Paraplegia after thoracotomy--not caused by the epidural catheter

BACKGROUND: Paraplegia and peripheral nerve injuries may arise after general anaesthesia from many causes but are easily ascribed to central block if the latter has been used. CASE REPORT: A 56-yr-old woman, with Bechterev disease but otherwise healthy, was operated with left-sided thoracotomy to remove a tumour in the left lower lobe. She had an epidural catheter inserted in the mid-thoracic area before general anaesthesia was started. Bupivacaine 0.5% 5 ml was injected once and the infusion of bupivacaine 0.1% with 2 micrograms/ml fentanyl and 2 micrograms/ml adrenaline (5 ml/h) started at the end of surgery. The patient woke up with total paralysis in the lower limb and sensory analgesia at the level of T8, which remained unchanged at several observations. Laminectomy, performed 17 h after the primary operation, showed a large piece of a haemostatic sponge (Surgicel) compressing the spinal cord, which was then decompressed but the motor and sensory deficit remained virtually unchanged both then and a year later. CONCLUSIONS: This case shows--once again--that although central blocks may cause serious neurological complications and paraplegia, other causes are possible and have to be considered. However, all patients with an epidural catheter must be monitored for early signs and symptoms of an intraspinal process and the appropriate treatment has to be instituted instantly.     

Study of a new oral beta-adrenergic drug,clenbuterol, in patients with chronic bronchitis

Summary In a double-blind, placebo-controlled, incomplete cross-over study the bronchodilator, cardiovascular, respiratory and metabolic effects of 3 different oral doses of clenbuterol were studied in 12 patients suffering from partly reversible airways obstruction due to chronic bronchitis. The ventilatory response to oral clenbuterol or placebo was assessed by measurement of specific airway resistance (sRaw) to detect changes in central airways, and of flow at 85% of vital capacity ( _{85% VC}) to detect change in peripheral airways. Clenbuterol 20, 30 and 40 µg produced a significant decrease in sRaw between 15 and 480 min after administration. Its effect on the large airways was not related to the dose. Clenbuterol 30 and 40 µg caused a significant increase in _{85% VC} between 60 and 480 min after administration. After 20 µg a significant improvement in _{85% VC} was found between 120 and 240 min. The over-all effect of 30 µg on the small airways was significantly more pronounced than that of 20 µg and was more sustained than that of 40 µg 120 min after administration. No significant changes in heart rate, ECG or blood pressure were noted. Decreases in PaO₂ and O₂-saturation after clenbuterol were not related to dose. Slight falls in PaO₂ and O₂-saturation were also observed after placebo. These observations are briefly discussed. There was negligible lipid mobilization after either the placebo or bronchodilator. A slight but insignificant rise in blood glucose was observed after both 30 and 40 µg of clenbuterol.     

Interaction of topiramate with glycine receptor channels

Glycine receptor channels are pentameric ligand-gated ion channels that respond to the application of inhibitory neurotransmitters by opening of a chloride-selective central pore. Topiramate (TPM) is a broad-spectrum antiepileptic drug used as add-on or monotherapy for focal seizures. In the present study the interaction of TPM with glycine receptor channels was studied on outside-out patches from HEK293 cells expressing alpha1beta glycine receptor channels. The patch clamp techniques combined with ultra fast solution exchange enabled us to investigate the kinetics of receptor channels in presence of TPM. Our study showed no agonistic or potentiating effect for TPM on glycine receptor channels. However, in presence of 1 mM glycine + 1 mM TPM, the desensitization got faster and the peak current amplitude decreased. After the end of glycine + TPM pulses, off-currents occurred, suggestive for a specific channel block mechanism.     

Effects of peribulbar bupivacaine as an adjunct to general anaesthesia on peri-operative outcome following retinal detachment surgery

Sixty premedicated, ASA physical status I or II patients weighing > 25 kg scheduled for elective retinal detachment repair were randomly assigned to receive either peribulbar block with 10 ml of 0.25% bupivacaine (block group) or intravenous morphine 150 microg.kg-1 (morphine group), prior to the induction of general anaesthesia (n = 30 in each group). Patients were evaluated for intra-operative oculocardiac reflex, peri-operative pain relief, recovery from anaesthesia and postoperative nausea and vomiting. Apart from significantly reducing the incidence of oculocardiac reflex (30% vs. 70%, p = 0.0019), peribulbar bupivacaine also attenuated the severity of the reflex. Postoperative pain relief was superior in the block group. More block group patients had the maximum recovery score in the immediate postoperative period (80% vs. 27%, p < 0. 0001) and they achieved complete recovery significantly faster than the morphine group (17.3 (14.7) min vs. 66.7 (29.7) min, p < 0.0001). The incidence (40% vs. 77%, p = 0.004) and severity of postoperative nausea and vomiting were significantly less in the block group. In summary, peribulbar bupivacaine, when administered together with general anaesthesia, attenuated oculocardiac reflex, provided comparable intra-operative and superior postoperative analgesia, resulted in significantly earlier and better recovery from anaesthesia, and significantly reduced the incidence and severity of postoperative nausea and vomiting.     

静脉全麻复合骶管阻滞在婴幼儿先天性心脏病介人封堵治疗的研究

目的比较静脉全麻复合单次骶管阻滞麻醉与单纯静脉全麻用于婴幼儿先天性心脏病介入封堵治疗的效果。方法616例婴幼儿先天性心脏病介入封堵治疗患者随机分成两组:骶管阻滞加静脉全麻(I组);另一组用全凭静脉麻醉(II组)。结果全麻药的用量,II组比I组明显增多(P<0.05);I组苏醒时间短,分泌物少,手术后呕吐发生率少(P<0.05)。结论静脉全麻复合小儿单次骶管阻滞麻醉比全凭静脉麻醉用于婴幼儿先天性心脏病介入封堵治疗麻醉费用少,生命体征平稳,麻醉并发症少,值得推广。     

线型和星型聚乙二醇-聚己酸内酯两亲嵌段共聚物聚集行为

分别以单甲氧基聚乙二醇和4臂聚乙二醇引发己酸内酯开环聚合制得线型和星型聚乙二醇-聚己酸内酯(PEG-PCL)两亲嵌段共聚物。IR1、H-NMR和GPC测试结果表明所合成的共聚物具有预期的结构。该PEG-PCL两亲嵌段共聚物中PEG组分具有结晶性。共聚物在水相中自组装形成聚集体,聚集体的水合直径小于50 nm。高浓度共聚物在水性介质中会发生凝胶-溶胶转变,在凝胶-溶胶转变温度以下,共聚物形成凝胶网状结构。共聚物中PEG组分的结晶性、在水相中生成的聚集体的水合直径以及凝胶-溶胶转变行为均与聚合物的组成以及分子形状密切相关。     

不同的阻滞方法对75岁以上高龄老人阻滞效果及循环功能的影响

为比较硬膜外隙阻滞(硬外)、蛛网膜下隙阻滞(腰麻)和单侧蛛网膜下隙阻滞(腰麻)在75岁以上高龄股骨颈骨折手术中的阻滞效果及对循环的影响.选ASAⅢ～Ⅳ级90例,随机等分为3组,Ⅰ组为硬外阻滞组(A组),用1.5%Lidocaine 4ml试验剂量并确认无脊麻后,根据情况追加1.5%Lidocaine 4～6ml;Ⅱ组为腰麻组,Ⅲ组为单侧腰麻组,两组注药速度均为0.1ml·s-1,注药过程均不作往返吸注.Ⅱ组用0.75%布比卡因1ml(7.5mg),注药后仰卧;Ⅲ组患侧在下侧卧,用0.75%布比卡因0.6ml(4.5mg)、10%葡萄糖液0.4ml,注药20min后平卧.结果显示:①患侧痛觉阻滞起效由快到慢为Ⅱ组、Ⅲ组和Ⅰ组.②三组阻滞前后的心率比较,均无显著性差异;Ⅲ组阻滞前后的平均动脉压也无显著性差异,但Ⅰ和Ⅱ组的阻滞前后的平均动脉压均有显著性差异.③患侧痛觉阻滞达标率(无痛平面达L1的百分率)为Ⅰ组93.3%,Ⅱ和Ⅲ组均为100%.④阻滞不全者Ⅰ组3例,而Ⅱ和Ⅲ组则无.⑤发生低血压者Ⅰ和Ⅱ组各3例,且同时都伴有ECG的ST段下移;Ⅲ组则无.表明①单侧腰麻组起效较快、阻滞完善和患侧痛觉阻滞达标率高.②单侧腰麻所用剂量小,阻滞范围小,对循环干扰轻和阻滞平面似乎更易控制.因此,小剂量布比卡因单侧腰麻可能更适合高龄老人下肢手术.