Newswise — PARK RIDGE, ILLINOIS – When general anesthesia is required for surgery or another procedure, a patient’s care team must be ready for anything—especially the rare, life-threatening syndrome known as malignant hyperthermia (MH). During MH Awareness and Training Month (March 2017), the 50,000-member American Association of Nurse Anesthetists (AANA) is reminding anesthesia professionals to be on the alert for MH during cases, and informing potential patients that:

  • Malignant hyperthermia is a rare, inherited syndrome that can affect patients who are receiving general anesthesia for surgery or other procedures. More than 80 genetic defects have been associated with MH. This syndrome can be triggered by certain inhaled general anesthetics or the muscle relaxant succinylcholine. Patients should ask their Certified Registered Nurse Anesthetist (CRNA) or other anesthesia professional if they might be susceptible.
  • The general signs of an MH crisis include increased heart rate, greatly increased body metabolism, muscle rigidity, and/or fever that may exceed 110 degrees F.


  • The onset of MH is rapid, requiring the patient’s care team to recognize that MH is occurring and respond quickly to treat it.
  • The muscle relaxant Dantrolene is currently the only clinically accepted drug treatment for an MH crisis. Patients should ask if the facility where they will be undergoing surgery has Dantrolene available.


  • During the preanesthesia assessment, patients should communicate any known familial history of MH-susceptibility and other anesthetic complications to their CRNA or other anesthesia professional. CRNAs use this information to assess a patient’s risk of experiencing MH.


  • Children of a patient with MH-susceptibility usually have a 50 percent chance of inheriting a gene defect for MH. However, it is important to note that not everyone who has a gene defect linked to MH develops the MH crisis upon exposure to the triggering anesthetics. Patients should know that genetic testing for MH is available.


  • Information is key to understanding the possibility of MH. Patients and healthcare providers can learn more about this rare syndrome at the Malignant Hyperthermia Association of the United States (MHAUS) website. The site includes testing information and helps patients locate MH-prepared facilities. Healthcare providers can also take advantage of AANA resources, including a position statement (Malignant Hyperthermia Crisis Preparedness and Treatment), a template facility policy and more.


The AANA is a partner member of MHAUS.

About the American Association of Nurse Anesthetists Founded in 1931 and located in Park Ridge, Ill., and Washington, D.C., the American Association of Nurse Anesthetists (AANA) is the professional organization representing more than 50,000 Certified Registered Nurse Anesthetists (CRNAs) and student registered nurse anesthetists across the United States. As advanced practice registered nurses and anesthesia specialists, CRNAs administer approximately 43 million anesthetics to patients in the United States each year and are the primary providers of anesthesia care in rural America. In some states, CRNAs are the sole anesthesia professionals in nearly 100 percent of rural hospitals. For more information, visit and and follow @aanawebupdates on Twitter.