Intralipid® 20% for Reversal of Local Anesthetics

Hospital for Special Surgery (HSS)

Status and phase: Active, not recruiting; Phase 4

Conditions: Anesthesia, Local

Treatments: Drug: Lidocaine 1%; Drug: Bupivacaine 0.25%; Drug: Lidocaine 2%; Other: Saline; Drug: Intralipid, 20% Intravenous; Other: Saline intravenously; Drug: Bupivacaine 0.5%

Study type: Interventional

Funder types: Other

Identifiers

NCT03968822

2018-2039

Details and patient eligibility

About

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.

Full 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.

Enrollment: 18 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: 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)

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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18 participants in 2 patient groups, including a placebo group

Intralipid 20% IV Bolus

Experimental group

Description:

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.

Treatment:

Drug: Bupivacaine 0.5%

Drug: Intralipid, 20% Intravenous

Other: Saline

Drug: Lidocaine 2%

Drug: Bupivacaine 0.25%

Drug: Lidocaine 1%

Saline

Placebo Comparator group

Description:

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.

Treatment:

Other: Saline intravenously

Drug: Bupivacaine 0.5%

Other: Saline

Drug: Lidocaine 2%

Drug: Bupivacaine 0.25%

Drug: Lidocaine 1%