1/3. Suspected recurrence of malignant hyperthermia after post-extubation shivering in the intensive care unit, 18 h after tonsillectomy.A 25-yr-old man, subsequently shown to be malignant hyperthermia (MH) susceptible by in vitro contracture testing, developed MH during anaesthesia for tonsillectomy. Prompt treatment, including dantrolene, led to rapid resolution of the metabolic crisis. Eighteen hours later the patient's trachea was extubated in the ICU, when he had been stable and apyrexial overnight. Twenty minutes after extubation, an episode of shivering was followed by the onset of tachycardia, hypertension, tachypnoea and a rapid increase in temperature. recurrence of MH was suspected and the patient was given another dose of dantrolene with good clinical effect. shivering in this patient may have been an indicator or a causative factor of recurrence of MH.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
2/3. Spinal block, after dantrolene pretreatment, for resection of a thigh muscle herniation in a young malignant hyperthermia susceptible man.We describe a young man who experienced malignant hyperpyrexia, probably triggered by suxamethonium and/or enflurane during his second operation for an epigastric hernia. His malignant hyperthermia susceptibility was later verified using the caffeine/halothane contracture test in vitro. Subsequently, a tumorous mass, consisting of herniated and hypertrophied muscle grew in his thigh, and was resected under spinal anaesthesia. Whereas dantrolene (2.5 mg/kg i.v.) pretreatment produced impaired swallowing, the subsequent high spinal block, in addition, resulted in laboured breathing. It is stressed that respiratory power should be monitored when patients pretreated with dantrolene are given spinal anaesthesia. The muscular symptoms and test results in the patient's relatives are also discussed.- - - - - - - - - - ranking = 2keywords = anaesthesia (Clic here for more details about this article) |
3/3. malignant hyperthermia.A specific inherited muscle membrane disorder predisposes to a variety of clinical problems. The most common is malignant hyperthermia (MH), a dangerous hypermetabolic state after anaesthesia with suxamethonium and/or volatile halogenated anaesthetic agents. MH may also be triggered in susceptible individuals by severe exercise in hot conditions, infections, neuroleptic drugs, and overheating in infants. Inbred pigs have provided a helpful model, and experiments on these animals and in MH-susceptible patients have shown that the essential biochemical abnormality is an increase in calcium ions in the muscle cells. This knowledge has led to a specific muscle test to identify susceptibility to MH and to a specific treatment, dantrolene; and as a result the case-fatality rate in MH has fallen from 70% in the 1970s to 5% today. In pigs susceptibility to MH is caused by a single mutation in the ryanodine receptor (RYR) in skeletal muscle. In man the genetics is more complex and three clinical myopathies that predispose to MH have been defined. By far the most common is inherited as a mendelian dominant characteristic and at present mutations in the human RYR account for no more than 20% of susceptible families.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |