Effect of adductor-canal-blockade on established, severe post-operative pain after total knee arthroplasty: a randomised study
Acta Anaesthesiologica Scandinavica, 07/27/2012
Jaeger P et al. – This proof–of–concept study shows promising results regarding the analgesic efficacy of adductor–canal–blockade in post–operative pain treatment after total knee arthroplasty (TKA), with a significant reduction in pain during flexion of the knee in the early post–operative period compared with placebo. However, the study was not sufficiently powered to permit final conclusions.Methods
- The authors enrolled patients scheduled for elective TKA into this double–blind, placebo–controlled, randomised study.
- During general anaesthesia, they placed a catheter in the adductor canal, and after obtaining pre–block pain scores 30min post–operatively, they injected 30ml of ropivacaine 0.75% (n=21) or saline (n=20) according to randomisation.
- Forty–two patients were randomised, and 41 were analysed.
- Mean (standard deviation) pain scores during flexion of the knee at 1h post–operatively were 58(22)mm and 67(29)mm, ropivacaine and placebo group, respectively (P=0.23) but was significantly reduced in the ropivacaine group when calculated as area under the curve for the interval 1–6h (P=0.02).
- There were no statistically significant differences regarding pain at rest (P=0.08), morphine consumption (P=0.06), nor morphine–related side effects, apart from nausea (P=0.04).