|
Test ID: Neonatal Blood Bank Screening
|
|
Neonatal Blood Bank Screening
|
|
Newborn Screening (NBS) - Tube Technique and Gel/Bead Technique
|
|
Useful For
|
- This test is performed to determine the ABO/Rh-D and Direct Antiglobulin Test (DAT) of the Neonate.
- The DAT is performed to determine if the red cells are coated in vivo with IgG or complement components.
|
|
Method name and description
|
- This test is a combination of two tests ABO/Rh-D typing and Direct Antiglobulin Test (DAT).
- The DAT is performed to determine if the red cells are coated in vivo with IgG or complement components caused by Hemolytic Disease of the Newborn (HDNB)
- The different methodologies used in Hamad Medical Corporation-Transfusion Medicine are microplate/gel card/glass beads and tube techniques
- Reflex Testing – (if applicable-one or more of the following tests)
- Acid Elution
- Antigen Phenotype
- Antibody Identification
|
|
Reporting name
|
Neonatal Blood Bank Screening (ABO/Rh-D + DAT)
|
|
Clinical information
|
- Adequate clinical diagnosis of the patient shall be provided including
- History of previous transfusions if applicable
- Mothers blood group and antibody screening results
- Diagnosis
|
|
|
Specimen type / Specimen volume / Specimen container
|
Neonates – 0 to 4 months – 1ml microtainer purple top (EDTA)
|
|
Collection instructions / Special Precautions / Timing of collection
|
- Collection Instructions
- The intended patient being tested, and the blood sample must be positively identified at the time of collection. The completed label must be attached to the tube of blood before leaving the bedside of the recipient.
- Special Precautions: Specimens are usually collected from veins in the antecubital area. Avoid collecting blood samples from the following sites:
- Veins with running I.V fluids
- Areas with extensive scar tissue
- Areas with hematomas
- Edematous areas
- Specimen labeling requirements:
- The ID label must include the following information.
- Patient’s first, middle and last names (full name)
- Hospital health card number.
- Signature and identification number of the person collecting the specimen (information may be electronic or manual)
- The date and time of blood collection, (information may be electronic or manual)
- Location
- Specimen should be collected from one patient at a time
- Specimen is labeled and the request form signed before moving to another patient.
- Specimens should NEVER be relabeled
|
|
Storage and transport instructions
|
- Specimens shall be transported at room temperature 20-24 degrees Celsius.
- Specimens should be transported immediately to blood bank and they will be processed as soon as it is received.
- Specimen retention
- 7 days from the time of collection
|
|
Specimen Rejection Criteria
|
- Following are the reasons for Specimen rejection, but not limited to:
- Unlabeled, Mislabeled or relabeled specimen tubes.
- Specimen tubes that do not carry the date and signature/ initials of phlebotomist.
- Specimen collected in wrong blood containers.
- Specimen in leaking / contaminated containers.
- Quantity Not Sufficient.
- Specimen not accompanied by a test order.
- Specimen accompanied by improperly completed test order.
- Specimen accompanied by test order not carrying the signature and stamp of the requesting physician.
- Specimen and test order with mismatched patient’s identification details.
- Grossly Hemolyzed Specimens, except for patients, Severe Burns, Hemolytic anemias like Autoimmune hemolytic anemia and sometimes severe septicemia.
|
|
|
Biological reference intervals and clinical decision values
|
- Blood Grouping
- Forward Type: Agglutination of the patient’s red blood cells in the presence of reagent anti-sera is a positive test result and indicates the presence of the corresponding antigen; lack of agglutination indicates absence of the corresponding antigen.
- Reverse Type: is not applicable for neonates as the development of antibodies is not complete in this age.
- Rh D: The agglutination in the tube is a Positive result and no agglutination in the tube is a Negative result.
-
|
ABO-D Interpretation
|
|
O Rh D Positive
|
|
A Rh D Positive
|
|
B Rh D Positive
|
|
AB Rh D Positive
|
|
O Rh D Negative
|
|
A Rh D Negative
|
|
B Rh D Negative
|
|
AB Rh D Negative
|
- Reporting Results (DAT):
- DAT is positive when agglutination is observed.
- DAT is negative if no agglutination is observed.
|
|
Factors affecting test performance and result interpretation
|
- Blood Grouping
- Some clinical disorders may cause weak or mixed field reactions such as
- Leukemia
- Hematological disorder
- History of Blood Transfusion
- Bone marrow transplantation
- Patients with high potency cold antibodies
- Abnormal concentrations of serum protein
- Wharton’s jelly
- Age – Newborns (4-6 months) and elderly persons
- DAT
- Causes of False Positive Results:
- Spontaneous Aggregation, Improper saline storage, inappropriate blood Specimen, a small fibrin clot has formed in the tube neutralizing the AHG, and Septicemia.
- Causes of False Negative Results:
- Improper washing, improper technique, improper saline storage and PH and delayed testing, under centrifugation, a delay in adding AHG, AHG is inactive, Ineffective Anti-globulin serum and reagent sensitivity
- A negative DAT does not necessarily mean that the red cells have no attached globulin molecules. Polyspecific and anti-IgG reagents detect as few as 200-500 molecules of IgG per cell, but patients may experience autoimmune hemolytic anemia when IgG coating is below this level.
|
|
Turnaround time / Days and times test performed / Specimen retention time
|
- Test is performed 24/7
- TAT – Routine 8 hours
- TAT – STAT 60 minutes
- All discrepant and abnormal results will be released in 3 working days
|
|
|
