CONCENTRATIONS OF ATRACURIUM AND LAUDANOSINE IN CEREBROSPINAL FLUID AND PLASMA DURING INTRACRANIAL SURGERY

Concentrations of atracurium and laudanosine in cerebrospinalfluid (CSF) and plasma were assayed in nine patients receivingatracurium infusions of 111–251 min duration to maintainneuromuscular block during intracranial surgery. The total doseof atracurium was 1.57–2.60 mg kg^–1 and the plasmaconcentration of atracurium was 1.27–5.44 µg ml^–1.Concentrations of laudanosine in CSF and plasma increased duringthe infusion period, and after 125–140 min reached meansof 202.5 ng ml^–1 and 1448.7 ng ml^–1, respectively.The highest recorded concentration of laudanosine in CSF was570 ng ml^–1, in one of two CSF samples found to containatracurium. After operation, two patients had fits, but thesewere not thought to be related to laudanosine. It is concludedthat during infusion of atracurium, laudanosine accumulatesin both plasma and CSF.