[Intoxications by hallucinogenic mushrooms]

In the context of excessive use of natural or synthetic psychoactive substances, with stimulating, psychedelic and hallucinogenic effects, an increase, if not a recurrence, in consumption of Psilocybe semilanceata has been observed in France over some fifteen years. Psilocybin and psilocin are the active compounds, responsible for the hallucinogenic effects and are a part of the substance group, derived from tryptamine and characterized by an indole nucleus. We report a clinical case observed in an emergency unit and review the historical, epidemiological and pharmacological data now available for these intoxications. Of particular interests in hallucinogenic mushroom abuse are: increased consumption in the context of youth cultural and entertainment movements; possible difficulties in the diagnosis in emergency conditions; possibility of severe and fatal complications.

2-Acetyl-4H-benzothiazin-3(2H)-one

The title compound, C(10)H(9)NO(2)S, has a boat-shaped heterocyclic six-membered ring such that the S and N atoms lie essentially in the plane of the benzene ring while the remaining two C atoms are above this plane.

Correlation between cerebral oxygen saturation measured by near-infrared spectroscopy and jugular oxygen saturation in patients with severe closed head injury

Near-infrared spectroscopy has been used to monitor cerebral oxygen saturation during cerebral circulatory arrest and carotid clamping. However, its utility has not been demonstrated in more complex situations, such as in patients with head injuries. The authors tested this method during conditions that may alter the arteriovenous partition of cerebral blood in different ways.

METHODS

The authors compared changes in measured cerebral oxygen saturation and other hemodynamic parameters, including jugular venous oxygen saturation, in nine patients with severe closed head injury during manipulation of arterial carbon dioxide partial pressure and after mean arterial pressure was altered by vasopressors.

RESULTS

The Bland and Altman representation of cerebral oxygen saturation versus jugular oxygen saturation showed a uniform scatter. Values for changing arterial carbon dioxide partial pressure were: bias = 1.1%, 2 SD = +/-21%, absolute value; and those for alterations in mean arterial pressure: bias = 3.7%, 2 SD = +/-24%, absolute value. However, a Bland and Altman plot of changes in cerebral oxygen saturation versus changes in jugular oxygen saturation had a negative slope (alteration in arterial carbon dioxide partial pressure: bias = 2.4%, 2 SD = +/-17%, absolute value; alteration in mean arterial pressure: bias = -4.9%, 2 SD = +/-31%, absolute value). Regression analysis showed that changes in cerebral oxygen saturation were positively correlated with changes in jugular venous oxygen saturation during the carbon dioxide challenge, whereas correlation was negative during the arterial pressure challenge.

CONCLUSIONS

Cerebral oxygen saturation assessed by near-infrared spectroscopy does not adequately reflect changes in jugular venous oxygen saturation in patients with severe head injury. Changes in arteriovenous partitioning, infrared-spectroscopy contamination by extracerebral signal, algorithm errors, and dissimilar tissue sampling may explain these findings.

[Interactions between naltrexone, an opioid antagonist, and opioids administered during general anesthesia]

We report a case of a probable interaction between sufentanil and naltrexone, an oral long acting opioid antagonist, prescribed for maintenance of abstinence in alcoholics and opioid addicts. The interaction resulted in an antagonisation of the effects of sufentanil and the necessity to increase the dosage. Anaesthetists should be aware of this potential drug interaction.