Cortosyn Stimulation Test

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

0.3 mL

Specimen Type: Plasma, Lithium heparin
Collection Container: Green top (Lithium heparin)

1. Centrifuge and separate cells after clot formation and within 4 hours of collection.
2. Remove serum if testing will be delayed more than 4 hours.

1. Baseline samples should be collected between 6 a.m. and 10 a.m. 
2. Draw baseline cortisol level immediately prior to cosyntropin administration (injection should be administered no later than noon).
3. Collect additional specimens at 30-minute and 60-minute post injection.
4. If cortisol stimulation testing is scheduled later in the day, baseline must be collected 30 minutes prior to injection.

Room temperature: Unacceptable
Refrigerated (on gel): 8 hours
Refrigerated (off gel): 14 days
Frozen: 1 month

Samples stored on gel >4 hours, unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements, cadaver specimens.

Daily

Same day

For diagnostic purposes, results should be used in conjunction with other data: symptoms, results of other tests, clinical impressions, etc.
Potentially interfering substances include : Hemoglobin  500 mg/dL; Bilirubin 20 mg/dL; Triglycerides  2000 mg/dL; Total Protein (low/high) 3/10 g/dL 
All cortisol measurements should be referenced to the time of day of sample collection due to diurnal variation.
Patients receiving fludrocortisone, prednisolone or prednisone may show artificially elevated cortisol values due to cross–reactivity.