False-negative results with muscle caffeine halothane contracture testing for malignant hyperthermia.

Abstract

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. In 1985 the protocol for the muscle strip caffeine halothane testing procedure adopted was that of the European Malignant Hyperthermia Society. 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 latter group, the authors believe they identified four false-negative results. 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.