Tryptase, an enzyme released from mast cells, is used to help distinguish causes of anaphylaxis or mastocytosis (overproduction of mast cells). This test measures the amount of total tryptase (both the alpha [α] and beta [β] forms) in the blood when mast cells are activated.
<11.5 ng/mL (total tryptase)
The blood sample should be obtained within 2 hours of suspected event that triggers mast cell activation—for example, allergic immune response.
Obtain a 5-mL venous blood sample (SST).
Observe standard precautions. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered. Place the specimen in a biohazard bag.
Tryptase is increased with:
Anaphylaxis and mastocytosis
Asthma
Myelodysplastic syndrome (bone marrow disorder)
Acute myelocytic leukemia
End-stage kidney disease
Pretest Patient Care
Explain test purpose and blood-drawing procedure.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Posttest Patient Care
Have patient resume normal activities.
Review test results; report and record findings. Modify the nursing care plan as needed.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.