STRICTLY CLINICAL Rapid Response

Malignant This potentially lethal condition calls for quick action. By Veronica Y. Amos, PhD, CRNA, PHCNS-BC

NATE MARTIN*, an 8-year-old boy, is admitted MH treatment. Andrew starts a second I.V. as for a full-mouth dental restoration under gen- Meg prepares by diluting the pow- eral . His parents report no family der with sterile water. Andrew administers history of anesthesia or surgical issues. Nate dantrolene 2.5 mg/kg. was given 20 minutes before the ABGs and serum levels reveal hy- procedure to reduce anxiety. perkalemia and , which are treated with Nate receives general anesthesia by induc- gluconate, glucose-insulin, and bicar- tion with a volatile inhalation agent (sevoflu- bonate. Meg inserts a urinary catheter and in- rane) and . Andrew, the CRNA, creases the normal saline infusion to 75 mL/hour starts an I.V. of normal saline. Before intuba- to maintain Nate’s urine output at >1 mL/kg/hr. tion, Andrew administers 25 mcg I.V. Within 30 minutes, his ETCO2 decreases to 39 and 80 mg I.V. mmHg and his HR drops to 90 bpm. Andrew maintains Nate’s anesthesia on Nate is transferred to the ICU where he’s , with a 2.5 minimal alveolar con- monitored for and disseminat- centration and oxygen 0.5 L/min. Meg, the OR ed intravascular coagulation. He recovers nurse, applies a lower-body warmer unit at quickly and is discharged home on day 4 with 100.4°F (38°C) and administers acetamino- an order for a follow-up - phen 250 mg rectally for postoperative pain. contracture test, used to diagnose MH. As the dentist begins the procedure, Nate’s vital signs are normal: BP 100/63 mmHg, HR Education 88 bpm, ETCO2 43 mm/Hg, blood oxygen MH is a genetic life-threatening disease of the 100% by pulse oximeter, and temperature musculoskeletal system. A on the 98.4° F (36.9° C) via skin probe. results in uncontrolled re- lease of calcium, triggering a hypermetabolic Clinical assessment state. Almost all MH oc- Approximately 45 minutes into the surgery, cur only after exposure to volatile Nate’s ETCO2 rises to 60 mm/Hg, his HR in- agents or succinylcholine. MH can occur any- creases to 106 bpm, and the dentist notes mas- time during general anesthesia or during the seter muscle stiffness. Despite Andrew’s efforts first 12 hours after the procedure. to decrease Nate’s ETCO2, his HR increases to MH signs and symptoms include , 120 bpm and his ETCO2 increases to 66 mm/Hg. , increased body temperature, and Nate’s breath sounds are clear bilaterally. An- muscle rigidity. The definitive treatment for MH drew suspects malignant hyperthermia (MH) is dantrolene to inhibit further calcium release. and alerts the team to activate the MH protocol. The discharge nurse tells Nate’s family they must alert providers to their son’s MH before Clinical management any procedure that requires anesthesia. She The dentist stops the surgery, and Meg brings also refers them to the Malignant Hyperther- the MH cart into the OR. Nate’s temperature is mia Association of the United States for infor- 102.9° (39.4°C), so Meg switches the lower mation and enrollment in the MH registry. AN body warmer unit to a cooling mode and ap- plies ice packs to his groin and axilla. Andrew *Names are fictitious. Access references at myamericannurse.com/?p=74251. discontinues sevoflurane and flushes the anes- thesia circuit with hyperventilation of 100% Veronica Y. Amos, PhD, is assistant director of the nurse anesthesia oxygen. He starts a propofol infusion to main- program and an assistant professor at the University of Maryland tain general anesthesia while Nate receives School of Nursing in Baltimore.

12 American Nurse Journal Volume 16, Number 5 MyAmericanNurse.com