MH FAQ1
Q: Are MHS Patients candidates for outpatient surgery?
A: MHS patients can safely undergo outpatient surgery using non-triggering anesthetics and may be discharged on the day of surgery if the anesthetic has been uneventful. A minimum period of 1.0 hour in PACU monitoring vital signs at least every 15 minutes and one hour and one-half hours in phase 2 PACU/step down is recommended.
Q: How often should my facility conduct mock MH drills?
A: One or more times each year, and for new staff. "Malignant Hyperthermia” (MH) is something that most facilities believe they are prepared for as long as they have a supply of IV dantrolene available as Dantrium® IV or dantrolene sodium for injection, and a protocol for managing MH. But this preparation is worth little if the entire staff does not know what their role is in handling an MH event.
"Do you know the early signs of MH? Do you have 36 vials of Dantrium® IV or dantrolene sodium for injection available on hand? Do you know what solution should be used for mixing? These are some of the questions that need to be answered in order for a team to be prepared to get a patient through an MH event.
Q: How do I get an emergency therapy poster?
A: The “Emergency Therapy for Malignant Hyperthermia” crisis protocol poster is available from the Malignant Hyperthermia Association of the United States. The laminated protocol poster addresses diagnosis versus associated problems, signs of MH, acute phase treatment, and post acute phase treatment. To order call: (800) 986-4287 or go to the MHAUS website at: www.mhaus.org.
Q: Who should stock Dantrium® IV or dantrolene sodium for injection and how much?
A: All facilities, including ambulatory surgery centers and offices, where MH triggering anesthetics (isoflurane, desflurane, enflurane, sevoflurane, methoxyflurane, halothane and succinylcholine) are administered. These facilities should stock a minimum of 36 vials along with the other drugs and devices necessary to treat an MH reaction. If none of these agents are ever in used in the facility, then IV dantrolene need not be kept on hand.
Q: How much Dantrium® IV or dantrolene sodium for injection should be stocked?
A: If any potent volatile agents are used, a full supply of Dantrium® IV or dantrolene sodium for injection, 36 vials, should be available on site. If potent volatile agents are not used, and succinylcholine is available for resuscitation, a minimum of 36 vials of Dantrium® IV or dantrolene sodium for injection should still be available. If neither potent volatile agents nor succinylcholine are used or available, IV dantrolene does not need to be present.
Q: Why is it recommended that we stock a minimum of 36 vials of Dantrium® IV or dantrolene sodium for injection, rather than 12 or 24?
A: To treat an MH episode, an initial dose of dantrolene at 2.5 mg/kg is recommended, with a suggested upper limit of 10 mg/kg. If a patient of average weight (approximately 70 kg) were to require dantrolene at the upper dosing limit, then at least 700 mg of dantrolene would be needed.
In addition, a review of cases has shown that in a “worse case” scenario of a very large person (i.e., about 100-110 kg or 220–250 pounds) having an acute MH incident, as much as 8-10 mg/kg will be needed for treatment; higher doses may be required on rare occasions. Thirty-six (36) vials of dantrolene will allow for initial stabilization and treatment while more vials are being acquired to continue treatment, as needed.
Q: Must we stock 36 vials of Dantrium® IV or dantrolene sodium for injection if our OR is very close to a fully equipped hospital and the patient could be transported there quickly?
A: Yes, a stock of 36 vials is recommended. The patient experiencing an MH episode must be stabilized before being transported. Stabilization of an MH episode may take 30 minutes or more with multiple doses of Dantrium® IV or dantrolene sodium for injection because, in some cases, MH progresses with explosive rapidity. The full 36 vials of Dantrium® IV or dantrolene sodium for injection should be available within five minutes of the diagnosis of MH.
Q: Where should Dantrium® IV or dantrolene sodium for injection is kept?
A: It should be kept in or very close to the operating room, so that it is available immediately if MH occurs. Dantrium® IV or dantrolene sodium for injection may be stored at room temperature. A supply of sterile water for injection USP (without a bacteriostatic agent) should be kept nearby to mix with Dantrium® IV or dantrolene sodium for injection before injection (60 ml/vial); the water for diluting IV dantrolene should not be stored in a refrigerator; it may be stored in a warming cabinet designed to maintain fluid temperatures between 35-39° C. All anesthesia and surgical team members should be aware of this location.
Q: How do I supply a surgicenter for an MH emergency?
A: A surgicenter in which general anesthesia is administered should be equipped to manage MH. Dantrium® IV or dantrolene sodium for injection (36 vials), sterile water, other drugs and equipment, and a protocol to treat an MH crisis should be available. The drugs and supplies should be assembled in an MH kit or cart (refer to MHAUS brochure “Drugs, Equipment and Dantrolene – Managing MH” for complete details). Surgicenters that propose to use succinylcholine as an emergency agent should also have 36 vials of Dantrium® IV or dantrolene sodium for injection available and an appropriate MH crisis protocol in place. Responsibility for treatment rests with the facility where the surgery is performed. Sharing is not a good alternative due to the limited time to react to an MH crisis.
Q: Are there any advantages in sharing a supply of Dantrium® IV or dantrolene sodium for injection?
A: No. Minutes count in an MH emergency. The Professional Advisory Council of MHAUS strongly recommends that an adequate supply of Dantrium® IV or dantrolene sodium for injection be available wherever general anesthesia is administered. Responsibility for treatment rests with the facility where the surgery is performed. Sharing is not a good alternative.
1 Author: Malignant Hyperthermia Association of the United States