Malignant hyperthermia is a potentially fatal pharmacogenetic disorder of skeletal muscle calcium regulation. It can occur after exposure to triggering agents such as inhalation anesthetics, stress, or exercise. It is considered a clinical syndrome rather than a single disease.
Malignant hyperthermia is a potentially fatal pharmacogenetic disorder of skeletal muscle calcium regulation. It can occur after exposure to triggering agents such as inhalation anesthetics, stress, or exercise. It is considered a clinical syndrome rather than a single disease.
Clinical signs include sudden and dramatic rise in body temperature, muscle rigidity, tremors, irregular heart beat and kidney failure.
Currently, the gold standard for diagnosis is an in vitro contracture test (IVCT). This is based on muscle fiber contracture in response to triggering agents such as caffeine. IVCT requires a surgical procedure (ie, muscle biopsy), this is only available at specialized testing centers. Genetic screening using DNA analysis is an alternative to the IVCT; it requires only a small blood sample to be sent to an accredited diagnostic laboratory to screen for RYR1 mutation.
Treatment entails administering Dantrolene which is a muscle relaxant that prevents calcium from being released into muscles. Along with ice packs to help cool the body temperature and corticosteroids to provide supportive care. Immersion in ice baths or cold water is not advised because this causes peripheral vasoconstriction, which can lead to further elevation of core body temperature. Applying tepid water to the skin, and using a fan for evaporative cooling is recommended.
Physical therapy for malignant hyperthermia focuses heavily on massage techniques to the contracted tissues. We use ultrasound, heat, shockwave therapy, laser therapy, massage, and stretching to try to loosen these tissues. We also address any secondary pain or swelling that may be associated with the contracture. We then slowly add in strengthening exercises. Exercises are focused on eccentrics, where we stretch the muscle bellies while contracting them. Our goal is to help provide pain control first followed by relaxation to areas of compensation followed by strengthening exercises to help regain overall mobility.
