Malignant Hyperthermia (MH) is a life threatening disorder induced in susceptible patients on exposure to certain anesthetic agents. Although relatively uncommon, the incidence of morbidity (incidence of an MH episode) and mortality (the incidence of death from MH) is high if the syndrome is unrecognized. More tragic still is that mortality and disability need not occur if MH is diagnosed early so that proper anesthetic agents can be used that do not trigger the MH Syndrome. Since it is well known that MH susceptibility can be inherited, it is important to diagnose that those family members who may be susceptible to MH in addition to the patient who may be at risk. Additionally, since the anesthesiologists often terminate cases when there are early signs of MH, it is important to determine if the patient truly was undergoing an MH crisis or whether the early signs of MH originated from other complications. 

At this time the only reliable diagnostic test for MH susceptibility is the contracture response of biopsied skeletal muscle to halothane and caffeine. Our laboratory is one of the few in the United States that performs this diagnostic test on a regular basis. Since 1974 we have performed over 1,000 diagnostic tests. Patients are referred to our facility because of our expertise with this test since it involves careful handling, dissection and testing in a rigorous manner.

The testing procedure is well recognized as a valid one for diagnosing susceptibility to MH and has been validated by several laboratories worldwide. Our laboratory strictly follows the guidelines of the North American MH group testing protocol (Anesthesia and Analgesia 69: 511-515, 1989).  There is no satisfactory test that can provide the diagnostic accuracy of the halothane and caffeine test.

Patients may forego the test and presume that they are susceptible if they have had an adverse reaction to anesthesia. However, should surgery be required in the future their options for anesthetic care are limited. It is for this reason as well as the implications for other family members that MH susceptibility in patients should be determined by having a diagnostic biopsy.

Following completion of the biopsy analysis, a letter is sent to the patient and to the referring physician describing the findings of the biopsy and advice for future medical care.

It is for these reasons that the diagnostic biopsy of MH susceptibility is not experimental and does have distinct implications for patient care and future medical treatment for the individual patient and his or her family.

Procedures for Obtaining Human Muscle Biopsies
Patients are selected for diagnostic testing based on suspicion of MH according to communications from referring physicians. A questionnaire is filled out by the patient or his family detailing family history, particularly with regard to muscle disease and reviewed by Dr. Henry Rosenberg.

Muscle biopsies are performed with nerve block anesthesia avoiding infiltration of the muscle with the anesthesia.  In some cases, general anesthesia is called for.  An overnight stay is no longer required unless there are complications. 

Contracture Test Protocol

1. The muscle tested in the quadriceps (vastus lateralis).
2. The muscle is biopsied and immediately placed in Krebs Ringer solutions and transported to the testing laboratory.
3. Fiber bundles are carefully dissected from the biopsy specimen and are mounted so that muscle tension can be monitored.
4. The test is performed at 37°C, and the Krebs Ringer solution bathing the muscle bubbled with carbogen (95% CO₂/5%0₂). Three muscle bundles are exposed to halothane and three caffeine.
5. The muscle tension developed in response to these agents is used for diagnosis.

Cost of the Biopsy

Physician Services
the following are involved in the care of the patient. Surgeon (to perform the biopsy) and an anesthesiologist. The total charge is usually about $1500.

Laboratory
Laboratory tests usually consist of charges for blood work, for pathologic review of the specimen (included in the hospital costs) and in some cases for x-ray and EKG (patients over 40 years).

Most commercial insurance carriers will pay this charge as will some Blue Shield plans.

The total fees for the hospital range from $6000-$7000.