Clinical Observation of Bupivacaine Liposome for Lower Extremity Nerve Block

NCT07366905 | Not Yet Recruiting Phase 2

• 2 other identifiers: HUMU2H-DCOEOP-CN-2025No.823RC592
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery; Knee Arthroscopic Surgery

Outcome Measures

Primary Outcomes (2)

• EC50 and EC95 for femoral nerve sensory block

  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.

  30 minutes after femoral nerve block placement

• EC50 and EC95 for femoral nerve motor block

  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 after sensory assessment 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). Motor function preservation is defined as an MRC score ≥4. A positive motor response (motor block) is defined as an MRC score ≤3, indicating clinically significant weakness or paralysis.

  30 minutes after femoral nerve block placement

Secondary Outcomes (7)

• 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.

Other Outcomes (1)

• Adverse events related to femoral nerve block

  From femoral nerve block placement until hospital discharge, assessed up to 30 days postoperatively.

Study Arms (1)

Ultrasound-guided femoral nerve block with liposomal bupivacaine

EXPERIMENTAL

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.

Drug: Liposomal bupivacaine, 266mg

Interventions

Liposomal bupivacaine, 266mg DRUG

Liposomal bupivacaine administered for ultrasound-guided femoral nerve block at varying concentrations using a modified up-and-down sequential dose-finding design.

Ultrasound-guided femoral nerve block with liposomal bupivacaine

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Hainan Medical College: lead
• The Second Affiliated Hospital of Hainan Medical University: collaborator

Study Sites (1)

Department of Anesthesiology,the Second Affiliated Hospital of Hainan Medical University

Haikou, Hainan, China

Location

Central Study Contacts

Dr.chen

CONTACT

+86 17378224751; Dr_chen1699@163.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate researcher

Study Record Dates

• First Submitted: January 8, 2026
• First Posted: January 26, 2026
• Study Start: February 1, 2026
• Primary Completion: March 1, 2026
• Study Completion: March 1, 2026
• Last Updated: January 26, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)