Neuromuscular disorders: relevance to anaesthesia and intensive care

Neuromuscular diseases are relatively rare but it is important for both anaesthetists and intensivists to have a working knowledge of the common diseases, as they may complicate general anaesthesia and result in neurogenic respiratory failure. The most common neurological condition seen in the intensive care unit is that of critical illness neuropathy; this subject is covered elsewhere in the journal. The diseases most commonly encountered in general anaesthetic practice include motor neurone disease, Guillain-Barré syndrome, botulism, myasthenia gravis and the muscular dystrophies.     

Adenosine and adenosine receptors: Newer therapeutic perspective

Adenosine, a purine nucleoside has been described as a ‘retaliatory metabolite’ by virtue of its ability to function in an autocrine manner and to modify the activity of a range of cell types, following its extracellular accumulation during cell stress or injury. These effects are largely protective and are triggered by binding of adenosine to any of the four adenosine receptor subtypes namely A1, A2a, A2b, A3, which have been cloned in humans, and are expressed in most of the organs. Each is encoded by a separate gene and has different functions, although overlapping. For instance, both A1 and A2a receptors play a role in regulating myocardial oxygen consumption and coronary blood flow. It is a proven fact that adenosine plays pivotal role in different physiological functions, such as induction of sleep, neuroprotection and protection against oxidative stress. Until now adenosine was used for certain conditions like paroxysmal supraventricular tachycardia (PSVT) and Wolff Parkinson White (WPW) syndrome. Now there is a growing evidence that adenosine receptors could be promising therapeutic targets in a wide range of conditions including cardiac, pulmonary, immunological and inflammatory disorders. After more than three decades of research in medicinal chemistry, a number of selective agonists and antagonists of adenosine receptors have been discovered and some have been clinically evaluated, although none has yet received regulatory approval. So this review focuses mainly on the newer potential role of adenosine and its receptors in different clinical conditions.     

“异丙酚＋芬太尼”在气管拔管术中的应用研究

目的：探讨“异丙酚＋芬太尼”用予气管拨管术减轻拨管对患者呼吸道，循环干扰的临床意义。方法：60例择期腹腔镜胆囊切除的患者随机分成两组，实验组在拔管前给予异丙酚0.5mg／kg，芬太尼0.75μg／kg静注；对照组按常规方法拨管，观察拨管前，吸引。拨管时及拨管后3、5、10分钟的血压，心率。结果：不同处理方法存在组间差别（P〈0.05），患者的收缩压，舒张压，心率在不同的处理方法下不同拔管时相蜜化的趋势不同（P〈0.01），其中实验组不同拨管时相收缩压，舒张压，心率均较为稳定。结论：在拔管期应甩适量异再酚和芬太尼对于呼吸道，心血管反应的抑制殛拨管期血流动力学的平稳有较好的作用。     

用麻醉方法抢救小儿重症哮喘1例

抢救 1例小儿重症哮喘时 ,使用普通呼吸机效果不佳后 ,改用麻醉呼吸机 ,配合药物治疗达到抢救目的     

The laryngeal mask airway in children

Clinical and fibreoptic assessment of the positioning of the laryngeal mask airway was performed in 100 children. Clinical observation indicated a patent airway in 98% and severe airway obstruction in 2% of cases. Perfect positioning, as judged by fibreoptic laryngoscopy, was found in 49% and the epiglottis was within the mask in 49%. Fibreoptic evidence of partial airway obstruction in 17% was not detected clinically.     

A prospective study of liver function in infants and children exposed to daily isoflurane for several weeks

Eleven infants and children presenting for daily radiotherapy for a period of at least 2 weeks were anaesthetised with isoflurane in 33% oxygen and nitrous oxide. They were unpremedicated and given no other agents to supplement anaesthesia. The average number of exposures was 24 (SD 11; range 10-39) and the total anaesthetic time per exposure varied between 15 and 30 minutes. Liver function was assessed by determining serum total bilirubin, aspartate amino transferase, gamma glutamyl transferase and alkaline phosphatase before the start of treatment and at 5-daily intervals thereafter. There was no measurable change in any of these determinants of liver function. All children accepted daily induction of anaesthesia with isoflurane. Induction, maintenance and recovery from anaesthesia were uncomplicated.     

Papaveretum infusions in infants under 6 months of age

The effectiveness of a continuous low dose papaveretum infusion for the relief of postoperative pain was assessed in 29 infants aged 1-6 months nursed on the infant surgical ward following major abdominal surgery. Trained nursing staff were able to adjust the dosage within prescribed guidelines and satisfactory analgesia was obtained with a regimen which delivered up to 0.0375 mg/kg/hour, approximately half the dose recommended in children older than 12 months. There was one case of clinically significant respiratory depression.     

Drawover anaesthetic systems

The factors that determine the inspired oxygen concentration delivered by drawover anaesthetic systems were studied in the laboratory and in anaesthetised patients. The inspired oxygen concentration is dependent upon oxygen flow, reservoir volume and total ventilation; respiratory rate and inspiration:expiration ratio have a small influence. A reservoir of at least of 1 m corrugated tube (internal volume 415 ml) makes optimal use of a 4 litres/minute oxygen flow. Delivery of a safe inspired oxygen concentration can be ensured with economical oxygen flows.     

Anaesthetic considerations for endovascular abdominal aortic aneurysm repair (EVAR)

Over the previous decade, the management of vascular disease has changed considerably. Abdominal aortic aneurysm can now be definitively treated by means of endovascular stenting. Though significant short- and long-term morbidity has been reported, this less invasive procedure is increasing in popularity and has been championed by some as an alternative option for high-risk patients who might otherwise be offered conservative management. We review the perioperative management of endovascular abdominal aortic aneurysm repair (EVAR) and cover the issues pertinent to anaesthetists.