From the Guidelines
Dantrolene should be administered immediately upon suspicion of malignant hyperthermia (MH), without waiting for diagnostic confirmation, with an initial dose of 2-2.5 mg/kg IV, repeated as needed until symptoms resolve, up to a maximum of 10 mg/kg, as recommended by the European Malignant Hyperthermia Group guidelines 1. The dosing regimen of dantrolene should be based on actual body weight, and the initial dose should be repeated every 10 min (or as often as possible if administration takes >10 min) until the signs of MH regress, with the criteria for stopping administration being PaCO2 < 6 kPa with normal minute ventilation and a decreasing core body temperature 1. Key considerations in the management of MH include:
- Eliminating trigger drugs
- Implementing MH treatment protocols
- Active body cooling
- Monitoring for recurrent signs of MH
- Treating secondary effects 1 It is essential to have a plan for an initial bolus dose of dantrolene to be available within 5 min of diagnosis of an MH reaction and to mobilize sufficient dantrolene to administer 2-2.5 mg/kg every 10 min until the reaction is controlled, with a typical stock level of 36 vials of dantrolene immediately available 1. Dantrolene should be available at all locations where volatile anaesthetic drugs or succinylcholine are used, with the exception of the pre-hospital emergency setting where it may not be practical to carry dantrolene 1. Prompt administration of dantrolene is critical, as mortality increases significantly with delays in treatment, and the drug's effectiveness diminishes as metabolic derangements progress 1.
From the FDA Drug Label
Dantrolene Sodium for Injection should be administered by continuous rapid intravenous push as soon as the malignant hyperthermia reaction is recognized As soon as the malignant hyperthermia reaction is recognized, all anesthetic agents should be discontinued; the administration of 100% oxygen is recommended Dantrolene Sodium for Injection should be administered by continuous rapid intravenous push beginning at a minimum dose of 1 mg/kg, and continuing until symptoms subside or the maximum cumulative dose of 10 mg/kg has been reached.
Dantrolene should be administered as soon as the malignant hyperthermia reaction is recognized, with signs such as:
- Tachycardia
- Tachypnea
- Central venous desaturation
- Hypercarbia
- Metabolic acidosis
- Skeletal muscle rigidity
- Increased utilization of anesthesia circuit carbon dioxide absorber
- Cyanosis and mottling of the skin
- Fever It can also be given preoperatively to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be malignant hyperthermia susceptible, at a dose of 2.5 mg/kg starting approximately 1-1/4 hours before anticipated anesthesia 2 2.
From the Research
Administration of Dantrolene
Dantrolene should be administered in cases of suspected malignant hyperthermia (MH) as soon as possible, as it is the only approved drug for the treatment of MH 3, 4, 5, 6, 7. The importance of instigating the use of dantrolene in cases of MH cannot be overemphasized, as it has significantly reduced the mortality rate associated with this condition 3, 4, 7.
Indications for Dantrolene Administration
The following are indications for dantrolene administration:
- Suspected malignant hyperthermia, characterized by symptoms such as hyperthermia, tachycardia, tachypnea, increased carbon dioxide production, and muscle rigidity 3, 4, 5, 6
- Family history or previous episodes of malignant hyperthermia, where prophylactic treatment with dantrolene may be necessary 7
- Use of triggering agents such as succinylcholine and volatile anesthetic gases, which can trigger MH in susceptible individuals 3, 4, 5
Timing of Dantrolene Administration
Dantrolene should be administered as soon as possible after the diagnosis of MH is made, as delayed treatment can increase the likelihood of complications and mortality 5, 6. The Malignant Hyperthermia Association of the United States guidelines recommend that dantrolene be available within 10 minutes of the decision to treat MH wherever volatile anesthetics or succinylcholine are administered 5.
Key Points to Consider
- Dantrolene is the only approved drug for the treatment of malignant hyperthermia 3, 4, 5, 6, 7
- Early administration of dantrolene is crucial in reducing the mortality rate associated with MH 3, 4, 5, 7
- Dantrolene should be available wherever general anesthesia is administered, particularly when triggering agents such as succinylcholine and volatile anesthetic gases are used 5