[A color test for rapid screening of gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL) in drink and urine]

OBJECTIVE

A rapid color test for screening gamma-hydroxybutyric acid (GHB) and its precursor gamma-butyrolactone(GBL) was investigated in drink and urine samples.

METHODS

In an acidic solution, GHB was converted to GBL, which reacted with hydroxylamine hydrochloride in presence of sodium hydroxide, forming hydroxamate. A purple complex was formed when hydroxamate reacted with ferric chloride in acidic condition.

RESULTS

Detection limit concentrations of GHB in drinks were between 0.5-2 mg/mL, less than the popular abuse concentrations of GHB. This method was usable for urine, with detection limit concentration 0.5 mg/mL. Interferences of common organic solvents and narcotics and depressants were surveyed.

CONCLUSION

This method is simple, safe, and rapid; it facilitates rapid screening of GHB and GBL in clinic and forensic laboratories.

Pharmacokinetics and anesthetic activity of eugenol in male Sprague-Dawley rats

Eugenol, the principle chemical constituent of clove oil, has recently been evaluated for its anesthetic and analgesic properties in fish and amphibians. The objective of this study was to determine the pharmacokinetic (PK) and anesthetic activity of eugenol in rats. Male Sprague-Dawley rats received single i.v. doses of eugenol (0, 5, 10, 20, 40 and 60 mg/kg) and anesthetic level was evaluated with the withdrawal reflex. For the 20 mg/kg dose level, blood and urinary samples were collected over 1 h for the PK assessment. Plasma and blood concentrations of eugenol, as well as metabolite identification in urine, were determined using a novel dansyl chloride derivatization method with liquid chromatography mass spectrometry (LC/MS/MS). PK parameters were calculated using noncompartmental methods. Eugenol-induced loss of consciousness in a dose-dependent manner, with mean (+/-SEM) recovery in reflex time of 167 +/- 42 sec observed at the highest dose level. Mean systemic clearance (Cl) in plasma and blood were 157 and 204 mL/min/kg, respectively. Glucuronide and sulfate conjugates were identified in urine. Overall, eugenol produced a reversible, dose-dependent anesthesia in male Sprague-Dawley rats.

A fatality related to the veterinary anesthetic telazol

A 45-year-old male veterinarian was found dead in bed. Police investigation showed no evidence of trauma or other suspicious circumstances. Autopsy was unremarkable except for cardiomegaly and hepatosplenomegaly. Toxicological analysis revealed the presence of Telazol and ketamine. Telazol is a veterinary anesthetic agent that is composed of equal parts of tiletamine and zolazepam. Tiletamine is a disassociative anesthetic similar to ketamine and phencyclidine, and zolazepam is a diazepine derivative tranquilizer used to minimize the muscle hypertonicity and seizures associated with tiletamine. Quantitation of tiletamine and zolazepam was performed using gas chromatography-mass spectrometry in the selected ion monitoring mode following a solid-phase extraction. Postmortem blood, urine, and liver concentrations of tiletamine were 295 ng/mL, 682 ng/mL, and 196 ng/g, respectively, whereas postmortem concentrations of zolazepam for the same tissues were 1.71 microg/mL, 1.33 microg/mL, and 15.5 microg/g, respectively. Blood and urine ketamine levels were 37 ng/mL and 381 ng/mL, respectively. The cause of death was ruled an acute mixed drug intoxication of tiletamine, zolazepam, and ketamine with the manner of death ruled as unclassified.

Relationship of inspired anesthetic concentration to plasma concentration and urinary excretion of sevoflurane metabolites in rats

In patients, plasma concentrations of sevoflurane metabolites may be independent of inspired sevoflurane concentration over a defined dose range. In contrast, studies using rabbits have found that plasma concentrations and urinary excretion of fluoride ion are dose-dependent up to 3% inspired sevoflurane. We measured sevoflurane metabolite concentrations in adult male Sprague-Dawley rats and related them to inspired sevoflurane concentrations. When plasma concentrations and urinary excretion of metabolites were measured in vivo, they were dependent on inspired anesthetic concentration at concentrations less than 1.25%, but became less dose-dependent at higher anesthetic concentrations. Sevoflurane metabolism by precision-cut liver slices in vitro became dose-independent at more than 10-30 microM sevoflurane. No evidence of substrate inhibition was observed. These data provide evidence that sevoflurane metabolite concentrations are almost independent of inspired anesthetic concentration over at least part of the clinically used concentration range.

[Measurements and environmental and biological monitoring of occupational exposure to inhalation anesthetics]

This paper reports the data of nitrous oxide (N2O) environmental pollution in 269 operating rooms of 47 hospitals in Italy in 1989-91. In 40% of the operating rooms the N2O concentrations are lower than 50 ppm, limit value proposed by Health Council for new operating rooms. In 65.4% of the operating room studied, N2O mean environmental concentrations are lower than 100 ppm, value proposed by the above-mentioned Health Council as limit value for the already existing operating rooms. Concerning the biological monitoring, the authors report several N2O data in urine (2193), whose levels confirm the data obtained with environmental monitoring. The authors believe that they presently have reliable methods to perform biological and environmental monitoring: the two techniques are complementary in the assessment of the exposure. The method of measuring N2O concentrations as exposure index, both for the environmental and biological monitoring, is considered very useful to simplify the performance of the analyses. In order to assess exposure more precisely, it is however necessary also to determine the environmental and/or biological measure of the other different anaesthetics used.

Pharmacokinetics, metabolism, and renal excretion of articaine and its metabolite articainic acid in patients after epidural administration

Articaine is metabolized into articainic acid. The half-lives of articaine are 0.54 +/- 0.05 and 2.44 +/- 0.30 h and that of its metabolite, 2.44 +/- 0.30 h. Of the administered dose approximately 2-5% is excreted unchanged, 40-70% is excreted as articainic acid, and 4-15% as articainic acid glucoronide. The percentage of the total dose recovered in the urine varies between 50% and 91%. Protein binding of articaine in patients varies between 50% and 70%, and that of articainic acid between 60% and 90%. Renal clearance of articaine varies between 12 and 28 ml min-1, while that of articainic acid is between 84 and 160 ml min-1.

[Proposal of the biological monitoring of inhalation anesthetics]

The long-term occupational exposure to inhalation anaesthetics might represent a health hazard; mainly it may have an adverse effect on the reproductive outcome. Nitrous oxide is the anaesthetic employed in the largest amount during general anaesthesia and it can be used as an indicator of occupational exposure to all the components the mixture; but if the pattern of dispersion of them (when leaking into the operating theater) are not the same, two indicators should be used: N2O (gas) + another component the mixture (vapour). Our results concern practically 5 points: --Analysis of N2O by means of a diffusive personal sampler (comparison with a conventional sampling method) --Analysis of N2O in urine collected after 4 hours of exposure during routine anaesthetic work (headspace method) --Comparison of environmental and biological data concerning N2O --Comparison of environmental and biological data concerning a component of the anaesthetic mixture, forane --Proposal of biological exposure indices for nitrous oxide and forane. A close relationship between air and urine was found in 363 subjects occupationally exposed to N2O and 45 subjects exposed to forane (r: 0.95 and 0.90 respectively). On the basis of such a relationship the biological exposure index for N2O corresponding to an ambient concentration of 100 ppm (European limit) turned out to be 55 micrograms/L; the ones for forane corresponding to ambient concentrations of 2 or 10 ppm are respectively 3.4 or 14.5 micrograms/L (urinary concentrations in samples collected after 4 hours of exposure).

Drug abuse in anesthesia training programs. A survey: 1970 through 1980

Experience at our institution with drug dependence among anesthesia residents, coupled with a lack of published data, prompted us to survey US anesthesia training programs. Two hundred eighty-nine programs were surveyed, 247 (85.5%) responded, and 184 (74%) of these programs had at least one suspected incident of drug dependence to report. Three hundred thirty-four confirmed persons were reported, including a substantial number of instructors. Meperidine and fentanyl were the most frequently mentioned drugs. Behavior changes were frequently noted by staff personnel, and in general such changes led directly to detection. After confirmation of abuse, the majority of impaired anesthetists were referred for psychiatric care, with few in need of actual detoxification. Detailed follow-up was available for about 40% of the total; 71 persons were offered a return to their original place of employment, while 30 persons died of drug overdose. Chemical impairment may be more common than usually thought in anesthesia, perhaps in part because of drug availability.