Osteogenesis imperfecta and malignant hyperthermia

We describe a patient with osteogenesis imperfecta who developed tachycardia, metabolic and respiratory acidosis (pH 7.14, PCO2 8.4 kPa, BE -8.5 mmol.l-1) and hyperthermia up to 40 degrees C during anaesthesia with barbiturates, fentanyl, pancuronium, and nitrous oxide. Malignant hyperthermia was suspected and the patient treated accordingly. Two years later the in-vitro contracture test for malignant hyperthermia was completely normal. We conclude that hypermetabolism in patients with osteogenesis imperfecta is due to unknown mechanisms other than malignant hyperthermia.