Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1196 page)

   The test is used to determine the presence of fetal–maternal hemorrhage by testing for the presence of D-positive fetal red cells in the circulation of a D-negative mother. If >30 mL of fetal (whole) blood or >15 mL of fetal red cells are present in the maternal circulation, the assay has a sensitivity of ≥99%.

   Interpretation

   The presence of a positive result indicates that the fetal blood is admixed with that of the mother. This happens when the fetus has hemorrhaged into the mother’s circulation and may require intrauterine transfusion or obstetric intervention.

   Limitations

   The rosette test is a qualitative screening test. If it is positive, the amount of fetal blood in the maternal circulation must be quantified using flow cytometry or the Kleihauer-Betke (acid-elution) assay (see p. 1021).

Suggested Readings

Anstee DJ. Red cell genotyping and the future of pretransfusion testing.
Blood.
2009;114:248–256.

Petrides M, Stack G.
Practical Guide to Transfusion Medicine
, 2nd ed. Bethesda, MD: AABB Press; 2007.

Roback J, Grossman B, Harris T, et al. (eds.).
Technical Manual
, 17th ed. Bethesda, MD: AABB Press; 2011.

SALICYLATES (ASPIRIN)
*

   Definition

   An acidic drug that is rapidly metabolized to an active metabolite, salicylate; also known as acetylsalicylic acid (ASA). Included in aspirin, sodium salicylate, oil of wintergreen, methyl salicylate.

   
Normal therapeutic range (serum):

   Analgesic/antipyretic use: <60 μg/mL

   Anti-inflammatory use: 150–300 μg/mL

   Use

   ASA and salicylate have analgesic, antipyretic, and anti-inflammatory properties; used in the treatment of RA.