Low Dose Intrathecal Clonidine Enhances the Effects of Ropivacaine and Improved the Quality of Recovery after Ambulatory Anorectal Surgery

The aim of this prospective, randomised double-blinded study was to explore the effects of clonidine with ropivacaine in intrathecal anesthesia, concerning the onset and regression of sensory and motor blockade and analgesic effects and improved the quality of recovery after ambulatory anorectal surgery.

We randomly selected 120 patients from the ASA grade I-III; these patients were scheduled for elective anorectal surgery. These patients were randomly select for two groups (n=60 in each group). In the group I: 0.75% ropivacaine (1ml) with isotonic saline and group II 0.75% ropivacaine (1ml) with 30 μg clonidine. An oral 7.5 mg midazolam premedication was given 2 hours preoperatively. Ringer's lactate hydration solution (15ml/kg body weight), a midline spinal puncture was performed at L4/L5 with the patient in the lateral decubitus position using a 26-gauge Quincke spinal needle. We assessed the sensory block with a pinprick, the motor block using the modified Bromage scale, analgesia with the visual analog scale and sedation with the modified Ramsay scale. We also recorded the hemodynamic parameters.

The both groups were demographically similar. The time to two segment S2 regression, and rescue analgesia were significant prolonged in group II as compared to group II (p<0.001). Modified Bromage score was significantly higher in group II (3.92 ± 0.15) as compared to group I (2.32 ± 0.19). Patients of both groups were hemodynamically stable throughout the surgery.

The intrathecal clonidine in combination with ropivacaine prolongs the duration and quality of spinal anesthesia; it also provides longer duration of postoperative analgesia, without side effects.