MRO Review & Interpretation 3 — Questions and Answers
Question 1: A donor tests positive for PCP. The donor claims they were exposed to PCP through passive inhalation at a party. How should the MRO respond?
- Report negative if the donor provides a written statement
- Report positive because passive inhalation is not a scientifically accepted explanation for a PCP positive (Correct answer)
- Cancel the test and request a hair follicle confirmation
- Request the lab to perform additional confirmatory testing
Correct answer: Report positive because passive inhalation is not a scientifically accepted explanation for a PCP positive
Passive inhalation is not a recognized scientific explanation for PCP positives at federally mandated cutoff levels.
Question 2: An employer receives a negative result for a pre-employment test. Three days later, the lab calls to report a clerical error and the result is actually positive. What should the MRO do?
- Issue a corrected verified positive report to the DER (Correct answer)
- The original negative stands because it was already reported
- Retest the specimen before issuing any correction
- Report to the federal agency and await their decision
Correct answer: Issue a corrected verified positive report to the DER
MROs must issue corrected reports when errors are discovered, and the corrected verified positive must be reported to the DER.
Question 3: Which laboratory result would cause an MRO to report a specimen as 'invalid' rather than 'adulterated'?
- Nitrite concentration of 500 mcg/mL
- pH of 2.8
- Presence of surfactant that interferes with testing (Correct answer)
- Specific gravity of 1.0005 with creatinine of 1.5 mg/dL
Correct answer: Presence of surfactant that interferes with testing
An invalid result is reported when the lab cannot obtain a valid test result due to an interfering substance or an unexplained inconsistency.
Question 4: When reviewing a positive cocaine metabolite result, the donor states they had dental anesthesia with cocaine. What is the MRO's correct response?
- Report negative because cocaine is used medically in some ENT and dental procedures
- Report positive because cocaine is a Schedule II drug and not a valid medical explanation for recreational use
- Cancel the test and order a hair sample
- Verify the dental procedure documentation and report negative if confirmed (Correct answer)
Correct answer: Verify the dental procedure documentation and report negative if confirmed
Cocaine is a Schedule II drug legitimately used as a topical anesthetic in some ENT procedures, and documented medical use is an acceptable explanation.
Question 5: Under DOT 49 CFR Part 40, how long does a donor have to request a split specimen retest after being notified of a positive, adulterated, or substituted result?
- 24 hours
- 48 hours
- 72 hours (Correct answer)
- 7 days
Correct answer: 72 hours
Under 49 CFR Part 40, the donor has 72 hours from being notified to request that the split specimen be sent to a second HHS-certified laboratory.
Question 6: A specimen tests positive for benzoylecgonine (cocaine metabolite). The donor says they used cocaine-containing tea purchased in South America. How should the MRO rule?
- Report negative because coca leaf tea is a legal beverage in some countries
- Report positive because cocaine metabolite is detected regardless of the source (Correct answer)
- Cancel the test because foreign substances cannot be regulated
- Defer to the SAP for a clinical determination
Correct answer: Report positive because cocaine metabolite is detected regardless of the source
Regardless of the source of cocaine ingestion, a positive confirmation of cocaine metabolite at or above the cutoff must be verified as positive.
Question 7: A donor's specimen arrives at the lab with the temperature strip showing out-of-range temperature. The collector noted the temperature was out of range and obtained a second specimen. How should the MRO handle this?
- Test only the second specimen; discard the first (Correct answer)
- Test only the first specimen since it was collected first
- Test both specimens and report the result of the first
- The test is automatically cancelled due to the temperature issue
Correct answer: Test only the second specimen; discard the first
When an out-of-range temperature is noted and a second specimen is collected under direct observation, only the second specimen is tested.
MRO Review & Interpretation 3
A donor tests positive for PCP.
The donor claims they were exposed to PCP through passive inhalation at a party.
How should the MRO respond?