Certified Transport Registered Nurse Certification Practice Exam

What is the effect of dantrolene in the context of malignant hyperthermia?

1. It acts as a sedative

2. It reverses muscle paralysis

3. It prevents calcium release from the sarcoplasmic reticulum

4. It induces hyperkalemia

The correct answer is: It prevents calcium release from the sarcoplasmic reticulum

Dantrolene is specifically indicated for the management of malignant hyperthermia, a life-threatening condition often triggered by certain anesthetics or muscle relaxants in susceptible individuals. During malignant hyperthermia, there is an abnormal release of calcium from the sarcoplasmic reticulum in skeletal muscle, leading to sustained muscle contraction, increased metabolism, and, ultimately, a dangerous rise in body temperature. Dantrolene works by inhibiting the release of calcium from the sarcoplasmic reticulum, thereby addressing the underlying pathophysiology of malignant hyperthermia. By preventing excessive calcium release, dantrolene helps to restore normal muscle function, reduce metabolic activity, and lower the elevated temperature. This mechanism makes it a crucial medication in the acute treatment of malignant hyperthermia, effectively countering the physiological disturbances caused by the condition. The other options describe effects that are not aligned with the action of dantrolene in the context of malignant hyperthermia. Sedation is not a property of dantrolene, as its primary function is to interfere with calcium dynamics rather than modulate consciousness. It does not reverse muscle paralysis; rather, its role is to mitigate the hypermetabolic process that can lead to paralysis. Inducing