There are many different types of local anesthetics. Lidocaine and bupivacaine are among the most commonly used. The medications differ primarily in the speed at which they cause numbness and how long their effect remains. Although topical formulations of local anesthetic exist (such as “numbing creams”), they typically do not have a role in reducing post-surgical pain.
Local anesthetic must be administered by a medical professional. Doses are calculated carefully based on body weight. Although generally extremely safe, local anesthetics do have the potential for side effects, just like any medication. Allergic reactions and permanent nerve damage are possible but very rare. In the overwhelming majority of people, sensation and muscle function return to normal once the anesthetic has worn off.
Local anesthetic, also known as numbing medicine, is medication that takes away the sensation of pain. Injection of local anesthetic has been used since the late 19th century. This medication can be injected in two ways:
1) Field block – the local anesthetic is injected directly into the surgical field (meaning the area where the surgery is being performed)
2) Nerve block – the local anesthetic is injected into a specific nerve (or bundle of nerves) outside of the surgical field. This creates numbness in a particular area of the body, depending on which nerve was injected.
A field or nerve block typically lasts for several hours, depending on the type of local anesthetic used, allowing a patient to awake from surgery without pain. Nerve blocks have many other uses outside of relieving postsurgical pain including therapeutic (treat chronic pain), diagnostic (determine the source of pain), and prognostic (determine if permanent nerve ablative procedures would be helpful).
It is important to note that nerve blocks may affect muscle control in addition to sensation, depending on which nerve was treated. Weakness from a block will resolve as the local anesthetic wears off.
Exparel© is a unique technology that allows for the local anesthetic pain-relieving effect to last 2-3 days. This is significantly longer than the 6-8 hours provided by traditionally available local anesthetics. Bupivicaine (the local anesthetic used in Exparel©) is suspended in small lipid particles that break down over 2-3 days, causing a continuous, gradual release of the pain-relieving medicine.
Studies done in surgical patients receiving Exparel© show a dramatic reduction in opioid (narcotic) use and significantly better pain control. This improved postsurgical pain may also result in more mobility after surgery, less risk of complications, and an overall faster recovery. Exparel© has also proven to be as safe as, if not safer, than traditional local anesthetics. Studies show no detrimental effect on wound healing.