What condition does an unexplained increase in end-tidal CO2 most reliably indicate?

• A. Acute respiratory distress.
• B. Malignant hyperthermia.
• C. Carbon dioxide poisoning.
• D. Cardiac arrest.

Answer: (B)

An unexplained increase in end-tidal CO2 is most reliably indicative of malignant hyperthermia. This condition is a rare but life-threatening reaction that occurs typically during or after the administration of certain anesthetic agents. In malignant hyperthermia, the body’s metabolism is significantly enhanced, leading to an increased production of carbon dioxide. This occurs due to uncontrolled muscle contractions and a hypermetabolic state, resulting in elevated levels of CO2 in the bloodstream, which is then reflected in the end-tidal CO2 levels.

In the context of malignant hyperthermia, monitoring end-tidal CO2 is crucial, as it provides immediate feedback on the patient’s metabolic status and can help in the timely recognition and treatment of this condition. The increase in end-tidal CO2 serves as a prompt for clinicians to initiate appropriate interventions, including the discontinuation of triggering agents and the administration of dantrolene, the specific antidote for malignant hyperthermia.

Other conditions like acute respiratory distress and cardiac arrest may show changes in end-tidal CO2 levels, but these changes are not typically consistent enough to serve as a reliable indicator of those conditions. Similarly, while carbon dioxide poisoning does reflect elevated CO2 levels, it is usually more associated with other clinical