A few searches online led me to the short answer: yes, anesthesia awareness is real.
A study from the University of Iowa's department of anesthesia found that some patients reported anesthesia awareness. Patients would mostly recall hearing sounds, and few patients actually reported this awareness during the stay in the operating room. Surprisingly though, most of the patients would report awareness much later, maybe as memory came back to them. Further, a study out of the University of Washington reported that some patients recalled pain! Terrifying. Both studies make note of the psychological trauma inflicted upon these patients. Among the more severe were post traumatic stress disorder and fears of future anesthesia.
These findings beg the question: how can we avoid this phenomenon? Surely anesthesiologists are highly trained individuals who know what they're doing. They artfully poison us, highlighting the delicate line between drug and poison – too much, we die, too little, we feel. They can't just crank up the knobs on their machine and deliver more Substance X to us, and there's no way for someone experiencing anesthesia awareness to ask for more Substance X. Thankfully, this experience happens in much less than %1 of all surgeries, which still doesn't seem to be a low enough number given the nature of the phenomenon. But either way, maybe it would be a better practice to be more heavy handed with the anesthesia? This is a hard thought experiment in my mind. There is so much variation among humans – height, weight, tolerance, medication use- that I find it miraculous we even have standards to calculate proper dosages for anesthesia. All I know is that if I had the choice between risking feeling awake during a major operation or having a groggy, rough awakening and subsequent “hangover” from being well put-under, it would be an easy choice for me to make.
References:
Bruchas R, Kent C, Wilson H, Domino K. Anesthesia Awareness: Narrative Review of Psychological Sequelae, Treatment, and Incidence. Journal of Clinical Psychology in Medical Settings. 18(3): 257-267. 2011
Ben,
ReplyDeleteVery interesting article and topic. It would be absolutely terrifying to be aware during any type of surgery. I like how you referred to anesthesia as poison and drew a clear line that we shoot for when we want to be put under. In the past year I have had to be put under for hip surgeries twice and it was always a fear of mine to wake up in the middle of it and not be able to move. Oddly enough, I was on the "too much" side of things and came out of the anesthesia throwing kicks and punches. Which makes me wonder, would it be worth the risk to give me less drugs so I come out smoother?
Regardless of that issue, I was curious to find if someone was doing anything about this. Some doctors in Melbourne, Australia are looking for ways to tell if someone is "aware" during anesthesia. The have found that some hemodynamic changes and electroencephalographic algorithms correlate to certain levels of awareness (Kostos 2012). I would think the gravity of the waking up during an open heart surgery would inspire more people to do research on this, but the data is slim.
Kostos L. 2012. Putting awareness to bed: improving depth of anesthesia monitoring. Australian Medical Student Journal. 3(2): 78-80
Ben, this was a very interesting blog post. Of course, I haven’t seen the movie and now want to, but this is another topic that I was not that familiar with, so I decided to do a bit more research and came across some pretty neat findings.
ReplyDeleteI found an article in which a woman was interviewed who is now an advocate for anesthesia awareness education after feeling wide-awake during the removal of her right eye. She recalled hearing things like “cut deeper” and “pull harder,” and she also remembered the surgery team discuss how long it would take to fix an instrument that they needed. What was worse, though, was that she described feeling extreme pain and could do nothing about it except for scream silently in her head to help her get through the two hours of surgery (Davis, 2007). How terrifying.
In the same article the interviewer included information that was adapted from another source that discussed a newer method for monitoring surgical sleep with the use of Bispectral Index Systems (BIS). This monitoring system permits anesthesiologists to access processed electroencephalography (EEG) information in order to gauge the effects of certain anesthetics. In other words, it observes and quantifies the electrical activity of the brain, which can indicate whether or not a patient is actually awake despite the paralyzing effects of anesthesia making it impossible for them to communicate. The BIS scale suggests that people who are awake and are not sedated usually have BIS values that are greater than 97. As the amount of anesthesia administered increases, BIS values decline, and as BIS values dip below 30, EEG suppression increases (Kelley, 2010).
While the BIS monitoring system helps prevent the chance of anesthesia awareness by guiding anesthesiologists to administer proper doses, it has its limitations, including influencing muscle tone in the forehead, aberrant EEG states, differences among anesthetics, and mechanical or electrical artifacts from medical devices; therefore, it cannot be solely relied upon as the sole monitoring parameter (Kelley, 2010).
References:
Davis R. 2007 Dec 4. Under the knife yet wide awake. USA Today [Internet]. Available from: http://usatoday30.usatoday.com/news/health/2007-12-03-anesthesia-awake_N.htm
Kelley SD. 2010. Monitoring consciousness: using the Bispectral Index during anesthesia. Covidien [Internet]. 2:1-40. Available from: http://www.biseducation.com/ uploadedfiles/assets/0000000012.pdf.
I find this very stressful, because I have had procedures done to me multiple times where they don't put me under and I receive the normal dose of local anesthetic, but I feel everything. Often they laugh and tell me that they know what they are doing when I tell them I will need almost a double dose. Sure enough I was right and they have to double up on the dose before they can proceed. I don't know if it is how my metabolism works, but my body needs more than the normal and I wonder if it applies to being put under. I think they should require a metabolism test, not just height and weight when figuring out the dose for procedures.
ReplyDeleteBen,
ReplyDeleteI laughed when you said "artfully poison us" that is definitely your voice in writing. When I had my surgery this summer, I was put under anesthesia for the first time. The last thing I remember prior to surgery is being wheeled into the room and the first thing post surgery I remember is saying "that was the greatest nap of my life." I am grateful I did not experience this, because I could not imagine being in pain, but not being able to move.
I wonder if some of these people have anxiety (which I am sure they do pre-operatively) and due to the effects of anesthesia aren't sure of the difference between what's real and what's not real. I have had plenty of dreams that feel so real and I feel like I am falling or in pain, but I wake up and it wasn't real.
There are many factors contributing to the effects of anesthesia which you mentioned. Something strange-- when I was in the dentist last, they had to use three times the amount of local anesthetic including giving me an injection in the hard palate (which hurt like the dickens). In the past, I have been told that fair-skinned individuals and those with red hair require more dosing as well. This is a little tangential from what you are talking about, but just an interesting thought. I even found a study that shows that red heads require more anesthesia than anyone else (Liem et al. 2006)
Liem E, Lin C, Suleman M, Doufar AG, Gregg RG, Veauthier JM, Loyd G, Sessler DI. Feb 2006. Anesthetic requirement is increased in red heads. NIH. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1362956/