Rhesus (Rh) Typing


The Rhesus (Rh) system classifies blood by the presence or absence of the Rh (D) antigen on the surface of RBC’s. In this test, a patient’s RBCs are mixed with serum containing anti-Rh (D) antibodies and are observed for clumping. If clumping occurs, the Rh (D) antigen is present, and the patient’s blood is typed Rh positive; if clumping doesn’t occur, the antigen is absent, and the patient’s blood is typed Rh-negative.

  • To establish blood type according to the Rh system.
  • To help determine the donor’s compatibility before transfusion.
  • To determine if the patient will require an Rh (D) immune globulin injection.
Patient Preparation
  1. Confirm the patient’s identity using two patient identifiers according to facility policy.
  2. Explain to the patient that Rh typing determines or verifies blood group to ensure safe blood transfusions.
  3. Inform the patient that he doesn’t need to restrict food and fluids for the test.
  4. Tell the patient that the test requires a blood sample. Explain that he may experience slight discomfort from the tourniquet and needle puncture.
  5. Check the patient’s history for recent administration of dextran, IV contrast media, or drugs that may alter test results.
  1. Perform a venipuncture and collect the sample in a 7-mL EDTA tube.
  2. Label the sample with the patient’s name, the hospital or blood bank number, the date, and your initial.
  3. If a transfusion is ordered, make sure a transfusion request form accompanies the sample to the laboratory.
Nursing Interventions
  1. Apply direct pressure to the veniouncture site until bleeding stops.
  2. If a hematoma develops at the venipuncture site, apply direct pressure.
  3. If necessary, give the pregnant patient a card identifying that she may need to receive Rh (D) injection.
Normal Results
  • If the D antigen is present, that person is Rh positive.
  • If the D antigen is absent, that person is Rh-negative.
  • Antibodies to Rh antigens develop only as an immune response after a transfusion or during pregnancy.
Abnormal Results
  • Rh incompatibility is the most common and severe cause of HDN, possible when Rh-negative woman and an Rh-positive man produce an Rh positive baby.
Interfering Factors
  • Unknown
  • Handle the sample gently and send it to the laboratory immediately.