Because surgery is typically painful, it is almost always preceded by the administration of some type of anesthetic, analgesic, or both. Anesthetics block the perception of pain by causing loss of sensation (numbness) or unconsciousness, and analgesics are drugs given to reduce pain. Anesthetics are typically given by health care practitioners specially trained and certified in providing anesthesia. These practitioners may be doctors (anesthesiologists) or nurse practitioners (nurse anesthetists). Nurse anesthetists practice under the direction of an anesthesiologist.
There are three types of anesthesia
Local
Regional
General
Local anesthesia and regional anesthesia
These types of anesthesia consist of injections of drugs (such as lidocaine or bupivacaine) that numb only specific parts of the body.
In local anesthesia, the drug is injected under the skin of the site to be cut, numbing only that site.
In regional anesthesia, which numbs a larger area of the body, the drug is injected around one or more nerves and numbs an area of the body supplied by those nerves. For example, injecting a drug around certain nerves can numb fingers, toes, or specific parts or all of limbs. One type of regional anesthesia involves injecting a drug into a vein (intravenous regional anesthesia). A device such as a woven elastic bandage or blood pressure cuff compresses the area where the limb joins the body, trapping the drug within the veins of that limb. Intravenous regional anesthesia can numb an entire limb.
During local anesthesia and regional anesthesia, the person remains awake. However, doctors sometimes give mildly sedating antianxiety drugs intravenously to relax the person. Rarely, numbness, tingling, or pain can persist in the numbed area for days or even weeks after the surgical procedure.
Spinal anesthesia and epidural anesthesia are specific types of regional anesthesia in which a drug is injected around the spinal cord in the lower back. Depending on the site of the injection and position of the body, a large area (such as from the waist to the toes) can be numbed. Spinal and epidural anesthesia are useful for operations of the lower body, such as hernia repairs and prostate, rectal, bladder, leg, and some gynecologic operations. These types of anesthesia also can be useful for childbirth. Headaches occasionally develop in the days after spinal anesthesia but usually can be treated effectively.
General anesthesia
In general anesthesia, a drug that circulates throughout the bloodstream is given, making the person unconscious. The drug can be given intravenously or can be inhaled. Because a general anesthetic slows breathing, the anesthesiologist s a breathing tube in the windpipe. For short operations, however, such a tube may not be necessary. Instead, the anesthesiologist can support breathing by using a handheld breathing mask. If the operation is long, a ventilator breathes for the person ( see Mechanical Ventilation). General anesthetics affect vital organs, so the anesthesiologist closely monitors the heart rate, heart rhythm, breathing, body temperature, and blood pressure until the drugs wear off. Serious side effects are very rare.
