Surgical Anesthesia
Conditions
Brief summary
This is a dose finding study to identify the minimum effective anesthetic concentration (MEAC) of ropivacaine to produce insensate body parts sufficient for surgery in supraclavicular and infraclavicular approaches to the brachial plexus, parasacral and popliteal approaches to the sciatic nerve, femoral nerve and transversus abdominis plane (TAP) blocks in adults.
Interventions
DRUGRopivacaine concentration
Single shot preoperative perineural injection of ropivacaine to achieve surgical anesthesia. The concentration of ropivacaine is lowered by 0.05% after every successful surgical anesthesia specific to that block and raised by 0.05% after every unsuccessful surgical anesthesia specific to that block
Sponsors
University of New Mexico
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists physical status I to III (patients may be healthy or have systemic disease, but any disease does not pose a constant threat to life, and patients are neither moribund, nor not expected to survive without the operation). * Age 18 or above * Undergoing elective ambulatory surgery of the upper limb (excluding the shoulder), lower limb (excluding the hip), or lower abdomen with sensory blockade as part of the pain management plan.
Exclusion criteria
* Body mass index of \>35 kg/m2 (higher chance of failure) * Deformities of the leg (for patients in the parasacral, femoral, and popliteal groups), or the chest or shoulder (for patients in the supraclavicular, infraclavicular, and TAP groups) * Preexisting infection at the injection site * Existing neurologic disease * Allergy to local anesthetic agents * Severe respiratory disease * Coagulopathy * Any other contraindication to the block being considered * Patients requiring total motor blockade as well as sensory blockade
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population | 1 day | The concentration of ropivacaine for each patient's nerve-block injection was determined per protocol. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Patients With Complications | 3 days | All patients were followed up for complications such as bleeding, infection, side effects, nerve damage |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Ropivacaine Each patient received ropivacaine-based nerve blockade at a fixed volume, with concentration determined per protocol | 49 |
| Total | 49 |
Baseline characteristics
| Characteristic | Ropivacaine |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 49 Participants |
| Gender Female | 19 Participants |
| Gender Male | 30 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 11 / 49 |
| serious Total, serious adverse events | 0 / 49 |
Outcome results
Primary
Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population
The concentration of ropivacaine for each patient's nerve-block injection was determined per protocol.
Time frame: 1 day
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Femoral Nerve Block | Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population | 0.09 percentage concentration, ropivacaine |
| Supraclavicular Blockade | Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population | 0.11 percentage concentration, ropivacaine |
| Infraclavicular Blockade | Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population | 0.16 percentage concentration, ropivacaine |
| Popliteal Nerve Block | Effective Concentration of Ropivacaine to Produce Surgical Anesthesia in 50% of Population | 0.37 percentage concentration, ropivacaine |
Secondary
Number of Patients With Complications
All patients were followed up for complications such as bleeding, infection, side effects, nerve damage
Time frame: 3 days
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Femoral Nerve Block | Number of Patients With Complications | 0 Participants |