Malignant hyperthermia is common with: (Repeat)
Ans: B. Succinyl cholineRef: Miller Textbook of Anaesthesia. 6th edExplanation:Malignant HyperthermiaIt is a clinical syndrome observed during GA associated with rapidly increasing temperature of > 1 degree/ 5 minEtiologyIt is due to the abnormality of Ryanodine receptor which is a calcium releasing channel of sarcoplasmic reticulum.The abnormality leads to excessive accumulation of calcium which causes sustained contraction of the muscleRisk FactorsDuchenne Muscular DystrophyArthrogryposis multiplex congenitalOsteogenesis imperfectCongenital strabismusCentral core diseasesHistory of Neuroleptic malignant syndromeMasseter spasm with succinyl cholineCausative AgentsMuscle Relaxants: Succinyl choline - MC drugInhalational agentsHalothane - MC agentIsofluraneDesfluraneEnfluraneSevofluraneMethoxyfluraneLocal Anesthetic: LignocaineOther drugs:Tricyclic antidepressantsMAO inhibitorsPhenothiazinesClinical featuresHyperthermiaHypoxiaCyanosisHyperkalemiaMuscle rigidityTachycardiaHypertensionCardiac ArrhythmiasRenal FailureD1CPulmonary edemaCerebral edemaDeathInvestigationsSevere Metabolic acidosis (pH < 7)Increased end tidal C02Increased CPK levelsIncreased MyoglobinTreatmentStop all anesthetics immediatelyHyperventilation with 100% 02Control Temperature by ice cooling and ice cold salineCorrect acidosis with Sodium bicarbonateCorrect electrolyte imbalance - HyperkalemiaMaintain urine outputSpecific therapyDAXTROLEiXE - 2mg/kg every 5 minutes to a maximum of 10 mg /kg
Local anesthetics
Succinyl choline
Propofol
Barbiturates
Depolarising Neuromuscular Blocking Agents