Françoise Vincent

Comparison of the prevalence of alcohol, cannabis and other drugs between 900 injured drivers and 900 control subjects: results of a French collaborative study

A collaborative case-control study was conducted in France in order to determine the prevalence of alcohol, cannabinoids, opiates, cocaine metabolites, amphetamines and therapeutic psychoactive drugs in blood samples from drivers injured in road accidents and to compare these values with those of a control population. Recruitment was performed in emergency departments of six university or general hospitals and comprised 900 drivers involved in a non-fatal accident and 900 patients (controls) who attended the same emergency units for a non-traumatic reason. Drivers and controls were matched by sex and age. Alcohol was determined by flame ionization-gas chromatography, drugs of abuse (DOA) by gas chromatography-mass spectrometry with the same analytical procedures in the six laboratories, and medicines by high performance liquid chromatography with diode array detection. Blood alcohol concentration exceeding 0.5 g/l (i.e. the legal French threshold) was found in 26% of drivers and 9% of controls. In the 18-27 years age range, alcohol was the only toxic found in blood samples of 17% drivers and 5% controls, leading to an odds-ratio (OR) of 3.8. A significant relationship was found between alcohol blood concentrations and OR values. All age groups confounded, the main active substance of cannabis, Delta(9) tetrahydrocannabinol (THC), was found in 10% of drivers and 5% of controls. In the less than 27 years old, THC (>1 ng/ml) was detected alone in the blood of 15.3% drivers and of 6.7% controls, giving OR=2.5, whereas there was no link between THC blood concentrations and OR value. THC was found alone in 60% of cases and associated with alcohol in 32%, with OR=4.6 between drivers and controls for this association. The difference in morphine prevalence between drivers (2.7%) and controls (0.03%) was highly significant (P<0.001), with OR=8.2. The number of positive cases for amphetamines and cocaine metabolites was too low for reaching any interpretation. The most frequently observed psychoactive therapeutic drugs were by far benzodiazepines, that were found alone in 9.4% of drivers and 5.8% of controls, which led to OR=1.7 (P<0.01). This study demonstrates a higher prevalence of opiates, alcohol, cannabinoids and the combination of these last two compounds in blood samples from drivers involved in road accidents than in those from controls, which suggests a causal role for these compounds in road crashes.

A Fatal Case of Chlorate Poisoning: Confirmation by Ion Chromatography of Body Fluids

A 49-year-old male chemical industry worker was admitted to intensive care with a 24-hour history of respiratory failure, vomiting, headache, stupor, arterial hypotension, and cyanosed face and limbs. He had acute haemolysis (3.9 g/L plasma haemoglobin concentration) and 30% methaemoglobinaemia. Whereas the search for alcohol, barbiturates and opiates was negative, benzodiazepines and tricyclic antidepressants were present. The patient was in fact being treated with fluvoxamine, amitryptiline, and alprazolam. As the clinical and biological signs suggested chlorate poisoning, chlorate was looked for by using an aniline color reaction. It was found in gastric content and urine. Treatment consisted in mechanical ventilation, vasoactive amines, methylene blue, plasma exchange, exchange transfusion, and haemodialysis. Despite this, the patient had several cardiac arrests and refractory metabolic acidosis. He died 12 h after his admission. Specific ion chromatography was used afterhand to assay the chlorate in various body fluids. The technique was based on a separation on an ion exchange Dionex AS 12A column coupled with conductivity detection. A quantitative estimation was carried out by using external calibration with a four-point calibration curve which was linear between 1 and 15 mg/L. The measured plasma levels of chlorate were 78 and 29 mg/L respectively before and after exchange transfusion. Gastric-lavage liquid contained 1300 mg/L of chlorate and urine 4300 mg/L. Ion chromatography, which is routinely used in environmental studies helped to confirm a massive oral intake of chlorate by measuring the corresponding blood and urine chlorate concentrations, data which had only rarely been reported previously.

Cyanide and its relationship to nervous suffering. Physiopathological aspects of intoxication.

On the basis of personal results in man and laboratory animal, we examined some aspects of acute and chronic cyanide intoxication: physiopathological aspects, hydroxocobalamins therapeutic action in treating acute intoxications and neurotoxic sufferings due to cyanide, and hydroxocobalamins biological action in decreasing the level of free cyanide appearing in blood and urine, a few days after sciatic nerve clamping in rabbits.

Poisoning by lavandin extract in a 18-month-old boy

An 18-month-old boy ingested a small amount of homemade lavandin extract. The child developed a central nervous system depression and a confused state three hours after ingestion. The electroencephalogram showed fast rhythm disorders consistent with a toxic etiology. The outcome was favorable. Poisoning was confirmed by headspace-gas chromatography-mass spectrometry. Linalyl acetate, linalyl formate, and acetone were identified in pure lavandin extract and in the childs blood and urine. We report the only case of lavandin extract poisoning confirmed by toxicological analysis.

Simultaneous determination of trimipramine and desmethyl- and hydroxytrimipramine in plasma and red blood cells by capillary gas chromatography with nitrogen-selective detection

A simple procedure is described that permits the simultaneous determination of trimipramine and its two major metabolites, desmethyl- and hydroxytrimipramine, in human plasma or red blood cells (RBCs) at therapeutic concentrations. The extracted biological fluids are injected into a capillary gas chromatograph with an OV-1 fused-silica column coupled to a nitrogen-phosphorus-selective detector. The limit of determination for trimipramine is 3 ng/ml and for that desmethyl- and hydroxytrimipramine is 4 ng/ml. The method permits the RBC/plasma ratios to be determined and to be correlated with the clinical response.

Internuclear Ophthalmoplegia in Patients with Toxic Coma Frequency, Prognostic Value, Diagnostic Significance

Internuclear Ophthalmoplegia (INO), a dysfunction of the medial longitudinal fasciculus, is frequently seen in toxic coma (7 out of 70 cases). INO is most often bilateral and can be associated with different stages of coma. Such an association is a strong argument for the toxic etiology of a coma. But INO has no value in determining the source of intoxication and is no prognostic indicator for the outcome.