[Induction-intubation sequence in neuroanesthesia. Usefulness of vecuronium in fractionated doses]. / Secuencia de inducción-intubación en neuroanestesia. Utilidad del vecuronio en dosis fraccionadas.

Muscular relaxant vecuronium bromide (Norcuron R, Organon Teknika Española, S.A.) was administered to 20 patients undergoing intracranial surgery with general anesthesia at a dose of 0.01 mg/kg weight followed by 0.1 mg/kg (intubation dose) four minutes later. Two minutes after the second dose and under careful manual mechanical ventilation with O2 100%, a laryngoscopy was performed to evaluate the conditions for intubation. Mean arterial pressure, heart rate, PaO2, and PaCO2 were measured at baseline and immediately before laryngoscopy. Neuromuscular function was monitored observing the response to a train of four stimuli applied on the cubital nerve. During the operation a continuous infusion of vecuronium at a rate of 1 microgram/kg/min was maintained. Conditions for intubation were excellent in 18 patients and good in two cases. Mean heart rate and PaCO2 did not show significant variations. In contrast, during prelaryngoscopy mean arterial pressure decreased and PaO2 increased with respect to the baseline values. During surgery all patients showed a good clinical relaxation. Thus, we believe that vecuronium is a good muscular relaxant agent, safe, and effective to be used in neurosurgery.

[Effect of succinylcholine on serum levels of potassium in patients treated for intracranial aneurysm]. / Efecto de la succinilcolina sobre los niveles séricos de potasio en pacientes intervenidos de aneurisma intracraneal.

A prospective study was carried out on 10 patients who were submitted to intracranial aneurysm clipping and who had bled some days before the operation. All patients received a precurarization dose of pancuronium (0.01 mg/kg) and lidocaine (1.5 mg/kg) during the preinduction and succinylcholine (1 mg/kg) to facilitate orotracheal intubation. The operation took place between the days 5 and 27 following the subarachnoid hemorrhage. Basal potassium plasma levels were determined at 1, 3, 5 and 10 minutes after succinylcholine had been administered. The levels (media +/- SD), expressed in mEq/l, were: basal 3.77 +/- 0.31; at first minute 3.64 +/- 0.38: 3 minutes 3.69 +/- 0.35; 5 minutes 3.78 +/- 0.31, and 10 minutes 3.82 +/- 0.39. Using the analysis of variance, no significant differences (p = 0.11) were observed among the average levels of potassium in the intervals of time studied. There is no significant correlations either between the potassium figures and the time elapsed since the subarachnoid hemorrhage occurred.