ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

The effects of ketamine hydrochloride on single-unit activities of various dorsal-horn Rexed laminae were studied with an extracellular microelectrode recording technique in decerebrate spinal cats. Ketamine hydrochloride, 2.5 mg/kg, iv, suppressed spontaneous single-unit activities of laminae 1 and 5 by 23 and by 43 per cent, respectively, while spontaneous activity of lamina 4 and that of lamina 6 were not significantly affected. This dose suppressed evoked unit activities of laminae 1 and 5 by 44 and by 64 per cent, respectively. As laminae 1 and 5 are known to respond principally to noxious stimali, a partial explanation for the analgesic effect of ketamine may be lamina-specific suppression of neuronal activity.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Physiologic and pharmacologic properties of the nucleus caudalis of the trigeminal complex were studied using an extracellular microelectrode recording technique in unanesthetized, mechanically ventilated, decerebrate cats after removal of the neural arch of the first cervical spine. Central trigeminal nociceptors were identified in the magnocellularis portion of the dorsal horn of the first cervical segment of the spinal cord. This finding resolved an apparent “paradox” reported previously. Cells responding to low-threshold cutaneous stimuli applied to the ipsilateral face were found dorsal and rostral to the central trigeminal nociceptors. Nitrous oxide (75 per cent) suppressed the spontaneous firing frequency of the central trigeminal nociceptors by 31-35 per cent, but facilitated spontaneous activity of the low-threshold cutaneous receptors of the nucleus caudalis by 20-31 per cent. The differential effects of nitrous oxide on trigeminal neurons were analogous to the effects of nitrous oxide on the nuclear aggregates of the dorsal horn of the feline lumbar spinal cord.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Functional residual capacity (FRC) and alveolarto-arterial oxygen tension difference (A-aDo2) were measured and compared in 16 patients prior to and during halothane: oxygen anesthesia with spontaneous respiration. After an hour of anesthesia (end-tidal halothane 1.0 per cent), FRC had decreased to 81 per cent of awake control values (range 50-104 per cent) and A-aDo2had increased from a preoperative value of 145 to 232 torr. The decrease in FRC correlated inversely with the changes in A-aDo2(r = 0.63,P< 0.01). Obese patients and those who had low preoperative values of per cent forced expiratory volume in one second (FEV1.0/FVC) had the greatest decreases in FRC. The authors conclude that although FRC and A-aDo2show inverse changes neither can be used to predict the absolute changes in the other: decreases in FRC during anesthesia are associated with obesity and reduction in forced air flow.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Optic nerves of mice given 40 mg/kg sodium pentobarbital, 1.5 per cent halothane, or no anesthetic were examined by electron microscopy. Microtubule and microfilament densities were analyzed to determine whether general anesthesia occurs with or without depolymerization of axonal microtubulesin vivo. Microtubule density was inversely related to axonal cross-sectional area. No quantitative difference between either experimental group and control was observed. Narcosis can be produced without depolymerization of axonal microtubules in mouse optic nerve.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Fifty-five patients scheduled for relatively short (1-2 hours) elective surgical procedures were divided into methoxyflurane and control groups. In both groups the potent inhalation agent used, methoxyflurane or halothane, was administered in the smallest amounts compatible with adequate anesthesia. Renal function was assessed by preoperative and postoperative measurements of serum urea, creatinine, sodium, and osmolality and urinary creatinine and osmolality and by calculation of creatinine, osmolar, and free-water clearances. In ten patients in each group serum and urinary fluoride levels were determined pre-and postoperatively. In addition, serum fluoride levels of 33 patients who had received methoxyflurane for vaginal deliveries were measured postpartum. No clinical or laboratory evidence of renal dysfunction was observed, and fluoride levels were markedly lower than those previously associated with renal toxicity.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

The concentrations of inorganic fluoride (F) and organic acid-labile fluoride (OALF) were studied in 15 patients at various times after receiving methoxyflurane. Sera contained 20.3 ± 7.2 (SD) µM F at the end of anesthesia and 35 ± 17 µM F the following day. OALF was present in concentrations of 212.1 ± 65 and 1,108 ± 247 µM at the end of anesthesia and the day after anesthesia, respectively. The concentrations decreased slowly after the second day. Three adolescent patients in the group showed little or no increase in serum F after anesthesia, but serum OALF showed the same levels and changes as in the other patients. The ratio of serum OALF/F remained constant after the first day. The renal clearances of F and OALF averaged 61 ± 43 and 12.7 ± 7.9 ml/min, respectively, and correlated with apparent urine flow rate (r = 0.6). The time course of the serum F concentration is consistent with the hypothesis that F is the causal agent for the polyuria that occasionally occurs after methoxyflurane anesthesia.

ISSN:0003-3022    

出版商:OVID    

年代:1973

数据来源: OVID