To ascertain the plasma concentration of propofol to achieve bispectral index-guided sedation using a target-controlled infusion in patients undergoing elective surgeries under neuraxial anaesthesia

Abstract

Background and Aims: Sedation improves patient satisfaction, comfort and acceptance of regional anaesthesia. Propofol using bispectral index (BIS)/target-controlled infusion (TCI) system can be an optimal method of sedation, as it combines objective measurement of sedation using BIS along with maintenance of a steady plasma concentration of propofol with the TCI device. The aim of this study was to ascertain the dose and safety of propofol using BIS/TCI system for sedation in patients undergoing surgeries under neuraxial anaesthesia. Methods: One hundred and seven adult patients, undergoing elective surgical procedures under spinal or combined spinal epidural anaesthesia, were recruited. Propofol infusion was started with TCI at an initial target plasma concentration (Cpt) of 1.2 μg/mL, and after equilibration between Cpt and effect site concentration (Ce), propofol was then adjusted in increments and/or decrements of 0.2 μg/mL in order to maintain a BIS value between 60 and 80. The average time to reach BIS = 80 after starting infusion was 7.32 ± 3.13 minutes. The objective was to calculate mean Cpt value maintaining BIS between 60 and 80 and to observe recovery time and complications. Results: Mean Cpt value was 1.13 ± 0.17 mg/mL with 95% confidence interval (1.10–1.16 μg/mL). In 85% of patients, a BIS value of 60–80 was maintained at Cpt ≤ 1.2 μg/mL. No patient had severe complications requiring stoppage of infusion. Conclusion: Propofol sedation using BIS/TCI system can provide safe and convenient sedation during neuraxial anaesthesia at very low plasma concentration, Cpt ≤ 1.2 μg/mL in majority of patients. There were no periprocedural complications, and recovery was rapid.

Determining the Target Concentration of Propofol for Sedation in Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Target-Controlled Infusion Approach

“…The median recovery time of seven minutes (IQR: 5-10 minutes) and clinical recovery time of seven minutes (IQR: 5-10 minutes) indicate a relatively swift recovery, enhancing the overall efficiency and safety of the sedation protocol. The recovery times align with those of Chhabra et al [ 13 ], who reported a recovery time of 7.39 ± 3.41 minutes while using TCI in patients undergoing surgery under neuraxial block. These findings suggest that the present TCI approach provides effective sedation with rapid onset and recovery, minimizing the duration of patient discomfort and procedural delays.…”

“…The only study that used BIS guidance for titrating the TCI rate is by Chhabra et al, who used it in patients undergoing surgery under neuraxial block. They reported a Cp of 1.13 ± 0.17 µg/ml [ 13 ]. The use of midazolam by Cashion and Treston and neuraxial block by Chhabra et al could have contributed to the lower Cp reported by them as compared to the present study.…”