Pain is easier to control, and often with lower doses, if medications are given before the painful event. It is also often more effective, as well as safer to use lower doses of multiple pain medications (referred to as a multi-modal approach) than to give a huge dose of a single drug and have a higher risk of side effects. Local anesthesia is one way to provide this pre-emptive pain management and can easily be combined into a multi-modal program; it is a simple and convenient way to provide pain management during dental procedures, such as extractions.
Local anesthesia allows us to control pain at the “root” of the problem (no pun intended). It blocks sensation exactly where it is applied. Strategic placement over a nerve will block the entire region of the body that that nerve innervates, as when a dentist freezes just the lower left side of your mouth. Veterinarians do the same type of local anesthesia for canine and feline extractions. There is no sedation, or “hangover” from local anesthesia, and these injections typically will last between 30 minutes to 4 hours, so while they are great for pain control during and shortly after the procedure, they do not provide prolonged pain control for after the fact. Thus, additional pain medications might be used at home afterward in a multi-modal approach to pain control.
While general anesthesia prevents some pain, successively higher doses are needed for more painful procedures like dental extractions. Higher doses of a general anesthetic can have significant deleterious effects on blood pressure and cardiovascular function. By using local nerve blocks, the pain control no longer falls entirely on the general anesthetic; a lower anesthetic dose is required to keep the patient comfortable and thus a lower chance for side effects on their heart rate, breathing, and blood pressure, resulting in an overall safer procedure and anesthetic.