A Slight Smell of Lemon.

We present here an example of urine substituted with a yellow cleaning product that leads us to develop the main risks to consider in urine toxicology analysis, ie, adulteration and analytical interferences, and how to deal with them. This grand round highlights the importance of the dialog between the clinician and a TDM consultant for optimal care of the patient.

Importance of Urinary Drug Screening in the Multiple Sleep Latency Test and Maintenance of Wakefulness Test.

STUDY OBJECTIVES: Multiple sleep latency testing (MSLT) and the maintenance of wakefulness test (MWT) are gold-standard objective tests of daytime sleepiness and alertness; however, there is marked variability in their interpretation and practice. This study aimed to determine the incidence of positive drug screens and their influence on MSLT, MWT, and polysomnographic variables. METHODS: All patients attending Eastern Health Sleep Laboratory for MSLT or MWT over a 21-mo period were included in the study. Urinary drug screening for amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, and opiates was performed following overnight polysomnography (PSG). Demographics and PSG variables were compared. RESULTS: Of 69 studies, MSLT (43) and MWT (26), 16% of patients had positive urinary drug screening (7 MSLT; 4 MWT). Drugs detected included amphetamines, cannabinoids, opiates, and benzodiazepines. No patient self-reported use of these medications prior to testing. No demographic, MSLT or MWT PSG data or overnight PSG data showed any statistical differences between positive and negative drug screen groups. Of seven MSLT patients testing positive for drug use, one met criteria for the diagnosis of narcolepsy and five for idiopathic hypersomnia. On MWT, three of the four drug-positive patients had a history of a motor vehicle accident and two patients were occupational drivers. CONCLUSIONS: These findings indicate drug use is present in patients attending for daytime testing of objective sleepiness and wakefulness. These data support routine urinary drug screening in all patients undergoing MSLT or MWT studies to ensure accurate interpretation in the context of illicit and prescription drug use.

Urine toxicology screen in multiple sleep latency test: the correlation of positive tetrahydrocannabinol, drug negative patients, and narcolepsy.

OBJECTIVE: Drugs can influence results of multiple sleep latency tests (MSLT). We sought to identify the effect of marijuana on MSLT results in pediatric patients evaluated for excessive daytime sleepiness (EDS). METHODS: This is a retrospective study of urine drug screens performed the morning before MSLT in 383 patients <21 years old referred for EDS. MSLT results were divided into those with (1) (-) urine drug screens, (2) urine drug screens (+) for tetrahydrocannabinol (THC) alone or THC plus other drugs, and (3) urine drug screens (+) for drugs other than THC. Groups were compared with Fisher exact tests or one-way ANOVA. RESULTS: 38 (10%) urine drug tests were (+): 14 for THC and 24 for other drugs. Forty-three percent of patients with drug screen (+) for THC had MSLT findings consistent with narcolepsy, 0% consistent with idiopathic hypersomnia, 29% other, and 29% normal. This was statistically different from those with (-) screens (24% narcolepsy, 20% idiopathic hypersomnia, 6% other, 50% normal), and those (+) for drugs other than THC (17% narcolepsy, 33% idiopathic hypersomnia, 4% other, 46% normal (p = 0.01). Six percent (6/93) of patients with MSLT findings consistent with narcolepsy were drug screen (+) for THC; 71% of patients with drug screen (+) for THC had multiple sleep onset REM periods (SOREMS). There were no (+) urine drug screens in patients <13 years old. CONCLUSION: Many pediatric patients with (+) urine drug screens for THC met MSLT criteria for narcolepsy or had multiple SOREMs. Drug screening is important in interpreting MSLT findings for children ≥13 years.

Correlation of daytime sleepiness with urine metabolites in patients with obstructive sleep apnea.

PURPOSE: The apnea-hypopnea index (AHI) is closely related with the severity of daytime sleepiness, but excessive daytime sleepiness (EDS) is not presented on all patients with obstructive sleep apnea (OSA). It is unclear why daytime sleepiness is not always present in OSA patients even if their sleep is disrupted from the perspective of polysomnographic findings. This study aimed to analyze the correlation between sleepiness and urine metabolites of neurotransmitters involved in the arousal system. METHODS: On the basis of AHI in polysomnography, 49 consecutive OSA patients were included. According to their Epworth sleepiness scale (ESS), 23 non-sleepy patients (ESS <11) and 26 sleepy patients (ESS ≥11) were included. Urine samples were collected before and after polysomnography and analyzed by gas chromatography-mass spectrometry with selective ion monitoring. Six metabolites of dopamine, norepinephrine and serotonin were analyzed. RESULTS: The dopamine metabolites, homovanillic acid (r = 0.366, P = 0.017) and 3,4-dihydroxyphenylacetic acid (DOPAC; r = 0.584, P < 0.0001), were significantly correlated with ESS after adjusting for age, sex, body mass index, AHI, sleep efficiency and total sleep time. A two-by-two table analysis revealed that the overnight increase in the urine DOPAC was more frequent in sleepy patients while its decrease was more frequent in non-sleepy patients (odds ratio = 3.54, P = 0.032). CONCLUSION: Urine dopamine metabolites may identify sleepy patients with OSA. In particular, the overnight change of urine DOPAC may indicate OSA patients with EDS.