| Test Name: |
|
Lidocaine
|
|
|
|
|
|
|
| Test Code(s): |
|
LIDO / HCLIDO
|
|
|
|
|
|
|
| CPT Code(s): |
|
80176
|
|
|
|
|
|
|
| Test Description: |
|
Test Component: Lidocaine and monoethylglycinexylidide (MEGX)
|
|
|
|
|
|
|
| Methodology: |
|
Gas Chromatography
|
|
|
|
|
|
|
| Clinical Significance: |
|
Antiarrhythmic, local anesthetic
|
|
|
|
|
|
|
| Days Performed: |
|
Daily, dayshift- Pathology Resident approval is required after hours.
|
|
|
|
|
|
|
| Turnaround Time: |
|
Stat: 3 hours.
Routine: 24 hours.
|
|
|
|
Specimen Requirements
|
|
|
|
| Specimen: |
|
Blood
|
|
|
|
|
|
|
| Collection Instructions: |
|
Collect specimen:
1) at least 12 hours after initiating therapy
2) if lidocaine toxicity is suspected
3) whenever ventricular dysrhythmias occur despite
lidocaine administration.
|
|
|
|
|
|
|
| Collection Container: |
|
Preferred: Red top
|
|
|
|
|
|
|
| Collection Volume: |
|
Preferred: 4 mL
Pediatrics: 3 mL
|
|
|
|
|
|
|
| Sample Analyzed: |
|
Serum
|
|
|
|
|
|
|
| Volume Required: |
|
Preferred: 2 mL
Pediatrics: 1 mL
|
|
|
|
|
|
|
| Specimen Processing: |
|
Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.
|
|
|
|
|
|
|
| Specimen Transport: |
|
Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.
|
|
|
|
|
|
|
| Unacceptable Criteria: |
|
Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.
|
|
|
|
|
|
|
| Stability: |
|
Refrigerated: 2 days
Frozen: 6 months
|
|
|
|
Interpretation
|
|
|
|
|
Interpretive Guidelines:
|
|
| Generally effective therapeutic concentration: |
| 18 years and up: |
Lidocaine 2.0-5.0 mcg/mL |
| |
MEGX 0.5-2.0 mcg/mL |
| |
|
| Toxic: |
|
| 18 years and up: |
Lidocaine >6 mcg/mL |
| |
MEGX >6 mcg/mL |
|
|
|
|
|
|
|
| Critical Calls: |
|
View
|
|
|
|
|
|
|
| Additional Information: |
|
Result of "BELOW" indicates that the result is below method detection limit of 0.1 mcg/mL. The half-life is approximately 1-2 hours. Lidocaine is metabolized to monoethylglycine-xylidine (MEGX).
This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories. This test meets the standards for clinical testing. This test should not be regarded as investigational or for research use. The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.
|
