What is the most common sign of malignant hyperthermia?

What is the most common sign of malignant hyperthermia?

• A. Hypotension with bradycardia.
• B. Rapidly rising end-tidal CO2 with tachycardia.
• C. Hypertension with decreased CO2.
• D. Hypoxemia without change in CO2.

Answer: (B)

Rapidly rising end-tidal CO2 with tachycardia is the hallmark early sign. When triggering agents provoke malignant hyperthermia in susceptible individuals, calcium surges in skeletal muscle cause a sudden burst of metabolism. That metabolic explosion produces CO2 faster than it can be expelled by ventilation, so the end-tidal CO2 climbs quickly. The heart rate also increases as part of the body’s response to the rising CO2, acidosis, and heightened metabolic demand. Hyperthermia typically comes later, after the crisis has already begun. Other patterns, like hypertension with decreased CO2 or hypotension with bradycardia, don’t fit the common early picture, and hypoxemia may occur but the CO2 rise is the more reliable early clue. Recognizing this pattern is crucial because immediate steps—halt triggering agents, give 100% oxygen, and administer dantrolene—can prevent progression to severe complications.

Rapidly rising end-tidal CO2 with tachycardia is the hallmark early sign. When triggering agents provoke malignant hyperthermia in susceptible individuals, calcium surges in skeletal muscle cause a sudden burst of metabolism. That metabolic explosion produces CO2 faster than it can be expelled by ventilation, so the end-tidal CO2 climbs quickly. The heart rate also increases as part of the body’s response to the rising CO2, acidosis, and heightened metabolic demand. Hyperthermia typically comes later, after the crisis has already begun. Other patterns, like hypertension with decreased CO2 or hypotension with bradycardia, don’t fit the common early picture, and hypoxemia may occur but the CO2 rise is the more reliable early clue. Recognizing this pattern is crucial because immediate steps—halt triggering agents, give 100% oxygen, and administer dantrolene—can prevent progression to severe complications.