Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of malignant hyperthermia in a Black boy is presented. He developed this condition during repair of a cleft palate, with halothane as the triggering agent. The importance of the high incidence of malignant hyperthermia in patients with certain musculoskeletal abnormalities is stressed. Despite a cool and well air-conditioned theatre, the patient's temperature was 41 degree C when the condition was suspected. At that stage general muscle rigidity was present. The patient was successfully treated with procainamide, sodium bicarbonate and hydrocortisone; surface cooling (with ice packs) was instituted and the stomach was washed out with ice-cold Ringer's solution. Over a period of 14 days serum creatine phosphokinase values decreased from 630 IU (on the day of the incident) to 12 IU. A muscle biopsy showed variation in muscle fibre size. Electron microscopical studies showed myofibrillar disruption and folding of the basement membrane. A modified version of Denborough's technique was used for the in vitro exposure of muscle strips to halothane and suxamethonium. Isometric contraction was measured and recorded. A severe contraction followed the exposure of muscle strips to halothane, which confirmed the diagnosis.
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PMID:[Malignant hyperthermia in a black child. A case report]. 69 25

Skeletal muscle from malignant hyperthermic (MH) pigs incubated at 37 C in 2.3 mM calcium-Krebs-Ringer solution contracts spontaneously when exposed to halothane. In contrast, halothane did not induce contracture in MH muscle incubated in 2.3 mM calcium-Krebs-Ringer solution at 25 C or in calcium-free Krebs-Ringer's solution at 37 C. Halothane did not induce contracture in normal control muscle in 2.3 mM Krebs-Ringer solution at 25 or 37 C. In the presence of halothane, addition of caffeine produced greater contracture in MH muscle than in normal controls. Halothane-caffeine-induced contractures of MH and control muscles at 25 and 37 C were similar. Elucidation that under certain experimental conditions halothane induces contracture in MH muscle, but not in normal muscle 1) may aid in development of a diagnostic test; 2) establishes further evidence for skeletal muscle as the target tissue for anesthetic-induced MH; 3) suggests that halothane may affect systems that regulate sarcoplasmic calcium concentration below contracture threshold in MH muscle. (Key words: Hyperthermia, malignant; Anesthetics, volatile, halothane; Ions, calcium; Muscle, skeletal, malignant hyperthermia.).
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PMID:Porcine malignant hyperthermia: effects of temperature and extracellular calcium concentration on halothane-induced contracture of susceptible skeletal muscle. 111 84

One hundred and fifty paired extensor long digital muscles were excised from Wistar rats and each muscle was prepared in Krebs-Ringer's solution (K-R solution) then gassed with a mixture of 95% O2-5% CO2. The medium for the control muscles was replaced with K-R solution containing 10(-6) M ryanodine and that for the experimental muscles was replaced with medium containing 10(-6) M ryanodine and local anesthetic (LA) (procaine, tetracaine, benzocaine, lidocaine or bupivacaine at various concentration). Isometric contracture tension was recorded throughout the experiment. The ratios of the maximal contracture tension (C-ratio) and the elapsed time (T-ratio) of the muscles treated with LA compared to those of control muscles were calculated. Tetracaine (0.125-1.0 mM) specifically reduced the C-ratio. Procaine (0.5-1.0 mM) and tetracaine (10-60 microM) increased the T-ratio. Procaine (8-16 mM), benzocaine (4-8 mM), lidocaine (0.5-4 mM) and bupivacaine (0.125-1 mM) reduced the T-ratio. The influences of LAs on ryanodine-induced contracture could be explained in terms of their effects on the Ca(2+)-induced Ca2+ release mechanism, direct Ca2+ efflux from sarcoplasmic reticulum (SR), activity of Ca2+ uptake into SR and ryanodine-receptor binding. The complexity of LA effects on ryanodine-induced contracture will affect the results of ryanodine contracture tests for malignant hyperthermia when the muscle specimen is excised under local anesthesia.
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PMID:[The influences of local anesthetics on ryanodine-induced contracture in rat skeletal muscle]. 774 90

The aim of this investigation was to assess the effect of halothane on the velocity of shortening and lengthening of muscle from normal subjects and from patients with malignant hyperthermia susceptibility. Strips were mounted horizontally at optimal length in normal Krebs-Ringer's solution and mechanical parameters were obtained before and after exposure to 3 vol.% halothane. The maximun shortening velocity at zero load (V(max)) was determined by using Hill's characteristic equation. The contraction and relaxation indices were measured under isotonic and isometric conditions: maximum shortening and lengthening velocities (maxV(c) and maxV(r), respectively); isometric peak twitch tension; peak of the positive (+dP/dt(max)) and negative (-dP/dt(max)) twitch tension derivative; ratio R1=maxV(c)/maxV(r) and ratio R2=(+dP/dt(max))/(-dP/dt(max)). In normal muscle, halothane markedly increased V(max), maxV(c) and peak twitch tension by 30+/-10%, 30+/-5% and 40+/-15%, respectively. The maxV(r) values increased concomitantly with the maxV(c) values, such that no change in the ratio R1 was observed. Both +dP/dt(max) and -dP/dt(max) increased such that the ratio R2 did not vary. In malignant hyperthermia susceptibility muscle, halothane induced a significant decrease in V(max) (-30+/-10%) and maxV(r) (-45+/-15%) without changing maxV(c). The decrease in maxV(r) was greater than that of maxV(c), such that the ratio R1 increased significantly. Peak twitch tension and +dP/dt(max) remained unchanged whereas -dP/dt(max) decreased significantly; the ratio R2 increased by 40+/-10%. These results suggest that halothane alters the contractile properties of malignant hyperthermia susceptibility muscle.
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PMID:Shortening velocity of skeletal muscle from humans with malignant hyperthermia susceptibility: effects of halothane. 1065 53

We hypothesized that IM halothane and caffeine injection increases local lactate concentration dose-dependently in malignant hyperthermia-susceptible (MHS) and nonsusceptible (MHN) pigs and that the hypermetabolic reaction measured by regional distribution of lactate and carbon dioxide is limited to a small muscle volume. Microdialysis probes were placed in the hindlimbs of 7 MHS and 7 MHN pigs and perfused with Ringer's solution. After equilibration, boluses of increasing halothane and caffeine concentrations were injected. For the second hypothesis regarding regional distribution, microdialysis probes were positioned in 7 MHS and 6 MHN pigs at the injection site for halothane and caffeine and at a distance of 10 mm and 25 mm. Lactate was measured in the dialysate by spectrophotometry. In addition, PCO2 was measured in the halothane experiments. Halothane and caffeine increased IM lactate dose-dependently in MHS pigs significantly more than in MHN pigs. Lactate and PCO2 were increased only at the injection site but not at 10 mm and 25 mm distance. MH susceptibility leads to a leftward shift of the dose-response curve for IM lactate after local injection of halothane and caffeine. The increase of lactate and carbon dioxide levels after local MH trigger injection is limited to a small area around the probe.
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PMID:The dose-response relationship and regional distribution of lactate after intramuscular injection of halothane and caffeine in malignant hyperthermia-susceptible pigs. 1642 44

There are several problems in anesthetic management for patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); susceptibility to malignant hyperthermia, metabolic disorders such as lactic acidosis and diabetes, and dysfunction of vital organs such as cardiomyopathy. Here we report an anesthetic management of emergency laparotomy in a 58-year-old woman with MELAS and systemic inflammatory response syndrome (SIRS). Pre-operative examinations revealed lactic acidosis, hyperglycemia, moderate cardiac depression, and slightly decreased renal function. We chose total intravenous anesthesia to avoid risks of malignant hyperthermia. Anesthesia was induced by rapid-sequence fashion and maintained using midazolam, propofol, ketamine, fentanyl and vecuronium. Based on arterial blood gas analyses, we adjusted ventilator settings, restored blood volume using acetated-Ringer's solution and alubumin preparation with transfusion, and administered sodium bicarbonate and catecholamines, to keep adequate oxygen demand/supply balance and improve acid-base balance. We applied a patient warming system to avoid the progression of hypothermia. After the surgery, the patient was transferred to the intensive care unit, and underwent the endotoxin absorption therapy as well as antibiotics therapy for the treatment of SIRS. The post-operative course was almost uneventful. We consider that careful anesthetic management was essential for the uneventful peri-operative course of this patient.
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PMID:[Anesthetic management of emergency total gastrectomy in a patient with mitochondrial encephalomyopathy: a case of gastric perforation accompanied by systemic inflammatory response syndrome]. 2056 Mar 85