Department of Anesthesiology, University of California San Diego, San Diego, California; Outcomes Research Consortium, Cleveland, Ohio.
Department of Anesthesiology, University of California San Diego, San Diego, California.
Anesthesiology. 2022 Jun 1;136(6):970-982. doi: 10.1097/ALN.0000000000004189.
The common technique using a basal infusion for an ambulatory continuous peripheral nerve blocks frequently results in exhaustion of the local anesthetic reservoir before resolution of surgical pain. This study was designed to improve and prolong analgesia by delaying initiation using an integrated timer and delivering a lower hourly volume of local anesthetic as automated boluses. The hypothesis was that compared with a traditional continuous infusion, ropivacaine administered with automated boluses at a lower dose and 5-h delay would (1) provide at least noninferior analgesia (difference in average pain no greater than 1.7 points) while both techniques were functioning (average pain score day after surgery) and (2) result in a longer duration (dual primary outcomes).
Participants (n = 70) undergoing foot or ankle surgery with a popliteal-sciatic catheter received an injection of ropivacaine 0.5% with epinephrine (20 ml) and then were randomized to receive ropivacaine (0.2%) either as continuous infusion (6 ml/h) initiated before discharge or as automated boluses (8 ml every 2 h) initiated 5 h after discharge using a timer. Both groups could self-deliver supplemental boluses (4 ml, lockout 30 min); participants and outcome assessors were blinded to randomization. All randomized participants were included in the data analysis.
The day after surgery, participants with automated boluses had a median [interquartile range] pain score of 0.0 [0.0 to 3.0] versus 3.0 [1.8 to 4.8] for the continuous infusion group, with an odds ratio of 3.1 (95% CI, 1.23 to 7.84; P = 0.033) adjusting for body mass index. Reservoir exhaustion in the automated boluses group occurred after a median [interquartile range] of 119 h [109 to 125] versus 74 h [57 to 80] for the continuous infusion group (difference of 47 h; 95% CI, 38 to 55; P < 0.001 adjusting for body mass index).
For popliteal-sciatic catheters, replacing a continuous infusion initiated before discharge with automated boluses and a start-delay timer resulted in better analgesia and longer infusion duration.
使用外周神经阻滞持续输注基础配方的常见技术常常导致在手术疼痛缓解之前局部麻醉剂储备耗尽。本研究旨在通过延迟启动、使用集成计时器和作为自动推注给予较低的每小时局部麻醉剂量来改善和延长镇痛。假设与传统连续输注相比，以较低剂量和 5 小时延迟给予自动推注的罗哌卡因（1）在两种技术均起效时（术后第一天平均疼痛评分）提供至少非劣效镇痛（平均疼痛差值不超过 1.7 分），（2）导致更长的持续时间（双重主要结局）。
接受隐神经-坐骨神经导管置入术的足部或踝关节手术患者接受罗哌卡因 0.5%加肾上腺素（20ml）注射，然后随机分为在出院前开始输注罗哌卡因（0.2%），以 6ml/h 输注或在出院后 5 小时开始使用计时器给予自动推注（每 2 小时 8ml）。两组均可自行给予补充推注（4ml，锁定 30 分钟）；参与者和结局评估者均对随机分组不知情。所有随机参与者均纳入数据分析。
术后第一天，接受自动推注的参与者疼痛评分中位数（四分位距）为 0.0（0.0 至 3.0），而连续输注组为 3.0（1.8 至 4.8），比值比为 3.1（95%CI，1.23 至 7.84；P=0.033），校正体重指数后。自动推注组的储液器耗尽中位数（四分位距）为 119 小时[109 至 125]，而连续输注组为 74 小时[57 至 80]（差异 47 小时；95%CI，38 至 55；校正体重指数后 P<0.001）。
对于隐神经-坐骨神经导管，用自动推注和启动延迟计时器代替出院前开始的连续输注可改善镇痛效果并延长输注时间。
