The Use of Intralipid® 20% Solution to Reverse the Anesthetic Effect of Local Anesthetics: a Proof of Concept Study in Volunteers
| Registry | NCT03968822 |
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| Status | Active not recruiting |
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| Phase | Phase 4 |
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| Study type | Interventional; randomized, crossover, masking: double, other |
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| Enrollment | 18 (Estimated) |
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| Sponsor | Hospital for Special Surgery, New York (Other) |
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| Conditions | Anesthesia, Local |
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| Interventions | Lidocaine 2%, Lidocaine 1%, Bupivacaine 0.25%, Bupivacaine 0.5%, Intralipid, 20% Intravenous, Saline intravenously, Saline (Drug, other) |
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| Dates | start 2019-07-26, primary completion 2026-10-01 (estimated), completion 2026-10-01 (estimated), first posted 2019-05-30, last updated 2025-12-08 |
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| Locations | 1 site in United States |
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Related Papers Related Patents Related Grants Related Experts
All trials for Anesthesia, Local All trials of Lidocaine 2% All trials of Lidocaine 1%
-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.
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+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.
+Arms and interventions
| Arm | Type | Interventions | Description |
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| Intralipid 20% IV Bolus | Experimental | Drug: Lidocaine 2%; Drug: Lidocaine 1%; Drug: Bupivacaine 0.25%; Drug: Bupivacaine 0.5%; Drug: Intralipid, 20% Intravenous; Other: Saline | This is 1 out of the 2 study visits. The patient will receive 6 injections (3 in each thigh). The 6 injections are:
1. lidocaine 1%
2. lidocaine 2%
3. bupivacaine 0.5%
4. bupivacaine 0.25%
5. saline
6. no injection
Each test solution will be injected over 5 seconds through a 27G needle and tuberculin syringe at a 30 degree angle.
The patient will also receive an intravenous bolus in the arm of Intralipid 20%.
Participant will be blindfolded for these activities so they will not know what they received during the visit. |
| Saline | Placebo comparator | Drug: Lidocaine 2%; Drug: Lidocaine 1%; Drug: Bupivacaine 0.25%; Drug: Bupivacaine 0.5%; Other: Saline intravenously; Other: Saline | This is 2 out of the 2 study visits. The patient will receive 6 injections (3 in each thigh). The 6 injections are:
1. lidocaine 1%
2. lidocaine 2%
3. bupivacaine 0.5%
4. bupivacaine 0.25%
5. saline
6. no injection
Each test solution will be injected over 5 seconds through a 27G needle and tuberculin syringe at a 30 degree angle.
The patient will also receive an intravenous bolus in the arm of Saline.
Participant will be blindfolded for these activities so they will not know what they received during the visit. |
- Lidocaine 2% (Drug), also known as Lidocaine Viscous, Lidoderm, Recticare: 3 mL of test solution to a skin area on the thigh, 2cm in diameter
- Lidocaine 1% (Drug), also known as Lidocaine Viscous, Lidoderm, Recticare: 3 mL of test solution to a skin area on the thigh, 2cm in diameter
- Bupivacaine 0.25% (Drug), also known as Marcaine, Sensorcaine: 3 mL of test solution to a skin area on the thigh, 2cm in diameter
- Bupivacaine 0.5% (Drug), also known as Marcaine, Sensorcaine: 3 mL of test solution to a skin area on the thigh, 2cm in diameter
- Intralipid, 20% Intravenous (Drug), also known as i.v. fat emulsion: a 250ml bag administered intravenously
- Saline intravenously (Other), also known as salt: a 250ml bag administered intravenously
- Saline (Other), also known as salt: 3 mL of test solution to a skin area on the thigh, 2cm in diameter
+Outcome measures
Primary outcomes
- 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 outcomes
- 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 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.
- 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 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 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.
+Eligibility
Sex: All, ages: 18 Years to any, accepts healthy volunteers
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)
+Locations (1)
| Facility | City | Country | Status |
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| Hospital of Special Surgery | New York, New York | United States | |
+Investigators