What characterizes malignant hyperthermia?

Malignant hyperthermia is a serious condition often triggered by certain anesthetic agents or muscle relaxants, characterized primarily by a rapid increase in body temperature and elevated end-tidal carbon dioxide (ETCO2) levels. The pathological process begins with a hypermetabolic state in skeletal muscle, leading to increased demand for oxygen and subsequent carbon dioxide production. This metabolic rate increase results in hypercapnia, which is reflected in the raised ETCO2 levels detected during monitoring.

The rapid rise in body temperature occurs due to the metabolic demands placed on muscle cells, as they utilize energy at an accelerated rate, leading to a breakdown of ATP and generating excess heat. This is a critical aspect of malignant hyperthermia, distinguishing it from other conditions that typically present with different symptoms or physiological responses.

In summary, the combination of a rapid rise in body temperature and increased ETCO2 is characteristic of malignant hyperthermia, making this answer the correct choice.