Anesthesiology resident Max Feinstein, MD, discusses patients' dreams while under anesthesia.
Following is a transcript of this video; note that errors are possible.
Feinstein: If an anesthesiologist asks a patient to imagine a very pleasant place like a sandy beach, as the medication is being pushed to go under anesthesia, is there any chance that that can influence what a patient dreams about while under anesthesia? But before we delve into that question, we first have to understand whether dreaming under anesthesia actually occurs with any meaningful frequency.
My name is Max Feinstein and I'm an anesthesiologist filming here at the Mount Sinai Hospital in New York City. Throughout the duration of my training, I never encountered any lectures or textbook material about dreaming under anesthesia. It was just not a part of what we learned about, so I was actually pretty surprised to learn that there are quite a few well-done randomized controlled trials about dreaming under anesthesia.
In a number of studies, which I have cited in the description below [the video on YouTube], the frequency of dreaming under anesthesia is reported to be approximately in the 20% to 30% range, but that depends, in part, on when you ask a patient.
If you ask a patient who is just emerging from anesthesia whether they had any dreams under anesthesia, that tends to be a higher percentage of patients who report yes compared to patients who are asked at an hour or several hours after they have emerged from anesthesia. I personally feel like this is my own experience when it comes to regular sleep and dreaming where I tend to remember my dreams pretty vividly right after I wake up, but then an hour later I probably won't remember much.
There are some similarities between non-rapid eye movement sleep and general anesthesia, including unconsciousness and minimal or no processing of the external world. There are some scientific studies that show that, neurologically, there are similarities between what's going on during non-rapid eye movement sleep and general anesthesia.
Having said that, the anesthetized state is not the same thing as regular sleep, so it's not a good idea to ask someone to anesthetize you to help you sleep and especially when that person is not qualified to deliver anesthesia, and especially when that's taking place outside of a healthcare setting. But I digress.
Part of what makes the idea of dreaming under anesthesia so interesting is what the contents of the dreams entail for patients who have been interviewed. One of the original studies on this topic that was published in 1970 reported a patient who dreamed about being at a party at a public house with a generous supply of gin where the landlord was none other than the anesthesiologist. But the potential practical implications of dreaming under anesthesia is the theoretical concern that dreaming could indicate either that the anesthesia is too light or that the patient is about to experience awareness under anesthesia.
One of the studies that set out to answer this question put a depth-of-anesthesia monitor on a patient's forehead and assessed whether there is a relationship between light anesthesia and a patient reporting having dreamed. I think the study was both pretty well-designed and also well-executed. What they found is that there was no relationship between light anesthesia and having dreamed under anesthesia.
But the research I find most fascinating is that which looks at the actual contents of dreams that patients report under anesthesia. Generally speaking, patients report having pleasant dreams that are unrelated entirely to the surgery or anything that's going on around them while they are under anesthesia.
For example, a 28-year-old gentleman who was having a laminectomy reported dreaming about catching a few fish on a river in the city. He took some friends out into the bay. The water was really rough. He was happy he caught a few fish; one was a snapper. There was also a report of a 31-year-old woman undergoing an appendectomy who dreamed about her puppy. She was cuddling it and walking it. Isn't that nice? Overall, the types of content that people report dreaming about under anesthesia tend to be related either to loved ones, vacations, or sports, among some other common topics.
Going back to the original question that I pitched of whether an anesthesiologist can influence the content of a patient's dreams under anesthesia, the answer suggested by one study is probably yes. In the study, one group of patients was coached for a few minutes, just before undergoing anesthesia, to think about being in their favorite place. As it turns out, many of these patients report dreaming about being in their favorite place after they emerged from anesthesia.
Will you or your patients dream under anesthesia? That probably depends on factors such as a patient's age, where younger patients tend to be more likely to dream. It's also dependent on what anesthetic agent is used, where patients who are maintained with anesthesia using propofol tend to dream more than patients who are maintained with other anesthetic agents like isoflurane or sevoflurane.
Watch the video above for more.
Max Feinstein, MD, is a PGY-4 anesthesiology resident at Mount Sinai Hospital in New York City, where he is also chief resident of teaching. His YouTube channel focuses on perioperative medicine, especially the role of the anesthesiologist.