Cerebrospinal fluid and plasma propofol concentration during total intravenous anaesthesia of patients undergoing elective intracranial tumor removal

Objective： The aim of this paper is to compare the propofol concentration in plasma and cerebrospinal fluid （CSF） in patients scheduled for intracranial tumor removal and anaesthetized using propofol as part of a total intravenous anaesthesia technique. Methods： Twenty-seven patients （ASA Ⅰ-Ⅱ） scheduled for elective intracranial tumor removal were studied. Anesthesia was induced with 2 mg/kg propofol for 5 min and infused at 10 mg/（kg·h） for 5 min and then stopped. CSF and arterial blood were collected simultaneously before infusion of propofol and at different time points after infusion ofpropofol according to bispectral index （BIS） values. Concentrations of propofol in plasma and CSF were measured by HPLC with fluorescence detection. The correlation coefficient and regression equation between plasma and CSF concentration of propofol were worked out by linear simple regression. Results： The propofol CSF concentration that we measured was 1.46% of the plasma concentration. The coefficient of relation between plasma and CSF concentration was 76.7%. Conclusions： The propofol CSF concentration was positively correlated with and much lower than the plasma concentration. Discrepancies may result from high plasma protein binding of propofol, intracranial pathology and sampling volume.