“What is "twilight" anesthesia used for?”

Some less invasive, short surgical procedures can be done under mild sedation without an endotracheal tube, it's called MAC (monitored anesthesia care) or twilight anesthesia, in layman’s terms.

Colonoscopy, endoscopy, minor biopsies, carpal tunnel surgery, etc.

Twilight anesthesia is light to moderate sedation given intravenously under supervision of an anesthesiologist for same day surgeries or procedures as well as various types of diagnostic tests which may cause discomfort.
Pt is monitored with ekg, continuous BP every 5 minutes, pulse oxymeter, and endtidal CO2 ,
The sedation can be lightened or deepened during the case depending upon the stimulus.
It is very convenient, as is used very commonly


Best regards

Anesthesia is on a spectrum. On the light side there is what we call MAC. You are relaxed and can respond to questions. Twilight anesthesia is just a bit deeper than this. You are more relaxed and feel like you are falling asleep. You may fall asleep and wake up several times but will not likely remember.

"Twilight anesthesia" actually refers to an older technique for moderate sedation using relatively long acting sedatives and opioids such as scopolamine and morphine. In today, modern practice, thesis drugs have been replaced with short acting drugs such as midazolam, propofol and fentanyl.

However, many surgeons still erroneously describe moderate to deep sedation for procedures where the anesthesiologist believes can be accomplished with a combination of local anesthesia and the drugs mentioned above without placement of a breathing tube as 'twilight anesthesia'.

Examples where this may occur are the sedation that takes place in the cardiac catheterization labs or interventional radiology or for colonoscopy.

“Twilight anesthesia” is the name given to what we call mild to moderate sedation. These terms have specific meanings: mild sedation implies responsiveness to voice or painful stimulation, without the need to support breathing in any way. Moderate sedation implies loss of responsiveness to voice but also with unsupported breathing.

The purpose of sedation Is to provide a calm patient without excessive movement. This is not really anesthesia. Anesthesia is usually provided by injections of local anesthetic at the site of the procedure itself, hence these forms of sedation are often referred to as “procedural sedation.”

Sedation Is suitable for a limited repertoire of procedures, for example extremity surgery, cardiac catheterization procedures, removal of lumps  and bumps with local anesthesia, and some interventions that radiologists perform.

Twilight anesthesia refers to a state during which a patient is not fully anesthetized and may move in response to pain, but will have no memory of pain. It is used for minor surgeries such as biopsies, hernia repairs, hammer toe and bunion repair, and GI endoscopy. Supplemental oxygen may be used, but not anesthetic gases. The airway is not protected as intubation is not employed.

Twilight anesthesia is simply a level of sedation as opposed to general anesthesia. It is used for minor procedures such as a colonoscopy as opposed to actual surgery. Twilight can be combined with a regional anesthetic such as an epidural or spinal for orthopedic surgery for example. But in no way does twilight equate to general anesthesia