Patient controlled sedation during central neuraxial anesthesia

Background: Patient controlled sedation (PCS) gives liberty to patients to choose the time of sedative administration to attain a desired level of comfort.
Aims: The PCS use was evaluated in patients during surgery under central neuraxial blockade.
Settings and Design: Prospective, cross-sectional, clinical study on consecutive patients in a tertiary care university hospital.
Materials and Methods: PCS technique, using propofol (1%) 2 ml in 2 min was used in 160 adult patients undergoing urologic procedures under central neuraxial block. We observed the time to first PCS activation by patient, duration of surgery, propofol dose, sedation score, hemodynamic stability, patient′s acceptability, and the factors correlating with the PCS use.
Statistical analysis used: Non-parametric two-tailed Pearson′s test, univariate correlation analysis for the factors favoring PCS use followed by multivariate logistic regression analysis amongst correlating factors.
Results: In our cohort, the majority (83%) of the patients activated PCS during surgery under central neuraxial blocks at median time of 30 min and (17%) did not activate PCS. Female patients activated sedation earlier (median 15 min) than male patients (median 30 min). All patients were hemodynamically stable and without significant side effects. Multivariate analysis showed that sedative use significantly ( P < 0.05) correlated with female gender (odds ratio-3.54 [IR-2.64 to 4.73]) and prolonged surgery (>90 min). Majority (91%) of patients rated PCS technique excellent to good.
Conclusions: PCS was very well accepted by patients during central neuraxial block. Propofol regimen (2 ml in 2 min) in PCS was safe, as it caused neither apnea nor significant hypotension.

Keywords
Central neuraxial anesthesia, epidural block, patient controlled sedation, propofol, subarachnoid block