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Malignant Hyperthermia

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Malignant Hyperthermia

  • See Also
  1. Serotonin Syndrome
  2. Neuroleptic Malignant Sydnrome
  • Definition
  1. Rare, inhalational Anesthetic related rapid rise in Body Temperature, Muscle rigidity, Hypertension and Tachypnea
  • Epidemiology
  1. Rare general Anesthesia complication
  2. Autosomal Dominant inherited defect
  • Causes
  1. Similar to Neuroleptic Malignant Syndrome (due to Antipsychotics)
  2. Anesthetic agents in combination with genetic predisposition
    1. Inhalational Anesthetics
    2. Succinylcholine
  • Pathophysiology
  1. Ryanodine receptor gene (RYR1) defect effects the Calcium release channel in Muscle
  2. Results in an unregulated increase in skeletal Muscle oxidative metabolism
  • Signs
  1. Hyperthermia
  2. Muscle Rigidity
  3. Hypertension
  4. Tachypnea
  • Lab
  • Abnormalities
  1. Metabolic Acidosis
  2. Respiratory Acidosis
  3. Creatinine Phosphokinase (CPK) increased (Rhabdomyolysis)
  4. Serum Creatinine increased
  • Complications
  1. Disseminated Intravascular Coagulation (DIC)
  2. Respiratory Failure
  3. Renal Failure
  4. Cardiovascular Collapse
  5. Rhabdomyolysis
  • Management
  1. Dantrolene (specific treatment of choice)
    1. Adult: 1 to 3 mg/kg IV
    2. Child: 0.5 to 1 mg/kg IV
  2. Supportive measures (especially until Dantrolene available)
    1. Benzodiazepines
    2. Cooling
  • References
  1. (2016) CALS, 14th Ed, 1:126