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Malignant Hyperthermia. Ri 劉家宏 劉志中. Definition. An uncommon pharmacogenetic disorder of skeletal muscle autonomic dominant inheritance 1:40,000 in adults 1:15,000 in children
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Malignant Hyperthermia Ri 劉家宏 劉志中
Definition • An uncommon pharmacogenetic disorder of skeletal muscle • autonomic dominant inheritance • 1:40,000 in adults • 1:15,000 in children • From Basic of anesthesia 3th edition , Robert K. Stoelting
Background • MH was first described by Dr Michael Denbo-rough in 1960. • Manawatu-Horowhenua Region in New Zealand • In the 1840s when a whaler landed in Wellington • eight generations with at least 1500 family members From www.pnh.org
Background • MH affects other species. • In 1966 a veterinarian submitted an article to the British Medical Journal entitled "Unusual reaction to Suxamethonium, Thiopentone and Halothane" • Mortality rate has reduced from 80% to less than 5% world wide in the last twenty years From www.pnh.org
Aetiology • The anaesthetic drugs that have been definitely • succinylcholine • all of the anaesthetic gases • halothane, enflurane, isoflurane sevoflurane and desflurane- not nitrous oxide • Central core disease and King denborough syndrome are the only known associated disorders.
Clinical picture • rigidity of the muscles • HR , RR • Temp. 39-40oC ( 46oC.) • From www.faseb.org
Clinical picture • Capnogram • Gradually increasing EtCO2
Pathophysiology An abnormal contraction state of the muscles • From www.mdausa.com
Pathophsiology • An increase in metabolic needs • Muscle cell die and release chemicals into the blood stream • an unstable heart rhythm and cardiac arrest • an inability of the lungs to oxygenate the blood properly • kidney failure requiring dialysis. From Ultrastructural Studies of skeletal muscle of the pig with Malignant Hyperthermia
Differential Diagnosis • Neuroleptic malignant syndrome • For sedation , psychiatric practice and also for nausea and vomiting • Heat-stroke or exercise-induced muscle breakdown
Differential Diagnosis • MDMA(搖頭丸/快樂丸) • 在安全劑量時,其抑制病況強度不佳,故沒有多大的醫學價值 • 害怕、憂鬱或產生妄想之精神病症狀 • 惡性高溫症候群(全身性血液凝結,肌肉崩解,腎衰竭及肝毒性) • 這些症狀會因使用者體力透支而惡化,特別是過度的跳舞及運動後 From www.homepage.renren.com
Diagnosis • Muscle biopsy test • a fascicle of quadriceps muscle • halothane and caffeine • contracture status of the muscle From www.faseb.org
Diagnosis • Biochemical tests • the specificity and sensitivity was unacceptable
Diagnosis • DNA-based tests • the gene encoding the formation of the calcium release channel • Ryanodine receptor gene (RYR1) • the chromosomal region 19q13.1 • altered amino acid residues in the skeletal muscle ryanodine receptor • Over 30 mutations have been described affecting <50% of all known susceptible families. From A complex satellite DNA polymorphism fanking the ryanodine receptor gene (RYR1)
Reference • Book • Basic of anesthesia 3th edition , Robert K. Stoelting • Clinical Anesthesia 2nd edition , G. Edward morgan, Jr. Maged , S.Mikhail • Website • www.pnh.org • www.homepage.renren.com • www.oridin.com • www.mdausa.com • www.faseb.org
Reference • Original article • A complex satellite DNA polymorphismflanking the ryanodine receptor gene (RYR1) • Werner Wolz, Ute Wendelmuth, Sylvie Rouquier#, Dominique Giorgi# and Clemens R. M • Ultrastructural Studies of skeletal muscle of the pig with Malignant Hyperthermia • David L. Liu, Stefan Andersson-Engels, Katarina Svanberg, Ingrid Wang, Christian Sturesson, Carl H. Håkansson and Sune Svanberg