The term “conscious sedation” (formerly “twilight sleep”) is used to describe a semi-conscious state that allows patients to be comfortable during certain surgical or medical procedures. However, there is no universal agreement on the meaning of these terms.
Analgesia refers to the relief of pain that is often included in sedation techniques. Sedation analgesia can provide pain relief as well as relief of anxiety that may accompany some treatments or diagnostic tests. It involves using medications for many types of procedures without using general anesthesia, which causes complete unconsciousness.
Sedation analgesia usually is administered through an intravenous catheter (IV), to relax you and minimize any discomfort you might experience. It often is used in combination with an injection of a local anesthetic, or “numbing medicine,” at the site of surgery. Sedation analgesia may have fewer side effects than may occur with general anesthesia. Frequently, there is less nausea from sedation techniques, and patients generally recover faster after the procedures.
When given appropriately, sedation analgesia is safe and effective for many procedures done in hospitals, ambulatory surgical centers and doctors’ or dentists’ offices. Ask the physician performing your diagnostic or therapeutic procedure about which level of sedation is appropriate for you, and whether an anesthesiologist will be involved in your care. Remember that anesthesiologists are physicians trained to administer all levels of sedation, including general anesthesia, should it be necessary for your comfort or safety.
The information on these pages will provide you with an introduction to sedation analgesia. Please discuss any additional questions with your physician or anesthesiologist.
Q&A with John Jeffrey Andrews, M.D.
Chair of the ASA Committee on Patient Safety and Education: Sedation Analgesia
Levels of Sedation
Although the effects of sedation are better described in terms of “stages” – as part of a scale – sedation usually is divided into three categories:
- Minimal sedation, or anxiolysis
- Moderate sedation
- Deep sedation
During minimal sedation, you will feel relaxed and you may be awake. You can understand and answer questions and will be able to follow your physician’s instructions.
When receiving moderate sedation, you will feel drowsy and may even sleep through much of the procedure, but will be easily awakened when spoken to or touched. You may or may not remember being in the procedure room.
During deep sedation, you will sleep through the procedure with little or no memory of the procedure room. Your breathing can slow, and you might be sleeping until the medications wear off. With deep sedation, supplemental oxygen is often given.
With any of the three levels of sedation, you may receive an injection of local anesthetic to numb the surgical site. You may or may not feel some discomfort as this medication is injected, depending on how sedated you are.
Administering the Analgesia
An anesthesiologist or a registered nurse or nurse anesthetist working with a qualified physician may administer the sedation. You should know who will be providing your sedation analgesia, what their level of training is, and who will be there to handle any medical situation that arises during the procedure.
Monitoring and Safety
As with any type of anesthesia, you will be monitored when receiving sedation analgesia. These monitors are very important to ensure your safety. They are used to monitor your heart rate and rhythm, blood pressure and the oxygen levels of your blood. During moderate and deep sedation, someone will be solely responsible for monitoring your vital signs and controlling your level of consciousness.
After the Procedure
If you have received minimal sedation only, you may be able to go home once the procedure is finished. If you have received moderate or deep sedation, you will probably require more time to recover. Often this may be within an hour. In the recovery room, you will be monitored until the effects of the medication wear off.
Any after-effects of the medication must be minimal or gone before you will be discharged from the facility. You will not be allowed to drive yourself, so arrangements should be made for a responsible adult to provide you with transportation. If you think you may need some assistance, you might consider having someone stay with you on the day of surgery.
Checklist: Questions to Ask Before Sedation Analgesia
Here are a few questions that you may want to ask prior to receiving sedation analgesia:
- Who will be responsible for the administration of sedative medications? What are his or her qualifications?
- How will I be monitored during my procedure?
- Will I have an IV (intravenous catheter)?
- Will I be receiving local anesthesia in addition to sedation?
- Will the level of sedation I receive be sufficient to make me comfortable during the procedure as well as the recovery period immediately afterward?
- Who will be monitoring my recovery after the procedure?
- In case of an emergency, what equipment and personnel will be available?
- Who will decide when I am ready to go home?
- Whom can I call if I have any problems or questions once I get home?