Population Pharmacodynamic Modeling of the Sedative and Side Effects of Propofol

Sedation during spinal anesthesia is very useful for patients' comfort. However, intermittent bolus of sedative frequently results in inappropriate sedation which comes with various side effects such as patients' discomfort and apnea. Therefore, it would be reasonable to use target-controlled infusion(TCI) to provide proper sedation without serious side effects. In this study, the investigators try to find the appropriate propofol target concentration with TCI device and build a pharmacodynamic non-linear mixed effect model between propofol target concentration and side effects.