ABSTRACT
Background and Aims: Propofol is the drug of choice for sedation in daycare procedures due to its pharmacokinetic properties. Propofol delivery using target-controlled infusion (TCI) pump reduces adverse effects like hypotension and apnoea. In this study, we estimated the median effective effect-site concentration of propofol in patients undergoing dilatation and curettage. Methods: Patients of the American Society of Anesthesiologists physical status class I-III, aged 40-70 years, undergoing elective dilatation and curettage were recruited for the study. All patients received 1 µg/kg fentanyl and 20 mg lignocaine. The first patient received an effect-site concentration of propofol at 4 µg/mL with TCI Schneider pharmacokinetic model. Failure was defined as patient movement at any time during the procedure. According to the 'BiasedCoin Design' up-and-down sequential method, the response of the previous patient determined the effect-site concentration of propofol of the next patient. The study was terminated once forty patients completed the procedures successfully. Probit analysis was used to determine EC50. Results: Fifty-three patients were recruited for the study. The various effect-site concentrations of propofol EC50, EC90, and EC95 in providing sedation for dilatation and curettage were 3.38 µg/mL, 4.29 µg/mL, and 4.60 µg/mL, respectively. The incidence of hypotension and apnoea were comparable among the various concentrations of propofol. The mean duration of the propofol infusion was 20 ± 2.86 min. The time to recovery from propofol sedation was 6.97 ± 1.76 min. Conclusion: A median effective effect-site concentration of 3.38 µg/mL of propofol is required to prevent patient movement during uterine dilatation and curettage.
ABSTRACT
BACKGROUND: The quality and duration of analgesia is improved when a local anesthetic is combined with alpha 2 adrenergic agonist. Though, the effects of clonidine on local anesthetics have been extensively studied, there are limited studies demonstrating the effects of epidural dexmedetomidine on local anesthetics. The aim of our study is to compare the effect of clonidine and dexmedetomidine when used as an adjuvant to epidural ropivacaine in lower abdominal and lower limb surgeries. MATERIALS AND METHODS: Patients were randomized into two groups-group ropivacaine with clonidine (RC) received 15 ml of 0.75% ropivacaine with 1 µg/kg clonidine and group ropivacaine with dexmedetomidine (RD) received 15 ml of 0.75% ropivacaine with 1 µg/kg dexmedetomidine epidurally. Onset of sensory analgesia using cold swab, onset of motor blockade using Bromage scale, time to 2 dermatome regression of sensory level, time to first demand for analgesia, sedation using Ramsay sedation scale, intra operative hemodynamic parameters and complications were assessed. RESULTS: The onset (RD-8.53 ± 1.81, RC-11.93 ± 1.96) and duration of sensory blockade (RD-316 ± 31.5, RC-281 ± 37, sedation were found to be significantly better in the dexmedetomidine group. No significant difference was found in terms of onset of motor blockade and hemodynamic changes. CONCLUSION: Dexmedetomidine at doses of 1 µg/kg is an effective adjuvant to ropivacaine for epidural anesthesia, which is comparable to clonidine.