Intralipid® 20% for Reversal of Local Anesthetics

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.