FALSE-NEGATIVE RESULTS WITH MUSCLE CAFFEINE HALOTHANE CONTRACTURE TESTING FOR MALIGNANT HYPERTHERMIA

Background: During the period 1985-1991, 350 muscle contracture studies have been performed in the authors' laboratory, and during this period, they became aware of an occasional false-negative result. The findings pertaining to the four cases so classified are presented in detail. Methods: In 1985 the protocol for the muscle strip caffeine halothane testing procedure adopted was that of the European Malignant Hyperthermia Society. Results: Thirty-six percent of the cases tested susceptible for malignant hyperthermia, 15% tested equivocal in that they responded either to halothane or to caffeine singularly, and 49% gave a normal response. In this tatter group, the authors believe they identified four false-negative results. Conclusions: This study documents the rarity of false-negative results and substantiates the reliability of caffeine halothane testing as a biologic test in diagnosing the presence of a potentially serious problem.