In vivo quantification of muscle damage in dogs after general anaesthesia with halothane and propofol

Muscle damage in dogs anaesthetised with halothane and propofol was quantified by measurement of the area under the curve of plasma creatine kinase (CK) versus time. Plasma CK remained unchanged during anaesthesia for two and a half and five hours. Following halothane anaesthesia of dogs (resting on one side directly on the surgical table or on cushions, and with or without rotation of the body every 30 minutes), plasma CK was elevated in some animals to 10,000 U/litre by the 12th hour (baseline value < or = 100 u/litre), whereas it remained almost unchanged in other animals. Plasma CK then returned to reference values on day 2 or 3. The mean equivalent of muscle damaged ranged from 0.6 to 0.9 g/kg bodyweight. No muscle damage could be demonstrated in animals anaesthetised with propofol. It is therefore concluded that plasma CK should not be used as a diagnostic aid following halothane anaesthesia because of false positives due to the halothane anaesthesia itself and that propofol is best suited for the investigation of muscle damage due to surgical procedures.