No abstract

Twelve ASA physical status I-III patients were enrolled in a double-blind, prospective, randomized, three-way, withinpatient Electroconvulsive therapy (ECT) may produce intense stimulation of the central nervous system resulting in hypertension and tachycardia, t'2 The haemodynamic effects of ECT could place the patient with coronary or cerebrovascular disease at risk of myocardial ischaemia/ infarction or stroke. 3-5 Esmolol hydrochloride (Brevibloc) is a new ultra-short acting betal selective adrenergic blocking agent. Esmolol bolus 6 and infusion 7 have been found to be effective in attenuating the cardiovascular response to ECT. However, comparison of the effects of different standardized bolus doses and their effect on the Douze patients de classe ASA I-III ont particip~ d trois sdances varides de notre (tude randomisde d double insu sur l'effet de deux doses d'esmolol en bolus (100 et 200 mg) sur les variables hdmodynamiques et la durde des convulsions assocides at•r dlectrochocs ( EC ). On leur injectait I'esmolol ou un placdbo une minute avant I' induction de l'anesthdsie puis detzx minutes avant

The combination of fentanyl and diazepam significantly decreases systemic vascular resistance and blood pressure. We attempted to elucidate the reason the combination of these drugs can reduce blood pressure. In alpha-chloralose-anesthetized dogs, we investigated the effects of fentanyl and diazepam on mean arterial pressure (MAP) and arterial baroreflex control of renal sympathetic nerve activity (RSNA) in both intact (Study 1) and baroreflex-denervated dogs (Study 2). Study 1 included five dogs that received fentanyl 10 micrograms/kg followed by diazepam 0.4 mg/kg after a 10-min interval. Five more received both drugs in reversed sequence. The arterial baroreflex depressor test was performed with sodium nitroprusside before and after administration of each drug. Sensitivity of arterial baroreflex was examined by using the ratio of maximum increase of RSNA to maximum decrease of MAP (delta RSNA/delta MAP). RSNA and MAP significantly decreased only after both drugs had been administered (P < 0.05). Fentanyl alone did not attenuate arterial baroreflex sensitivity. Diazepam after fentanyl and diazepam alone attenuated baroreflex sensitivity to the same extent (P < 0.05). Study 2 comprised 14 dogs that underwent further surgical preparation of bilateral carotid sinus, aortic, and vagal nerve denervations. Seven received fentanyl, 5 and 10 micrograms/kg, and the other seven received diazepam, a total of 0.4 mg/kg. Fentanyl decreased both RSNA and MAP. Diazepam decreased only MAP significantly. The results indicate that fentanyl decreases mainly sympathetic outflow, whereas diazepam attenuates arterial baroreflex. We conclude that these combined effects of fentanyl and diazepam significantly decrease arterial blood pressure.