Expert: Mary Gordon - 2/4/2010

Question
My ex father-in-law (70 years old) with diabetes and high blood pressure went in for a 5x heart bypass almost 4 weeks ago. Physically his wounds healed, but he is completely confused and seems to hallucinate. This situation seems to get worse and today (almost a month after the operation) he was the worst I've seen him. He recognizes us, but does not seem to realize that he is still in hospital and had an operation. He does not answer questions or show any concentration - he tells fantasy stories and talk about things that don't exist like horses with golden heads and uses words that don't exist. He is no longer on any pain medication. He receives a sleeping tablet and something to calm him down. Last night he became very aggressive with the nursing staff of the hospital and wanted to break their computer.  We read about post operative dementia on the internet and wonder if this could be the problem. Is this a permanent situation?

Answer
Hi Irene - yes, his mental decline is likely to be related to the bypass surgery. It sometimes gets called pump head or POCD - and yes, this might be permanent - it's hard to tell at this point. Here are a couple of good articles about the phenomenon

http://heartdisease.about.com/cs/bypasssurgery/a/pumphead.htm
http://chestjournal.chestpubs.org/content/128/5/3664.full


In a nutshell, it's frighteningly common - a significant number of people will show cognitive decline, memory problems etc. after undergoing coronary bypass surgery.  I've seen figures above 50% after surgery, and many of these people will still have problems years later.

Any surgery involving general anesthesia can cause impacts to the brain, but cardiac surgery, particularly involving a heart lung machine seems to be the worst. Risk goes up with age, high blood pressure, lung disease and alcohol consumption. Some people who lose some cognitive ability will gradually regain their intellectual abilities within six to 12 months.

No one really knows why this is. My mother in law really went for a loop after she broke a hip and had surgery to repair it. Before her fall, she had not been diagnosed with any dementia, and the only problem she had was being a little forgetful. She lived on her own, looked after herself, managed her money, got herself to appointments, had a social life.  After the surgery, she was so completely confused and out of it that the hospital sent a social worker to talk to us. They thought we were in denial about her condition and that we were lying when we told them she'd been okay before the surgery. They wanted to put her into a nursing home right away.  She did gradually get better, but it took months and months, and she never got back to where she'd been prior to the surgery. I think in her case, the Alzheimer's was brewing before the surgery, and we just didn't realize it. It was as if the surgery unmasked what was going on underneath the surface.

It certainly is true that for anyone with pre-existing dementia, surgery very often makes them much worse - and although they may recover some ground, they never get back where they were before the surgery. It's common and dramatic enough that many families decide not to allow the person to have general anesthesia unless the person needs the surgery to prevent suffering (such as in the case of a broken limb).

It's possible with your dad's very serious grouping of risk factors, he may have had cognitive problems brewing prior to his heart surgery - he would have been at very high risk for multi-infarct dementia (also called vascular dementia), which is caused by tiny strokes. Each tiny stroke may not cause obvious symptoms, but each one causes a bit of damage, and over time, this accumulates to the point where symptoms of impairment appear.

The heart lung machine itself (probably used in your dad's surgery), can create clots which form in the machine. These clots can cause strokes and blockages in the blood vessels of the brain, lungs and heart. The machine can also introduce tiny bubbles to the blood supply that can block circulation. Another risk of coronary bypass surgery is that plaques — the fatty deposits  in the walls of coronary arteries and other vessels - can break loose from the walls of the aorta when it is clamped shut for the heart-lung machine. This debris can lodge in the blood vessels of the brain, causing a blockage or "infarct" and in turn brain damage. The machines are very rough on platelets, and the damaged platelets stick together and form clumps - again that can block brain blood supply.

Another thing that can happen is inflammation in the brain, which is also associated with mental impairment.

I wish I could tell you something more positive. He may recover slowly over the coming months, but it is hard to say how far he might come back, if at all - or if he is now on a downward slide mentally. I suspect you will just have to watch and wait - I know this is very difficult. Does his doctor have any insight into what is going on?

Thinking of you.

Mary G.
Toronto