Epinephrine, Plasma (37560X)

Test Code

22301P

CPT Codes
82542

Preferred Specimen

2 mL frozen plasma collected in a sodium heparin (green-top) tube

Patient Preparation
Patients should be relaxed in either a supine or upright position before blood is drawn. States of anxiety and stress can cause fluctuations in the catecholamine levels. Patients should avoid alcohol, coffee, tea, tobacco and strenuous exercise prior to collection. Overnight fasting is required.

Minimum Volume

1 mL

Other Acceptable Specimens

Frozen plasma collected in an EDTA (lavender-top) tube

Instructions

Draw specimen in a pre-chilled green-top tube. Plasma should be separated in a refrigerated centrifuge within 30 minutes of collection and then frozen immediately at -20° C in plastic vials. Each specimen will be invoiced separately.

Transport Temperature

Frozen

Specimen Stability

Room temperature: 6 hours
Refrigerated: 6 hours
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Received thawed • Received room temperature • Received refrigerated

Methodology
Liquid Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Mon-Fri; Report Available: 3-6 days

Clinical Significance

This test, when used in conjunction with the measurements of other catecholamines, may aid in evaluating catecholamine-producing pheochromocytomas and paragangliomas (PPGLs). However, measurements of plasma free or urinary fractionated metanephrines (ie, the O-methylated catecholamine metabolites) are preferred for the initial biochemical evaluation of PPGLs because of their overall high diagnostic sensitivity [1].

Most PPGLs secrete catecholamines and can cause catecholamine excess, resulting in hypertension, arrhythmia, and hyperglycemia. Left untreated, PPGLs often lead to life-threatening cardiovascular complications. The estimated prevalence of PPGLs is 0.05% to 0.1% in adults with hypertension and 1.7% in children with hypertension [2]. Recognizing the possibility of a PPGL and performing appropriate biochemical testing are crucial for the diagnosis [1]. Plasma or urine catecholamine levels may be used, in addition to metanephrine levels, to provide additional information during the initial biochemical evaluation of PPGLs (eg, when detecting dopamine-secreting paragangliomas) [2].

Intermittent or insignificant secretion of catecholamines by some PPGLs may not increase catecholamine measurements. Physiological stress and certain medications (eg, acetaminophen, labetalol, and sotalol) may increase catecholamine measurements [1].

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

References
1. Lenders JW, et al. J Clin Endocrinol Metab. 2014;99(6):1915-1942.
2. National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology (NCCN Guidelines®). Neuroendocrine and Adrenal Tumors. V1.2022. Accessed June 28, 2022. http://www.nccn.org

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.