Atracurium and its antagonism by neostigmine (plus glycopyrrolate) in patients susceptible to malignant hyperthermia.

Forty patients undergoing diagnostic muscle biopsy as part of investigation for malignant hyperthermia (MH) were given atracurium 0.45 +/- 0.10 mg kg-1 for muscle paralysis. The neuromuscular blockade was antagonized with neostigmine 2.4 +/- 0.4 mg given with glycopyrrolate 0.47 +/- 0.09 mg. Rectal, muscle and skin temperatures and blood lactate concentration and venous Pco2 were measured before, during and after anaesthesia. Susceptibility to MH was established by in vitro contracture tests according to the regimen of the European MH Group. Fifteen patients were susceptible to MH (MHS), 19 were MH-negative (MHN) and six were MH-equivocal (MHE). No side effects of the drugs were noted. There were no differences between the three groups of patients in any of the measurements.