Postoperative epidural analgesia after total knee arthroplasty with sufentanil 1 microg/ml combined with ropivacaine 0.2%, ropivacaine 0.125%, or levobupivacaine 0.125%: a randomized, double-blind comparison.

BACKGROUND AND OBJECTIVES: Total knee replacement is associated with severe postoperative pain that, if treated insufficiently, interferes with early rehabilitation. The purpose of the present study is to compare the efficacy of ropivacaine (0.2% and 0.125%) and levobupivacaine (0.125%), all in combination with sufentanil 1 microg/mL with regard to postoperative pain relief and absence of motor block in a patient-controlled epidural analgesia setting.

METHODS: The study design was randomized and double-blind. Sixty-three patients scheduled for total knee replacement under combined spinal-epidural anesthesia were randomly allocated to receive ropivacaine 0.2%/sufentanil 1 microg/mL (group 1), ropivacaine 0.125%/sufentanil 1 microg/mL (group 2), or levobupivacaine 0.125%/sufentanil 1 microg/mL (group 3) for postoperative epidural pain relief. Primary endpoints were numerical rating scores for pain and patient satisfaction, motor block scores, time to first demand of the patient-controlled epidural analgesia device and average hourly consumption of local anesthetic and sufentanil.

RESULTS: There were no significant differences between the 3 groups regarding numerical rating scores for pain, patient satisfaction, and motor block scores at any of the time intervals; time to first demand and average hourly sufentanil consumption were similar. Patients in group 1 used significantly more local anesthetic than patients in groups 2 and 3.

CONCLUSIONS: All 3 solutions provided adequate analgesia and minimal motor block. The higher concentration of ropivacaine 0.2% was associated with a higher consumption of local anesthetic and did not result in a decrease in the consumption of sufentanil. Under the conditions of this study, patient-controlled epidural analgesia consumption of the epidural mixture was predominantly determined by sufentanil.