What is recognized as the earliest and most sensitive sign of malignant hyperthermia?

In the context of malignant hyperthermia, increased end-tidal carbon dioxide (ETCO2) is recognized as one of the earliest and most sensitive clinical signs. Malignant hyperthermia is a life-threatening condition that occurs in response to certain anesthetic agents, leading to a hypermetabolic state in muscle cells. As muscle metabolism accelerates, carbon dioxide production increases significantly.

The rise in ETCO2 occurs rapidly following the onset of malignant hyperthermia, often before other symptoms manifest. This makes it a paramount variable for monitoring during anesthesia, as it can provide an early indication of the condition's onset, allowing for prompt intervention. While factors like body temperature and heart rate do change during malignant hyperthermia, their increase typically follows the rise in ETCO2, which is why the latter is given special emphasis as an early sign.

Monitoring ETCO2 effectively contributes to the identification of this potentially fatal reaction, underlining the importance of vigilant anesthetic monitoring in at-risk populations.