Comparison of clonidine and fentanyl as an adjuvant to intrathecal bupivacaine for spinal anaesthesia and postoperative analgesia in patients undergoing caesarian section

Background Fentanyl and clonidine both prolong sensory and motor block of spinal anaesthesia and duration of postoperative analgesia when used as an adjuvant to intrathecal bupivacaine. Lack of studies that directly compare them regarding their efficacy prompted us to compare both drugs as an adjuvant to intrathecal bupivacaine for spinal anaesthesia and postoperative analgesia in patients undergoing caesarian section.

Methods and Material In a prospective, randomized, study forty parturients between 18 to 35 years of age, of ASA grade I or II, awaiting caesarian section were randomly distributed into two equal groups. Patients were given 2.0 ml of hyperbaric bupivacaine 0.5% with either 60μg of clonidine or 25μg of fentanyl intrathecally. Duration of effective analgesia (primary outcome measure), onset peak and duration of sensory and motor blockade, level of sedation, maternal haemodynamic parameters and foetal parameters (secondary outcome measures)were compared.

Results Both groups were comparable with respect to demographic profile, onset, peak and duration of sensory and motor block and overall haemodynamic stability. Duration of analgesia was significantly higher in bupivacaine with clonidine 60μg group (BC60 group) than in bupivacaine with fentanyl 25μg group (BF25 group). Sedation was more prevalent in BC60 group.

Conclusion Intrathecal addition of 25μg fentanyl to bupivacaine provides good analgesia with less sedation and is a better option when sedation is not desirable. However intrathecal addition of 60μg clonidine to bupivacaine provides longer duration of postoperative analgesia than 25μg of fentanyl and is a preferred option when sedation is acceptable or required.

DOI: http://dx.doi.org/10.4038/slja.v22i1.6158