Jæger Pia, Koscielniak-Nielsen Zbigniew J, Schrøder Henrik M, Mathiesen Ole, Henningsen Maria H, Lund Jørgen, Jenstrup Morten T, Dahl Jørgen B
Department of Anaesthesia, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Department of Orthopaedic Surgery, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
PLoS One. 2014 Nov 11;9(11):e111951. doi: 10.1371/journal.pone.0111951. eCollection 2014.
Revision knee arthroplasty is assumed to be even more painful than primary knee arthroplasty and predominantly performed in chronic pain patients, which challenges postoperative pain treatment. We hypothesized that the adductor canal block, effective for pain relief after primary total knee arthroplasty, may reduce pain during knee flexion (primary endpoint: at 4 h) compared with placebo after revision total knee arthroplasty. Secondary endpoints were pain at rest, morphine consumption and morphine-related side effects.
We included patients scheduled for revision knee arthroplasty in general anesthesia into this blinded, placebo-controlled, randomized trial. Patients were allocated to an adductor canal block via a catheter with either ropivacaine or placebo; bolus of 0.75% ropivacaine/saline, followed by infusion of 0.2% ropivacaine/saline. Clinicaltrials.gov ID: NCT01191593.
We enrolled 36 patients, of which 30 were analyzed. Mean pain scores during knee flexion at 4 h (primary endpoint) were: 52 ± 22 versus 71 ± 25 mm (mean difference 19, 95% CI: 1 to 37, P = 0.04), ropivacaine and placebo group respectively. When calculated as area under the curve (1-8 h/7 h) pain scores were 55 ± 21 versus 69 ± 21 mm during knee flexion (P = 0.11) and 39 ± 18 versus 45 ± 23 mm at rest (P = 0.43), ropivacaine and placebo group respectively. Groups were similar regarding morphine consumption and morphine-related side effects (P > 0.05).
The only statistically significant difference found between groups was in the primary endpoint: pain during knee flexion at 4 h. However, due to a larger than anticipated dropout rate and heterogeneous study population, the study was underpowered.
Clinicaltrials.gov NCT01191593.
翻修膝关节置换术被认为比初次膝关节置换术更痛，且主要在慢性疼痛患者中进行，这对术后疼痛治疗提出了挑战。我们假设，对初次全膝关节置换术后疼痛缓解有效的收肌管阻滞，与翻修全膝关节置换术后使用安慰剂相比，可能会减轻膝关节屈曲时的疼痛（主要终点：4小时时）。次要终点为静息时疼痛、吗啡消耗量及吗啡相关副作用。
我们将计划在全身麻醉下进行翻修膝关节置换术的患者纳入这项双盲、安慰剂对照、随机试验。患者通过导管接受收肌管阻滞，注入罗哌卡因或安慰剂；给予0.75%罗哌卡因/生理盐水推注，随后输注0.2%罗哌卡因/生理盐水。Clinicaltrials.gov标识符：NCT01191593。
我们招募了36例患者，其中30例接受分析。4小时时膝关节屈曲时的平均疼痛评分（主要终点）分别为：罗哌卡因组52±22与安慰剂组71±25毫米（平均差值19，95%可信区间：1至37，P=0.04）。以曲线下面积（1 - 8小时/7小时）计算时，膝关节屈曲时的疼痛评分分别为：罗哌卡因组55±21与安慰剂组69±21毫米（P = 0.11），静息时为39±18与45±23毫米（P = 0.43）。两组在吗啡消耗量及吗啡相关副作用方面相似（P>0.05）。
两组间唯一具有统计学意义的差异在于主要终点：4小时时膝关节屈曲时的疼痛。然而，由于失访率高于预期且研究人群异质性较大，该研究效能不足。
Clinicaltrials.gov NCT01191593。
