anesthesiamh (MH ** )

Malignant Hyperthermia

• Hotline: 1-800-644-9737
• Signs and symptoms
  1) Increasing EtCO₂
  2) Truncal or total body rigidity
  3) Masseter spasm or trismus with succinylcholine
  4) Tachycardia, tachypnea
  5) Acidosis
  6) Increasing temperature (a late sign)
• Unexpected cardiac arrest in children
  1) Presume elevated potassium and begin treatment
  2) Measure CK, myglobin, ABG’s
  3) Consider dantrolene
  4) Can be due to occult myopathy
  5) Resuscitation long and difficult
• Masseter spasm with succinylcholine?
  1) Can be early sign of malignant hyperthermia
  2) If limbs rigid, start dantrolene
  3) If surgery is emergent, continue with non-triggering agents
  4) Consider dantrolene
  5) ICU for 12 hours
  6) Follow CK and urine myoglobin
• Therapy for malignant hyperthermia
  1) Get help, get dantrolene
  2) Notify surgeon
  3) Discontinue volatile agents and succinylcholine
  4) Give 100% O₂, hyperventilate, 10 liters/minute O₂
  5) Stop the procedure ASAP
  6) Dantrolene 2.5 mg/kg rapidly, repeat until symptoms decrease, can give up to 10 mg/kg, dissolve each vial in 60 ml sterile H₂O (vials contain NaOH and mannitol)
  7) 1-2 meq/kg of sodium bicarb if ABG’s not available
  8) Cool patient with lavage, ice
  9) Standard therapy for dysrhythmias but do NOT use calcium channel blockers
• Therapy for hyperkalemia:
  1) Hyperventilation
  2) Sodium bicarb 1-2 meq/kg
  3) Insulin and glucose
  4) Pediatrics – 0.1 units/kg insulin and 1 ml/kg 50% glucose
  5) Adult – 10 units regular insulin and 50 ml 50% glucose
  6) Calcium — Calcium chloride 10 mg/kg
• Avoid succinylcholine and inhalational agents. Nitrous oxide and local anesthetics are non-triggering agents.