Test Name: Digoxin
Health Link Test Code: DIG
LIS Test Code: DIGO
CPT Code(s): 80162
Methodology: Particle Enhanced Turbidometric Inhibition Immunoassay (PETINIA)
Days Performed: Daily, 24 hours.
In-Lab Turnaround Time: 4 hours.
Stat In-Lab Turnaround Time: 1 hour.
Collection Container: Red top
Also Acceptable: Green top
Collection of specimen must be at least 6 hours after an IV dose or at least 8 hours after a PO dose.
Collection Volume: 2 mL
Pediatric Collection Volume: 0.4 mL
Sample Analyzed: Serum
Testing Volume: 1 mL
Pediatric Testing Volume: 0.2 mL
Centrifuge. Transfer cell-free serum or plasma to plastic vial. Refrigerate.
Transport specimen to the laboratory. Transport with coolant pack if coming from clinic location.
Specimens collected in red cap with yellow ring (SST) or green cap with yellow ring (PST) tubes are not acceptable.
Generally effective therapeutic concentration: 0.5-0.9 ng/mL
Administration of Digibind makes Digoxin levels invalid until Digibind (digoxin immune fab) has been cleared from the patient's system, approximately six weeks.
Endogenous, digoxin-like immunoreactive factors (DLIF) have been detected in the serum and plasma of neonates, pregnant women, and patients in renal and hepatic failure. Several studies have established that these factors can cause falsely elevated digoxin measurements when assayed by commercially available immunoassays.
Critical Calls: yes
Result of "BELOW" indicates that the result is below the method detection limit of 0.2 ng/mL. Patient response to the drug varies. Potassium depletion increases sensitivity to the drug. Renal dysfunction decreases elimination of digoxin, causing an accumulation of the drug in the serum. Half-life is 32-48 hours depending on patient's renal function and can be 100 hours in anephric patients.