Anesthesia, Local
Conditions
Brief summary
In order to determine if Intralipid 20% can be used to reverse the effects of local anesthetics, the investigators will recruit 18 volunteers who will be asked to come to HSS for two study visits. Small amounts of local anesthetics will be injected into the volunteers' thighs during both visits. During one visit volunteers will receive Intralipid 20% and during the other visit they will receive a saline solution. The study team will measure how quickly normal sensation returns to the thighs when the volunteers get Intralipid 20% compared to saline.
Detailed description
The purpose of this study is to determine if a fat solution (Intralipid 20%) given intravenously can reverse the effects of local anesthetics. Local anesthetics are drugs that cause numbness when they are injected into different parts of the body. Local anesthetics are important drugs because they allow doctors to perform surgeries and other procedures on patients; however, there are certain instances where it would be helpful to reverse the effects of local anesthetics and reduce the amount of time that they produce numbness. In order to determine if Intralipid 20% can be used to reverse the effects of local anesthetics, the investigators will recruit 18 volunteers who will be asked to come to HSS for two study visits. Small amounts of local anesthetics will be injected into the volunteers' thighs during both visits. During one visit volunteers will receive Intralipid 20% and during the other visit they will receive a saline solution. The study team will measure how quickly normal sensation returns to the thighs when the volunteers get Intralipid 20% compared to saline.
Interventions
DRUGLidocaine 2%
3 mL of test solution to a skin area on the thigh, 2cm in diameter
DRUGLidocaine 1%
3 mL of test solution to a skin area on the thigh, 2cm in diameter
DRUGBupivacaine 0.25%
3 mL of test solution to a skin area on the thigh, 2cm in diameter
DRUGBupivacaine 0.5%
3 mL of test solution to a skin area on the thigh, 2cm in diameter
DRUGIntralipid, 20% Intravenous
a 250ml bag administered intravenously
OTHERSaline intravenously
a 250ml bag administered intravenously
OTHERSaline
3 mL of test solution to a skin area on the thigh, 2cm in diameter
Sponsors
Hospital for Special Surgery, New York
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
Patients will be blinded to which treatment they are receiving both times they come in for the study.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* English speaking * BMI 18-25, with body weight between 50-100kg
Exclusion criteria
* ASA III or higher * Pregnant Women * Allergy to study medications (lidocaine, bupivacaine, soybeans, eggs) * Use of drugs affecting the sensorium (including opioids, benzodiazepines, antipsychotics, gabapentinoids)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to complete normal sensation after lidocaine 1% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of both cold swab and pinprick at the injection site of lidocaine 1%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to complete normal sensation after lidocaine 2% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of both cold swab and pinprick at the injection site of lidocaine 2%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to complete normal sensation after Bupivacaine 0.5% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of both cold swab and pinprick at the injection site of Bupivacaine 0.5%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to complete normal sensation after Bupivacaine 0.25% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of both cold swab and pinprick at the injection site of Bupivacaine 0.25%. Although measured for each individual participant, the average time across all participants is reported. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Time to normal pinprick sensation after Bupivacaine 0.5% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of pinprick at the injection site of Bupivacaine 0.5%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal cold swab sensation after Bupivacaine 0.5% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of cold swab at the injection site of Bupivacaine 0.5%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal cold swab sensation after lidocaine 1% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of cold swab at the injection site of lidocaine 1%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal pinprick sensation after Bupivacaine 0.25% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of pinprick at the injection site of Bupivacaine 0.25%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal cold swab sensation after Bupivacaine 0.25% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of cold swab at the injection site of Bupivacaine 0.25%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal pinprick sensation after lidocaine 1% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of pinprick at the injection site of lidocaine 1%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal cold swab sensation after lidocaine 2% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of cold swab at the injection site of lidocaine 2%. Although measured for each individual participant, the average time across all participants is reported. |
| Time to normal pin prick sensation after lidocaine 2% | up to 24 hours | The time (measured in minutes) when the participant reports normal sensation of pinprick at the injection site of lidocaine 2%. Although measured for each individual participant, the average time across all participants is reported. |
Countries
United States
Outcome results
None listed