Study of Dexmedetomidine as an intrathecal adjuvant to ropivacaine for postoperative analgesia

Background: Knowledge and use of adjuvant drug therapy has rendered neuraxial analgesia more effective in the management of both acute and chronic pain conditions. α-2 adrenergic agonists have both analgesic and sedative properties when used as adjuvant in regional anaesthesia. Aim: To study the effects of intrathecal dexmedetomidine added to ropivacaine for surgeries under spinal anesthesia. Materials and methods: This clinical study was conducted on 50 patients of ASA PS 1 and 2 in the age group of 18 -50 years of either sex posted for elective lower limb orthopaedic and lower abdominal surgeries under spinal anaesthesia after taking informed consent, study done over a period of 12 months. Results: All demographic details are insignificant. Average duration of surgery was 94.4 min ± 34.4 min. 76% (n= 38) of subjects belonged to ASA grade 1 and 34% (n=12) subjects belonged to ASA grade 2. Mean duration for onset of Sensory block was 4.12 minutes (SD: ± 1.69) and the mean duration for onset of motor block was 10.12 minutes (SD: ± 2.89). Pulse rate in all the patients was maintained in normal range during the observation period. Mean pulse rate was 76 ±4.3 beats per min. average mean systolic pressure was 117.7 ± 14.3 mm Hg and diastolic pressure 68.7± 4.6 mmHg. Mean values of SBP and DBP were maintained in the study population. However, when considered individually, Hypotension was observed in 3 patients after SAB (Fall in SBP > 20%). The hypotension was mainly observed after 4 to 6 min after SAB. The mean Ramsay sedation scale was 2.08 with SD 0.27. Side effects observed were mainly hypotension, nausea and shivering. Conclusion: To conclude, 5 microgram dexmedetomidine seems to be an attractive alternative as an adjuvant to spinal ropivacaine in surgical procedures, especially those requiring long time. This combination (ropivacaine and dexmedetomidine) provides very good quality of haemodynamic stability. It has excellent quality of postoperative analgesia with minimal side effects.