Moderate Sedation

(Conscious Sedation; Monitored Anesthesia Care; MAC; Sedation, Conscious; Sedation, Moderate)


Moderate sedation is used during surgery. It will put you in a comfortable, sleepy, and pain-free state. Moderate sedation is different from general anesthesia because it does not require breathing support. It will also be easy to arouse you, so you can respond to questions or commands during surgery.

Reasons for Procedure

Moderate sedation can be used for a range of procedures. If your overall health is poor, your doctor may recommend this type of sedation instead of general anesthesia.

The potential benefits include:

  • Faster recovery time
  • Fewer complications

Also, moderate sedation does not require you to be connected to a ventilator.

Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

  • Nausea and vomiting
  • Headache
  • Temporary memory problems—you may be unable to recall the surgery
  • Breathing problems during the surgery

Factors that may increase the risk of problems include:

  • Smoking
  • Advanced age
  • Obesity
  • Poor overall health, such as cardiovascular disease

What to Expect

Prior to Procedure

You will meet with an anesthesiologist who will evaluate you and ask about:

  • Your medical history, including any previous reaction to anesthetics
  • Medications, herbs, or supplements you are taking

You may be instructed to:

  • Avoid eating and drinking 8-12 hours before the surgery
  • Take an anesthetic the morning of the surgery

Description of Procedure

The anesthetic drugs and other medications will be delivered by an IV in your arm. The doctor may also use local anesthesia at the surgery site.

Medications Delivered Through an IV

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You will be carefully monitored during the surgery. Your medications may need to be adjusted to keep a certain level of sedation. The goal will be to make sure you are comfortable and pain-free.

Your sedation may be increased so that you are fully asleep. If this is the case, a ventilator will be used to support your breathing.

Immediately After Procedure

The hospital staff will monitor your vital signs.

How Much Will It Hurt?

You will not have any pain during the surgery.

Average Hospital Stay

The length of your stay will depend on the reason you had surgery. You may be able to go home the same day as the procedure. However, you may need to stay a few nights.

Post-procedure Care

If you are discharged on the same day as the surgery, do not drive or operate machinery. The medications can affect your mental and physical abilities.

Call Your Doctor

It is important to monitor your recovery. Alert your doctor to any problems. If any of the following occur, call your doctor:

  • Signs of infection, such as fever and chills
  • Nausea and vomiting
  • Pain that cannot be controlled with the medications you were given
  • Cough, shortness of breath, or chest pain
  • Lightheadedness

If you think you have an emergency, call for emergency medical services right away.


American Association of Nurse Anesthetists
American Society of Anesthesiologists


Canadian Anesthesiologists' Society


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Ghisi D, Fanelli A, Tosi M, Nuzzi M, Fanelli G. Monitored anesthesia care. Minerva Anestesiol. 2005;71(9):533-538.
Moderate (conscious) sedation FAQ. American College of Emergency Physicians website. Available at: Updated May 26, 2015. Accessed October 2, 2017.
Monitored anesthesia care. Northeastern Anesthesia Services website. Available at: Accessed October 2, 2017.
Patient education brochures. American Society of Anesthesiologists website. Available at:
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Accessed October 2, 2017.
Thompson K. Chapter 47: Monitored anesthesia care. University of North Carolina at Chapel Hill website. Available at:
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Accessed August 20, 2014.
Last reviewed September 2018 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 8/20/2014

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