In malignant hyperthermia, which sign typically appears earlier than fever and is considered an early indicator?

In malignant hyperthermia, which sign typically appears earlier than fever and is considered an early indicator?

• A. Fever
• B. Rising end-tidal CO2
• C. Hypertension
• D. Rhabdomyolysis

Answer: (B)

Malignant hyperthermia is a rapid, deadly hypermetabolic crisis triggered in susceptible individuals by certain anesthetics or muscle relaxants. The early signal comes from the muscles’ explosive Ca2+ release, which drives extremely high metabolic activity and CO2 production. Because CO2 is produced so quickly, the capnograph shows a noticeable rise in end-tidal CO2 early in the course, often before any fever develops. Fever tends to appear later as the body’s heat load accumulates from ongoing metabolism. Hypertension and rhabdomyolysis can occur during the crisis but are not as early or as sensitive an indicator as rising end-tidal CO2. Recognizing the early rise in ETCO2 prompts prompt treatment with MH-directed measures, such as dantrolene, and avoidance of triggering agents.

Malignant hyperthermia is a rapid, deadly hypermetabolic crisis triggered in susceptible individuals by certain anesthetics or muscle relaxants. The early signal comes from the muscles’ explosive Ca2+ release, which drives extremely high metabolic activity and CO2 production. Because CO2 is produced so quickly, the capnograph shows a noticeable rise in end-tidal CO2 early in the course, often before any fever develops. Fever tends to appear later as the body’s heat load accumulates from ongoing metabolism. Hypertension and rhabdomyolysis can occur during the crisis but are not as early or as sensitive an indicator as rising end-tidal CO2. Recognizing the early rise in ETCO2 prompts prompt treatment with MH-directed measures, such as dantrolene, and avoidance of triggering agents.