What is the treatment for malignant hyperthermia?

• A. Dantrolene 2.5 mg/kg
• B. Sodium bicarbonate
• C. Epinephrine 1 mg
• D. Cooling blanket only

Answer: (A)

Malignant hyperthermia is a life-threatening reaction in susceptible individuals triggered by certain anesthetics, caused by excessive calcium release in skeletal muscle leading to a hypermetabolic crisis. The treatment that stops this process is dantrolene, which directly counters the pathophysiology by inhibiting the ryanodine receptor and reducing calcium release from the sarcoplasmic reticulum. This decreases sustained muscle contraction, heat production, and the metabolic derangements that follow.

The recommended initial dose is 2.5 mg/kg given IV, and it can be repeated every 5–10 minutes up to a cumulative dose as symptoms respond (often up to about 10 mg/kg or more if needed). After the crisis resolves, ongoing maintenance dosing may be required for 24–48 hours. Along with dantrolene, stop triggering agents, provide 100% oxygen, aggressively cool the patient, and correct metabolic abnormalities (acidosis, hyperkalemia) with appropriate supportive care.

Sodium bicarbonate and cooling measures alone do not address the underlying cause, and epinephrine is not a specific treatment for MH, so they are not sufficient stand-alone therapies.