RESUMO
Seventy patients 1-10 years of age were submitted to isoflurane (I) or halothane (H) anaesthesia (O2:N2O = 1:3); H was used as a reference substance. Under I anaesthesia, haemodynamic parameters proved to be well preserved. While the pulse rate under I increased significantly, the diastolic pressure decreased as a result of peripheral vascular dilatation. Baroceptor reflexes seemed to function more properly under the effect of I. Spontaneous respiration was definitely depressed by I. Respiratory rate, minute volume, end-expiratory CO2 and pCO2 values indicated CO2 accumulation. Younger children breathing spontaneously were subject to airway problems in I more than in H anaesthesia by decreasing negative occlusion pressures. Increasing doses of vecuronium bromide (5, 10, 15 and 70 micrograms/kg body wt.) accomplished muscular relaxation of various degrees, as tested by the train-of-four (TOF) method. The use of I in two age groups resulted in faster onset, more profound muscular relaxation, and longer duration in comparison with H; these results were statistically significant.
Assuntos
Anestesia , Isoflurano , Éteres Metílicos , Fatores Etários , Dióxido de Carbono/sangue , Criança , Pré-Escolar , Feminino , Halotano , Hemodinâmica/efeitos dos fármacos , Humanos , Lactente , Isoflurano/farmacologia , Masculino , Éteres Metílicos/farmacologia , Relaxamento Muscular , Respiração/efeitos dos fármacosRESUMO
Horizontal vestibulo-ocular reflex (VOR) with covered eyes was tested in 15 healthy subjects sitting on a rotation chair (40 degrees, 0.05, 0.1, 0.2, 0.33 Hz) under two conditions: (a) head fixed to chair by a neck support; (b) with instruction to turn the head together with the passively moved trunk. In situation (b), saccadic amplitudes/sec, nystagmus frequency, gain of nystagmus slow phase velocity and amplitudes of maximum eye shift were enhanced significantly. The phase of maximum eye shift changed from 180 degrees up to 270 degrees with respect to stimulus position. The distribution of nystagmus saccades over the stimulus period showed enhanced peak values and a slight phase shift.