控制性降压在鼻内窥镜手术中的应用

目的 :观察控制性降压在鼻内窥镜手术中应用的意义。方法 :80例双侧鼻息肉、鼻窦炎患者 ,局麻、鼻内窥镜下行双侧鼻息肉摘除、全筛切除及开放上颌窦自然开口。其中 38例术中控制性降压 (降压组 ) ,另 42例作为对照。结果 :降压组术中出血 (6 1 39± 38 5 2 )ml,对照组出血 (140 12± 81 82 )ml,差异有显著性意义 (P <0 0 1) ;手术时间分别为 (4 9 2 5± 7 0 6 )min和(6 2 4 0± 9 90 )min ,差异有显著性意义 (P <0 0 1)。结论 :控制性降压可明显减少术中出血 ,缩短手术时间。     

Transfer of clonidine and dexmedetomidine across the isolated perfused human placenta

Background: The placental transfer of the a₂ receptor agonist clonidine, earlier used as an adjuvant in obstetric epidural analgesia, was compared with the transfer of the newer and more %-selective agonist dexmedetomidine.
Methods: Term placentas were obtained immediately after delivery with maternal consent and a 2-hour recycling perfusion of a single placental cotyledon was performed. Disappearance from the maternal circulation, accumulation in placental tissue and appearance in the fetal circulation of clonidine or dexmedetomidine with the reference compound antipyrine were followed in 4 experiments for both drugs.
Results: At 2 hours the percent dexmedetomidine found in the fetal circulation was 12.5 (SD 5.1)%, while 48.1 (SD 20.3)% was found in the perfused placental cotyledon. A higher mean clonidine than dexmedetomidine concentration was achieved in the fetal circulation (1.90 vs. 0.56 nmol/l, P <0.05). At 2 hours the percent clonidine found in the fetal circulation was 22.1 (SD 2.4)% ( P <0.05), while 11.3 (SD 3.3)% ( P <0.05) was re tained in the perfused placental cotyledon. The transfer indexes, describing maternal-to-fetal transfer of dexmedetomidine and clonidine normalized with the transfer of antipyrine, were 0.88 (SD 0.07) and 1.04 (SD 0.08) respectively ( P <0.05).
Conclusions: Dexmedetomidine disappeared faster than clonidine from the maternal circulation, while even less dexmedetomidine was transported into the fetal circulation. This was due to its greater placental tissue retention, the basis for which probably is the higher lipophilicity of dexmedetomidine.     

Should nitrous oxide be discontinued before desflurane after anaesthesia with desflurane/N2O?

Background : The appearance of hypoxaemia immediately after anaesthesia with nitrous oxide may be partially explained by diffusion hypoxia. This study was undertaken to evaluate circulatory and respiratory variables during emergence after desflurane/nitrous oxide anaesthesia, and whether there are any differences depending on which gas is discontinued first. Methods : 20 patients were studied after gynaecological laparoscopic surgery. The depth of anaesthesia was reduced 10 min prior to the emergence by stopping the administration of one of the two inhalational agents. Desflurane was discontinued first in Group 1, nitrous oxide in Group 2. Ventilation was controlled with E'C0₂ maintained at 5% until the administration of the second anaesthetic gas was discontinued. Thereafter, the patients breathed spontaneously. Results : The PaC0₂ at which the respiratory drive reappeared after controlled normoventilation was similar in both groups, 6.1–6.5 kPa, and extubation was performed after 10–11 min. At extubarion, the end–tidal C0₂ and total MAC were similar in the groups, about 6.2 vol% and 0.16, respectively. Mean arterial blood pressure was significantly higher in Group 1. The cardiac output increased in both groups from about 6 1/min at the conclusion of anaesthesia to 9.0 and 7.6 1/min at 15 min in the recovery period. End–tidal O₂ decreased and CO₂ increased in both groups during the first 10 min in the recovery period. pH was reduced at 15 and 30 min in both groups. Conclusion : Irrespective of which agent was discontinued first, there was an increase in cardiac output, decrease in oxygenation and a modest acidosis in the first 30–min recovery period. The only significant difference between the groups was in mean arterial blood pressure in the early emergence phase with a greater MAP when N₂O had been used until the conclusion of anaesthesia.     

Scintigraphic visualization of intrathecal liposome biodistribution

Background: Liposomes containing local anaesthetics have been administered intrathecally and in the epidural space. Poor attention has been given to the pharmacokinetics of liposomes as drug carriers. Therefore, we observed the biodistribution of liposomes after intrathecal injection in rats by scintigraphic imaging during 24 h.
Methods: We administered ⁹⁹Tc-labeled multilamellar (MLV) and small unilamellar vesicles (SUV) of defined size and volume dispersities into the cerebrospinal fluid at the lumbar level. Those vesicles were free of contamination by radiolabeled colloids as visualized by light and electron microscopy and of neurotoxic products from phosphatidylcholine hydrolysis and peroxidation, both during the preparation process and after 24 h incubation in cerebrospinal fluid at 37°C in vitro.
Results: SUV immediately diffused from the lumbar site of injection to the head and were cleared between 1 and 24 h after injection. MLV were cleared more slowly from the spinal space and appeared in the head region 1 h after injection where they accumulated up to 24 h. These differences were explained in terms of vesicle sizes and volumes. SUV with 0.05 μm diameters were rapidly absorbed into the blood through the arachnoid granulations. In contrast, particles larger than the upper size limit of the arachnoid granulations permeability (±8 μm) could accumulate in the head with a slow elimination rate.
Conclusion: This difference in clearance from the intrathecal space outlines the importance of defining the size of the liposomes, the distribution of a tracer or a drug inside the liposomal preparation, the chemical stability and the absence of toxic degradation products of liposome formulations before clinical use.     

代氟醚和安氟醚低流量循环密闭吸入全麻的临床观察

使用低流量循环密闭回路内注入给药法，比较１ＭＡＣ代氟醚和安氟醚各１４例维持全麻时循环动力苏醒情况和不良反应。结果；代氟醚在维持阶段对心血管系统的抑制较安氟醚为轻，很可能和代氟醚能使交感神经兴奋性增加有关。     

硬膜外注入异氟醚－氧化亚氮气体增强利多卡因麻醉作用

我们对５０例子宫、卵巢手术病人，使用利多卡因做硬膜外麻醉，其中２５例向硬膜外腔内注入异氟醚－氧化亚氮气体。２组对比发现，实验组麻醉平面明显高于对照组，在同样手术时间内实验组所使用的利多卡因量明显少于对照组。表明异氟醚－氧化亚氮气体有增强利多卡因的硬膜外麻醉作用，同时未发现注入吸入麻醉药产生副作用。     

碳酸利多卡因硬膜外麻醉用于乳腺癌根治术的评价

40例乳腺癌根治术患者，美国麻醉医师协会（ASA）分级Ⅰ-Ⅱ级，随机分为2且，第1组硬膜外阻滞＋臂丛神经阻滞，应用1．33％盐酸利多卡因＋0．15％盐酸地卡因＋1：20万肾上腺素，硬膜外阻滞首量12ml，臂丛神经阻滞20ml;第2组硬膜外阻滞，应用1．73％碳酸利多卡因＋1：20万肾上腺素，首量15ml。两组硬膜外阻滞选为T4－5间隙穿刺。首量给完后测定麻醉药效，并监测患者心率（HR）、平均动脉压（MAP）、血氧饱和度（SpO2)，在麻醉前、后30、60、120min抽取动脉血作血气分析。结果显示：第2组麻醉的起效时间、阻滞完善时间要比第1组短（P＜0．01）。感觉神经阻滞分段数要比第1组多（P＜0．01）；两组病人的HR和MAP，麻醉手术中改变不明显。麻醉后面罩给氧。两组病人的SpO2、PaO2增加，PaCO2有所下降，两组比较无统计学意义，但组内前后对照有显著差异（P＜0．05）。结果提示碳酸利多卡因硬膜外麻醉下施行乳腺癌根治术具有良好的麻醉效果和更高的安全性。     

不同麻醉方法对28例胃癌手术患者红细胞醛糖还原酶及血浆一氧化氮的影响

目的:观察不同麻醉方法对胃癌手术患者红细胞醛糖还原酶(AR)活性及血浆一氧化氮(NO)浓度的影响。方法:28例胃癌手术患者随机分为两组,组1吸入1.5～2.0最小肺泡吸入有效浓度(MAC)的异氟醚,组2为0.5～1.0MAC异氟醚复合硬膜外麻醉。分别于麻醉前30min、手术90min、术后60min、术后1天和术后2天5个时间点抽取静脉血,测定血糖浓度、红细胞AR活性及血浆NO浓度。结果:与麻醉前值相比,组1病人血糖浓度于手术90min、术后60min、术后1天明显升高(P<0.05或P<0.01);术后1天红细胞AR活性明显升高(P<0.05),同时血浆NO浓度显著下降(P<0.05)。组2病人血糖浓度于手术90min、术后60min显著升高(P<0.01);红细胞AR活性及血浆NO浓度,虽有与组1病人相似的变化趋势,但与麻醉前值相比,各时间点无明显变化。术后1天组1病人红细胞AR活性明显高于组2(P<0.05),而血浆NO浓度则相反(P<0.05),两组间血糖无明显差异。结论:胃癌手术病人在应激高血糖状态下,红细胞多元醇途径被激活的同时血浆NO合成受抑制。全麻联合硬膜外阻滞能较好抑制这一改变。     

局麻下深龋充填对成人牙科畏惧症的影响

目的　探讨局麻下深龋充填对成人牙科畏惧症的影响。方法　采用Corah’s牙科畏惧症评分法 ,筛选出 10 0例需深龋充填的DF成人患者 ,分为实验组与对照组。实验组在局麻下行深龋充填术 ,对照组则为常规的牙科治疗。结果　实验组DF程度明显降低 ,与治疗前以及对照组比较都有显著性差异 (P <0 .0 1)。牙科治疗过程中两组脉搏的变化有显著性差异 (P <0 .0 1)。结论　局麻下行深龋充填术 ,对成人牙科畏惧症有治疗作用     

Lateral position prevents respiratory occlusion during surgical procedure under general anesthesia in the patient of huge anterior mediastinal lymphoblastic lymphoma

Lymphoblastic lymphoma, an aggressive mediastinal mass, is recognized as serious threat to the patient in developing cardiac tamponade or airway obstruction. Surgical procedure is often required to relieve clinical emergency and to establish prompt pathological diagnosis. However, in such a patient, acute respiratory occlusion in the spine position can be a life-threatening complication during general anesthesia. We describe a 17-year-old man whose cardiac tamponade was treated by pericardial-pleural window through a left anterior thoracotomy in the lateral position. The patient recovered from hemodynamic compromise without showing respiratory occlusion during general anesthesia and remained in the lateral position until extubation. Pathological diagnosis was precursor T-lymphoblastic lymphoma. There were no complications attributable to the operative procedure. Further chemotherapy reduced the mediastinal mass in size after two weeks when the patient developed sepsis and died. Lateral position prevents respiratory occlusion during surgical procedure under general anesthesia in the patient of huge anterior mediastinal tumor with airway obstruction.