Types of Anesthesia

General Anesthesia is a technique during which the patient is rendered unconscious. General Anesthesia provides analgesia (you have no pain), amnesia (you are unaware and have no memory), and relaxation (your muscles are relaxed to give the surgeon better operating conditions).

General Anesthesia is usually started and maintained by giving the patient an intravenous drug (into a vein), an inhalation drug (a gas which you breathe), or a combination of both. The anesthesia provider will monitor the progress of the surgery and the depth of your anesthesia. The depth of anesthesia can be changed by increasing or decreasing the amount of drug given. As the surgeon finishes the procedure, the anesthesia provider reduces the depth of anesthesia so the patient will awaken at the end of the procedure or shortly thereafter.

Spinal anesthesia is a technique in which the patient is given an injection in the lower back that blocks the nerves that supply feeling to the lower half of the body. The medication is injected into a sac of fluid in your lower back (the subarachnoid space) which contains the spinal nerves. The medication blocks the nerves in the lower half of the body. The loss of feeling is temporary and should last from 1 to 4 hours depending on the medication given and other factors.

Epidural anesthesia involves inserting a tiny plastic tube into the epidural space. The spinal nerves (which carry the sensations from your body) pass through the epidural space. Medicine is injected through this tiny plastic tube (or epidural catheter) into the epidural space. This medicine blocks the messages of sensation that tell the brain what your body is feeling.

The epidural catheter is usually placed in the lower back for procedures below the umbilicus (belly button). The catheter may be placed higher in the back for procedures of the chest or upper abdomen. For example, for knee or hip surgery, the epidural catheter is placed in the lower back. This allows the medicine to anesthetize or block the feelings in the lower half of your body. After surgery, the medicine can be changed to control your pain or discomfort after surgery.

This anesthesia is similar to a Spinal Anesthetic. The Spinal Anesthetic is a single shot of medication which may last from 1 to 4 hours. The epidural catheter, however, allows repeated injections of the medication. This may permit many hours of anesthesia. In addition, the epidural catheter may be used after surgery for pain control.

Regional Anesthesia involves blocking sensations to one part of the body. By injecting local anesthetic (or numbing medicine) around a group of nerves, the anesthesia provider can block the sensation from one part of the body, such as the arm, the hand, or the foot. Most of the time the patient is given sedation before and during the procedure. A regional block can often give the patient several hours of pain relief after surgery. Regional anesthesia can be given alone, with sedation, or in combination with General Anesthesia. Your anesthesia provider may use this technique to provide anesthesia for your surgery or simply to provide pain relief after your surgery. Use of this technique will depend on the type and length of your surgery, your medical history, and your anesthesiologist and surgeon's preference.

M.A.C. or Monitored Anesthesia Care, refers to sedation while under the care of the Anesthesia provider. This sedation may range from mild sedation to a state of unconsciousness. Throughout this sedation, the patient's heart, blood pressure, and breathing are monitored closely by the Anesthesia provider. Additional oxygen or breathing assistance may be given if necessary. M.A.C. is usually given in addition to Local or Regional Anesthesia.