Malignant Hyperthermia: Is your OR really ready?

by Sherry Poulos, MSN, RNC-NIC, CNL

Preparation for high risk, low frequency events is imperative to safe, quality care and positive outcomes for patients receiving volatile anesthetic agents.

Malignant Hyperthermia (MH) is just one of these events that may occur without warning in susceptible individuals receiving certain triggering anesthetics. According to the Malignant Hyperthermia Association of the United States (MHAUS),¹ approximately one in 2,000 people have a genetic predisposition that puts them at risk of developing MH. 

What is it, exactly? 

MH is a genetic disorder of skeletal muscle calcium regulation. It is linked to the ryanodine receptor and is triggered by certain volatile agents, such as inhaled general anesthetics, and, less commonly thought of as a triggering agent, succinylcholine chloride injections. This triggering of the skeletal muscles can lead to hypermetabolism, skeletal muscle damage, hyperthermia, and even death, if left untreated.²

While the exact incidence of the disorder is unknown, it is estimated to occur in one in 100,000 administered anesthetics, although this may be an underestimate due to unrecognized, mild, or atypical reactions.³ Approximately 700 suspected cases of MH occur in the United States each year.⁴ While data vary, the fatality rate for untreated MH is approximated in the range of 90% and is believed to be about 80% without medication intervention and supportive therapy only. While the mortality rate decline of six to ten percent has been seen in patients who received supportive care, medication administration, and diagnostic testing,³ the morbidity rate is still high at 34.8%.⁵ The high risk associated with MH makes it imperative for organizations to prepare their staff with the knowledge, skills, competencies, equipment, and resources to immediately recognize and respond to MH emergencies and ensure optimal patient outcomes.  

Recognizing and Managing a Malignant Hyperthermia Event

The complications risk increased 1.6 times for every 30 minutes treatment with dantrolene was delayed from the first sign of MH, and 100% of patients experienced complications when the time from first sign of MH to dantrolene treatment was 50 minutes or longer.³ So how does an OR team prepare? 

PLAN

1. Assess risk by identifying all locations within a facility that is using anesthetic triggering agents for MH. Although triggering anesthetics are frequently used in general operating rooms, other patient care areas with potential for MH events to occur include obstetrics operating rooms, post-anesthesia care units (PACU), intensive care units (ICU), medical-surgical floors, postpartum units, emergency departments and other patient care areas that utilize succinylcholine chloride injections for intubation or recovery of patients after surgery.
2. Establish policies and procedures that are evidence-based and follow national standards of practice. The organization’s policies must address early identification of clinical deterioration, management of malignant hyperthermia, and create MH kits or require supplies and equipment on emergency carts for an MH emergency.
3. Follow national standards of practice and recommendations for the quantity of Dantrolene to have immediately available. Plan storage locations quickly accessible to where triggering agents may be used. 
4. Provide quick-reference resources and charts for the management of an MH crisis, medication dosing guides, and phone numbers to national organizations such as MHAUS, and post the resources in conspicuous spaces so they are easily accessible for staff use. 
5. Conduct pre-admission and pre-anesthesia patient risk assessments. Be aware that it is possible for MH susceptible adults and children to have previously received an anesthetic triggering agent without suffering a reaction or development of MH.

TRAIN and TEST

1. Conduct initial and annual training on early recognition and management of MH with an emphasis on competency assessment and multidisciplinary, hands-on training and simulation exercises for all providers and staff who may be required to respond to an MH crisis.

1. • If the supply of Dantrolene is shared between departments, perform simulations to evaluate the process and timing of medication retrieval and delivery to the location of the MH emergency.

1. Record, review, and trend all safety events related to MH and act on learning gleaned from reviews such as process or workflow changes and increased education.

AUDIT AND EVALUATE

1. Routinely audit emergency carts and/or MH kits to verify expiration dates and security of required supplies and medications.

The result? A state of constant readiness! 

With malignant hyperthermia, speed is of the essence. Organizational leadership must make MH preparedness a priority to protect patients from the devastating outcomes that can result from an MH crisis. Providers and staff must be trained to quickly recognize and competently manage an MH event. This includes knowing what supplies, equipment, and medications are needed, and how to access, prepare, and administer them efficiently and without delay. From an accreditation perspective, demonstrated MH preparedness is part of your patients’ right to receive care in a safe setting. 

Sherry Poulos is senior standards interpretation specialist for ACHC acute care and critical access hospitals. Before joining ACHC, she worked as a simulation education specialist and has over 20 years of experience as a staff nurse, clinical coordinator, NICU navigator, and NICU educator. 

References

¹ Malignant Hyperthermia Association of the United States. (2023, June 12). Frequently asked questions. Retrieved June 12, 2023 from https://www.mhaus.org/

² Watt, S, McAllister, R.K. Malignant Hyperthermia. 2023 NIH https://www.ncbi.nlm.nih.gov/books/NBK430828/

³ Rosenbaum, H. & Rosenberg, H. (2023, May). Malignant hyperthermia: Diagnosis and management of acute crisis. UpToDate. https://www.uptodate.com/contents/malignant-hyperthermia-diagnosis-and-management-of-acute-crisis

⁴ Chapin, J. (2020, July 24). Malignant hyperthermia clinical presentation. Medscape. https://emedicine.medscape.com/article/2231150-clinical

⁵ Min, J., Hong, S., Kim, S. & Chung, M. (2021, September 29). Delayed-onset malignant hyperthermia in the postanesthetic care unit: a case report. Journal of International Medical Research, 49(9), 1-10.   http://dx.doi.org/10.1177/03000605211044201