Anesth Analg 2003;96:153-158
© 2003 International Anesthesia Research Society
ANESTHETIC PHARMACOLOGY
Extending the Skeletal Muscle Viability Period in the Malignant Hyperthermia Test
Saiid Bina, PhD,
Stephen Holman, MD, and
Sheila M. Muldoon, MD
Department of Anesthesiology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
Address correspondence and reprint requests to Saiid Bina, PhD, Department of Anesthesiology, USUHS, 4301 Jones Bridge Rd., Bethesda, MD 20814. Address e-mail to sbina{at}usuhs.mil
The caffeine halothane contracture test (CHCT) is the only validated test for diagnosing malignant hyperthermia (MH) susceptibility (MHS) and phenotyping MHS families. Although most diagnostic laboratory tests can check intra- and interlaboratory consistency through the use of standard control samples, there has been no practical way to achieve this goal for the CHCT. The distances between diagnostic centers and time constraints of the CHCT protocol (5 h) prohibit centers from sharing tissue samples. In this study, we investigated varying storage conditions to extend the standard viability period of skeletal muscle to 24 h. Twenty MHS patients were tested according to the North America protocol. After standard CHCT, the surplus muscle samples were placed in one of the following four treatment groups. In Groups 1 and 2, muscles remained under tension and were stored in Krebs buffer (pH 7.4) at 23°C–25°C (clamped-warm) and 4°C (clamped-cold), respectively. In Groups 3 and 4, muscle strips were dissected, and the ends were tied with silk sutures, cut from the clamp, and placed in Krebs buffer at 23°C–25°C (free-warm) and 4°C (free-cold), respectively. The responses of the treatment groups to halothane (3%) and caffeine (0.5–32 mM) were tested at 22–26 h after excision. The clamped-warm storage group correctly diagnosed MHS in all patients.
IMPLICATIONS: Varying conditions for storage of muscle were investigated to extend the viability period of muscle in the malignant hyperthermia (MH) test from 5 to 24 h. Muscles stored for 24 h under tension at room temperature remained viable and correctly diagnosed MH susceptibility in all patients.
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