Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.

Three days ago, I was giving anesthesia for six consecutive colonoscopy patients. Following my first case, I checked my phone and discovered that the President of the United States Joe Biden was having a colonoscopy at Walter Reed Medical Center that very morning. The headlines stated that for the first time, temporary acting presidential power was being turned over to a woman, Vice President Kamala Harris, during the time of President Biden’s colonoscopy anesthesia.

I mentioned this to the gastroenterologist I was working with that day, and he asked, “How long do you think he will be unable to make decisions as the President? We tell our patients not to drive the rest of the day, and not to make any important life decisions after their general anesthetic. Biden has the most difficult and most important job on Earth. When can he return to duty?”

I answered, “My guess is that he’ll have the same propofol anesthetic we’re administering today. The procedure will last thirty minutes, he’ll begin to awaken five minutes after the propofol is discontinued, and within an hour he’ll feel clear-headed.” The gastroenterologist was dubious that the leader of the free world would be alert enough to resume power only one hour after receiving propofol. Joseph Biden was one day short of his 79th birthday when the colonoscopy took place. Later that morning the news services reported that the President had transferred presidential powers to Kamala Harris at 10:10 a.m. EST and resumed his presidential powers at 11:35 a.m., a mere 1 hour and 25 minutes later. 

The evening after the colonoscopy, comedian Colin Jost of Saturday Night Live joked about Biden’s colonoscopy.  During Weekend Update, Jost reported on Biden’s resumption of all his presidential responsibilities immediately following the colonoscopy, and noted that Biden had just turned 79. “Half the country already thinks he’s senile,” Jost said. “You can’t drop all that on him the second he comes out of the gas.”

A note from an anesthesiologist to the comedy writers: No one uses “gas” for anesthesia for a colonoscopy. The anesthetic is solely from intravenous (IV) drug(s).

I have no specific knowledge of what anesthetic drug regimen the President received for his colonoscopy, but more likely than not he received propofol. Anesthesia for colonoscopy is typically administered so that patients have no awareness during this procedure, a procedure which does not involve surgical pain, but rather involves the uncomfortable entrance of a 66-inch-long flexible hose, one-half-inch in diameter, into their anus, rectum, and colon. 

For the quickest recovery after colonoscopy, one option is no anesthesia at all. Very few patients sign up for a colonoscopy without any intravenous anesthesia. The press reports about Biden’s colonoscopy stated that he had anesthesia, so let’s discount the option that he had the procedure while awake. 

Colonoscopy sedation is typically done with one of two recipes: 1) conscious sedation with a combination of intravenous Versed (generic name midazolam, a benzodiazepine in the Valium family) plus intravenous fentanyl, such that the patient has no memory of the procedure; or 2) intravenous general anesthesia with propofol by continuous infusion or by intermittent boluses so that the patient is unresponsive. The combination of Versed and fentanyl leads to a slower wakeup and recovery than with propofol. The duration of effect of Versed is approximately 30 to 45 minutes after a single dose, with a recovery time of 2 to 6 hours. The duration of effect of IV fentanyl begins within minutes and lasts for 30 to 60 minutes after a single dose. 

Propofol for colonoscopy leads to a quicker wakeup, a quicker discharge home, and less hangover. Virtually every surgical general anesthetic in the United States includes propofol, and anesthesiologists are experts at the administration and pharmaceutical properties of the drug. Propofol is an intravenous nonbarbiturate anesthetic which induces anesthesia quickly and provides a rapid emergence from anesthesia. The onset of action is within 20 – 40 seconds. The anesthesia provider for a colonoscopy will continue administering IV propofol until the procedure is over. A typical colonoscopy will last 20 – 40 minutes, depending on whether the gastroenterologist needs to take extra time to remove any colonic polyps. In Biden’s case, a single 3 mm benign-appearing polyp was identified and removed.

Propofol’s pharmacokinetics are described by two phases:

In the first phase (red curve), the plasma concentration decreases rapidly because the drug redistributes, or spreads, out of the bloodstream into other tissues of the body. The halflife of this fast redistribution is only 2 – 8 minutes, meaning the concentration of propofol in the bloodstream is halved every 2 to 8 minutes. This first phase explains the quick transition to wakefulness up after the drug is stopped. The second phase (black curve) is the elimination of propofol from the body. The half-life time of this elimination from the body is 4 – 7 hours (reference: MILLER’S ANESTHESIA, 9thedition, chapter 23 on Intravenous Anesthetics).

The graph below depicts the timeline after propofol is discontinued. After a one-hour infusion, the concentration of propofol in the blood drops to near zero within 30-40 minutes.


The website affirms this, stating that “Recovery from anesthesia is rapid (8 to 19 minutes for 2 hours of anesthesia) and is associated with minimal psychomotor impairment.” The PDR also states that “The elimination half-life of 3 to 12 hours is the result of slow release of propofol from fat stores. About 70% of a single dose is excreted renally (by the kidneys) in 24 hours.”

While the President would be awake one hour after receiving 30 minutes of propofol, and the blood concentration would be minimal, it still takes 24 hours for 70% of a single dose of propofol to be excreted by the kidneys. Therefore, one hour after the propofol was discontinued, even though the blood concentration was minimal, a significant amount of the drug would still be in the President’s body.

I’ve had propofol anesthesia for a colonoscopy, and I can attest that I woke up promptly and was in an automobile heading home within 45 minutes after the end of the procedure. I felt alert, albeit a bit woozy, after 60 minutes of recovery time. Did I feel it would have been safe for me to resume my duties administering general anesthetics to patients at that time? No. Would a major American airline allow one of its pilots to fly passengers at that time? No. Would the U.S. Army allow a general to command thousands of soldiers at that time? I doubt it.

One hour after a propofol colonoscopy anesthetic, the President would be awake enough to converse and give a “thumbs up.” Would he be alert enough at that point to make decisions regarding the nuclear football, a potential attack on Taiwan by mainland China, or a terrorist attack on a major United States city? Was this nearly 79-year-old man safe to make all the acute decisions the United States President could have to make, only one hour after discontinuing propofol? 

The Mayo Clinic website states that, “After the exam (colonoscopy), it takes about an hour to begin to recover from the sedative. You’ll need someone to take you home because it can take up to a day for the full effects of the sedative to wear off. Don’t drive or make important decisions or go back to work for the rest of the day.” 

Was Biden fit to run the country 55 minutes after his colonoscopy anesthetic? 

Hmmm. The decision as to whether he was recovered enough to resume running the country . . . was a decision made by President Biden’s doctors on that day.



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