During general anesthesia with sevoflurane after succinylcholine, a client develops a rapidly rising end-tidal CO₂ from 38 to 72 mm Hg despite increased ventilation, generalized muscle rigidity, sinus tachycardia, mixed acidosis, and potassium 6.1 mEq/L. Core temperature is 38.1°C (100.6°F). Complete the bowtie by selecting the condition, two actions the nurse should take, and two parameters the nurse should monitor.

Malignant hyperthermia; stop triggers with 100% oxygen; give IV dantrolene; monitor hypermetabolism and muscle-injury complications.

A rapid unexplained rise in end-tidal carbon dioxide with rigidity, acidosis, hyperkalemia, and tachycardia after sevoflurane and succinylcholine is characteristic of malignant hyperthermia. High fever is not required before treatment.

Triggering agents are stopped immediately, the client is hyperventilated with 100% oxygen, and dantrolene is administered promptly. Cooling or diagnostic confirmation must not delay dantrolene.

Falling end-tidal carbon dioxide, heart rate, and rigidity indicate crisis control. Core temperature, potassium, creatine kinase, urine output, and urine myoglobin detect ongoing hypermetabolism and muscle breakdown.

When a trigger-specific emergency has a definitive antidote, remove the trigger and give the antidote while monitoring both response and life-threatening complications.

Continuing volatile anesthesia, delaying dantrolene for cooling, and using calcium-channel blockers are unsafe. Thyroid tests, INR, and antipyretic response do not show control of malignant hyperthermia.

• Malignant hyperthermia — A life-threatening hypermetabolic skeletal-muscle reaction triggered by susceptible anesthetic agents.
• Dantrolene — The specific treatment used promptly to control a malignant-hyperthermia crisis.