Analgesic dose-response relation in cervical epidural block

The relationship between the age and the spread of analgesia from different epidural anesthetic doses was examined by studying analgesic dose responses in cervical epidural analgesia. Two different anesthetic doses (5ml or 10ml) of 2% mepivacaine were injected into the cervical epidural space at a constant pressure (80mmHg) using an intravenous apparatus, and the spread of analgesia to pinprick was assessed. The significant correlation was found between the patients age and the number of spinal segments blocked (5ml:r = 0.8498, P < 0.01, 10ml:r = 0.5988, P < 0.01). The inverse linear relationship was found between the patients age and the segmental dose requirement (5ml:r = –0.6754, P < 0.01, 10ml:r = –0.5784, P < 0.01). Patients under 39 years of age showed a direct relationship between the dose injected and the number of spinal segments blocked, enabling prediction of the number of segments blocked with a given dose of local anesthetic. Doubling the epidural dose approximately doubled the number of spinal segments blocked. The analgesic dose-response relation in patients over 60 years of age differed from that in patients under 39 years of age and doubling the epidural dose did not double the number of spinal segments blocked. Progressively more extensive analgesia was obtained from a given dose of local anesthetic with advancing age. It was difficult to limit the extent of analgesia by injecting a smaller dose of local anaesthetic in the elderly.(Hirabayashi Y, Matsuda I, Inoue S et al.: Analgesic dose-response relation in cervical epidural block. J Anesth 2: 22–27, 1988)     

硬膜外镇痛联合应用乙酰氨基酚在剖宫产术后的镇痛效果

目的：比较对乙酰氨基酚联合自控硬膜外镇痛的多模式术后镇痛与单纯自控硬膜外镇痛用于剖宫产产妇术后镇痛效果。方法：200名行剖宫产的产妇随机分为实验组（S组）和对照组（C组）,S组产妇在术前15min静脉注射对乙酰氨基酚1g,C组产妇在术前15min静脉注射安慰剂（生理盐水）。两组产妇均采用腰硬联合麻醉方案,缝合切口时启动自控硬膜外镇痛泵。术前、术后即刻、术后1天、术后2天观察疼痛强度和血清IL-6、IL -10水平;记录新生儿出生Apgar评分、术后阿片类药物使用量及术后不良反应、产妇满意度和对母乳喂养的影响程度。结果：术后1天疼痛评分S组显著低于C组。术后即刻、术后1天S组IL-6表达水平低于C组,而该时点S组IL-10表达水平高于C组（P＜0.05）。两组间不良反应、新生儿出生Apgar评分、产妇满意度和母乳喂养情况无统计学差异（P＞0.05）。结论：剖宫产术前静脉注射对乙酰氨基酚联合自控硬膜外镇痛比单独应用自控硬膜外镇痛能够为产妇提供更好的术后疼痛管理。     

Changes in the antinociceptive effect of mesencephalic stimulation produced by analgesics and tranquilizers

Chronic experiments on cats showed that analgesics, in subanalgesic doses, not only exhibit an antinociceptive effect when accompanied by subthreshold stimulation of the mesencephalon, but also potentiate the analgesic action of central stimulation. Tranquilizers only facilitate the development of an analgesic effect during subthreshold mesencephalic stimulation. The possible reasons for differences in the action of these substances are discussed.Department of Pharmacology, I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 1, pp. 36–41, January, 1978.     

激活AMPA受体抑制大鼠骶髓后连合核神经元NMDA反应──制霉菌素穿孔法膜片钳研究

在急性分离的大鼠骶髓后连合核神经元上，采用制霉菌素穿孔法膜片钳技术，研究ＡＭＰＡ受体和ＮＭＤＡ受体的相互作用．结果显示，激活ＡＭＰＡ受体可逆性地抑制ＮＭＤＡ反应，该效应依赖于细胞外钙离子．而且，通过ＡＭＰＡ受体通道内流的钙离子单独即足以抑制ＮＭＤＡ受体介导的反应．本结果证明，钙离子可透性ＡＭＰＡ受体可能参与了脊髓伤害性信息的调控．该过程可能与针刺镇痛的机制有关．     

Reduced nocturnal morphine analgesia in mice following a geomagnetic disturbance

Latency to respond to an aversive thermal stimulus and the degree of analgesia induced by morphine were examined in mice injected with either isotonic saline or morphine sulfate (10 mg/kg) during midscotophase of a 12:12 h LD cycle. When mean response latencies were compared to the degree of geomagnetic disturbance (Ap index) present on test days, it was found that during the geomagnetic storm on December 17th, 1982, a significant reduction (P<0.01) in response latency was evident in both saline- and morphine-treated mice. The reduction in response latencies was greater, and lasted longer in the morphine-treated animals. It is suggested that the pineal gland may mediate this biomagnetic effect.     

针刺过程中有衣小泡的形成、形态特征及其数量变化的研究

针刺大鼠“人中”、“四白”穴使之产生明显镇痛效果后,再将针刺时间分别延长至1、2、4、6、8、10、12h,到预定时间立即将动物灌流杀死取材,采用定量电镜方法观察计数了三叉神经尾侧脊束核胶状质亚核内各种有衣小泡的数量、形态以及在不同针刺时间内数量的变化。结果发现:大单壁有衣小泡的形成与针刺时间无明显正比例关系;而双壁有衣小泡则显然与之不同,它不仅形态多样,数目也随针刺时间而改变。本文将观察到的双壁有衣小泡归纳为以下五种类型:1、尚未与相邻两终末质膜脱离的孤立存在者。2、游离于终末内孤立存在者。3、与终末质膜相连且融合而成簇存在者;4、游离于终末内融合成簇者;5、树突棘凸入另一轴突或树突内并与之共同形成的不典型的双壁有衣小泡簇。本研究还发现,在针刺过程中双壁有衣小泡在1～8h内的形成与时间成正比,即1h时开始增多,4h显著增多,8h达高峰;以后开始下降,10h已恢复到4h的水平,到12h恢复到针刺前的状态。对照组仅见少数孤立的双壁有衣小泡,其形成基本上不随时间而变化。本文认为双壁有衣小泡的形成,是较大单壁有衣小泡的形成更为有效地继大致密核心小泡非突触部位胞吐之后膜再循环的一条新途径。     

Intra-articular morphine and postoperative analgesia after knee arthroscopy

The aim of this study was to evaluate the postoperative analgesic effect of intra-articular administration of a low- and a high-dose morphine solution after knee arthroscopy. Thirty patients who underwent diagnostic arthroscopy or arthroscopic meniscectomy were allocated in three groups. At the end of the arthroscopic procedure patients in Group A received intra-articularly 20 ml normal saline (N/S), Group B received 5 mg morphine in 20 ml N/S and Group C received 15 mg morphine in 20 ml N/S. The postoperative pain was assessed using a visual analogue scale for 24 h, while all the patients stayed at hospital. Side effects from the central action of opioids were not detected. Although the pain scores in the group of low-dose morphine were lower than in the control group, we failed to detect any significant differences in pain scores among the three groups. There was evidence that a high-dose can cause hyperalgesia.     

舒芬太尼用于腹部手术患者自控静脉镇痛的临床观察

目的探讨腹部手术病人自控舒芬太尼静脉镇痛的临床效果及安全性。方法选择气管内插管全身麻醉腹部手术患者计80例，ASA分级Ⅰ～Ⅱ级，年龄18～86岁，高中以上文化程度。随机分为两组，每组40例，一组为舒芬太尼镇痛组（S组），术后镇痛药物配方：舒芬太尼2μg／kg＋格拉司琼6mg加生理盐水至100ml；另一组为芬太尼镇痛组（F组），术后镇痛药物配方：芬太尼20μg／kg＋格拉司琼6mg加生理盐水至100ml。镇痛泵参数均设置为：负荷剂量4ml，背景输注速度1ml／h，自控剂量0．5ml，锁定时间15min。观察S组与F组的镇痛效果及不良反应。结果S组在各个时段静态和动态VAS评分均低于F组（P〈0．05）；S组镇静效果较F组评分略高，但两者差异无统计学意义（P〉0．05）；S组不良反应发生率少于F组（P〈0．01）；两组患者均未见明显的呼吸抑制发生。术后随访两组患者对镇痛效果的总满意度均在90％以上。结论腹部手术病人自控舒芬太尼静脉镇痛，具有良好的镇痛和镇静作用及安全性，且心血管的稳定性好，不良反应低。     

Effect of phosphoramidon - a selective enkephalinase inhibitor - on nociception and behaviour

Phosphoramidon (100-350 micrograms i.c.v.), a selective enkephalinase inhibitor, induced in the rat a decrease of nociception to pressure stimulation without evident respiratory depression. In addition, intensive behavioural changes such as grooming (licking the fur, face washing and scratching), mounting behaviour and wet dog shakes were observed. Naltrexone pretreatment (1 mg/kg i.p.) caused a significant decrease in the phosphoramidon-induced nociception and behavioural changes. Puromycin (30 micrograms i.c.v. or 7.5 mg/kg i.p.) caused no changes in nociception or behaviour.