Cerebrospinal fluid concentrations of propofol during target-controlled infusion
- VernacularTitle:靶控输注异丙酚在脑脊液中药物浓度的实验研究
- Author:
Jie YI
;
Ailun LUO
;
Xiangyang GUO
- Publication Type:Journal Article
- Keywords:
Pharmacokinetics;
Propofol;
Cerebrospinal fluid;
Target-controlled infusion
- From:
Chinese Journal of Anesthesiology
1996;0(09):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the relationship between bispectral index (BIS) and cerebrospinal fluid (CSF) concentrations of propofol or effect-site concentrations during target-controlled infusion (TCI) of propofol and evaluate the accuracy of the infusion system targeting at effect-site concentration.Methods Twelve healthy mongrel dogs weighing (17.04? 1.53) kg were anesthetized with intramuscular ketamine 5 mg?kg-1 followed by enflurane inhalation. A catheter was inserted into subarachnoid space and advanced to the base of skull for the collection of CSF. BIS, hemodynamics and PETCO2 were monitored continuously during the experiment. Target effect-site propofol concentration was set at 3 ?g?ml-1 and infusion was continued for 15 min. CSF was collected at 1, 3, 5, 10, 15, 20, 30, 45 and 60 min after infusion was started for determination of propofol concentration by high performance liquid chromatography with fluorescence detection. Results The equilibrium between predicted plasma and effect-site concentration was reached at 10.9 min and the target effect-site concentration was maintained at 3 ?g?ml-1 .The peak CSF concentration of propofol was (0.29? 0.14)?g?ml-1 .CSF concentrations were much lower than the effect-site concentrations at all sampling times (about 18.7% of the effect-site concentration on average) . BIS was consistent with the CSF concentrations of propofol. Both of them reached the lowest or peak values at 5 min after infusion was started, while the peak effect-site concentration was reached relatively later. BIS was found to be better correlated with CSF concentration (? = 0.9195) than with the effect-site concentration (? = 0.554) . The dogs developed hypotension as expected but no other severe adverse effect was observed. Conclusion The inconsistency of BIS with effect-site concentration during TCI of propofol may result from its pharmacokinetic parameters. Good correlation between BIS and CSF concentration indicates that CSF concentration can reflect the pharmacokinetic profileof propofol at effect-site more accurately than the plasma concentration during TCI of propofol targeting at effect-site concentration.
