Certified Nurses Operating Room (CNOR) Practice Exam

What is the primary rescue medication used for malignant hyperthermia?

1. Sodium bicarbonate

2. Dantrolene

3. Lidocaine

4. Calcium gluconate

The correct answer is: Dantrolene

The primary rescue medication used for malignant hyperthermia is dantrolene. This medication directly acts on the skeletal muscle to decrease calcium release from the sarcoplasmic reticulum, which effectively reduces the hypermetabolic state that occurs during a malignant hyperthermia crisis. Malignant hyperthermia is a rare but serious reaction to certain anesthesia drugs, leading to a rapid increase in metabolic rate, hypercapnia, acidosis, tachycardia, and elevated body temperature. Dantrolene's mechanism of action is crucial because it targets the underlying pathophysiology of malignant hyperthermia by mitigating the release of calcium ions that cause sustained muscle contraction and increased metabolic activity. Timely administration of dantrolene can be life-saving, which is why it is classified as the first-line treatment during a malignant hyperthermia episode. In contrast, sodium bicarbonate is often used to treat metabolic acidosis that may arise from excessive lactic acid production during such events, but it does not address the core problem of the condition. Lidocaine is primarily used as an antiarrhythmic agent and is not indicated for treating the cause of malignant hyperthermia. Calcium gluconate may be administered in cases of hypocalcemia