General Anesthesia

During general anesthesia the patient is unconscious. Light general anesthesia allows the patient to breath on his own; deep anesthesia requires ventilation of the patient by the anesthesiologist. A short case can be done with a mask, but is usually done with an endotracheal tube, which is placed through the mouth or nose into the trachea. Both intravenous and gaseous agents can be used to provide general anesthesia. These agents work on the brain rather than on the spinal cord, as in spinal anesthesia.

The benefits of general anesthesia are that the patient is not aware of what is transpiring and the anesthesia can be prolonged as long as necessary for the procedure. It is also somewhat safer in regards to maintaining adequate oxygenation, when the patient is intubated (has a tube put in the trachea, as discussed above).

Some risks and side effects should be considered. The general anesthetic gaseous agents and the endotracheal tube cause mild irritation of the airway and can cause breathing difficulties after surgery, including a small risk of pneumonia. There is also some grogginess and lethargy as the anesthesia agents slowly clear over several hours post-operatively. General anesthesia can also cause precipitous drops in blood pressure. These can usually be prevented by adequate hydration, but may be a problem in some patients with compromised cardiovascular systems. This lowered blood pressure and possibly lowered perfusion of the brain and heart, can cause (in a very small number of patients) a heart attack or stroke. Post-operative nausea can also occur while the anesthetic agents are cleared from the body over the first few hours following the procedure. This can usually be managed by other medications.