From the Guidelines
Malignant hyperthermia requires immediate treatment with dantrolene sodium as the primary intervention, with an initial dose of 2-3 mg/kg IV, as recommended by the most recent guidelines 1. The treatment of malignant hyperthermia involves a multi-faceted approach, including:
- Discontinuing all triggering agents, particularly halogenated anesthetics and succinylcholine
- Administering dantrolene sodium, with a recommended initial dose of 2-3 mg/kg IV, and repeating as needed until symptoms resolve, up to a cumulative dose of 10 mg/kg 1
- Implementing active body cooling measures, such as cold IV fluids, ice packs to major vessels, and cooling blankets
- Hyperventilating with 100% oxygen to mitigate respiratory acidosis
- Monitoring core temperature, end-tidal CO2, electrolytes, creatine kinase, coagulation studies, and urine output
- Treating secondary effects, such as metabolic acidosis, hyperkalemia, and dysrhythmias, as needed
The criteria for stopping administration of dantrolene include a PaCO2 < 6 kPa with normal minute ventilation and a decreasing core body temperature 1. It is also essential to continue dantrolene 1 mg/kg IV every 4-6 hours for 24-48 hours to prevent recurrence, as the hypermetabolic features of malignant hyperthermia may recur within the first 24 hours after initial resolution 1. The availability of dantrolene is crucial, and it should be readily available wherever volatile anaesthetic agents are used, as well as at all locations where succinylcholine is used routinely, except in the pre-hospital emergency setting 1.
From the FDA Drug Label
The administration of intravenous dantrolene sodium to human volunteers is associated with loss of grip strength and weakness in the legs, as well as subjective CNS complaints In the anesthetic-induced malignant hyperthermia syndrome, evidence points to an intrinsic abnormality of skeletal muscle tissue. It is hypothesized that addition of dantrolene sodium to the "triggered" malignant hyperthermic muscle cell reestablishes a normal level of ionized calcium in the myoplasm. The efficacy of intravenous dantrolene in the treatment of human and porcine malignant hyperthermia crisis, when considered along with prophylactic experiments in malignant hyperthermia susceptible swine, lends support to prophylactic use of oral or intravenous dantrolene in malignant hyperthermia susceptible humans Clinical experience has shown that early vital sign and/or blood gas changes characteristic of malignant hyperthermia may appear during or after anesthesia and surgery despite the prophylactic use of dantrolene and adherence to currently accepted patient management practices These signs are compatible with attenuated malignant hyperthermia and respond to the administration of additional intravenous dantrolene
The treatment for malignant hyperthermia (MH) is intravenous dantrolene 2.
- Dantrolene works by reestablishing a normal level of ionized calcium in the myoplasm, which helps to reverse or attenuate the metabolic and biochemical changes associated with malignant hyperthermia.
- Intravenous dantrolene should be administered as directed, and vital signs and blood gas changes should be monitored for early signs of malignant hyperthermia.
- Additional intravenous dantrolene may be necessary if signs of malignant hyperthermia appear despite prophylactic use of dantrolene 2.
From the Research
Treatment Overview
The treatment for malignant hyperthermia (MH) involves several key steps, including:
- Discontinuation of the triggering agents, such as volatile inhalational anesthetics and/or succinylcholine 3, 4, 5
- Administration of intravenous dantrolene, initially at a dose of 1 mg/kg 3, 4, 6, 7
- Reduction of the body temperature 3, 4
- Correction of metabolic and respiratory acidosis 4, 5
- Management of complications, such as hyperkalemia and arrhythmias 4, 7
Importance of Early Diagnosis and Treatment
Early diagnosis and sufficient treatment with dantrolene and body temperature reduction are essential to relieve the patient's MH crisis and prevent morbidity and mortality 3, 4, 7. Prompt recognition and treatment are vital to prevent complications and improve patient outcomes.
Dantrolene Administration
Dantrolene is the first-line treatment agent for an MH response, and its administration should be immediate and in sufficient doses 4, 6, 7. The drug should be continued for a short time after the crisis has been resolved 4.
Additional Considerations
Other aspects of treatment include: