How do Blood Transfusions Work?

Blood Transfusions Video

Blood transfusions are a life-saving treatment that the nurse must be able to administer safely as well as recognize & manage adverse reactions with speed & confidence.

As a nurse, it is important to be familiar with the types of blood components you will be transfusing.

Whole blood contains all blood components – RBCs, WBCs, & platelets, plasma (liquid component of blood), clotting factors, & immunoglobulins. It is used only when a patient loses a large amount of blood because it has a greater effect on body fluid volume. It must be transfused within 24 hours of collection since coagulation factors deteriorate after that. Patients rarely need all the components of whole blood, so it is more efficient & effective to give only the component needed to manage the specific condition.

Packed RBCs contain hemoglobin, an iron-containing protein responsible for transporting oxygen in the blood. RBCs are separated from plasma & platelets and given for anemia and blood loss due to trauma or surgical blood loss.

Platelets are a cellular component that assist in the clotting process in blood vessel injuries. They are given for thrombocytopenia (low platelets in the blood) and platelet-function abnormalities.

Granulocytes are a type of WBC separated from whole blood given to patients with low granulocyte count or as supportive therapy for patients on chemotherapy.

Fresh frozen plasma (FFP) is taken from whole blood and frozen within 24 hours of collection. Plasma is the liquid portion of blood, containing 92% water and 8% plasma proteins, including albumin, fibrinogen, globulins, & other clotting proteins. FFP is given for clotting deficiencies, liver disease, & hemophilia.

Cryoprecipitate, often referred to as “cryo,” is the precipitated material obtained from FFP when thawed. It contains coagulation factors VIII and XIII, fibrinogen, von Willebrand factor, & fibronectin. It is given to prevent or control bleeding in patients with hemophilia, von Willebrand disease, to correct low fibrinogen levels, & for other clotting disorders.

When giving a blood transfusion, it is important to know how blood is grouped.

The ABO system is based on the presence or absence of the A and B antigens:

Type A blood has the A antigen

Type B blood has the B antigen

Type AB has both

Type O has neither

The compatibility of blood types between donor & recipient is dependent on the presence or absence of A and B antigens and antibodies.

The Rh system is based on the presence or absence of the major D antigen on the surface of the RBCs.
A person who has the D antigen is Rh-positive.
A person who does not have the D antigen is Rh-negative.

Compatible blood types:
If patient has: They can receive:
Type O Only type O
Type A Types A or O
Type B Types B or O
Type AB Any - type A, B, AB or O
Known as “universal recipients”
If patient has: They can donate to:
Type A Types A and AB
Type B Types B and AB
Type AB Only type AB
Type O All types A, B, AB, O
Known as “universal donors”

Safe practice starts with several key actions that must be taken before beginning a transfusion.

  • Accurately collect blood samples for a type & crossmatch – this will determine the patient’s ABO group and Rh type.
  • Verify the physician’s order for the transfusion. The physician should have discussed with the patient the benefits as well as the potential adverse effects of the transfusion.
  • Verify that the patient’s religious or cultural beliefs do not prohibit transfusions of blood or blood components.
  • Confirm that the patient has signed an informed consent, which is required for transfusing all blood & blood products.
  • Obtain baseline vital signs & do a physical assessment of the patient to help identify later changes. Assessment should include IV assessment (check for patency and preferred catheter
    size, 20 gauge or larger, to prevent blood hemolysis), assess breath sounds, presence of rash or not, and sufficient voiding of at least 30 ml/hr. Document all findings.
  • Educate the patient regarding the basics of the procedure, including the need for IV access, monitoring vital signs, & S/S to watch for that could indicate a transfusion reaction, such as
    nausea, difficulty breathing, back or chest pain, or chills.
  • Reassure the patient that donor blood has been thoroughly screened & tested to identify the presence of viruses.
  • Once the blood bank has issued the blood component to the nurse, the transfusion needs to be started within 30 minutes or returned to the blood bank.

When arriving at the patient bedside, two licensed RNs (or according to hospital policy) will check the blood or blood product and document all of the following:

  • Patient’s name
  • Patient’s medical record number
  • Patient’s unique blood bank identification blood band number
  • Patient’s blood type
  • Type of blood or blood product ordered for patient
  • Expiration date of blood product
  • Blood unit identification number

If any information does not match or there is an abnormal appearance of the product, the blood product will be returned to the blood bank & the physician will be notified.

Normal saline (0.9% sodium chloride) IV solution should be primed through the sterile Y-connector blood administration set, which has a filter to retain particles potentially harmful to the patient.

It is wise to start the NS at 30 ml/hr while picking up the blood from blood bank to ensure that the IV site is patent and IV lines are ready for the blood to be started.

Important notes:

  • Blood administration tubing can be used for up to 2 units of blood. However, under usual circumstances, the blood transfusion will take around 3-4 hours, so tubing will need to be changed with each unit of blood.
  • Each unit of blood or blood product must be transfused within 4 hours of issue from blood bank.
  • Do not give any drugs through the IV line in which blood is transfusing – NS is the only solution that can be added to blood or blood products.

All vital signs – temperature, blood pressure, pulse, & respiration must be assessed and documented according to the hospital policy, an example follows:

  • Before initiating the transfusion
  • 15 minutes after transfusion is initiated
  • Every 30 minutes x2, then hourly
  • At completion of blood transfusion

The physician may order for the patient to be pre-medicated prior to the transfusion with Tylenol or Benadryl to help immunologic transfusion reactions, such as fever or histamine release.

The RN stays with the patient during the first 15 minutes, assessing for S/S of ‘Transfusion Reactions,’ which could include anything from a mild rash or itching to a life-threatening acute hemolytic reaction.

Assess for the following:

  • Skin rash / hives, itching, flushing
  • Increased body temperature
  • (more than 1.8 degrees F)
  • Body chills/shivering
  • Shortness of breath, difficulty breathing
  • Significant changes in vital signs
  • Changes in mental status
  • Pain, anxiety, nausea
  • Chest pain, tightening sensation

Continue to monitor the patient for any of these symptoms throughout the transfusion.

If any ‘Transfusion Reaction’ symptoms are observed, act immediately by:

  • Stopping the blood transfusion
  • Maintain the IV line with Normal Saline at 30 ml/hr
  • Provide emergency care if needed
  • Notify the physician & obtain orders
  • Notify the blood bank of ‘Transfusion Reaction’
  • Return remaining blood & tubing to the blood bank in a sealed container.

An incident report needs to completed for the blood transfusion reaction.

Remember, blood transfusions are life-saving for the patient, and you as a nurse, want to be confident of the steps to take before & during the administration of blood & blood components.


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by Mometrix Test Preparation | This Page Last Updated: July 20, 2023