Packed Red Blood Cells

https://meditropics.com/662-2/

Tushar Shailat

Post graduate resident, department of medicine, LHMC

 

 

Why PRBCs(Packed red blood cells) are preferred?

One unit of whole blood can be used to extract multiple important blood components like PRBCs, platelets, granulocyte concentrate, plasma and cryoprecipitate. All the blood components might not be required in a patient which can lead to wastage of resources. Also, due to less volume the chances of volume overload are less compared to transfusing whole blood.

Preparation of PRBCs

PRBCs are prepared from whole blood by separating them from plasma using via slow centrifugation or undisturbed sedimentation. Commonly used anticoagulants are Citrate phosphate dextrose (CPD), CPD adenosine and SAGM(Sodium chloride, adenine, dextrose, D–mannitol) . After preparation, PRBCs can be stored at 4-6 degree Celsius for a variable period depending upon the anticoagulant used.

Testing

PRBCs are tested for following before storing them for use

1. Blood group- ABO blood groups
2. Rh(D) type antibodies
3. Lab tests for infectious diseases like Hep A, B and C, HIV, Malaria, Syphilis
4. sterility test by culture at 4, 22 and 37 degree Celsius

 

TYPES OF PRBCs

1. Leucocyte depleted PRBCs

Leucocyte depletion is done by using leucocyte filter (size – ). During this procedure, around 2-5 billion leucocytes are reduced down to less than 5 million. They help in preventing Allo-immunisation, FNHTR amd CMV transmission.

They are commonly used in chronically transfused patients, previous FNHTR, patients receiving organ or hematopoietic cell transplants and patients of acute leukemia and other malignancies.

2. Irradiated PRBCs

PRBCs are irradiated at 2500 cGY to inactivate the lymphocytes to prevent transfusion associated graft vs host disease.

They are used in congenital cell mediated immunodeficiency states, lymphoma patients and patients on potent immunosuppressive therapies.

3. Frozen RBCs

 PRBCs are kept frozen at -80 to -196 degree Celsius which can be used upto 10 years. This method is for storage for rare red cell phenotypes like Bombay phenotype.

4. Washed PRBCs

PRBCs are washed .9% saline to remove residual plasma. They are used for patients have IgA deficiency, repeated allergic reactions and those who are risk of hyperkalemia.

INDICATION FOR PRBCs TRANSFUSION

The main indication for PRBCs transfusion is inadequate oxygen delivery to tissues as a result of anemia.

Recommendations

1. Hb <7 – PRBC transfusion is recommended
2. If Hb is between 7-10 gm/dl –

PRBCs transfusion is recommended in specific conditions like

Acute coronary syndrome – PRBC transfusion recommended for Hb <8.

Hemodynamically unstable or symptomatic patients.

In hemodynaically stable patients with no symptoms transfusion thresholds have been given by

Pre-existing CAD – 8 gm/dl

ICU – 7gm/dl

Non cardiac surgery – 8gm/dl

Cardiac surgery – 7.5 gm/dl

3. If Hb is >10

PRBCs should be transfused in case of rapidly declining Hb levels i.e. >2 gm/dl/day or if active bleeding is present

 

PRBCs transfusion in Anemia

Anemia due to nutritional deficiency

It is rarely indicated in nutritional deficiency if the patient is asymptomatic and there is time for correction of underlying nutritional deficiency leading to anemia.

PRBCs can be considered in nutritional deficiency in case of elderly patient with angina or comgestive heart failure, iron deficiency with active bleed and life threatening anemia i.e. Hb <6.5 gm/dl.

 

Thalassemia

Patients with thalassemia require frequent blood transfusions and treatment goal is to maintain Hb level between 9.5 to 10.5 gm/dl. Cross-matched and washed PRBCs are preferred.

 

Hemolytic anemia

Transfusion is indicated if Hb <6gm/dl. In autoimmune haemolytic anemia, transfusion of serologically incompatible cells may be necessary for life saving. Risk of complications are increased in presence of undetected alloantibodies.

 

Massive haemorrhage

In case of emergency, Blood group O is preferred in case of non availability of group specific or cross-matched PRBCs.

1:1:1 PRBC:Platelets:FFP regimen is preferred for patients with severe trauma.

ADMINISTRATION

Prerequisites

1. Informed consent
2. Confirmation of patient details
3. Confirmation and Inspection of PRBC unit.

Infusion rate should be 60-120 ml/hr for first 15 min and then as rapidly as tolerated. Slower infusion and diuretics prevent circulatory overload due to transfusion. Once started transfusion should be completed within 4 hours.

MONITORING

 

Pulse rate, blood pressure, respiratory rate and temperature should be documented at

Pre transfusion – <60 min before transfusion

During transfusion – 15 min after starting the transfusion

Post transfusion – within 60 minute of completion.

Regular visual monitoring should be done throughout the transfusion. Post transfusion CBC can be sent 15 min after the procedure is complete.

On completion, documentation of date and time of completion should be done along with details of any transfusion reaction

 

PRBCs alternatives

Two alternatives have been used i.e. Hemoglobin based oxygen carriers (HBOC) and Perfluorocarbons.

Most common PRBC alternative used is HBOC-201 aka Hemopure

HBOC-201 is a purified, crosslinked, polymerized acellular bovine haemoglobin. It can be used through FDA expanded access protocols only. Hemopure use is documented in cases of ALL patient with life threatening anemia, autoimmune haemolytic anemia and sickle cell anemia where the patient had refused PRBC transfusion. Adverse effects are vasoconstriction, hemostatic effects, GI symptoms and Immunosupression.

Under development

1. In-vitro RBC production – cultured RBCs from hemopoeitic progenitor cells like umblical cord cells and multipotent stem cells
2. Elimination of blood group antigens – by enzymatic conversion of A,B and AB blood groups to O blood group
3. Oxyvita – Liposome encapsulated polymerized bovine haemoglobin
4. Vidaphor – a perfluorocarbon that has been used in 35000 transfusions in Russia and is undergoing trials by FDA.