Comparing Clonidine and Fentanyl as Adjuvants to Intrathecal Hyperbaric Ropivacaine in Elective Infraumbilical Surgeries- A Randomised Clinical Study

Abstract

Introduction: Ropivacaine is popular as a safe intrathecal anaesthetic drug due to its higher safety profile over bupivacaine. Intrathecal additives are known to increase the quality of anaesthesia and analgesic duration. Aim: To compare the effects of clonidine and fentanyl as intrathecal adjuvants to hyperbaric ropivacaine in elective infraumbilical surgeries. Materials and Methods: This randomized, double-blinded, clinical study was undertaken at Krishnarajendra hospital and Cheluvamba hospital, attached to Mysore Medical College and Research Institute, Mysuru, Karnataka, India, from January 2018 to June 2018. Total 60 adult patients aged between 18-60 years of age, American Society of Anesthesiologists (ASA) I and II status, and posted for infraumbilical surgeries, were randomized to two groups of 30 patients each i.e., group C patients receiving 2.5 mL of hyperbaric 0.42% ropivacaine and clonidine 15 mcg, and group F patients receiving 2.5 mL of hyperbaric 0.42% ropivacaine and fentanyl 25 mcg. The onset, extent and duration of sensory and motor blockade, heart rate, mean arterial pressure, prolongation of analgesia in the post operative period, and any complications were observed. Statistical analysis was done using student’s t-test, and Chi-square test to test significance of variables. The p-value <0.05 was taken as statistically significant. Results: Demographic characteristics were comparable in both the groups. The onset of sensory blockade and the maximum height of sensory blockade attained were similar in both groups i.e., group C-2.12±0.22 min vs group F-2.24±0.66 min, group C-4.94±0.91 min vs group F-5.12±1.38 min, respectively. The duration of sensory blockade was prolonged in group C (148.5±10.84 min vs 109.37±14.5 min), resulting in delayed demand for analgesic after surgery in this group. The onset of motor block and the complete motor blockade was prolonged in group C patients (3.22±1.01 min vs 1.16±0.3 min, 6.8±1.49 min vs 3.72±1.31min). The recovery from motor blockade was also significantly delayed in Group C (125.17±13.29 min vs 95.47±13.08 min). The incidence of hypotension was similar in both the groups. Conclusion: Clonidine, and fentanyl both provide early and adequate spinal anaesthesia, but the former (clonidine 15 mcg), prolongs the duration of spinal anaesthesia with Ropivacaine 0.42% hyperbaric solution, and significantly increases the time for the demand for analgesia in the recovery period, compared to fentanyl