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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malignant hyperthermia is now recognized as a distinct entity in anesthetic practice and can be considered as a pharmacogenetic disease of obscure etiology occuring in man and pigs with a dominant inheritance. A close association with myopathy has been noted. Commonly used muscle relaxants or anesthetic drugs can act as triggering agents in genetically susceptible patients, who develop a real hypermetabolic state, characterized by a rapid rise in body temperature, muscular rigidity, tachycardia and tachypnoea, cyanosis and severe respiratory and metabolic acidosis, the lethality being about 60%. Other clinical, biochemical and histopathological features of this condition are described. The prevention and early diagnosis of this syndrome is very important. Therefore, it is necessary in the preanesthetic evaluation, to obtain information from the patient, with regard to previous anesthetic experiences, and to have a more exact anamnesis in patients with muscular diseases or with other members of the family under suspicion. Some screening methods are described. The prognosis of malignant hyperthermia depends on an early diagnosis. Although the incidence is, fortunately, small, this condition is sufficiently significant and acute in nature to require that anesthesiologist be aware of its clinical pathophysiology and prepared to recognize and treat it promptly. Therefore body temperature should be controlled continuously in all anesthetized patients, particularly in the younger age group and especially in those in which symptoms of muscle rigor have been observed particularly after application of succinylcholine and halothane. A regime of treatment is suggested, based on current concepts of the pathogenesis. It consists in establishing effective and rapid cooling, reversal of tissue hypoxia and correction of respiratory and metabolic acidosis and hyperkalemia. Specific therapy with dantrolene sodium may prove to be an answer to this serious problem.
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PMID:Malignant hyperthermia. 70 24

Malignant hyperthermia is a rare but severe complication of modern anesthesia, induced by halothane and succinylcholine. The syndrome is characterized by a rapid sustained and extreme rise in body temperature associated with muscular rigidity, tachycardia, tachypnoea and cyanosis. The lethality is about 60%. The present paper describes the histological, histochemical and electron microscopical findings performed on muscle biopsies of 3 patients with malignant hyperthermia (1 patient died) and a so called risk patient. In all patients morphological findings consistent with a pre-existent myopathy were found. Histologically there were acute necrotic muscular fibers as well as in types I and II, variations in the fiber diameter and centralization of the nuclei. In two cases even fibers that had a normal aspect in HE slides, showed a pathologic pattern after phosphorylase reaction. In addition to acute rhabdomyolysis, electron-microscopic investigations revealed cystic expansion of the cisterns of the sarcoplasmic reticulum with a peculiar proliferation of the sarcolemma. In a degenerating mitochondrium, a crystalline inclusion was identified. These findings support the pathogenetic concept of Britt and coworkers of a functional defect in the calcium release or binding mechanism of sarcoplasmic reticulum. Since it is known that malignant hyperthermia has a familial predilection, it seems very important that clinical, biochemical, and morphological investigations be performed such as CPK estimations and muscular biopsies not only of the patients but also of the relatives in order to rule out this type of latent myopathy.
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PMID:[Histological, histochemical, and ultrastructural findings in malignant hyperthermia (author's transl)]. 80 99

Two cases of malignant hyperthermia with different clinical courses are reported. The patients showed the classical signs of malignant hyperthermia consisting of tachycardia, tachypnoea, ocasional peripheral cyanosis, high body temperature as well as characteristic rise in serum enzymes. In one of the patients the symptoms were recognized early during the operation. The immediate commencement of therapy with ice-cooled. Ringer-Lactate-Solution, Procainmedication, Corticoids as well as physical body cooling favourably influenced the clinical course and the patient survived. In both cases the patients underwent succinylcholine and halothane anaesthesia, but the symptoms of the second patient appeared after the reduction of anaesthesia. In spite of vigorous therapy the hyperpyrexia resulted in heart arrest and death. Morphologically, both patients showed signs of preexistent myopathy with volumetric alterations of the muscle fibres, centralisation of the nuclei and acute muscle fibre necrosis. On the basis of the observed variable course, the various symptom complexes reported in the literature to data are reviewed. A detailed discussion of the "carrier problem" and the available treatment possibilities is also made. Realising that malignant hyperthermia is an inheritable disease, prophylactic measures such as, f.i. the issue of medical certificates to the patient and his relatives are suggested.
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PMID:[Report on 2 cases of malignant hyperthermia with different clinical courses]. 96 90

A moderate malignant hyperthermia developed in a Labrador Retriever anaesthetized with isoflurane for a femoral shaft fracture repair. Signs of malignant hyperthermia included progressive increases in PETCO2 and rectal temperature up to 39.8 degrees C, tachycardia, cyanosis, and elevated serum levels of potassium, inorganic phosphorus, AST, CK and alkaline phosphatase. Treatment initiated in the early recovery period consisted of hyperventilation with 100% oxygen, stomach lavage with iced water, body surface cooling, and intravenous administration of cold isotonic saline solution. Cooling was continued until the rectal temperature had dropped to 37.3 degrees C. After treatment the dog recovered uneventfully. Clinical signs, pathophysiology, therapy, prevention of malignant hyperthermia and its association with other disorders are discussed.
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PMID:[Malignant hyperthermia as a complication of anesthesia in the dog]. 144 May 99

In pigs, the serotonin-2 (5-HT2) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), 0.8 mg/kg, induced "psychotic" behaviour (e.g., grimacing, backward locomotion, blank stare) and a muscular syndrome, which is known as malignant hyperthermia (MH) in pigs and humans. This syndrome is characterized by generalized skeletal muscle rigidity, leading to an increase in body temperature, marked acidosis, hyperkaliaemia, cyanosis and elevation of lactate, carbon dioxide and the muscle enzyme creatine kinase (CK) in plasma. In pigs which were selectively bred for susceptibility to MH induction by known triggering agents, such as halothane, the administration of DOI was fatal in 3 out of 5 animals. In genetically susceptible pigs, MH was also induced by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), 0.5-1.8 mg/kg, and D-lysergic acid diethylamide (LSD), 60-110 micrograms/kg. Furthermore, 5-MeO-DMT and LSD induced head shakes in the animals, which had not been observed after DOI and could not be blocked by 5-HT2-antagonists, ketanserin (0.5-5 mg/kg) and ritanserin (1-2.5 mg/kg). The psychotomimetic effects of 5-MeO-DMT could be blocked by ketanserin or ritanserin, which, depending on the dose, also reduced or totally prevented the hyperthermia and metabolic changes induced by 5-MeO-DMT in pigs. Administration of 5-MeO-DMT, 1.8 mg/kg, was fatal in 4 of 5 MH-susceptible pigs, whereas pigs injected with this dosage after pretreatment with ketanserin (0.5-5 mg/kg) or ritanserin (1-2.5 mg/kg) did not die. In pigs from MH-resistant littermates, administration of 5-MeO-DMT was not fatal. Comparison of metabolic changes in susceptible and non-susceptible pigs suggested that the marked increase in plasma potassium, which arises principally from damaged muscle cells, is primarily responsible for the fatal effect of DOI and 5-MeO-DMT in genetically susceptible individuals. In MH-susceptible pigs, which were anesthetized, relaxed and artificially ventilated, 5-MeO-DMT did not induce hyperthermia, thus substantiating that the marked hyperthermia observed in conscious pigs was a result of muscle activation and not due to effects on thermoregulation or blood pressure. The results indicate that hallucinogenic drugs with 5-HT2 agonistic effects trigger a life-threatening syndrome, MH, in genetically susceptible pigs. 5-HT2 antagonists, such as ketanserin or ritanserin, are capable of counteracting the fatality of this syndrome.
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PMID:Pharmacodynamic effects of serotonin (5-HT) receptor ligands in pigs: stimulation of 5-HT2 receptors induces malignant hyperthermia. 211 35

The anaesthetic records of 61 patients who had experienced adverse reactions thought to be malignant hyperthermia (MH) were reviewed retrospectively to evaluate the diagnostic importance of clinical symptoms. Using the in vitro contracture test, 38 (62%) patients were identified as MH susceptible (MHS), the remainder showing normal test results (MHN). Generalized rigidity, ventricular arrhythmias, cyanosis and postoperative myoglobinuria were observed significantly more often in MHS patients. Median values of body temperature and creatine kinase serum concentrations were significantly greater in the MHS group. Masseter spasm and sinus tachycardia were as common in MHS as in MHN individuals. Statistical models using generalized rigidity, ventricular arrhythmias, cyanosis and fever exceeding 38 degrees C for prediction of MH showed a maximum sensitivity and specificity of 78% and thus are not acceptable for clinical use. For definitive diagnosis of MH, the well established in vitro contracture test remains essential.
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PMID:Prediction of malignant hyperthermia susceptibility: statistical evaluation of clinical signs. 233 13

This is the first report of a case of malignant hyperthermia (MH) from Saudi Arabia. MH was probably triggered by response to Halothane. The diagnosis was suspected by the clinical signs of tachycardia, severe rigidity, cyanosis and rising temperature. The case was successfully managed by vigorous cooling, dantrolene sodium and diuresis.
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PMID:Malignant hyperthermia in a Saudi child. 299 70

Investigation of malignant hyperthermia (MH) was started in 1975; by March 1986, 79 suspected cases had been reported. In vitro contracture tests were performed in 66 probands or their parents; in 61 of these (92%), MH was confirmed and 5 (8%) proved negative. In 4 lethal crises, the parents refused biopsy, but because of well-documented clinical histories these were also included as confirmed MH reactions. We were able to analyse 65 cases of documented MH, and 9 patients are still to be investigated. About 18% of all Austrian hospitals (29 of 158) had reported 1-14 MH reactions (mean 2.7/hospital); it must therefore be assumed that a high number of crises are either not detected or not reported, and the total incidence of MH cannot be estimated. In our hospital (the University Hospital of Vienna), the incidence was 1:23,600 (including children and adults), whereas in Bludenz (Vorarlberg), the incidence was as low as 1:1,300 (in children only). This might partly be explained by genetic factors (such as inbreeding); we identified 3 families, all from Vorarlberg (which is a small, secluded mountain area), in which both parents were carriers of the MH trait. Fulminant crises (of which three times as many were rigid as were non-rigid) accounted for 58%, and masseter spasm for 26%, of all MH reactions. There was a significant influence of sex (72% males) and age (71% less than 20 years) on incidence. Neuromuscular symptoms or other signs reported to be associated with MH were found in only 5 patients (8%). During crises, cardiac symptoms (81%) and cyanosis (71%) were frequently observed; rigidity (45%) and body temperature above 39 degrees C (27%) showed remarkably low incidences. The overall mortality was 17% (11 of 65); it was significantly increased if the maximum temperature exceeded 39 degrees C, after acute surgery or anaesthesia lasting greater than 60 min, and in patients aged over 20 y. Most crises required no specific therapy; dantrolene was administered to only 10 patients. In the future, earlier detection via better monitoring, improved documentation, and mandatory reporting of suspected MH reactions should allow a more detailed description of MH and could further decrease the mortality associated with this condition.
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PMID:[Malignant hyperthermia in Austria. I. Epidemiology and clinical aspects]. 354 44

Malignant hyperthermia is one of the most devastating crises encountered in anaesthesia and it frequently occurs unexpectedly. Although malignant hyperthermia develops in young individuals (mean age approximately 22 years), older people can also be affected. The case of a 41-year-old woman with a history of several previously uneventful general anaesthetics is described. She developed the complete symptomatology of malignant hyperthermia triggered by halothane anaesthesia, with tachycardia, cardiac arrhythmia, cyanosis, combined respiratory and metabolic acidosis and hyperpyrexia. Because treatment with dantrolene and hyperventilation with 100% O2 was started immediately, the symptoms of malignant hyperthermia were stopped within a short time. It should always be remembered, that the life threatening crises which can be caused by malignant hyperthermia can occur at any age and even after several uneventful anaesthetics.
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PMID:[Malignant hyperthermia in a 41-year-old woman]. 371 38

A 51-year-old male patient with no history of musculo-skeletal or myopathic abnormalities, but suffering from manic-depressive psychosis, attempted suicide with an overdose of dolpersin hydrochloride (Mydocalm), dipenzepine hydrochloride (Noveril), meprobamate (Mepronox) and nitrazepam (Mogadon). He developed high fever, muscle rigidity, tachycardia, arrhythmias, hypotension and mottled cyanosis, symptoms well-known in persons with malignant hyperthermia, an autosomally inherited disease of skeletal muscle. There is also discussed the manifestation and the symptoms of an acute rhabdomyolysis. The diagnosis was confirmed by chemical pathological laboratory findings, including respiratory and metabolic acidosis, myoglobinaemia accompanied by myoglobin diuresis, and elevated creatine phosphokinase (CPK values up to 2790 U/l). Electron microscopic examination of muscle tissue revealed signs of myolysis and mitochondrial reactions with pleoconic hyperplasia. No inhalation anaesthetics or skeletal muscle relaxants, such as succinyl choline, were used in this case. Therefore, malignant hyperthermia might have been induced by a combination of drugs which were not known to induce this abnormal muscular reaction. However, the muscle relaxant effect of dolpersin hydrochloride may have acted as a possible inducer of the attack.
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PMID:[Possible malignant hyperthermia as reaction to an overdose of myotonolytic, antidepressive and sedative drugs (author's transl)]. 611 87


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