sleep during colonoscopy

Colonoscopy is the most effective way to screen for colorectal cancer. It is also the best to way to diagnose diseases of the colon. After questions regarding bowel prep, people often have questions regarding sedation during colonoscopy.  Do I go to sleep during colonoscopy? Is colonoscopy painful? What medications are used for sedation during colonoscopy? What are the adverse events related to sedation in colonoscopy?


Types of sedation

  • Minimal sedation. This is a drug-induced state in which patients can still respond to verbal commands.
  • Moderate sedation. This is also known as conscious sedation or “Twilight sedation.” It is a drug-induced depression of consciousness in which patients can respond to tactile stimulation.
  • Deep sedation. This is a drug-induced depression of consciousness in which patients cannot be easily aroused though they may respond to painful stimuli.
  • General anesthesia. This is a drug-induced depression of consciousness in which the patient is not arousable even with painful stimuli. With general anesthesia, patients need assistance maintaining their airway. An anesthesiologist helps the patients breathe.

Sedation is a continuum. It is difficult to predict how patients will respond to sedatives. Patients may slip into any level of sedation at anytime. Some patients may sleep through a colonoscopy with medications used for minimal or moderate sedation.


What is MAC sedation or anesthesia? 

  • MAC stands for monitored anesthesia care. It is a specific service in which an anesthesiologist has been requested to perform sedation for a patient undergoing a procedure like colonoscopy.
  • Having an anesthesiologist administer anesthesia instead of the gastroenterologist increase the overall cost of colonoscopy. An anesthesiologist is however necessary for certain colonoscopies.


Do I go to sleep during colonoscopy?

It depends. You can choose to be awake or asleep during colonoscopy. Because colonoscopy can be done without sedation, you can choose to watch your own colonoscopy. If you want to be asleep during colonoscopy, there are 2 main ways to achieve this.

You can choose moderate sedation or deep sedation.  With moderate sedation, patients are usually arousable at all times. This means they can be woken up if necessary. You may wake up during the procedure. This is not necessarily a bad thing because it alerts your physician to your discomfort so they can change their technique or give you more medications.

Moderate sedation is achieved with use of fentanyl and midazolam. Sometimes benadryl is also added. Deep sedation is achieved with use of propofol. In many places, an anesthesiologist or a nurse anesthetist administers the propofol.

Rarely is general anesthesia used for colonoscopy.


What medications are used for sedation during colonoscopy?

  • Several medications are available for sedation in the U.S. These include midazolam (versed), diazepam (valium), diphenhydramine (benadryl), promethazine (phenergan), meperidine (demerol), fentanyl, and propofol.
  • Midazolam and propofol are the most commonly used sedatives. Fentanyl is the most commonly used analgesic.
  • Propofol can be used alone whereas midazolam is often used in combination with fentanyl and benadryl.
  • Benadryl potentiates the effect of midazolam and fentanyl. It is particularly useful in patients that are difficult to sedate.


What are the adverse effects of sedatives during colonoscopy?

  • Some adverse effects are universal. These include drowsiness and impaired cognition for up to 24 hours after the procedure. This is the reason you need a an adult person to drive you home and why you should take the entire day off from work.
  • These medications can cause respiratory depression meaning your breathing may slow down. To prevent  this complication, you are given oxygen during the procedure. Also, you are monitored throughout the procedure. In addition, the medications are given a little at a time to gauge your response.
  • Midazolam can cause retrograde amnesia which is not bad for the procedure itself. It can also cause nasal itching and hiccups.
  • All drugs may cause adverse reactions. Life threatening reactions are rare.


How to make patients comfortable during colonoscopy without medication

  • Use water instead of air to inflate the colon. Room air causes abdominal cramps and bloating.
  • Inflate the colon with carbon dioxide (C02) instead of room air. Carbon-dioxide can be absorbed by the body and therefore less likely to cause abdominal distention, abdominal cramps and perforation.
  • Use a pediatric colonoscope instead of adult colonoscope for certain patients. Petite people as well as those with diverticulosis and known stricture may benefit from a smaller pediatric colonoscope.
  • Play a soft music. Music has been shown in some studies to reduce discomfort during colonoscopy.
  • Talk to patients. For patients that elect no sedation or minimal sedation, you can talk to them if they are awake. You can give a commentary of what you’re seeing on the screen.


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