Effects of alfuzosin on urethral and blood pressures in conscious male rats.

This study was undertaken to determine simultaneously the effects of alfuzosin on urethral and blood pressures in the same conscious male rat. Alfuzosin (i.v., 3, 10 and 30 micrograms/kg) dose-dependently decreased urethral pressure without affecting mean arterial blood pressure. At the higher dose, blood pressure was only slightly and transiently decreased while a marked decrease (-40%) in urethral pressure was observed. Therefore, this experimental model is suitable to assess uroselectivity.

[Acute involuntary intoxication with gamma-hydroxybutyric acid]. / Intoxication aiguë involontaire à l'acide gamma-hydroxybutyrique (gamma-OH).

Dangerous misuse of anaesthetic drugs is illustrated in a case of gamma-hydroxybutyrate (gamma-OH) poisoning. A 36-year-old patient, coming from USA ingested approximately 200 mL of a liquid. He presented a non reactive coma (Glasgow coma scale at 3), abnormal movements, hypotension and bradycardia. Outcome was favorable with symptomatic treatment including tracheal intubation and ventilation. The patient was discharged 24 hours later. This case was a typical gamma OH poisoning. Its consumption is current in the United States for body-builders. Poisoning was involuntary, due to a dilution mistake. Toxicological analysis assessed this diagnostic. Such poisoning is exceptional in France.

[Complications related to the seated position of the aged patient in neurosurgery]. / Complications liées à la position assise chez le sujet âgé en neurochirurgie.

The advantages of the sitting position for neurosurgery of the posterior fossa are evident and universally admitted. However, respiratory and haemodynamic consequences make this position uncommon and even exceptional for the old patient whose existing physiological cardiovascular and pulmonary disturbances may result in greater risks. In this study, the complications observed during and after surgery in twenty-two patients over 65 years are analysed. These patients underwent functional neurosurgical procedures in sitting position. According to the results, old age does not appear to be an absolute contra-indication of the sitting position for this type of surgery.

[Place of neuroleptics in neurosurgical anesthesia-resuscitation]. / Place des neuroleptiques en anesthésie-réanimation neuro-chirurgicale

The interest of neuroleptics in neurosurgery should be examined in the light of physiopathological and pharmacological data concerning cerebral circulatory autoregulation and intracranial pressure. The fairly favourable conclusions permit one to consider their wide use justified, especially, by the feeble hypnogenic effects, without any marked disturbance of the E.E.G., associated with an anticatecholaminergic and stabilizing effect on the autonomic nervous system. They therefore occupy a place of choice, in particular during induction of anesthesia in high risk patients, during operations requiring neurological or continuous E.E.G. investigations, in surgery of intracranial aneurysm and, finally, to obtain sedation and post-operative autonomic control.

Comparative alpha-1 adrenoceptor subtype selectivity and functional uroselectivity of alpha-1 adrenoceptor antagonists.

We investigated the relevance of selectivity for a given alpha-1-adrenoceptor subtype for in vivo uroselectivity of several alpha-1-adrenoceptor antagonists (alfuzosin, doxazosin, prazosin, tamsulosin, terazosin and 5-Me-urapidil). Comparison of the affinities of these alpha-1-adrenoceptor antagonists at the cloned alpha-1a, alpha-1b and alpha-1d-adrenoceptor subtypes revealed that tamsulosin and 5-Me-urapidil showed selectivity for the alpha-1a subtype. No significant correlations were found between the affinities for alpha-1b or alpha-1d-adrenoceptors and the pK(B) values obtained against phenylephrine-induced contraction of the rabbit prostate in vitro. In contrast, the antagonist potencies in rabbit prostate were correlated (r = 0.89, P < .05) with the pKi values for the alpha-1a-adrenoceptor subtype. However, the pK(B) values were consistently smaller (by 0.6 to 1.9 log unit) than the pKi values for the alpha-1a-adrenoceptor subtype, a result that suggests that the alpha-1-adrenoceptor mediating urethral contractions does not have all the characteristics of the alpha-1a-adrenoceptor. The simultaneous measurement of urethral and arterial pressures in the same conscious male rat allows evaluation of the functional uroselectivity of these antagonists based on their respective effects on both pressures. Dose ranges were selected according to effects on urethral pressure and most antagonists were found effective within the 3 to 100 microg/kg i.v. range. Alfuzosin markedly decreased urethral pressure and either did not decrease blood pressure (10-30 microg/kg) or slightly decreased it at the highest dose tested (100 microg/kg). Doxazosin did not produce sustained reductions in urethral pressure until a dose of 30 microg/kg. Blood pressure was not reduced until 100 microg/kg. Prazosin reduced urethral pressure and blood pressure within the same dose-range whereas terazosin did not decrease urethral pressure at doses that significantly decreased blood pressure (30 and 100 microg/kg). 5-Me-urapidil, an alpha-1a-selective compound did not significantly modify urethral and blood pressure whereas tamsulosin, another alpha-1a-selective compound reduced urethral pressure and blood pressure within the same dose range. In conclusion, in the conscious male rat the functional uroselectivity is not correlated with a selective affinity for the alpha-1a-adrenoceptor subtype.

[Treatment of facial neuralgias: retrogasserian thermocoagulation under iterative discontinuous narcosis with propanidid]. / Traitement des névralgies faciales: la thermocoagulation rétrogassérienne sous narcoses discontinues itératives au propanidide.

Coagulation of the Gasserian ganglian is currently recommended in the treatment of trigeminal neuralgia due to the slight risks that it presents. It is accompanied by brief but intense periods of pain which necessitate the need of an Anaesthetist. As well as we have been able to verify in the course of sixty-two of these procedures, a discontinuous narcosis obtained by reiterated injections of propanidid presents a satisfying solution. It permits the neurological examinations, which need absolute cooperation of the patient, before each new coagulation to be accomplished in good conditions.