Patients Eligible for Elective Lower Extremity Femoral Nerve SurgeryPhase 2NCT07366905
Clinical Observation of Bupivacaine Liposome for Lower Extremity Nerve Block
A Phase 2 study testing Liposomal bupivacaine, 266mg in people with Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery and Knee Arthroscopic Surgery, run by Hainan Medical College at 1 site in China.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery, Knee Arthroscopic Surgery
- What is being tested?
- Liposomal bupivacaine, 266mg
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 79 participants
- Where
- 1 siteChina
- Study dates
- 1 Feb 2026to 1 Apr 2026
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
China1 site
Department of Anesthesiology,the Second Affiliated Hospital of Hainan Medical University
Haikou, Hainan
About this study
Official title: Clinical Observation of Bupivacaine Liposome for Lower Extremity Femoral Nerve Block
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.
Read the detailed description
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.
Motor block group
Motor function of the quadriceps muscle is evaluated 30 minutes after block placement using a standardized motor strength assessment. 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.
The primary objective of this study is to estimate the EC50 and EC95 of liposomal bupivacaine for:femoral nerve sensory blockade, and femoral nerve motor blockade, based on sequential allocation data and appropriate dose-response modeling.
Secondary objectives include describing the differential sensory-motor block profile of liposomal bupivacaine and evaluating its clinical feasibility and safety for femoral nerve block applications. All patients are monitored for block-related adverse events, including signs of local anesthetic systemic toxicity, nerve injury, and other complications throughout the perioperative period.
- Conditions
- Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery, Knee Arthroscopic Surgery
- Being tested
- Liposomal bupivacaine, 266mg
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Liposomal bupivacaine, 266mgDrug
Liposomal bupivacaine administered for ultrasound-guided femoral nerve block at varying concentrations using a modified up-and-down sequential dose-finding design.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Drug: Liposomal bupivacaine, 266mg |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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 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.
Measured: 30 minutes after femoral nerve block placement
Secondary outcomes (7)
Postoperative Resting pain intensity assessed by VAS
Postoperative Resting pain intensity is assessed using the Visual Analog Scale (VAS, 0-10, where 0 indicates no pain and 10 indicates the worst imaginable pain). VAS scores will be recorded while the patient is at rest on postoperative day 1 and postoperative day 2 to evaluate pain at rest following femoral nerve block. A higher score indicates more severe pain.
Measured: postoperative day 1 and day 2
Postoperative movement-evoked pain assessed by VAS
Movement-evoked pain is assessed using the Visual Analog Scale (VAS, 0-10). VAS scores are recorded during active movement of the operated limb on postoperative day 1 and postoperative day 2 to evaluate pain associated with mobilization following femoral nerve block.
Measured: Postoperative day 1 and day 2
Quadriceps muscle strength after surgery
Quadriceps muscle strength on the operated side is evaluated using the Medical Research Council (MRC) muscle strength scale (0-5). Assessments are performed on postoperative day 1 and postoperative day 2 to evaluate recovery of motor function following femoral nerve block.
Measured: Postoperative day 1 and day 2
Length of hospital stay
Length of hospital stay is defined as the number of days from the date of surgery to the date of hospital discharge.
Measured: From the date of surgery until hospital discharge, assessed up to 30 days postoperatively.
Time to first ambulation after surgery
Time to first ambulation is defined as the time interval from the end of surgery to the patient's first out-of-bed ambulation with or without assistance.
Measured: From the end of surgery until the first out-of-bed ambulation, assessed up to 72 hours postoperatively.
Intraoperative heart rate
Intraoperative heart rate is continuously monitored and recorded during surgery to assess intraoperative physiological stability.
Measured: From skin incision to the end of surgery, assessed continuously during the intraoperative period.
Intraoperative mean arterial pressure
Intraoperative mean arterial pressure is continuously monitored and recorded during surgery to assess intraoperative hemodynamic stability.
Measured: From skin incision to the end of surgery, assessed continuously during the intraoperative period.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jan 2026
- Study start1 Feb 2026
- Primary completion31 Mar 2026
- Study completion1 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Patients Eligible for Elective Lower Extremity Femoral Nerve SurgeryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Health services research
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 79 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hainan Medical College
- Sponsor type
- University, hospital or other
- Collaborators
- The Second Affiliated Hospital of Hainan Medical University
- Responsible party
- Principal investigator, Xin Chen, Hainan Medical College
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07366905
- Sponsor's protocol ID
- HUMU2H-DCOEOP-CN-2025
- Other IDs
- No.823RC592
- Status last verified
- May 2026
- First submitted
- 8 Jan 2026
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Clinical Observation of Bupivacaine Liposome for Lower Extremity Femoral Nerve Block
- ClinicalTrials.gov ID
- NCT07366905
- Acronym / sponsor ID
- HUMU2H-DCOEOP-CN-2025
- Conditions
- Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery, Knee Arthroscopic Surgery
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 79 participants (actual)
- Lead sponsor
- Hainan Medical CollegeUniversity, hospital or other
- Collaborators
- The Second Affiliated Hospital of Hainan Medical University
- Study start
- 1 Feb 2026 (actual)
- Primary completion
- 31 Mar 2026 (actual)
- Study completion
- 1 Apr 2026 (actual)
- First posted
- 26 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Motor block group
Motor function of the quadriceps muscle is evaluated 30 minutes after block placement using a standardized motor strength assessment. 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.
The primary objective of this study is to estimate the EC50 and EC95 of liposomal bupivacaine for:femoral nerve sensory blockade, and femoral nerve motor blockade, based on sequential allocation data and appropriate dose-response modeling.
Secondary objectives include describing the differential sensory-motor block profile of liposomal bupivacaine and evaluating its clinical feasibility and safety for femoral nerve block applications. All patients are monitored for block-related adverse events, including signs of local anesthetic systemic toxicity, nerve injury, and other complications throughout the perioperative period.
Study design
- Primary purpose
- Health services research
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ultrasound-guided femoral nerve block with liposomal bupivacaine | Experimental | Drug: Liposomal bupivacaine, 266mgParticipants 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. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (8 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Liposomal bupivacaine, 266mgLiposomal bupivacaine administered for ultrasound-guided femoral nerve block at varying concentrations using a modified up-and-down sequential dose-finding design. | Drug | Ultrasound-guided femoral nerve block with liposomal bupivacaine |
Primary outcome
EC50 and EC95 for femoral nerve sensory block
Time frame: 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
Time frame: 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.
7 secondary outcomes
Postoperative Resting pain intensity assessed by VAS
Time frame: postoperative day 1 and day 2
Postoperative movement-evoked pain assessed by VAS
Time frame: Postoperative day 1 and day 2
Quadriceps muscle strength after surgery
Time frame: Postoperative day 1 and day 2
Length of hospital stay
Time frame: From the date of surgery until hospital discharge, assessed up to 30 days postoperatively.
Time to first ambulation after surgery
Time frame: From the end of surgery until the first out-of-bed ambulation, assessed up to 72 hours postoperatively.
Intraoperative heart rate
Time frame: From skin incision to the end of surgery, assessed continuously during the intraoperative period.
Intraoperative mean arterial pressure
Time frame: From skin incision to the end of surgery, assessed continuously during the intraoperative period.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Liposomal bupivacaine, 266mg in people with Patients Eligible for Elective Lower Extremity Femoral Nerve Surgery and Knee Arthroscopic Surgery, run by Hainan Medical College at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
EC50 and EC95 for femoral nerve sensory block (time frame: 30 minutes after femoral nerve block placement). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.