In vitro contracture test for diagnosis of malignant hyperthermia following the protocol of the European MH Group: Results of testing patients surviving fulminant MH and unrelated low-risk subjects

Background: Determination of sensitivity and specificity of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility using the European MH Group (EMHG) protocol has been performed in some laboratories but only on a small sample from the combined EMHG. Thus, the purpose of the present study was to determine combined EMHG sensitivity and specificity of the test. Methods: Results of IVCT of patients with previous fulminant MH and normal, low-risk subjects (controls) were collected from 22 centresof the EMHG. IVCT was performed according to the EMHG protocol. Patients were included inthe study if the clinical crisis had a score of at least 50 points with the Clinical Grading Scale. Low-risk subjects were included provided they did not belong to a family with known MH susceptibility, they had not developed any signs of MH at previous anaesthetics, and they did not suffer from any neuromuscular disease. For inclusion of both MH patientsand low-risk subjects, at least 1 muscle bundle in the IVCT should have twitches of 10 mN(1 g) or more. For evaluation of individual tests, only muscle bundles with twitch heights of 10 mN (1 g) or more were used. Results: A total of 1502 probands had undergone IVCT because of a previous anaesthesia with symptoms and signs suggestive of MH. Of these, 119 had clinical scores of 50 and above. From these 119 MH-suspected patients and from 202 low-risk subjects, IVCT data were collected. Subsequently, 14 MH-suspected patients were excluded from further analysis for thefollowing reasons: In 3 patients, the suspected MH episode could be fully explained by diseases other than MH; in 11 MHS patients, IVCT was incomplete (n=l), data were lost (n=3), or none of the muscle bundles fulfilled twitch criteria (n=7). Of the remaining 105 MH-suspected patients, 89 were MHS, 10 MHEh, 5 MHEc, and one MHN. Thus, we observed a diagnostic sensitivity of the IVCT of 99.0% if the MHE group is considered susceptible(95% confidence interval 94.8–100.0%). Of the 202 low-risk subjects, 3 were MHS, 5 MHEh, 5 MHEc, and 189 MHN. This gives a specificity of the IVCT of 93.6% (95% confidence interval 89.2–96.5%). Conclusion: The IVCT for diagnosis of MH susceptibility in Europe has a high sensitivity and a satisfactory specificity.     

左旋布比卡因蛛网膜下腔阻滞的进展

左旋布比卡因是一种新型的长效酰胺类局麻药,为麻醉中常用局麻药物布比卡因的左旋体.左旋布比卡因中枢神经系统和心脏毒性明显低于布比卡因,且具有儿乎与布比卡因相同的麻醉效能.长效局麻药用于蛛网膜下腔的安全性长期以来一直是麻醉学家关注的问题,近年来国内外已有很多学者对左旋布比卡因蛛网膜下腔的应用进行了大量研究.现就左旋布比卡因蛛网膜下腔阴滞的安全性、可行性和临床应用等方面的进展作一综述.     

Hyperaemia in rat neocortex produced by acute exposure to methylenedioxymethamphetamine

Cerebral blood flow and glucose utilization were measured in rat neocortex, hippocampus and striatum following methylenedioxymethamphetamine injection (5 mg/kg, i.v.), using the tracers [¹⁴C]iodoantipyrine and [¹⁴C]2-deoxyglucose, respectively. In control rats, blood flow was coupled to glucose metabolism, but in methylenedioxymethamphetamine-treated rats, marked hyperperfusion was measured in frontal and parietal cortex with no change in glucose use. This suggests that methylenedioxymethamphetamine has the potential to disrupt cerebrovascular control.     

四肢带表浅静脉干的局部皮瓣在创伤修复中的应用

设计4种带表浅静脉干的局部皮瓣用于修复四肢创面14例,获得了满意的效果。该皮瓣所包含的一条浅静脉干,不仅有利于静脉回流,且其血流对皮瓣亦有营养作用。因此,该皮瓣容易成活,长宽比值可大于传统任意型皮瓣。并具有操作简便,不损伤主要动脉等优点。文中介绍了皮瓣的设计及手术方法,并对该皮瓣的血液循环特点、适应证及供区选择等进行了讨论。     

Response of lower esophageal contractility to changing concentrations of halothane or isoflurane: A multicenter study

A multiple-center study was performed to determine the relationship between lower esophageal contractility, clinical signs, and anesthetic concentration as expressed by minimum alveolar concentration (MAC). One hundred four American Society of Anesthesiologists Class I through III patients were exposed to isoflurane (with and without nitrous oxide) or halothane in concentrations of 0.5, 1.0, and 1.5 MAC. Heart rate and systolic blood pressure were continuously monitored. Both the amplitude and frequency of spontaneous and provoked lower esophageal contractions were measured in situ by using a 24-F probe equipped with provoking and measuring balloons. Combined results demonstrated statistically significant correlations (P<0.001) between lower esophageal contractility and MAC. Spontaneous lower esophageal contractions decreased from 1.10±0.12 (SEM) contractions per minute (0.5 MAC) to 0.42±0.05 (1 MAC) to 0.18±0.05 (1.5 MAC). Provoked lower esophageal contractility values decreased from 45±4 mm Hg (0.5 MAC) to 29±3 (1 MAC) to 19±2 (1.5 MAC). Heart rate changes did not correlate with MAC, and systolic blood pressure correlated in only one of three centers. Intracenter and intercenter analyses failed to demonstrate a significant relationship between lower esophageal contractility and heart rate or systolic blood pressure. No intracenter differences in either amplitude or frequency of lower esophageal contractions were observed, despite differences in volatile agents, induction techniques and agents, patient populations, and duration of anesthesia. Our studies indicate that lower esophageal contractility may be an indicator of anesthetic depth as reflected by MAC, but further studies are needed to quantify the effects of surgical stimulus, intravenous anesthetics, vasodilators, anticholinergics, calcium channel blockers, beta-adrenergic agonists, and the presence of a nasogastric tube.     

硬膜外腔阻滞对胸部手术应激反应的影响

目的 观察硬膜外腔阻滞对胸部手术应激激素和细胞因子的影响。方法20例食管癌手术病人,随机分为两组,每组10例,即全麻复令硬膜外腔阻滞(GEA)组和全麻(GA)组,分别测定麻醉诱导前、手术2h、手术4h、术毕、术后1d及术后3d的血浆去甲肾上腺素、肾上腺素、血清促肾上腺皮质激素(ACTH)、皮质醇、C-反应蛋白、IL-6及IL-10的水平。结果 血浆去甲肾上腺素和血清皮质醇GEA组术中术后无显著改变,但GA组术毕和术后1d显著升高(P<0.05),术后3d恢复至术前水平,组间比较前者有显著差异(P<0.05)。两组血浆肾上腺素、IL-10术中术后均无显著变化。两组血清ACTH、IL-6及CRP术中术后均显著升高(P<0.05),组间比较无显著差异。结论 硬膜外腔阻滞可以减轻胸部手术的应激反应。IL-6是较CRP更灵敏的反映组织损伤的炎性指标。     

Effects of posture and pneumoperitoneum during anaesthesia on the indices of left ventricular filling

Background. Laparoscopic surgery requires the use of pneumoperitoneum (PP). When combined with positional changes, pneumoperitoneum may cause marked circulatory alterations.
Methods. Eight anaesthetized cardiovascularly healthy patients, scheduled for laparoscopic cholecystectomy, were studied before and during pneumoperitoneum in three different postures (supine, Trendelenburg and reversed Trendelenburg), employing transesophageal echocardiography and pulmonary artery pressure monitoring.
Results. PP significantly increased end-diastolic area (EDA) and pulmonary capillary wedge pressure (PCWP) irrespective of posture. PCWP was significantly influenced by postural changes, whereas EDA was not. Further, changes in EDA and PCWP covaried during the investigation, but showed no linear correlation. Systolic function, measured as end-systolic area (ESA) and fractional area shortening (FAS), was not altered. Diastolic function, as assessed by the velocity rate of the trans-mitral flow during the early filling phase (E) and the atrial contraction (A), showed no change of the E/A ratio, whereas after the induction of PP there was a significant reduction of the E component.
Conclusions. In cardiovascularly healthy patients, the left ventricular volume is increased during pneumoperitoneum. Further, changes in invasive pressure determinations (PCWP) do not correlate linearly with changes in volume indices of left ventricular filling (EDA).     

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     

Office-based anaesthesia for vitreoretinal surgery

The objectives of this study were to consider the effectiveness of local anaesthesia (LA) for office-based vitreoretinal (VR) surgery, the requirement to supplement the anaesthetic blockade, the demographic pattern of the sample and the acceptance of LA by patients. This prospective observational audit involved 111 patients that had undergone 128 VR procedures. Assessment data included: patient’s information, details of type of anaesthetic, and pain during surgery. A clinical audit was also carried out with telephone survey to establish the postoperative use of analgesics, the frequency of nausea, emesis, and insomnia. Results suggest that VR surgery can be carried out effectively and safely with LA, in an office-based surgery, provided that experienced surgeons exist. We noted a high degree of patient acceptance, a reasonable level of postoperative pain and a low frequency of nausea and vomits.     

An electron microscopic study of local anesthetic-induced skeletal muscle fiber degeneration and regeneration in the monkey

An electron microscopic study was done on abductor pollicis brevis muscles of 18 Rhesus monkeys after intramuscular injections of 0.75% bupivacaine, 2% mepivacaine, or 2% lidocaine + epinephrine. The muscles were examined for from 2 h to 28 days. Severe muscle fiber damage, consisting of breakdown of sarcolemma and myofibrils, was seen as early as 2 h. Phagocyte mediated fragmentation of the degenerating muscle fibers was at its peak during the third and fourth days. Myoblasts were abundant during the fourth day. Early myotubes appeared on the fifth and sixth days, and they matured during the second week. Satellite cells appeared alongside mature myotubes. Overall, the local anesthetic-induced breakdown and regeneration of skeletal muscle fibers in the monkey followed a course quite similar to that seen in the rat.