Key Concepts
Overview
Malignant hyperthermia ties high-yield nursing judgment to airway, perfusion, infection control, and safe medication administration. Malignant hyperthermia (MH) is a pharmacogenetic hypermetabolic crisis triggered most characteristically by volatile anesthetics (e.g., sevoflurane, desflurane) and succinylcholine in susceptible patients (RYR1/CACNA1S mutations). Uncontrolled calcium release from the sarcoplasmic reticulum produces sustained muscle rigidity, extreme heat production, hypercapnia, mixed respiratory–metabolic acidosis, hyperkalemia, and rhabdomyolysis—progressing to DIC, acute kidney injury, and cardiac arrest if untreated. Nurses in perioperative and PACU areas must recognize unexpected hyperthermia, masseter muscle rigidity after succinylcholine, unexplained rising ETCO₂ despite minute ventilation increases, tachycardia out of proportion to depth, coagulopathy, and dark urine (myoglobinuria). MH is not simple “fever from infection” in the first minutes; it is a supply-and-demand mismatch with massive oxygen consumption. Definitive treatment is dantrolene (ryanodine receptor antagonist) plus aggressive cooling, hyperventilation to blow off CO₂, treat hyperkalemia, maintain urine output for myoglobin clearance, and discontinue triggering agents while finishing surgery with non-triggering anesthetic if needed. Document timing, serial vitals, labs, and dantrolene doses for medicolegal clarity and family communication. Cross-link US RN lessons hub · [Canada RN...