There are four main categories of anesthesia: local, regional, MAC (monitored anesthesia care), and general. Each has many forms and uses. Your anesthesiologist, in consultation with your surgeon, will determine the best type of anesthesia for you, taking your desires into consideration whenever possible. These options will be discussed during your preoperative interview with the anesthesiologist.
If your case is to be done with local anesthesia alone, typically the anesthesia care team is not involved. The anesthetic drug is usually injected by the surgeon into the tissue to numb just the specific location of your body requiring minor surgery, for example, on the hand or foot. The injection may feel like a brief sting.
During “monitored anesthesia care” (M.A.C.), the surgeon usually injects the local anesthetic and the anesthesiologist and CRNA monitor and stabilize vital signs and frequently give intravenous sedatives. With modern sedatives, the experience of the patient is frequently identical to that of patients receiving a general anesthetic, that is, it is as if they were “asleep”.
In regional anesthesia, your anesthesiologist or CRNA makes an injection near a cluster of nerves to numb the area of your body that requires surgery. You may remain awake, or you may be given a sedative. You do not see or feel the actual surgery take place. Regional anesthesia can include spinal blocks, epidural blocks or peripheral nerve blocks. Spinal and epidural blocks involve interrupting sensation from the legs or abdomen by injecting local anesthetic medication in or near the spinal canal and are frequently preferred for childbirth and prostate surgery. Peripheral nerve blocks can be performed for surgery on your extremities, or limbs, blocking sensations from the arm or leg. An ultrasound machine may be used to determine the exact injection site, where local anesthetic medicines will be injected. Two of the most frequently used peripheral nerve blocks are the femoral nerve block, which is produced by an injection in the leg region, and the brachial plexus block, which is produced by an injection in the arm and shoulder region. These blocks are frequently performed for surgery in the knee, shoulder, or arm.
In general anesthesia, you are unconscious and have no awareness or other sensations. There are a number of general anesthetic drugs. Some are gases or vapors inhaled through a breathing mask or tube and others are medications introduced through a vein. During anesthesia, you are carefully monitored, controlled and treated by your anesthesiologist and CRNA, who use sophisticated equipment to track all your major bodily functions. A breathing tube may be inserted through your mouth and frequently into the windpipe to maintain proper breathing during this period. The length and level of anesthesia is calculated and constantly adjusted with great precision. At the conclusion of surgery, your anesthesia providers will reverse the process and you will regain awareness in the recovery room.