False Positive Drug Screens /Guidelines to collection

[SilentfadesRPA]

there was recently a question submitt looking for information about a persons drug screen and how to correct this -- this was correctly closed.

i'm not in any way trying to attempt to respond to the author of that link however, i do think that there are important factors that all nurses who work in emergency room's, outpatient clinics, private offices as well as corrections and industrial centers should know about drug testing, as well as collection.

the office i work often this drug testing for various employment facilities for preemployment drug screen. the stories that we have heard in regards to positive screens from from candidates at times are laughable and at other times are pathetic.

many times we are asked what is a remedy that would on expedite for metabolism of foreign substances that have been ingested. we always responded there is no scientific method known to do so. and as well taking any over-the-counter substance and/or those sold on web sites have the potential of causing bodily harm and even inhibiting the rapid metabolism of normal body waste.

the overall basic empiric lab evidence is that in very few positive drug screens are false.

i am listing some important criteria in regards for clinicians that are that finding themselves involved in collecting specimens.

it is imperative that your office emergency room or place of employment have a set policy about drug screening

it is critical that screening initially can be done in the office with a pocket type of test should be sent to a qualified laboratory that does gaschromatograhphy and has a toxicologist who will be part of the personnel involved in the interpretation. one of the mandates we have in this office is in the toxicologist signs each and every report.

be cautious of patients who are requesting drug screens, often this is a challenge to a previous drug screen done by an employer and/or probation officer, and there are many techniques persons have in falsifying a drug screen -- they even have false member for purchase on line that will appear to deliver a real urine as the urine is kept warm on another body part.

if at all possible observation should be directly done./specific gravity obtained on all urines/and temperature measured not despite the feeling of warmth, but by temperature buy thermometer as well as documented.food coloring should be in the toliet voided in (to discount any attempt to dilute)

should the a clinician in the drawing serum for drug screens in stately for a blood alcohol level is remember to use betadine and not an alcohol prep pads. though the possibility of contamination from alcohol prep causing a false etoh screen is almost non existant --it gives a defense attorney a defense on the techique of collection.

all of obtaining drug screens should be witnessed by two personnel, and as well should be sealed and marked as so and sent to lab as chain of custody.

do not draw any and/or obtain a drug screen upon a police officer request.

do not say anything to law enforcement that would make them question the patients state for the need for etoh screen or drug screen.

a police officer does not have the authority to request a drug screen without a court ordered subpoena.

drug screening can only be ordered by physician, a physician assistant, and or a nurse clinician practitioner. typically when a clinician orders a drug screen it is solely for the medical evaluation of the patient and this should be documented in the nursing notes -- as well do not write the patient appreared intoxicated but rather the behaviour and clear objectives signs --

aob -- slurred speach -- pupil resonse -- loc -- tract marks old fresh ect.

to be legally charged there charge would have to be served with the medical record would have to be subpoenaed or a faxed order from a judge unless other policy exist.

use a clean catch so that one can not say that personal hygiene materials affected or altered the test

if possible have the patient disrobe and in a gown only (minus underwear)

one may find themselves very much involved in a particular situation that would be questionally ethical. even knowing or trying to be a friend of the cop like it or not it is the patient who you should be a total legal advocate for.

be aware that if you do while or obtain a drug screen without the patient's permission, unless there rendered unconscious or unable to give permission and by medical order. you can be liable.

regardless whether the patient submits to a drug screen, for employment or for any other recent ascertained that permission is given to release medical records. also if a screen is positive the patient may rescind his/her permission and no documentation should be given regardless of who is paying for the drug screen. allow the indivigual to respond to the agency for the record.

we follow the department of transportation guidelines, which is an.

resource and has been thoroughly researched to prevent any backlash of legal reprecussions against clinicians. however anyone can sue anyone and thisust be kept ever present in mind.

see the websites below for more extensive information in collection of samples as well as knowledge of drugs screening

http://transit-safety.volpe.dot.gov/publications/substance/doturine/html/urine.htm

http://www.nlm.nih.gov/medlineplus/ency/article/003364.htm

what abnormal results mean

if the test result is positive, it is helpful to confirm the results with gas-chromatography mass spectrometry (gc-ms). in some case, a test will register a false positive. this can result from interfering factors such as some foods, prescription medications and other drugs. the gc-ms will help to eliminate some of the other possibilities.update date: 4/8/2005

http://www.stanford.edu/~johnbrks/thecafe/substance/urine.html

(abbreviated)

alcohol - not much causes a false positive result....

amphetamines - because amphetamines consist of racemic amphetamines, dextroamphetamines, methamphetamines as well as many legal substances (pseudoephedrine, phentermine, ephedrine, phenylpropanolamine, and phenylephrine), there can be a higher incidence of false positives. note that selegeline is metabolized to l-amphetamine and l-methamphetamine (l isomers do not produce euphoria...) and causes false positives..

barbiturates - there is no significant incidence of false positives.

benzodiazepines <..> - many assays are calibrated with either oxazepam or nordiazepam because these are common metabolites of other benzodiazepines. in fact, few laboratories screen for anything other than oxazepam or nordiazepam.

cannabinoids - the risk of a false-positive result because someone is in a room with marijuana smoke is miniscule. it doesn't matter what you heard in high school.

cocaine - is metabolized in the liver and serum and is converted in the blood to benzoylecgonine and ecgonine methyl ester. both of these metabolites are excreted in the urine. typically, assays target benzoylecgonine.

opiates - are metabolized mainly in hepatocytes, but also in the cns, kidneys, lungs, and placenta. opiates are excreted primarily in the urine unchanged as are many of their metabolites.

phencyclidine - very few things will cause a false-positive pcp.

i sincerely hope this is an informative for fellow practitioners.

.

marc

[traumaRUs, MSN, APRN]

I would like to add that different states and indeed different institutions have different rules about release of drug screen test. Chain of custody must always be documented too. Thanks for the info.