Most healthy people don't have any problems with general anesthesia. Although many people may have mild, temporary symptoms, general anesthesia itself is exceptionally safe, even for the sickest patients. The risk of long-term complications, much less death, is very small. In general, the risk of complications is more closely related to the type of procedure you're undergoing, and your general physical health, than to the anesthesia itself.

Some of the factors that can increase your risk of complications include:

  • Smoking
  • Obstructive sleep apnea
  • Obesity
  • High blood pressure
  • Diabetes
  • Other medical conditions involving your heart, lungs or kidneys
  • Medications, such as aspirin, that can increase bleeding
  • History of heavy alcohol use
  • Drug allergies
  • History of adverse reactions to anesthesia

Rare complications, which may occur more frequently in older adults or in people with serious medical problems, include:

  • Temporary mental confusion
  • Lung infections
  • Stroke
  • Heart attack
  • Death

Anesthesia awareness

Estimates vary, but about 1 or 2 people in every 1,000 may wake up briefly while receiving general anesthesia. The person usually doesn't feel pain, but is aware of his or her surroundings.

In very rare situations, some people experience excruciating pain in spite of general anesthesia. In this situation, because of muscle relaxants given prior to surgery, people aren't able to move or speak or make others aware of their distress. Some people may develop long-term psychological problems, similar to post-traumatic stress disorder.

The following factors appear to make this phenomenon — also called unintended intraoperative awareness — more likely:

  • Emergency surgery
  • Cesarean surgery
  • Depression
  • Use of certain medications
  • Heart or lung problems
  • Daily alcohol use
  • Lower anesthesia doses than necessary used during procedure
  • Errors by the anesthesiologist, such as not monitoring the patient or measuring the amount of anesthesia in the patient's system throughout procedure
Jan. 19, 2013