| A 25-year-old man admitted with severe upper torso trauma displayed masseter muscle spasm after suxamethonium given during resuscitation. Anaesthesia was initially maintained with intravenous agents during transfer and X-ray angiography. However, during surgery to correct a brachial artery injury, malignant hyperthermia was triggered when isoflurane was given, 2.5 h after the suxamethonium. He responded to treatment, including dantrolene administration. Peak serum and urine myoglobin were 12,947 micrograms.l-1 and 54,571 micrograms.l-1, respectively, while maximum serum creatinine kinase was 17,300 IU. The patient made an uneventful recovery and later proved positive for malignant hyperthermia susceptibility on muscle contracture tests. ( info) |
| We report a case of compartment syndrome complicating malignant hyperthermia (MH) in a previously healthy patient. An intraoperative MH crisis responded to treatment with intravenous dantrolene. The patient subsequently developed a lower limb compartment syndrome which required fasciotomy. Recognition of the link between MH and compartment syndrome helps ensure prompt diagnosis and treatment of this rare complication of MH. ( info) |
| PURPOSE: To discuss the problems encountered when halothane was detected in a presumed 'clean' patient circuit during the 'trigger-free' anesthetic management of a known malignant hyperthermia Susceptible (MHS) patient for routine orthopedic surgery. CLINICAL FEATURES: A 29-yr-old MHS woman had a wrist arthroscopy/exploration/fusion under general anesthesia. During the course of the 'trigger-free' anesthetic the respiratory gas analyser detected end-tidal halothane in the patient circuit. The patient was disconnected from the circuit as attempts to identify the source of the readings were undertaken. After ruling out the presence of halothane by various clinical manoeuvre the patient was reconnected to the circuit without sequelae. CONCLUSION: By exclusion the problem was presumed to be a factitious reading resulting from the respiratory gas analyser incorrectly identifying patient-expired methane as halothane. ( info) |
4/306. Screening of the ryanodine receptor gene in 105 malignant hyperthermia families: novel mutations and concordance with the in vitro contracture test. malignant hyperthermia (MH) in man is an autosomal dominant disorder of skeletal muscle Ca(2 )-regulation. During anesthesia in predisposed individuals, it is triggered by volatile anesthetics and depolarizing muscle relaxants. In >50% of the families, MH susceptibility is linked to the gene encoding the skeletal muscle ryanodine receptor (RYR1), the calcium release channel of the sarcoplasmic reticulum, on chromosome 19q12-13.2. To date, 21 RYR1 mutations have been identified in a number of pedigrees. Four of them are also associated with central core disease (CCD), a congenital myopathy. Screening for these 21 mutations in 105 MH families including 10 CCD families phenotyped by the in vitro contracture test (IVCT) according to the European protocol revealed the following approximate distribution: 9% Arg-614-Cys, 1% Arg-614-Leu, 1% Arg-2163-Cys, 1% Val-2168-Met, 3% Thr-2206-Met and 7% Gly-2434-Arg. In one CCD family, the disease was caused by a recently reported MH mutation, Arg-2454-His. Two novel mutations, Thr-2206-Arg and Arg-2454-Cys were detected, each in a single pedigree. In the 109 individuals of the 25 families with RYR1 mutations cosegregation between genetic result and IVCT was almost perfect, only three genotypes were discordant with the IVCT phenotypes, suggesting a true sensitivity of 98.5% and a specificity of minimally 81.8% for this test. Screening of the transmembraneous region of RYR1 did not yield a new mutation confirming the cytosolic portion of the protein to be of main functional importance for disease pathogenesis. ( info) |
| 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. ( info) |
| malignant hyperthermia is a life-threatening complication of general anesthesia. Its cause is not precisely known but it appears to be related to a genetic defect that allows increased release or decreased reaccumulation of calcium by the sarcoplasmic reticulum whech then results in a hypermetabolic state. As with any unexpected complication when a patient is under general anesthesia, early diagnosis and treatment are essential. The early clinical signs that the surgeon and anesthesiologist shoulc be alert to are unexplained tachycardia, unexplained tachypnea, muscular rigidity, and increased temperature. Therapy should be accurate and immediate. The essentials of therapy are discontinuance of the anesthetic agent; immediate, active, and aggressive cooling; administration of procaine or procaine amide, 1 mg/kg/min until the pulse slows; correction of electrolyte and acid-base imbalances; maintenance of urinary output with furosemide and large volumes of fluids, intravenously; and supportive care. A thorough knowledge of the management of malignant hyperthermia ahd the pathophysiology of the complications that may occur with general anesthesia will allow the oral surgeon to fully meet his obligations to his patients. ( info) |
7/306. Medical treatment of a grossly enlarged adenomyotic uterus with the levonorgestrel-releasing intrauterine system. adenomyosis is an important cause of menorrhagia. Besides hysterectomy, the treatment options for adenomyosis have been limited. Presented here is the successful treatment of adenomyosis in a woman presenting with menorrhagia, dysmenorrhea, and an enlarging uterus, for whom conservative therapy initiated with mefenamic acid was unsatisfactory. The patient had insertion of the levonorgestrel-releasing intrauterine system (LNG-IUS). A marked decrease in uterine size occurred within 12 months of insertion accompanied by resolution of the menorrhagia and dysmenorrhea. Thus, the LNG-IUS is a viable option and represents a real advance in the treatment of adenomyosis. ( info) |
| malignant hyperthermia (MH) is an inherited autosomal dominant pharmacogenetic disorder and is one of the main causes of death subsequent to anaesthesia. Around 50% of affected families are linked to the ryanodine receptor (RYR1) gene. To date, 19 mutations have been identified in the coding region of this gene and appear to be associated with the MH-susceptible phenotype. Here we report the identification by two independent methods of a novel mutation associated with the MH-susceptible phenotype in the RYR1 gene: the 6488G-->C transversion, resulting in the replacement of the Arg2163 with a proline residue. ( info) |
9/306. Suxamethonium-induced rhabdomyolysis in a healthy middle-aged man. A 43-year-old man developed rhabdomyolysis after uvulo- palatopharyngoplasty. After induction with thiopentone and suxamethonium the anesthesia was maintained with halothane. The patient responded to treatment and made an uneventful recovery. In earlier reports of rhabdomyolysis after general anaesthesia with halothane and suxamethonium almost all the patients had malignant hyperthermia (MH) or muscular dystrophy. About 50% of malignant hyperthermia patients carry a mutation in the RYR1 gene. Our patient did not have mutations in the four MH-associated genes tested, but the total amount of different mutations is by now about twenty. Therefore, despite these negative tests rhabdomyolysis may be a sign of subclinical malignant hyperthermia which cannot be ruled out by our investigations. This rare case of rhabdomyolysis in a healthy man suggests careful monitoring of the patient when-ever suxamethonium is used. ( info) |
| malignant hyperthermia continues to be a life-threatening emergency that can occur without warning. With early discharge, this crisis may even occur at home. Perioperative, anesthesia, and Post-anesthesia Care Unit (PACU) nursing staff need to be educated in the signs, symptoms, treatment, and care of a malignant hyperthermia patient. This is a US government work. There are no restrictions on its use. ( info) |