Effects of epidural dexmedetomidine and low-volume bupivacaine on postoperative analgesia after total knee replacement

Abstract EN

Background Postoperative pain after total knee arthroplasty is a major interest.

Epidural analgesia is considered the preferable method of postoperative analgesia for total knee arthroplasty in many countries.

Dexmedetomidine is an a-2 agonist, which has many beneficial effects when administered epidurally.

Purpose The aim of the study was to provide effective postoperative analgesia with hemodynamic stability through reduction in the amount of local anesthetic administered epidurally using dexmedetomidine as an adjuvant to epidural bupivacaine.

Patients and methods A total of 50 patients who were 40–60 years of age, had ASA physical status I–III, and who were undergoing elective total knee arthroplasty were randomly divided into two equal groups: group D received 2.5 ml of a mixture of bupivacaine 0.125% and dexmedetomidine 0.2 μg/kg/h and group B received only 0.125% bupivacaine 5 ml/h for postoperative analgesia.

Postoperative pain was scored by visual analogue scale; sedation score and cardiorespiratory parameters were recorded every 6 h for 48 h postoperatively.

Data were recorded and statistically analyzed.

Results The demographic data were comparable in both groups.

Visual analogue scale of pain showed a significant reduction between the two groups at both rest and movement, and the total dose of nalbuphine consumption during the study period was significantly reduced (P < 0.002) in group D (5 ± 5.15) than in group B (11 ± 7.63).

Sedation scores were significantly higher in group D compared with group B.

Heart rate was significantly reduced in group D from 18 h postoperative until the end of the study, and the mean arterial blood pressure was significantly reduced in group B than in group D throughout the study period.

Conclusion Dexmedetomidine is an ideal adjuvant to epidural bupivacaine for postoperative analgesia in patients undergoing total knee arthroplasty.