Spinal anaesthesia: comparison of plain ropivacaine 5 mg ml(-1) with bupivacaine 5 mg ml(-1) for major orthopaedic surgery.

BACKGROUND: Ropivacaine provides effective spinal anaesthesia for total hip arthroplasty. This study was designed to compare the efficacy and safety of plain ropivacaine with plain bupivacaine for spinal anaesthesia in patients undergoing total hip arthroplasty. METHODS: Sixty-six patients, ASA I or II, were randomized to receive an intrathecal injection of one of two local anaesthetic solutions. Group R (n=32) received 3.5 ml of ropivacaine 5 mg ml(-1) (17.5 mg). Group B (n=34) received 3.5 ml of bupivacaine 5 mg ml(-1) (17.5 mg). The onset and duration of sensory block at dermatome level T10, maximum upper and lower spread of sensory block and the onset, intensity and duration of motor block were recorded, as were safety data. RESULTS: Onset of motor and sensory block was rapid with no significant differences between the two groups. The median time of onset of sensory block at the T10 dermatome was 2 min (range 2-5 min) in Group R and 2 min in Group B (range 2-9 min). The median duration of sensory block at the T10 dermatome was 3.0 h (range 1.5-4.6 h) in Group R and 3.5 h (2.7-5.2 h) in Group B (P<0.0001). The median duration of complete motor block (modified Bromage Scale 3) was significantly shorter in the ropivacaine group compared with the bupivacaine group (2.1 vs 3.9 h, P<0.001). CONCLUSIONS: Intrathecal administration of either 17.5 mg plain ropivacaine or 17.5 mg plain bupivacaine was well tolerated and an adequate block for total hip arthroplasty was achieved in all patients. A more rapid postoperative recovery of sensory and motor function was seen in Group R compared with Group B.

Post-operative analgesia following total knee replacement: an evaluation of the addition of an obturator nerve block to combined femoral and sciatic nerve block.

BACKGROUND: Femoral and sciatic nerve block may not provide complete post-operative analgesia following total knee replacement. This study was designed to evaluate whether the addition of an obturator nerve block to combined femoral and sciatic nerve block improves the quality of post-operative analgesia following primary total knee replacement. METHODS: Sixty patients were randomised into one of two groups: combined femoral and sciatic nerve block with 15 ml 0.75% ropivacaine to each nerve or combined femoral and sciatic nerve block with 15 ml 0.75% ropivacaine to each nerve and an obturator nerve block with 5 ml 0.75% ropivacaine. RESULTS: Peripheral nerve blocks were successful in 85% of patients. The group which received the obturator nerve block showed a significant increase in the time until their first request for analgesia (mean 257.0 vs. 433.6 min) and a significant reduction in the total requirements for morphine throughout the study period (mean 83.8 vs. 63.0 mg) (P<0.05). There were no systemic or neurological sequelae in any of the groups. CONCLUSIONS: The addition of an obturator nerve block to femoral and sciatic blockade improved post-operative analgesia following total knee replacement.

Total knee replacement: a comparison of ropivacaine and bupivacaine in combined femoral and sciatic block.

BACKGROUND: Femoral and sciatic nerve block may improve post-operative analgesia following total knee replacement. OBJECTIVES: To compare the post-operative analgesia following primary total knee replacement provided by spinal anaesthesia alone or in combination with femoral and sciatic nerve block with bupivacaine or ropivacaine. METHODS: Seventy-five patients were randomised into one of three groups: spinal anaesthesia only; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg x kg(-1) bupivacaine 7.5 mg x ml(-1) to each nerve; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg x kg(-1) ropivacaine 7.5 mg x ml(-1) to each nerve. RESULTS: The mean (SD) time to first morphine request was significantly prolonged for both groups receiving combined femoral and sciatic block, 912 (489) min for the bupivacaine group and 781 (394) min for the ropivacaine group (P<0.001) compared with 413 (208) min for the group receiving spinal anaesthesia alone. Morphine consumption was significantly reduced in both groups receiving combined femoral and sciatic block. There were no systemic or neurological sequelae in any of the groups. CONCLUSIONS: Femoral and sciatic blockade following intrathecal bupivacaine/diamorphine provided superior analgesia when compared with intrathecal bupivacaine/diamorphine alone. There were no significant clinical differences between the group receiving bupivacaine 7.5 mg x ml(-1) and the group receiving ropivacaine 7.5 mg x ml(-1).

Intrathecal ropivacaine for total hip arthroplasty: double-blind comparative study with isobaric 7.5 mg ml(-1) and 10 mg ml(-1) solutions.

This study was designed to evaluate the efficacy and safety of two concentrations of intrathecal ropivacaine, 7.5 and 10 mg ml(-1), in patients undergoing total hip arthroplasty. One hundred and four patients, ASA I-III, were randomized to receive an intrathecal injection of one of two concentrations of isobaric ropivacaine. Group 1 (n=51) received 2.5 ml of 7.5 mg ml(-1) ropivacaine (18.75 mg). Group 2 (n=53) received 2.5 ml of 10 mg ml(-1) ropivacaine (25 mg). The onset and offset of sensory block at dermatome level T10, maximum upper and lower spread of sensory block and the onset, intensity and duration of motor block were recorded, as were safety data. Onset of motor and sensory block was rapid with no significant differences between the two groups. The median time of onset of sensory block at the T10 dermatome was 2 min (range 1-25 min) in Group 1 and 2 min (range 1-21 min) in Group 2. The median duration of sensory block at the T10 dermatome was 3.0 h (range 0.5-4.2 h) in Group 1 and 3.4 h (1.1-5.9 h) in Group 2 (P=0.002). The median duration of complete motor block was significantly prolonged (P<0.05) in Group 2 compared with Group 1 (1.9 vs 1.2 h, respectively). Anaesthetic conditions were excellent in all but one patient. Intrathecal ropivacaine, in doses of 18.75 and 25 mg, was well tolerated and provided effective anaesthesia for total hip arthroplasty.