Corvetto, Marcia A. MD; Taekman, Jeffrey M. MD
From the Department of Anesthesiology (M.A.C.), Pontificia Universidad Catolica de Chile, Human Simulation and Patient Safety Center and Department of Anesthesiology (M.A.C., J.M.T.), Duke University Medical Center, Durham, NC.
Reprints: Marcia A. Corvetto, M.D., Human Simulation and Patient Safety Center and Department of Anesthesiology, Duke University Medical Center, 4th Floor Purple Zone, Room 4057, Durham, NC 27710 (e-mail: email@example.com).
Case Title: Malignant Hyperthermia
Patient Name: Jose Perez
Scenario Name: Recognizing and treating malignant hyperthermia
Simulation Developers: Marcia Corvetto, M.D., and Jeffrey M. Taekman, M.D.
Simulator: Laerdal Simman
Date of Development: October 2009
Appropriate for following learning groups:
* Residents: Postgraduate years 2, 3, and 4
* Specialties: Anesthesiology
* Nurse Anesthesia Students: 1 and 2
Malignant hyperthermia (MH) is a rare autosomal dominant genetic disease of calcium metabolism.1 Specifically, it is a pharmacogenetic disorder of the skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases, such as halothane, sevoflurane, desflurane, and the depolarizing muscle relaxant succinylcholine.2 The incidence of MH reactions ranges from 1:15,000 anesthetics in children and adolescents and 1:50,000 to 1:150,000 anesthetics in adults.3 Early diagnosis and improved intervention have decreased the reported mortality of MH. In fact, after introduction of Dantrolene, the mortality decreased from 80% in the 1960s to <10% today.4 Although most anesthesiologists will not see a case of MH during their career, it is a disease that we should know how to recognize and treat. Many have used simulation to teach the diagnosis and management of MH.5–8
Accreditation Council for Graduate Medical Education General Competencies:
1. Medical knowledge
* List the triggering agents of MH
* Describe the pathophysiology involved in the development of MH
* List the signs and symptoms associated with MH
* Generate a differential diagnosis of other disorders that should be considered
2. Patient care
* Demonstrate capacity of recognition and treatment of MH
* Demonstrate knowledge of and proper use of Dantrolene
* Demonstrate knowledge of management of MH susceptible patients
3. Practice-based learning and improvement
* Discuss Malignant Hyperthermia Association of the United States (MHAUS) system and how it works
4. Interpersonal and communication skills
* Demonstrate appropriate teamwork and communication (4 and 5)
6. Systems-based practice
* Demonstrate knowledge of MH postprocedural care (intensive care unit)
* Discuss how to counsel the patient and family
* Describe the diagnostic testing options to evaluate MH susceptibility
Guided Study Questions
What drugs are known to trigger MH?
How do triggering agents cause an MH crisis?
What are the signs and symptoms associated with MH?
Is Masseter Muscle Rigidity related to MH?
What should I do to manage an acute MH case?
How much Dantrolene should be used to manage an acute MH case?
How should I counsel the patient and family?
How can a diagnosis of MH be confirmed?
How should the anesthesia machine and the operating room be prepared before surgery for an MH susceptible patient?
Noninvasive blood pressure cuff
Other Equipment Required
60 mL syringes
Setup: 5 minutes
Preparation: 5 minutes
Simulation: 15 minutes
Debrief: 35 minutes
Jose Perez is a 19-year-old man with no significant medical history who suffered a severe fall while mountain biking. The surgical team determined that he has an open left fractured ankle. The plan is to perform an external fixation under general anesthesia.
Background and Briefing Information for Facilitator/Coordinator’s Eyes Only
In this simulation case, the patient is in the operating room, with routine monitoring equipment applied and peripheral venous access initiated. He will receive a general anesthesia, because he rejected regional anesthesia. The induction must be with a rapid sequence intubation, because he has a full stomach. If succinylcoline is used by learners, the patient will develop masseter muscle rigidity during 90 seconds, after which laryngoscopy and intubation are possible. Then, the anesthesia will continue uneventful until the surgery starts. After that, the patient will develop incipient signs of MH progressing into a crisis within the next 10 minutes (Table 1).
The objective of this simulation is to have the learner reflect on the presentation and treatment of MH.
Patient Data Background and Baseline State
Jose Perez is a 19-year-old man who fell while mountain biking. After the fall, he was brought by ambulance to the Emergency Department.
In the Emergency Department, physical examination revealed an open left ankle fracture. X-ray confirmed the fracture of his left ankle. The plan is to perform an external fixation. Hemodynamic and neurologic statuses are stable.
The anesthesiologist’s interview revealed that the patient was a young man with no significant medical history. He had the lunch 2 hours before the fall. He refuses any kind of regional anesthesia for his operative procedure.
Medical history: Occasional tobacco and alcohol.
Surgical history: Knee arthroscopy. No history of anesthetic complications.
Family history: Family history of hyperthyroidism.
Review of Systems
General: Coryza and cough this morning
Current medications and allergies: No known drug allergies.
Vital signs: Temperature 37.9°C; blood pressure, 145/79; heart rate, 115; respiratory rate, 25.
General: Thin male lying in bed with pain. Glasgow 15.
Weight, Height: 70 kg, 175 cm.
Airway: Mallampati Class 1, adequate thyromental distance, mouth opening 3 finger breadths, good dentition.
Lungs: Clear to auscultation bilaterally.
Heart: Regular rhythm.
Laboratory, Radiology, and Other Relevant Studies
Chest x-ray: No cardiopulmonary disease. No ribs fractures.
Cervical x-ray: No fracture or displacement.
1. Pessah IN, Allen P. Malignant hyperthermia. Best Pract Res Clin Anaesthesiol 2001;15:277–288.
2. Rosenberg H, Davis M, James D, Pollock N, Stowell K. Malignant hyperthermia (Review). Orphanet J Rare Dis 2007;2:21.
3. Ali SZ, Taguchi A, Rosenberg H. Malignant hyperthermia. Best Pract Res Clin Anaesthesiol 2003;17:519–533.
4. Krause T, Gerbershagen MU, Fiege M, Weisshorn R. Dantrolene—a review of its pharmacology, therapeutic use and new developments. Anaesthesia 2004;59:364–373.
5. Gaba DM, Howard SK, Flanagan B, Smith BE, Fish KJ, Botney R. Assessment of clinical performance during simulated crises using both technical and behavioral ratings. Anesthesiology 1998;89:8–18.
6. i Gardi T, Christensen UC, Jacobsen J, Jensen PF, Ording H. How do anaesthesiologists treat malignant hyperthermia in a full-scale anaesthesia simulator. Acta Anaesthesiol Scand 2001;45:1032–1035.
7. Berkenstadt H, Yusim Y, Ziv A, Ezri T, Perel A. An assessment of a point-of-care information system for the anesthesia provider in simulated malignant hyperthermia crisis. Anesth Analg 2006;102:530–532.
8. Harrison TK, Manser T, Howard SK, Gaba DM. Use of cognitive aids in a simulated anesthetic crisis. Anesth Analg 2006;103:551–556.
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