What is the relation between rhabdomyolysis and severe heat illness?

What is the relation between rhabdomyolysis and severe heat illness?

• A. Rhabdomyolysis occurs only in dehydration, not in heat.
• B. Heat stress can cause skeletal muscle breakdown, releasing CK and myoglobin, risking acute kidney injury and electrolyte disturbances.
• C. Rhabdomyolysis occurs with cold exposure.
• D. Heat stress prevents electrolyte disturbances.

Answer: (B)

Rhabdomyolysis is rapid breakdown of skeletal muscle with release of intracellular contents, especially CK and myoglobin. Severe heat illness creates an environment of extreme heat, dehydration, and sustained exertion that damages muscle fibers, causing them to rupture and spill their contents into the bloodstream. The released myoglobin can clog and injure renal tubules, increasing the risk of acute kidney injury. At the same time, the breakdown dumps intracellular potassium and phosphate into the bloodstream and disrupts calcium handling, leading to potentially serious electrolyte disturbances. Clinically this is why heat stress is linked to muscle breakdown and to kidney problems and electrolyte imbalances. Other statements miss the key point: rhabdomyolysis can occur with heat exposure (not only with dehydration) and cold exposure is not the primary trigger here. Heat stress does not prevent electrolyte disturbances; it can exacerbate them through massive intracellular release.

Rhabdomyolysis is rapid breakdown of skeletal muscle with release of intracellular contents, especially CK and myoglobin. Severe heat illness creates an environment of extreme heat, dehydration, and sustained exertion that damages muscle fibers, causing them to rupture and spill their contents into the bloodstream. The released myoglobin can clog and injure renal tubules, increasing the risk of acute kidney injury. At the same time, the breakdown dumps intracellular potassium and phosphate into the bloodstream and disrupts calcium handling, leading to potentially serious electrolyte disturbances. Clinically this is why heat stress is linked to muscle breakdown and to kidney problems and electrolyte imbalances.

Other statements miss the key point: rhabdomyolysis can occur with heat exposure (not only with dehydration) and cold exposure is not the primary trigger here. Heat stress does not prevent electrolyte disturbances; it can exacerbate them through massive intracellular release.