Vilhelmsen Frederik, Nersesjan Mariam, Andersen Jakob Hessel, Danker Jakob Klim, Broeng Leif, Hägi-Pedersen Daniel, Mathiesen Ole, Thybo Kasper Højgaard
Department of Anesthesiology, Naestved Hospital, Naestved, Denmark.
CAR, Department of Anesthesiology, Centre of Anaesthesiological Research -ZealandUniversity Hospital, Koege, Denmark.
BMC Anesthesiol. 2019 Aug 28;19(1):165. doi: 10.1186/s12871-019-0833-4.
Nerve block of the lateral femoral cutaneous nerve (LFCN) is a predominantly sensory block. It reduces pain following total hip arthroplasty (THA), but the non-responder rate is high. We hypothesized, that an increased volume of ropivacaine, would result in greater coverage of incisions used for THA.
We conducted a randomized, blinded trial in 20 healthy volunteers. Participants were randomized to receive bilateral LFCN-blocks with 8 mL ropivacaine 0.75% on the left side and 16 mL ropivacaine 0.75% on the right side, or vice versa. Allocation was blinded to both participants and outcome assessors. Before nerve block performance, incision lines for posterior and lateral THA approaches were depicted with invisible ultraviolet-paint, thereby securing sufficient blinding during outcome assessment. The blocked area was mapped using temperature and mechanical discrimination tests. Quadriceps muscle strength was monitored. Primary outcome was coverage of the posterior incision line assessed by temperature discrimination test.
We found no difference in coverage of the posterior or lateral incision lines when comparing LFCN-blocks with 8 mL versus 16 mL of ropivacaine. The blocked area was significantly larger in the 16 mL group, assessed by both temperature discrimination test (p = 0.012) and mechanical discrimination test (p = 0.034). We observed no difference between groups regarding quadriceps muscle strength (p = 1.0).
A LFCN-block with increased volume of ropivacaine from 8 mL to 16 mL did not result in a greater coverage of posterior or lateral incision lines used for THA, but in a larger blocked sensory area.
Clinicaltrials.gov: NCT03138668 . Registered 3rd of May 2017.
股外侧皮神经（LFCN）阻滞主要是一种感觉阻滞。它可减轻全髋关节置换术（THA）后的疼痛，但无反应率较高。我们推测，增加罗哌卡因的剂量会使THA手术切口的覆盖范围更大。
我们对20名健康志愿者进行了一项随机、双盲试验。参与者被随机分为两组，左侧接受8毫升0.75%罗哌卡因的双侧LFCN阻滞，右侧接受16毫升0.75%罗哌卡因的双侧LFCN阻滞，反之亦然。参与者和结果评估者均处于盲态。在进行神经阻滞之前，用不可见的紫外线涂料描绘THA后侧和外侧入路的切口线，从而在结果评估期间确保充分的盲态。使用温度和机械辨别测试绘制阻滞区域。监测股四头肌力量。主要结果是通过温度辨别测试评估后侧切口线的覆盖范围。
比较8毫升与16毫升罗哌卡因的LFCN阻滞时，我们发现后侧或外侧切口线的覆盖范围没有差异。通过温度辨别测试（p = 0.012）和机械辨别测试（p = 0.034）评估，16毫升组的阻滞区域明显更大。我们观察到两组在股四头肌力量方面没有差异（p = 1.0）。
将罗哌卡因剂量从8毫升增加到16毫升进行LFCN阻滞，并没有使THA后侧或外侧切口线的覆盖范围更大，但使感觉阻滞区域更大。
Clinicaltrials.gov：NCT03138668。2017年5月3日注册。
