Nearly every surgical procedure involves the administration of some type of anesthesia for pain relief and to keep patients relaxed and still during surgery. Forms of anesthesia range from local anesthesia, where just a small area is numbed, to general anesthesia, where the patient is so deeply asleep that a ventilator must be connected to deliver oxygen during the surgery.
General Anesthesia
General anesthesia is used for surgeries that require complete relaxation of the patient. Patients under general anesthesia are in a very deep sleep and can't breathe on their own, so they need to have a breathing tube placed for use with a mechanical ventilator. General anesthesia is usually given in the form of an inhaled gas; intravenous sedating drugs may also be given. The patient may be given paralyzing medications to ensure he won't move at all.
General anesthesia has risks, so careful monitoring of vital signs and vigilant observation of the patient's condition must be carried out by the anesthesiologist or nurse anesthetist. These are the only personnel qualified to administer general anesthesia. Nausea, vomiting and constipation often occur after general anesthesia, which slows the action of the gastrointestinal system. Irregular heartbeat, confusion, and in rare circumstances, brain damage or death can occur, according to the University of Michigan Health System.
Regional Anesthesia
Spinal and epidural anesthesia are used for surgeries where complete relaxation and paralysis is not required. Patients are awake, although intravenous sedation to keep them calm and relaxed may be given. The patient breathes on her own but is completely numb below the desired area of anesthesia. Numbing medication is injected into the area around the spinal nerves and blocks the nerves in the spinal cord from feeling pain, the NetWellness site of the University of Cincinnati explains. Spinal anesthesia works quickly and causes complete paralysis below the level of anesthesia; epidural anesthesia takes a few minutes to take effect and patients may still have some ability to move below the level of anesthesia. Epidural anesthesia is often used for pain control in labor.
Complications of regional anesthesia include nerve damage or an allergic reaction to the numbing agents. If regional anesthesia is injected too high into the spine and affects nerves above the level of the lungs, the chest muscles may be paralyzed and the patient may need a breathing tube and mechanical ventilation.
Intravenous Sedation
Intravenous or IV, sedation, can be nearly as sedating as general anesthesia, or just mildly sedating, depending on the medication used and the amount given. IV sedation that puts the patient in a deep sleep is called monitored anesthesia care, or MAC. IV sedation that makes a patient drowsy but doesn't induce a deep sleep is known as conscious sedation. A breathing tube usually isn't required, and the patient is able to respond to painful stimuli. Drugs used for MAC or conscious sedation include amnesia drugs, which cause short-term memory loss, anti-anxiety medications such as Valium and pain medications, and hypnotic agents that put patients into a deep sleep. MAC has fewer side effects than general anesthesia, and is less likely to affect the GI system and cause serious complications.
Local Anesthesia
Local anesthesia is used for minor surgeries and can be administered by medical personnel other than an anesthesiologist or nurse anesthetist. Local anesthetics, or numbing agents, are injected into the skin around the area that needs numbing. For example, local anesthesia can be injected around a cut that needs suturing. Allergic reactions may occur but in general, local anesthesia is safe.
