it is equivalent to one drawn at one hour and 14 hours following the transfusion.

Fresh frozen plasma (FFP)

Description

• One unit of FFP is plasma separated from 450 ml of blood and frozen at < 30 °C within 6–8 hours of its collection. The volume of unit is approximately 200–250 ml but variation may be expected. FFP contains all coagulation factors present in fresh plasma.

Cryo poor plasma (CPP)

• Prepared from FFP after cryoprecipitate is removed.
• Plasma cryoprecipitate reduced contains 20–30% reduced level of factor VIII, von Willebrand factor, fi brinogen, fi bronectin and factor XIII.
• Indicated for the use of thrombotic thrombocytopenic purpura (TTP).

Indications of FFP

• Active bleeding and documented coagulopathy (INR >1.7 or PT and/or a PTT greater than 1.5 times upper limit of normal range). Common setting includes:
  • Liver disease with coagulopathy
  • Emergent/urgent reversal of warfarin effect
  • Disseminated intravascular coagulation (DIC). Evaluate for hypofi brinogenaemia and consider cryoprecipitate administration.
  • Dilution coagulopathy
    • Best guided by timely testing
    • With massive transfusion and damage control resuscitation for trauma patients, earlier use of plasma (FFP: PRBC ratio 1:1 TO 1:2) is recommended.
  • Replacement of single factor defi ciency for which no single factor concentrate product is available (e.g. factor XI and V)
• Prophylaxis in patients undergoing surgery or invasive procedure and documented coagulopathy (INR >1.7; PT or a PTT greater than 1.5 times upper limit of normal range)
• Replacement fl uid in therapeutic plasma exchange when bleeding or additional bleeding risk is present.
• Treatment of TTP.
• Treatment of patients who have acute onset of angioedema related to ACE inhibitor or in hereditary angioedema (C1 esterase defi ciency) and who are refractory to standard of care.

Contraindications (inappropriate uses)

• Plasma products are not indicated for volume expansion, nutritional
• supplementation or if PT/INR and a PTT are normal.
• Correction of hypoalbuminaemia.
• Immunoglobulin replacement.

Doses of FFP

• Dose of plasma is determined by the patient’s size and clinical condition.
• Dose is 10–20 ml/kg of body weight. Post-transfusion assessment of levels of aPTT, PT and fi brinogen is done for monitoring the effect of FFP.
• If FFP is used as a source of coagulation factors it should be used immediately after thaw and in any case of any delay for 3–4 hours stored at 4–6 °C after thaw.
• If used for a purpose other than labile coagulation factor replacement, it can be transfused within 12 hours after thaw if stored at 4–6 °C.
• Factor levels in plasma are variable, but can be assumed to be approximately 1 U/ml.
• Transfusion of one unit of plasma for an average size adult is considered under dosing and is inadequate for the replacement of coagulation factor.
• Each dose (10–20 ml/kg) increases a patient’s coagulation factor levels by 30–40%. Haemostasis usually requires coagulation factor levels of approximately 30%. Plasma should be administered in doses calculated to achieve a minimum of 30% of plasma factor concentration.
• In a 70 kg patient, one unit of FFP usually increases most factors by 2.5% and four units by 10%.
• Post-transfusion recovery of transfused factor may be less than expected due to extra vascular distribution or consumption.

FFP administration

• FFP should be transfused with disposable, sterile blood administration set with standard in-line fi lter having pore size 170–200 microns.
• Transfuse at a rate of 10–15 ml per minutes. Transfusion of one unit of fresh frozen plasma should be fi nished within one hour.

Compatible blood groups in case of non-ABO group-specifi c transfusion

Choice of donor cells and plasma is listed in the order of preference

Cryoprecipitate

Description

• A cryoprecipitate unit is prepared by thawing one unit of FFP between 1–6 °C and recovering insoluble precipitate. Cryoprecipitate is frozen within one hour.
• Cryoprecipitate contains concentrated levels of fi brinogen, factor VIII, Vwf (von Willebrand factor), factor XIII and fi bronectin.
• One unit of cryoprecipitate has

Indications

• Haemophilia A (recombinant factor VIII concentrate is a better choice)
• von Willebrand disease (newer factor VIII concentrate containing vWF is preferred)
• Congenital or acquired fi brinogen defi ciency (main indication)
• Acquired factor VIII defi ciency (e.g. DIC, massive transfusion) Formula for calculating the dose of Factor VIII
• Units of factor VIII required = Plasma volume × [Desired factor VIII (units/ ml) – Initial factor VIII (units/ml)]
• Example: Patient weight 70 kg; HCT 40%; Initial factor VIII level 2 units/dl (0.02 units/ml), desired factor VIII level raised to 50 units/dl (0.5 units/ml) or 50%
• Blood volume = body wt. × 70 ml/kg or 70 kg × 70 ml
• Plasma volume = blood volume × (1 – HCT), (70 × 70) × (1 – 0.4)
• Factor VIII required = (70 × 70) × (1 – 0.4) × (0.5 – 0.02) = 1411 IU
• Quantity of factor VIII per bag is 80 IU
• No. of cryoprecipitate bags required = 1411 ÷ 80 = 18 bags
• The half-life of factor VIII is about 12 hours, infusion is repeated after 8–12 hours.
• Factor VII concentrate is used to treat severe haemophilia A.
• Currently mild factor VIII defi ciency (haemophilia A) is usually treated with desmopressin acetate (1-desamino-8-D-arginine–vasopressin) [DDAVP] 0.3–0.4 μg/kg. Levels of factor VIII vWF generally remain elevated for 8–12 hours and the dose can be repeated after that period.

Calculation of the cryo dose for fi brinogen replacement

• Example: Patient weight is 70 kg, HCT 40% and fi brinogen is to be increased from 30 mg/dl to 100 mg/dl or by 70 mg/dl.
• Blood volume = body wt. × 70 ml/kg or 70 kg × 70 ml = 4900 ml
• Plasma volume = blood volume × (1 – HCT), 4900 ml × (1–0.4) = 240 ml
• To calculate the amount fi brinogen to infuse, fi rst convert required fi brinogen mg/dl to mg/ml, divide mg/dl by 100 (70÷100 = 0.7 mg/ml)
• Multiply 0.7 mg/ml, by the plasma volume 3000 ml, we thus require 2100 mg fi brinogen (0.7 mg/ml × 3000 ml = 2100 mg fi brinogen)
• To calculate the number of bags of cryoprecipitate required, desired amount of fi brinogen is divided by 150 mg fi brinogen in a bag (2100÷150= 14 bags).
• A typical dose for the treatment of hypofi brinogenaemia is one cryoprecipitate unit per 7–10 kg of body weight.
• One unit of cryoprecipitate per kg of body weight should raise plasma fi brinogen concentration by 50 mg/dl in absence of continued consumption or massive bleeding.

Administration

Compatibility testing for cryoprecipitate is not required. Rh type need not be considered. It is preferable to use cryoprecipitate that is ABO compatible with the recipient.

Platelet concentrates

• Platelets are a part of blood; essential for blood coagulation. In case of haemorrhage or bleeding, platelets come into act and homeostasis occurs.
• Platelets are also referred to as whole blood-derived platelets, random donor platelets, platelet concentrates or RDPs. Platelet apheresis is also referred as single donor apheresis.
• Different platelet preparations available are:
  • Random donor platelet concentrate buffy coat removed derived from whole blood; contains ≥5.5×1010/unit per bag in approximately 70–90 ml of plasma. Buffy coat removed platelet concentrate are having Log 1 reduced leukocytes.
  • Platelet apheresis (prepared by cell separator) has ≥3.0×1011/unit (Log 3 reduced leukocytes) suspended in 200–300 ml of plasma.
  • Platelet apheresis with additive solution known as PAS: Platelet count and leucocytes reduction is a unit is similar to those of standard apheresis unit. In this type approximate 70% of plasma from the unit is removed and substituted with PAS.

Selection

• Platelet concentrates are ready to transfuse.
• SDPs and RDPs should be ABO identical with the recipient when possible. PAS platelet apheresis can be transfused to a recipient of any ABO group.
• Rh-negative female recipient of childbearing age should receive Rh-negative platelets. Consider administering Rh immune globulins if Rh-positive platelets need to be administered.
• Patients at risk of transfusion associated graft versus host disease (TA-GVHD) should receive gamma-irradiated platelets.
• Platelets collected from a fi rst degree relative of the patient should be transfused after gamma irradiation.

Indications for platelet transfusion

The normal range of platelet count is between 1.5 lakh to 4.5 lakh/μl.

• Active bleeding and platelet count < 50,000/μl or presumed/known platelet function defect.
• Prophylaxis treatment in haematology/oncology patients
  • Platelet count < 10,000/μl in a stable patient
  • Platelet count < 20,000/μl and the presence of a risk factor for bleeding (H/O bleeding, infection, disseminated intravascular coagulopathy)
• Surgical/invasive procedures:
  • Platelet count < 100,000/μl for CNS, eye, airway or other areas with minimal bleeding risk.
  • Platelet count < 50,000/μl for non-nuraxial surgery procedure with minimal bleeding risk.
  • Presumed known platelet function defect.
  • Open heart surgery and cardiopulmonary bypass with perioperative bleeding and thrombocytopenia and/or platelet dysfunction.
• Platelet count < 5000/μl regardless of clinical condition.
• Platelet count < 50,000/μl in DIC increased destruction of platelets.
• The trigger value of platelet count is 20,000/μl for prophylactic platelet transfusion to prevent bleeding.
• In the setting of massive transfusion support for patient who are massively bleeding and when platelet count could not be measured in a timely manner.

Dosages

• One unit of apheresis is equivalent to approximately 6 units of random donor platelets concentrates.
• The dose of platelets (×109 ) can be calculated from the desired platelet increment (PI), the patient’s blood volume in litres (BV, estimated by multiplying the patient’s body surface area by 2.5 or 70 ml/kg in adult) and a correction factor (F) of 0.67 to allow 33% of transfused platelets in the spleen, using the following formula:

  Dose = PI × BV × F –1

• For example, if a platelet increment of 40 × 109 /L is required for a patient with a blood volume of 5 litre, a dose of 300 × 109 or 3 × 1011 is required.
• In small children (<20 kg), 10–15 ml/kg up to the adult dose of one platelet concentrate is used.
• In older children, an adult dose of platelet should be used.
• Therefore, information such as the average number and range of platelets in platelet concentrate should be available to the clinical user.

Platelet response

The post-transfusion increment is generally measured between 10 minutes and 1 hour after the completion of the transfusion and expressed as a corrected count increment (CCI).

The percentage platelet recovery (R) is calculated from the platelet increment (× 109 /L) PI, the blood volume (BV) in liters and the platelet dose transfused (× 109 ) (PD):

R (%) = PI × BV × PD –1 × 100

Corrected count increment (CCI)

CCI is calculated from the corrected count increment (PI), the body surface area of the patient in the squire meter (BSA) and the dose of platelet transfused (× 1011) (PD):

CCI = PI × BSA × PD –1

A successful transfusion may produce a platelet recovery of about 67% in a stable patient, but the minimum platelet recovery to defi ne a successful transfusion is considered as >30% at 1 hour post-transfusion and >20% at 20–24 hour or a CCI of >7.5 × 109 /L at 1 hour and >4.5 × 109 /L at 20–24 hour.

OR

Measure platelet count from 10 minutes to three hours after transfusion generally expect a adult platelet count increment of approximately 7–10,000/mm3 for each RDP given or 30–60,000/mm3 for each SDP given. In neonates and infants a dose of 5–10 ml/kg of platelets (RDP or SDP) should result in a 50–100,000/mm3 increment.

At least 7.1 × 109 /L are consumed daily in endothelial support functions, the equivalent of approximately one RDP daily for a 70 kg adult with marrow failure.

If the 10 minute increment count is less than 50% of that expected on two occasions the patient is considered refractory to platelet. Further transfusion for refractory patients should be with HLA-matched platelets.

Choice between random donor platelets and single donor platelets prepared by apheresis:

• If 4–6 units of random donors platelets are required the choice should be one unit of single donor platelets prepared by apheresis (platelet apheresis). It is the therapeutic dose of platelets. The single donor platelets have leukocytes reduced to ≤5.5 × 106 and have negligible number of red blood cells. There is no risk of immunization and platelet refractoriness. The patient is not exposed to many donors, which reduces the risk of transfusion-transmitted infections.
• Contraindications to platelet transfusion:
  • Thrombotic thrombocytopenic purpura (TTP), idiopathic thrombocytopenia (ITP), heparin-induced thrombocytopenia, unless life-threatening haemorrhage exists.
  • Surgery or invasive procedure where platelet count is >50,000/μl prophylactic platelet transfusion is not indicated.
• Administration
  • Platelet concentrates should be infused as soon as possible and as rapidly as tolerated by the patient, with a disposable, sterile administration set with standard in-line fi lter having a pore size 170–200 microns.
  • Transfusion of one unit of platelet should be completed within 30 minutes to one hour due to the risk of bacterial contamination.
  • Since platelets are stored on agitator, indent and collect platelets from blood bank just before transfusion.
  • They should not be refrigerated.

Autologous blood donation/transfusion

Autologous donation is the donation of blood by the patient for his/her own use. It may be:

• Preoperative autologous blood collection – blood is drawn and stored for anticipated need.
• Perioperative blood collection and administration. It may be:
  • Acute normovolaemic haemodilution
  • Intraoperative blood collection (salvage)
  • Postoperative collection of blood from drainage and reinfused to the patient.

Preoperative autologous blood donation

• Two or more units of blood are drawn and stored prior to the elective surgery required within 42 days (shelf-life of red cells) from the date of autologous donation. Collection is done in the department of blood transfusion services.
• Patient’s age, signifi cant cerebral and cardiac diseases – unstable angina or arrhythmias are carefully evaluated by his/her physician before referring the patient for autologous blood donation.
• It requires written advice of the patient’s physician.

Eligibility for preoperative autologous blood donation

• Haemoglobin : 11 g/dl before each unit of autologous blood donation.
• Weight : Patient of 60 kg can donate 450 ml blood or 7–8 ml blood per kg body weight can be collected.
• Frequency : At the interval of 7 days or even after 4 days if the Hb is 11 g/dl. The last phlebotomy can be performed 72 hours or more before the requirement.
• If not contraindicated patient should be given iron supplements.

Indications

• Major abdominal surgery (splenectomy).
• Obstetrics and gynaecological conditions (patients having multiple antibodies or antibodies to high frequency antigens).
• Patients for whom cross-matched compatible blood cannot be arranged, as in patient of rare blood group or with multiple antibodies.

Contraindications

• Bacteraemia or acute localized infection
• Myocardial infarction within past 6 months
• Unstable angina
• Aortic stenosis
• Congestive heart failure
• Ventricular arrhythmias
• Marked uncontrolled hypertension
• Cerebrovascular accident within 6 months
• Laboratory testing and storage:
• ABO and Rh(D) grouping and labelling.
• Label ‘For Autologous use only’ with patient’s name and registration number.
• Testing of infectious markers not necessary.
• Autologous blood unit should be stored in a separate shelf or at specifi ed space in the blood storage cabinet at 4–6 °C.
• There must be method of confi rming the identity of the autologous unit with the recipient.

Cross-over of the autologous unit

It is not recommended to cross-over autologous blood for allogenic purposes because patient/donor does not meet medical and laboratory criteria for a voluntary/allogenic blood donor.

Acute normovolaemic haemodilution

A second approach to autologous blood transfusion involves the withdrawal of one or two units of blood immediately before surgical operation and replacing the blood with crystalloid, colloid or both thereby haemodiluting the patient’s blood and creating normovolaemic anaemia. This procedure is performed in the operation theatre the blood is transfused during the surgery. Patients who are not eligible for preoperative autologous blood donation may be benefi ted from acute normovolaemic haemodilution.

Intraoperative blood salvage

A third approach to autologous transfusion is the collection and transfusion of blood lost during intraoperative bleeding. It is done with the use of an anticoagulated vacuum pump suction device.

Indications

It is done in surgical procedures like:

• Cardiovascular
• Vascular
• Orthopaedic procedures (like total hip replacement, spinal surgery)
• Liver transplant
• Ruptured ectopic pregnancy
• Trauma

Contraindications

• Infection – re-infusion of contaminated, even washed blood, may lead to bacteraemia.
• Malignancy (malignant cells) – re-infusion of malignant cells may lead to metastatic spread.
• Foecal contamination.

Adverse transfusion reaction

• Transfusion like other treatments can both benefi t and do harm to the patient. Severe reactions are most likely to occur within 15 minutes of starting transfusion of each individual unit of blood products.
• If the patient experiences an adverse reaction during or following transfusion of a blood component, clinical staff must report this to the blood bank as soon as possible.

Acute haemolytic transfusion reaction

• One of the most severe transfusion reactions is the acute haemolytic transfusion reaction (AHTR).
• In this life-threatening condition, immune-mediated intravascular haemolysis occurs as recipient (host) IgM antibodies bind to donor RBCs and activate complement almost always because of an ABO mismatch.
• The most common causes for AHTRs remain patient misidentifi cation and clerical error.
• The classical signs and symptoms of an AHTR include fever, chills and haemolglobinuria.
• In addition, the patient may develop hypotension, pain at the IV site, nausea/vomiting, dyspnea, renal failure or bleeding due to DIC.
• In a conscious patient, even a few millilitres of ABO incompatible blood may cause symptoms within a few minutes of starting the transfusion.
• In an unconscious or anaesthetised patient, hypotension and uncontrollable bleeding due to DIC may be the only signs of an incompatible transfusion Oliguria is common and is often followed by acute renal failure.
• A suspicion of AHTR may be confi rmed by laboratory results showing a positive DAT, haemoglobinemia, haemoglobinuria, reduced haptoglobin, elevated bilirubin, elevated urine haemosiderin and renal abnormalities.

Treatment

• If an AHTR is suspected, the transfusion should be stopped immediately and a normal saline drip should be started to maintain IV access.
• The purpose of initial therapy is to maintain blood pressure and renal blood fl ow. As such, IV saline and a diuretic (if necessary) should be administered so that urine output is maintained at 100 ml/hour (adequate urine output must be ensured as this dilutes the blood and helps to prevent acute tubular necrosis).
• Additional treatment is supportive to manage complications such as bleeding caused by DIC.
• The patient’s identity should be referenced to that on the blood product label to check for error.
• The blood bank should be notifi ed and samples should be sent from the patient and the remaining blood products for testing.

Allergic reactions

• Allergic reactions are common and are mediated by the recognition of donor plasma antigens by preformed recipient IgE antibodies to plasma proteins or allergens.
• Mild: pruritis urticaria;
• Severe allergic (anaphylactic) reactions severe: wheezing or angioedematous reactions, +/- pruritus and urticaria
• These severe allergic reactions often occur when blood products are transfused to patients with IgA defi ciency and who have antibodies directed against the IgA in these products.

Treatment

• For mild allergic reactions, STOP or slow transfusion, administer antihistamines. Resume transfusion at slower rate and observe more frequently. If symptoms/signs worsen, STOP transfusion.
• For severe allergic reactions, STOP transfusion, administer antihistamines hydrocortisone, adrenaline. Intubation may also be necessary. Prophylactic measures for future transfusions for these patients include antihistamines and corticosteroids before the transfusion.

Febrile non-haemolytic transfusion reaction (FNHTR)

• Transfusion reaction associated with an isolated fever is likely a febrile non-haemolytic transfusion reaction (FNHTR).
• A FNHTR is defi ned as an otherwise unexplained rise in temperature of at least 1 °C during or after transfusion with a blood product.
• This type of reaction may be due to cytokines from the plasma of the donor or to recipient antibodies directed against antigens on the cells of the donor.
• Occurs towards end of infusion or within hours of completion in 1% of transfusions. The incidence is reduced with leucocyte-depleted blood components.

Treatment

Treatment for a FNHTR is symptomatic with antipyretics. These may also be used prophylactically for future transfusion as well.

Infective shock

• Bacterial contamination of blood component is rare but very severe with high mortality rate. Usually during fi rst 100 ml.
• Onset of high fever, severe chills, hypotension or circulatory collapse during or soon after transfusion.
• Platelets are more likely to be associated with bacterial contamination than red cells, as they are stored at a higher temperature.
• Blood cultures positive and congruent for both donor and recipient blood.

Treatment

Stop transfusion, manage septicaemia. Fluids and intravenous antibiotics. Seek urgent critical care/haematology advice, return transfused unit and giving set to the blood bank.

Transfusion-related acute lung injury

• Transfusion-related acute lung injury (TRALI) is an acute respiratory distress syndrome secondary to transfusion of blood products and causes hypoxia and bilateral non-cardiogenic pulmonary oedema.
• Its incidence is not precisely known, but is estimated between 1 in 1200 and 1 in 5000.
• Symptoms include dyspnoea, hypoxaemia, hypotension and fever. There is no evidence of CHF – there is no jugular venous distension and right arterial pressure is normal.
• The aetiology of TRALI is unclear, however it is believed that there is either a transfer of biologically active lipids or a transfer of HLA/ granulocyte antibodies from the donor to the recipient. (It is believed that multiparous female donors have an increased number of these antibodies as a result of previous pregnancies, and therefore receiving blood from these donors poses a greater risk of developing TRALI.)

Treatment

• Management of this type of transfusion reaction includes cessation of the transfusion, maintenance of the IV line with normal saline, as well as supportive care including oxygenation or mechanical ventilation, if necessary.
• CXRs must be performed and the blood bank notifi ed.
• Steroids and diuretics are NOT indicated in the treatment of TRALI.

TACO (transfusion-associated cardiac overload)

• TACO is caused by heart failure leading to pulmonary oedema as a result of rapid infusion or large volumes of blood products.
• It is usually due to rapid or massive transfusion of blood in patients with diminished cardiac reserve or chronic anaemia.
• Patients over 60 years of age, infants and severely anaemic patients are particularly susceptible.
• TACO occurs in approximately 1% of older patients receiving transfusions. It is frequently confused with TRALI as a key feature of both is pulmonary oedema and it is possible for these complications to occur concurrently. Hypertension is a constant feature in TACO whereas it is infrequent and transient in TRALI.
• Criteria for diagnosis of TACO are characterized by any four of the following within 6 hours of transfusion: Acute respiratory distress, tachycardia, raised blood pressure, acute or worsening pulmonary oedema on CXR, evidence of positive fl uid balance.
• The cardiac marker, brain natriuretic peptide (BNP) is often elevated in TACO.
• ‘At-risk’ patient to give each unit of red cells slowly (50 ml/hour)
  • Maximum rate is 4 hours from removal from temperature-controlled storage.
  • Units may need to be split.
  • The patient may require additional diuretic therapy (for example IV furusemide).
  • Oxygen may be required.
  • Closely monitor the patient for signs and symptoms of TACO.
• Differential diagnosis – TRALI, TAD.

Graft-vs-host disease (GvHD)

• GvHD is a rare complication of transfusion, caused by T-lymphocytes.
• Immunodefi cient patients, especially allogenic bone marrow recipients and foetuses receiving intrauterine transfusions, are at greatest risk.
• Transfusion-associated GvHD is almost always fatal (mortality rate 75– 90%) and there is no effective treatment.
• Acute GvHD begins between day 4 and day 30 following transfusion, with high fever and diffuse erythematous skin rash progressing to erythroderma, diarrhoea and abnormal liver function. Patients deteriorate with bone marrow failure and death occurs through overwhelming infection.
• Transfusion-associated GvHD is preventable with the irradiation of cellular blood products. Patients requiring irradiated blood include:
  • Allograft bone marrow and stem cell recipients (for at least 6 months and some centres recommend indefi nitely).
  • Patients who have in the past received purine analogue treatment.
  • Patients with Hodgkin’s disease.
  • Patients with congenital cellular immunity defi ciency.

Delayed haemolytic transfusion reaction (DHTR)

• DHTR is a haemolytic reaction occurring 24 hours or more following transfusion, in a patient who has been immunized to a red cell antigen by an earlier transfusion or pregnancy.
• The level of antibody may be so low that it cannot be detected in the pretransfusion sample.
• After transfusion of red cells bearing the target antigen a rapid, secondary immune response boosts the antibody level so that after a few days, transfused red cells bearing the relevant antigen may be rapidly destroyed.
• Antibodies of the Kidd (Jk) and Rh systems are the most frequent cause of DHTR.
• The signs of a delayed haemolytic transfusion reaction normally appear 1–14 days after transfusion.
• Usual features include fever, falling haemoglobin (or a failure of the haemoglobin to rise), jaundice and occasionally haemoglobinuria or renal failure.

Transfusion-transmitted infections

• Blood donors, like anyone else, can occasionally carry an infectious agent, sometimes for a long period, without having any clinical signs or symptoms.
• Donors are interviewed thoroughly as part of pre-donation counselling to take high-risk history or go for self-exclusion.
• Tests are performed on every blood donation. No part of the donation should be released until all these tests are known to be clear.
• A good donor selection and testing procedures makes the risk of infection through the contamination of blood components and products extremely small.

Steps to follow when an acute transfusion reaction is suspected

• Firstly it is important to understand that early recognition and intervention will prevent morbidity and mortality.
• Once a reaction is suspected the nurse must initiate supportive care and summon support from attending medical offi cer immediately.

Actions

• Stop transfusion immediately!
• Commence normal saline infusion (except in suspected TACO) using a new intravenous administration set.
• Ensure; airways are open, vital signs are stable, oxygen and emergency supplies available (crash cart in ready).
• Verify identity of the patient; make certain that the unit being infused was unmistakably meant for that patient (review obligatory identifi ers).
• Notify the blood bank, complete the transfusion administration record sheet and send to the blood bank with patient’s immediate post-transfusion laboratory samples and remnants of transfused components with blood transfusion set (as indicated) for the evaluation of transfusion reaction.
• Collect fi rst post-transfusion urine sample and send to the haematology laboratory for free haemoglobin.
• Management as clinical scenario dictates chest X-ray – all observations, actions and treatment must be fully documented in the medical record.
• Further investigations (by blood bank and medical staff) of probable cause and implementation of corrective actions should be taken where warranted.

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