Clinical Observation of Bupivacaine Liposome for Lower Extremity Femoral Nerve Block
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 发起方
- 入组人数
- 79
- 试验地点
- 1
- 主要终点
- EC50 and EC95 for femoral nerve sensory block
研究概览
简要总结
This prospective, sequential dose-finding clinical observational study aims to estimate the median effective concentration (EC50) and the 95% effective concentration (EC95) of liposomal bupivacaine for ultrasound-guided femoral nerve block. Sensory and motor block endpoints are evaluated separately at 30 minutes after block placement using a modified up-and-down (sequential allocation) design, with trial termination after eight reversal points.
详细描述
This prospective clinical observational, sequential dose-finding study is designed to determine the effective concentrations of liposomal bupivacaine for ultrasound-guided femoral nerve block in patients undergoing lower limb surgery or related procedures.
All patients receive ultrasound-guided femoral nerve block performed by an experienced anesthesiologist using a standardized technique. A fixed injection volume of liposomal bupivacaine is administered, while the drug concentration is adjusted according to a modified up-and-down sequential method. The concentration for each subsequent participant is determined based on the response of the preceding participant. Following a positive response, the concentration is decreased; following a negative response, the concentration is increased by a pre-specified step size. The study is terminated after eight reversal points (crossovers) are observed.
To independently characterize sensory and motor block dose-response relationships, participants are allocated into two endpoint-specific observation groups:
Sensory block group
Sensory function in the femoral nerve distribution is assessed 30 minutes after block placement using standardized sensory testing. Complete loss of sensation at 30 minutes is defined as a positive response, while preserved sensation is defined as a negative response.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Sequential
- 主要目的
- Health Services Research
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults aged 18 to 85 years
- •Scheduled for elective unilateral lower limb surgery
- •Unilateral ultrasound-guided femoral nerve block clinically indicated as part of routine perioperative anesthesia and analgesia management
- •Ability to clearly distinguish between the blocked (operated) limb and the contralateral (non-blocked) limb for sensory and pain assessments
- •Ability to understand the study procedures and provide written informed consent
- •Ability to cooperate with sensory and motor assessments, including visual analog scale (VAS) scoring and quadriceps muscle strength testing
排除标准
- •Known allergy or hypersensitivity to bupivacaine, amide-type local anesthetics, or any component of liposomal bupivacaine
- •Infection at or near the planned injection site
- •Coagulopathy or clinically significant bleeding disorder, or anticoagulant/antiplatelet therapy incompatible with peripheral nerve block
- •Pre-existing neurological deficits, neuropathy, or motor weakness affecting either lower limb that could interfere with sensory or motor assessments
- •Severe hepatic dysfunction or other conditions that increase the risk of local anesthetic systemic toxicity
- •Pregnancy or breastfeeding
- •Emergency surgery
- •Inability to complete study assessments or comply with study procedures
研究组 & 干预措施
Ultrasound-guided femoral nerve block with liposomal bupivacaine
Participants receive ultrasound-guided femoral nerve block with liposomal bupivacaine administered at varying concentrations using a modified up-and-down sequential dose-finding design. Sensory and motor block responses are assessed 30 minutes after block placement to estimate EC50 and EC95.
干预措施: Liposomal bupivacaine, 266mg (Drug)
结局指标
主要结局
EC50 and EC95 for femoral nerve sensory block
时间窗: 30 minutes after femoral nerve block placement
The median effective concentration (EC50) and the 95% effective concentration (EC95) of liposomal bupivacaine for ultrasound-guided femoral nerve sensory blockade are estimated using a modified up-and-down sequential dose-finding design. Sensory block is assessed 30 minutes after block placement in the femoral nerve distribution on the blocked side, including the anterior thigh (anterior femoral cutaneous nerve territory) and the medial aspect of the lower leg (saphenous nerve territory). Sensory testing is performed using pinprick testing and/or cold stimulation with an ether-soaked cotton swab, with the contralateral non-blocked limb used as an internal control. Sensory block is graded as follows: 0 = no block (sensation identical to the non-blocked limb); 1 = partial block (reduced sensation); 2 = complete block (absence of pain sensation). A positive sensory response is defined as a sensory block score of 2.
EC50 and EC95 for femoral nerve motor block
时间窗: 30 minutes after femoral nerve block placement
The median effective concentration (EC50) and the 95% effective concentration (EC95) of liposomal bupivacaine for ultrasound-guided femoral nerve motor blockade, estimated using a modified up-and-down sequential dose-finding design. Motor function is evaluated immediately by assessing quadriceps muscle strength. Patients are instructed to perform a straight leg raise in the supine position or actively extend the knee. Muscle strength is graded using the Medical Research Council (MRC) scale (0-5). The successful (positive) quadriceps motor block is defined as a decrease of ≥1 grade in the muscle strength of the quadriceps compared with that before the block.
次要结局
- Postoperative Resting pain intensity assessed by VAS(postoperative day 1 and day 2)
- Postoperative pain intensity assessed by VAS(2, 6, 12, 24, and 48 hours postoperatively)
- Postoperative movement-evoked pain assessed by VAS(Postoperative day 1 and day 2)
- Quadriceps muscle strength after surgery(Postoperative day 1 and day 2)
- Length of hospital stay(From the date of surgery until hospital discharge, assessed up to 30 days postoperatively.)
- Time to first ambulation after surgery(From the end of surgery until the first out-of-bed ambulation, assessed up to 72 hours postoperatively.)
- Intraoperative heart rate(From skin incision to the end of surgery, assessed continuously during the intraoperative period.)
- Intraoperative mean arterial pressure(From skin incision to the end of surgery, assessed continuously during the intraoperative period.)
研究者
Xin Chen
Associate researcher
Hainan Medical College