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Signs and treatment of MH
Knowing the signs of MH is crucial to effective treatment
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Signs may arise at any time during anesthesia or the early postoperative period.1

Malignant Hyperthermia Signs2

Early Metabolic Signs
Early metabolic signs
  • Inappropriately elevated carbon dioxide production
    (manifested as raised end-tidal CO2 on capnography or as tachypnea if the patient is breathing spontaneously)
  • Increased oxygen consumption
  • Mixed metabolic and respiratory acidosis
  • Profuse sweating
  • Mottling of skin
Early cardiovascular signs
Early cardiovascular signs
  • Inappropriate tachycardia
  • Cardiac arrhythmia (especially ectopic ventricular beats and ventricular bigemini)
  • Unstable arterial pressure
Muscle Rigidity
Muscle rigidity
  • Masseter spasm if succinylcholine has been used
  • Generalized muscle rigidity
Later signs of MH
  • Hyperkalemia
  • Rapid increase in core body temperature
  • Grossly elevated blood levels of creatine phosphokinase and myoglobin
  • Dark urine (myoglobinuria)
  • Severe cardiac arrhythmia and cardiac arrest
  • Disseminated intravascular coagulation
Treatment
Treatment should be started as soon as an MH crisis is suspected.2

MH Treatment

Suggested treatment protocol for MH includes
  • Immediate discontinuation of all trigger agents
  • Administration of nontriggering anesthetic if necessary
  • Hyperventilation with 100% oxygen
  • Dantrolene sodium, administered by continuous rapid intravenous push
  • Cooling procedures until body temperature is <38.5°C
  • Dextrose, insulin, calcium chloride, and possibly dialysis for correction of hyperkalemia
  • Hyperventilation and possibly sodium bicarbonate for management of acidosis
  • Antiarrhythmic drug treatment, if necessary
  • Diuretic and fluid therapy to maintain high urinary output

Please see full prescribing information for Revonto.

References:
  1. Rosenberg H, Davis M, James D, et al. Malignant hyperthermia. Orphanet J Rare Dis. 2007;2:21.
  2. Glahn KP, Ellis FR, Halsall PJ, et al. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group. Br J Anaesth. 2010;105(4):417-420.
Indication
Revonto is indicated, along with appropriate supportive measures, for the management of fulminant hypermetabolism of skeletal muscle characteristic of malignant hyperthermia crises in patients of all ages. It is also indicated preoperatively and sometimes postoperatively, to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be malignant hyperthermia susceptible.
Important Safety Information
The use of Revonto in the management of malignant hyperthermia crisis is not a substitute for previously known supportive measures. These measures must be individualized, but it will usually be necessary to discontinue the suspect triggering agents, attend to increased oxygen requirements, manage the metabolic acidosis, institute cooling when necessary, monitor urinary output, and monitor for electrolyte imbalance. Patients who receive i.v. dantrolene sodium preoperatively should have vital signs monitored.
If patients judged malignant hyperthermia susceptible are administered dantrolene sodium preoperatively, anesthetic preparation must still follow a standard malignant hyperthermia susceptible regimen, including the avoidance of known triggering agents. Monitoring for early clinical and metabolic signs of malignant hyperthermia is indicated because attenuation of malignant hyperthermia, rather than prevention, is possible.
Despite initial satisfactory response to i.v. dantrolene there have been reports of fatality, which involve patients who could not be weaned from dantrolene after initial treatment. The administration of i.v. dantrolene is associated with loss of grip strength and weakness in the legs, as well as drowsiness and dizziness. There have been reports of thrombophlebitis following administration of intravenous dantrolene. Tissue necrosis secondary to extravasation has been reported. Injection site reactions (pain, erythema, swelling), commonly due to extravasation, have been reported. Fatal and non-fatal liver disorders of an idiosyncratic or hypersensitivity type may occur with dantrolene sodium therapy.
To report SUSPECTED ADVERSE REACTIONS contact USWM, LLC at 1-888-900-8796 or MEDWATCH at 1-800-FDA-1088 (1-800-332-1088) or https://www.FDA.gov/medwatch.
For additional information, see full prescribing information for Revonto.

 

Open ISI
Indication
Revonto is indicated, along with appropriate supportive measures, for the management of fulminant hypermetabolism of skeletal muscle characteristic of malignant hyperthermia crises in patients of all ages. It is also indicated preoperatively and sometimes postoperatively, to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be malignant hyperthermia susceptible.
Important Safety Information
The use of Revonto in the management of malignant hyperthermia crisis is not a substitute for previously known supportive measures. These measures must be individualized, but it will usually be necessary to discontinue the suspect triggering agents, attend to increased oxygen requirements, manage the metabolic acidosis, institute cooling when necessary, monitor urinary output, and monitor for electrolyte imbalance. Patients who receive i.v. dantrolene sodium preoperatively should have vital signs monitored.
If patients judged malignant hyperthermia susceptible are administered dantrolene sodium preoperatively, anesthetic preparation must still follow a standard malignant hyperthermia susceptible regimen, including the avoidance of known triggering agents. Monitoring for early clinical and metabolic signs of malignant hyperthermia is indicated because attenuation of malignant hyperthermia, rather than prevention, is possible.
Despite initial satisfactory response to i.v. dantrolene there have been reports of fatality, which involve patients who could not be weaned from dantrolene after initial treatment. The administration of i.v. dantrolene is associated with loss of grip strength and weakness in the legs, as well as drowsiness and dizziness. There have been reports of thrombophlebitis following administration of intravenous dantrolene. Tissue necrosis secondary to extravasation has been reported. Injection site reactions (pain, erythema, swelling), commonly due to extravasation, have been reported. Fatal and non-fatal liver disorders of an idiosyncratic or hypersensitivity type may occur with dantrolene sodium therapy.
To report SUSPECTED ADVERSE REACTIONS contact USWM, LLC at 1-888-900-8796 or MEDWATCH at 1-800-FDA-1088 (1-800-332-1088) or https://www.FDA.gov/medwatch.
For additional information, see full prescribing information for Revonto.