Does anesthesia “fry” the elderly brain?

One of the most common fears of people undergoing anesthesia and surgery is that anesthesia will cause harm, even permanent damage, to the brain. The traditional view is that anesthetic agents are rapidly metabolized (broken down) and/or excreted from the body, their effects are readily reversed, and anesthesia is therefore unlikely in the long run to cause neurologic injury.

We know that anesthetic agents affect many aspects of brain physiology, altering blood supply to the brain, metabolism, neurotransmitters, cerebrospinal fluid production, and more. These effects are being investigated in the laboratory and through the use of special imaging techniques. The picture that emerges is as complex as the brain itself, and is sometimes surprising. For instance, certain anesthetic agents seem to protect, not injure, the brain – at least in animal experiments.

Your Brain on Drugs

More than 50 years ago, it was reported that some older people have brain problems after surgery, and recent research challenges the belief that a well-conducted anesthetic and complication-free surgical procedure is totally neurologically benign.

The term postoperative cognitive dysfunction (POCD) has been coined to describe the mental changes, (in the areas of thinking, attention and memory) that do occur in some patients after anesthesia and surgery.

Depending on when the presence of these changes is assessed, and in what population, as many of 50% of patients can show some change in cognitive function, though most patients seem to recover in time.

A large clinical study from Duke University now appears to confirm earlier findings, in an important 1998 Lancet publication, showing that significant numbers of elderly people experience long term (3 months or more) changes in higher order brain function after anesthesia and surgery. This study and similar recent research raises many questions about how and why the changes that lead to POCD occur.

1064 patients were studied. They were classified as young (18-39), middle-aged (40-59), or elderly (60 or older) and had a variety of surgeries not involving the heart. Before surgery, at discharge from the hospital, and 3 months after hospital their mental function was tested with a battery of tests. Patients were discharged from the hospital an average of 4 days after their anesthesia.

The main findings:

  • At discharge from the hospital, signs of POCD were present in 30-41% of patients.
  • At the 3 month mark, young and middle aged patients had recovered, but 12.7% of elderly patients (over 60) still showed cognitive impairment.
  • Risk of POCD at 3 months after surgery was increased in patients aged over 60, those with a low educational level, a history of previous stroke (despite recovery from that stroke), and POCD at hospital discharge.
  • Patients with POCD were more likely to die in the year after surgery.

Some observations:

  • This is an important study (it is accompanied by an editorial) and confirms that elderly patients are at risk of POCD.
  • This study cannot tell us whether POCD is due to (1) anesthesia, (2) surgery, or (3) some aspect(s) of recovery from surgery (e.g. pain, pain medication, other medications, infection, inflammation, sleep disruption, etc).
  • A 22 month gap occurred between submission of the paper and eventual publication in the January 2008 edition of the journal. I wonder whether Anesthesiology’s peer reviewers were not entirely happy with the paper’s methods or conclusions.
  • Controls – the patients against whom the patients getting surgery were compared – were family members. They showed approximately a 5% incidence of cognitive impairment incidence which seems pretty high.
  • Young patients (age 18-39) had higher cognitive impairment rates than middle-aged patients (though not reaching statistical significance) which also seems surprising.
  • The type of anesthesia used in each case is unfortunately not recorded.

Researchers suggest that, in patients who develop POCD, limited brain “reserve” has been somehow “unmasked” by anesthesia and surgery, or that anesthesia and surgery somehow accelerates the ageing process in the brain. Inflammation might be the culprit. Inflammation is part of the body’s response to the trauma of surgery but has possibly harmful effects. Previous research has shown signs of inflammation in cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) after surgery but it is not clear whether this is the cause, or the result of POCD.

The study authors speculate that patients who develop POCD may become less able to recognize their own difficulties and to take care of themselves, including accessing needed medical care, explaining the greater risk of death in these patients after hospital discharge. It has been shown in other studies that, quite apart from surgery, elderly people with cognitive decline die sooner than those without.

What you can do about it:

Not much. Not many of us are going to volunteer for surgery without anesthesia. Even if anesthesia is in some way responsible for this syndrome (not proven by this study), we do not yet know, and this study certainly doesn’t give us any clues, whether any particular type, or even dose, of anesthetic, increases the risk of long term POCD.

We don’t know of any way to protect against the development of POCD. What we can do, is what we do routinely, that is maintain measured physiology (“homeostasis”) as close to normal as possible during each case (heart and lung function in particular).

It seems intuitive that general anesthesia might be more harmful than regional or local anesthesia but this is not proven. There is some evidence that early recovery from POCD (at 1 week) is better with regional anesthesia but differences disappear at or before 3 months.

Should the elderly avoid surgery because of the risk of POCD? Every surgery should be accompanied by a careful evaluation of the risks and benefits for that patient. This study suggests that when elderly patients are assessed for surgery and are found to have a history of stroke, or have a poor educational background, extra caution is warranted. Those that develop POCD may need a prolonged period of additional support and care at home.

Reference:
Monk TG, et al. Predictors of cognitive dysfunction after major noncardiac surgery. Anesthesiology 2008; 108:18–30. Link to this article here.

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24 Responses to Does anesthesia “fry” the elderly brain?

  1. I read your blog for quite a long time and must tell that your articles always prove to be of a high value and quality for readers.

  2. never again says:

    Don’t let anybody use Versed/Midazolam a drug designed to deliberately cause brain dysfunction. Medical professionals are enamored of this drug because it creates an extremely obedient, unquestioning patient, (also pads the bill) but this drug can cause disastrous POCD.

  3. grace droste says:

    I hated the post op cognitive discomfort

  4. Carol Heubach says:

    My 88 y.o. mother has severe POCD after general anesthesia. She has had 4 o 5 major surgeries related to two hip replacements which were absolutely necessary, and subsequent revisions due to infection. She is currently post-op 8 days and is slowly coming out of her POCD. She has a long history of Ativan dependence, along with a huge cocktail of antidepressants for many years. This apparently makes POCD alot worse. So far warning to anyone in need of surgery with these predisposing issues and age. She does always seem to come out of it though. She goes through total confusion, then severe forgetfulness, agitation, and then slowly becomes her old self.

    • surgiprep says:

      The evidence from studies goes along with your mother’s experience. Many elderly patients develop POCD but most recover within about 3 months. Surprisingly, regional anesthesia (spinal, epidural) does not seem to lower the risk of POCD.

    • Lorraine says:

      Help. My 81 year old mother had general anasthesia two months ago today and she is a different person. She was full of life, fun, worked, drove, was in a choir, and was a hairdresser. She does nothing now is very anxious, fearful, can’t be left alone, forgetful, and said she feels like her body is breaking down from the inside out. She is foggy, and can’t function. Does not want to shower, can’t be around crouds (loved people) and is just a mess.
      They gave her ativan, lexapro, clonipin and effixor not of which worked.

      I need to know if this will ever get better.

      I read what you wrote and would love to talk to you.

      Thank you.

      Lorraine

  5. Betty Ann Sherretta says:

    My mother is 93 and had a ruptured appendix. She is physically recovering, but she can not “stay awake” she is very “nervous”, she is afraid she is dying, and she has had anxiety attacks since surgery, it has been 1 week. how long will the sleepiness last, and is there anything we should be doing to help? She also has no appetite.

  6. Jay Latman says:

    My mother underwent a colon cancer surgery 10 years ago when she was 82. She went into the surgery room completely lucid and without any problems with memory or cognitive issue. She came back almost like a vegetable. She did not react on any thing or anybody around her. She was very agitated and upset.
    A couple of month after the surgery, she was better but her short time memory was definitely damaged. Now 10 years later she’s unable to care for herself and even mid-term (10-30 years) is gone. I believe that all these problems were clearly due to POCD.

  7. phyllis simpson says:

    Our mother is 4 mo. out from her knee surgery and is really showing signs of much slower reflexes, severe hand shaking, and just basically shutting down. Things that used to be easily accomplished like, buttoning her blouse, now take her much, much, longer and she is not participating in conversations at all. She is 82 yrs. old and has now become incognant, she will sit and stare at a blank television, she will go all day without eating if the food is not introduced to her by someone else. This is totally out of her normal character. She has changed tremendously after this surgery. She has become much more dependent on others for her daily care. I would not recommend anyone to have knee surgery if they are of this age and can get around at all.

  8. Be warned says:

    My mother just experienced the scary symptoms of PCOD after back surgery. She had a previous stroke. We had NO IDEA of the risks! Thank you, Carol, for explaining your mom’s experience. We are going through the same cycle & are now at 1 month post-op.
    She is slowly coming back but the short-term memory is definitely impaired.
    We pray that she will be 100% in time.
    Caution: do weigh the risks before having your parent undergo surgery–Especially if they have had a previous stroke.

  9. Mary Ireland Durrett says:

    My 85 year old mother has had three major surgeries (hysterectomy, colon, and double knee replacement) in the past 8 years. I have seen her memory deteroriate to the point now that she cannot remember what she did yesterday!! She cannot remember what she ate for breakfast!! But, she knows who we are, but can’t remember the last time she spoke to me or saw me.
    It’s not alheimers nor does it sound like dementia to me after looking that up on the internet. I feel like her poor brain IS fried from the anesthesia. She is on very little meds. Blood pressure and thyroid meds. Her appetite is diminishing but her spirits are still good. My brother lives with her and makes sure she takes her meds and eats. It’s very frustrating for him and all of us involved. Any suggestions?

    • surgiprep says:

      It sounds like it could well be Alzheimer’s disease because that is the commonest cause of the kind of short term memory loss you describe. The surgery and anesthesia may have contributed – but we don’t have any way of testing that.

      I’ll be writing another post about postoperative cognitive dysfunction soon, so look out for it.

      I don’t have any suggestions that you probably haven’t already thought of….get a good primary care physician and/or geriatrician involved in her care to make the right diagnosis and try to access all the support services in your community. Some of the new meds for Alzheimer’s might help a bit, but there is no real effective treatment at this point.

  10. Blanche Pinson says:

    My personal observation of my father before and after surgery has left me totally disillusioned and heart-broken about the effect of anesthesia in the very elderly.

    After my husband abandoned me in 2009, Dad moved into my home from a different State. Aged 87, he was whistling tunes, playing his violin, walking with a 4-footed cane (which he swung before him jauntily), and interested in politics and conversation.

    Dad’s only real complaint, and a constant one, was that he had an old hernia which had prolapsed into his scrotum, followed by his bowel. He could not even hold his huge scrotum fully in his two large hands. When my personal physician saw it, shocked and concerned, he arranged for us to visit with a surgeon that same day.

    Immediately after surgery, Dad was somewhat more likely to slip to the floor, no longer conversant, and his memory had significantly deteriorated. The day following the surgery, at home, assessing the level of care and watchfulness he required, I put to sleep my aged and delicate pet; I could not provide the needed care for both of them.

    Within months, Dad deteriorated quickly into full dementia, not Alzheimer’s, and failing physical abilities. After a year, he never walked again, had no recall of the current year or his age, could speak little, showed no interest in his violin, and was in hospice care. In fact, as his caretaker, I had to be alert 24-hours every day lest he try to stand and inevitably fall, and was virtually house-bound with him.

    When I could no longer care for him because of my physical limitaions and lack of sleep, we placed him in a nursing home, which makes me squirm internally because of the facility’s many shortcomings and our lack of funds.

    Now it is 2 years after his surgery, and he is completely lost to me as a personality, though he still has a sweet nature. His only evident pleasure is anticipating a cup of coffee and some bites of glazed donut, neither of which he can quite swallow. Any words are rare, hesitant and garbled, and never in a sentence. He appears to have trouble comprehending simple statements, but he recognizes me after a few minutes when I visit him.

    I am praying that the medical profession, and especially that of anesthetics, is making an effort to determine how surgery in the very elderly can be safely (and painlessly) executed without sacrificing the person. As “Baby Boomers” who are living with some of the best medical care available, we are nearing the ages in which surgery is much more dangerous for possible after-effects that can rob us of quality years ahead.

  11. Nancy Henneberry says:

    My husband is 82..had some dementia but lived at home with me..then 3/31/11 he fell down the basement stairs..backwards..hitting his head on the concrete but had no broken bones.Had acute therapy for a couple of weeks then moved to a local nursing home for more therapy.Dementia (Alzheimer’s) seemed worse but still not too bad…was planning on coming home by July 1st….then had 2 pancreatic attacks and finally had gallbladder surgery on June 27th.Back to nursing home in 48 hours. Is absoutely off the wall…sometimes knows me sometimes not..will this ever clear up..how long does it take?

  12. Wayne Coetzer says:

    My 71-year-old dad had surgery to remove blood from his brain (“extensive right cerebral hemispheric chronic subdural haemorrhage”) on Tuesday 9 August. He was in ICU due to convulsions after the surgery, but the convulsions have since ceased. He is now in “hi-care” and not on any sedative. As of today, he does wake up for a bit and can respond and speak and does recognise his family, but then he spontaneously falls asleep again. Is this drowsiness/confusion as a result of the anesthesia and is it normal in older patients?

  13. nita says:

    @Mary Ireland–my 76yo father had heart valve replacement surgery 2 years ago, and has never fully recovered from his POCD. He still has moments of delirium, and has similar memory issues to your mother. However, he has been tested more than once now for Alzheimer’s and passed with flying colors. So, your mother’s memory difficulties don’t necessarily mean she has Alzheimer’s! It IS frustrating for all involved, and I try to help my mom stay calm so she doesn’t harass him, because I’m sure he’s the most frustrated of all. Hang in there–we are lucky to still have our parents with us, whether they can remember what they did yesterday or told you 5 minutes ago or not.

  14. joycebarb says:

    i just found this article, my Mom had surgery last monday. She is 86 and is frail with failing memory, but lives with me and can stay home alone, read, etc. Her deterioration after hip surgery has been shocking. She has been tormented by hallucinations, both visual and auditory, and delusions. Those abate a little, but her cognition is shot, i.e. she does not know where she is physically despite being told many times and has no idea what month it is, etc. I had never heard of POCD, was not warned about it, and am very upset. The nursing staff has no idea what her mental state was before the surgery, they think she was like this all the time. I tell them my concerns, they are currently telling me it is urinary track infection, which can cause confusion in eldery women. But her fever is gone, she has been on antibiotics for3 days, and she still has the unfortunate and sad delusion that she has died, is crying and very distressed. Wish this risk had been explained to us ahead of time, it is very difficult to see. Hard to believe she could go in for a hip pin and lose her mind as a result.

    • surgiprep says:

      There is a high rate of temporary cognitive decline in the elderly who have surgery. This decline is common also in patients who have hospital admissions without surgery. We probably don’t do enough to tell patients and their families about this risk but it is hard to assess the risk for an individual – some people do well from the start, others have a temporary setback and get back to baseline within 3 months or so.

      You don’t say whether your mother had a fall and a hip fracture, as is common in women of that age. What you have to realise is that failure to perform this surgery, and to repair the fracture early, condemns these patients to spend the rest of their lives in bed, and, very often, an early death from pneumonia.

  15. diann says:

    My mother is 73, and 2 months ago had hernia surgery, since then she describes her brain as “not being able to make the right connections” She could knit and crochet b4 surgery with her eyes closed or practically in her sleep, when asked if she can now she says no, not even a crochet chain. She goes in the refrigerator looking for her cereal and once you ask her what she is looking for and tell her it’s not in there she then is able to figure it out. My father has Parkinson’s and she has been his care taker. We live 8 hours away. At first I thought maybe it was her potassium level and maybe going into renal failure but the Dr said those levels were good. The next step is a brain MRI, will POCD show in an MRI? Do they recover from this , this far out?

    • surgiprep says:

      POCD is a syndrome and there are no specific findings on MRI. An MRI may however reveal other findings that could explain your mother’s cognitive deterioration. Even patients who don’t have surgery can experience a cognitive decline after hospital admission. We don’t know what the relative contributions to POCD are of surgery, anesthesia, other drugs, infection, pain, metabolic changes, sensory deprivation, bedrest, etc.

      It is a big challenge but don’t lose hope for you mother’s recovery. Even patients with severe strokes can recover function if they have enough self-motivation, and intensive support and encouragement. In the mean time however it sounds like it will be difficult for her to take care both of herself and your father.

  16. Susan Brandt says:

    Our 90 year old father had knee replacement surgery on June 8th. He was sent home two days later to my mother who has had a stroke. Her cognition is excellent though she is compromised physically. Unable to care for Dad completely, I went to stay with them for two weeks. During that time, Dad fell on his new knee, breaking the knee cap. This was discovered a week after the fall. I had gone home (1500 miles away) and had to return to take care of them. Another surgery ensued. He is currently two weeks post-op from the knee cap surgery. We’ve had a visiting nurse who has 34 years experience with geriatric patients. Her observation is twofold: The elderly rarely come out of the anesthesia “fog,” and issues that may have been on the surface previously will present themselves with a vengeance post-op. My father, who is educated and ran a corporation, can’t even put sentences or complete thoughts together. This is not the man who went to the hospital for his surgery. He is now frail and confused. I do hope he gets better but we can’t be sure.

    • surgiprep says:

      I’m sorry about your dad. I hope he recovers; many patients are back to normal in 6 months or so.
      POCD is not “anesthesia fog” – it is much more complex than that.
      We now know the phenomenon is as common in medical as in surgical patients.

  17. Lisa Riegel says:

    My mother is due to have major (spinal fusion, laminectomy) non-cardiac surgery – maybe a 5 or 6 hr surgery. She is 79 and works stil. Her father never recovered from severe POCD after a simple hernia operation. She seems genetically a lot like him and we’re all petrified. How genetic is POCD? Is there anything the anasthesiologists/staff can do to minimize her risk? Is regional anasthesia less risky? If we opt to only do the laminectomy, we might be able to find a surgeon to do it with regional.

    • surgiprep says:

      So far, we don’t have evidence that regional anesthesia is less risky. It also isn’t clear what role anesthesia has in the development of POCD. Many factors seem to be involved:
      Surgery involves anesthesia but also the deliberate injury of tissues (trauma), hospitalisation and many other drugs. There is evidence that medical patients (i.s. those wo do not have surgery) have a similar rate of POCD to surgical patients. No anesthesia there!
      The peripheral systemic response to trauma, hospitalisation and drugs includes cellular damage, inflammatory mediators and so on.
      What happens in the brain that causes POCD is not known exactly but may involve inflammation also, direct toxicity to brain cells, and laying down of abnormal protein.
      Complicated!

      There seems to be an association between postoperative delirium i.e. acute brain injury, and long term cognitive problems. If we can prevent the delirium maybe the chances of POCD will decrease. This means:
      Treating pain – round the clock analgesia; avoid pethidine; avoid catheters
      Avoid sedatives whenever possible – benzodiazepines, anticholinergics, antihistamines
      Maintain orientation – glasses, hearing aids, clock/calendar, radio
      Ensuring sleep – non-pharmacologic sleep aids (music, massage)
      Prevent/detect severe complications of surgery including infection and heart attack
      Mobilisation – avoid physical restraints
      Nutrition – e.g. preoperative carbohydrate drink

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