Causes Of Delirium

[ photo by Anni Roenkae]

Delirium, a common condition in aging parents.

The majority of the elderly will at some point end up in the hospital. If you are caring for an aging parent, there is a good chance your loved one has experienced what is so common in the hospital; that is delirium.

Let me take a sidebar here and give you the definition of delirium. This can often be confused or used interchangeably with dementia, but these are two different things. They both involve impaired memory and judgement, confusion, disorientation and even possible hallucinations or paranoia.  Dementia is usually caused by anatomic changes to the brain with a slow onset of symptoms and is irreversible. Delirium, on the other hand, is typically acute or quite sudden in onset and is often due to illness, sleep deprivation, or some sort of drug or metabolic toxicity.  Delirium in someone without underlying dementia is usually reversible. 

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A typical case of delirium.

I recently had a patient in rehab, let’s call her Diane, who came to me after having a planned spine surgery. She had struggled with back pain for many years and had tried every treatment option available to her. Unfortunately, nothing was really helping. She was using some narcotics intermittently when the pain became severe, but she was really trying to avoid using these medications very often. Her surgeon felt confident she would get some relief with a surgery to relieve the pressure on the nerves coming off of the spinal cord, so she decided to do it.

There were not any complications during the surgery but in the five days following the surgery, she became very confused! She was originally scheduled to go home a couple of days after the surgery, but the confusion put her in the hospital for longer than anyone had expected. Because of this, she ended up qualifying for inpatient rehab, thus the reason she came to my hospital.

Her children were with her when I first met her. She had been living in an assisted living facility prior to the surgery but was independent with most of her mobility and activities of daily living. She did use a walker when she would walk to and from her dining room and then would use the walker in her apartment on particularly bad pain days. Her son managed all of her finances, so she did not need to worry about that. She had recently stopped driving, so her daughter accompanied her to all of her doctor’s appointments. The assistance from her children was definitely helpful for her and needed, but other than that, she was doing well on her own. 

(Related blog post: How To Tell Elderly Parent Not To Drive)

So, back to my first meeting with her and her children. They said she was incredibly confused after the surgery. They both reported they had never seen her act like that before. She had no idea of the date or time of day. They said there were times she would report things that happened in her hospital room that definitely never happened.

Evaluating causes of delirium.

As per the usual routine, she had a work-up done by her treating physicians that included blood work and urinalysis to rule out an infection and metabolic abnormality that could be causing the delirium. These were both normal. An MRI of her head was done to rule out a possible stroke. This too did not reveal any acute findings, though it did show some evidence of “microvascular disease,” which are changes in the small vessels of the brain. In the same way one can have coronary artery disease or peripheral vascular disease, the same can occur in the brain. These changes can ultimately lead to vascular dementia. With these causes ruled out, it was determined that her confusion was likely due to the use of the post-surgery pain medications as well as a likely element of the effects of her anesthesia. 

(Related blog post: Recovery After Stroke)

She remained hospitalized for a few more days. Her medications were adjusted, though it took some time to find the balance of adequate pain control and avoiding further worsening of her delirium. In addition, her kids took turns being with her to ensure there was someone with her to remind her of where she was, the date, why she was there, etc. When she was eventually ready to come to rehabilitation, her kids reported that she was the clearest cognitively that she had been since the surgery. Her children were excited that she seemed to be heading in the right direction from a cognitive standpoint and were hopeful she would begin true steps towards her physical improvement with rehab, as well.

(Related blog posts: Caring For Dementia Caregivers, Acute Rehabilitation Versus Subacute Rehabilitation: What’s The Difference?)

Common causes of delirium.

There is a commonly taught acronym in medical school to help remember the most common causes of delirium. It is a good one to share because I think it can help you know what to watch for in your loved ones should they start showing some evidence of delirium.

The first is D for dementia. Those with dementia are much more susceptible to periods of delirium, especially when they are removed from their normal environment. For E we have electrolyte disorders. This is why lab work is done to see if the sudden confusion can be explained by an abnormality of an electrolyte that might be easily fixed. For instance, a sodium level that is too high or low can lead to changes in one’s cognition. Now we have L for lung, liver, heart, kidney, and brain. This is when scans and additional blood work are done to determine if one of the organs is not functioning properly, thus leading to altered mental status.

The letter I refers to infection. Oftentimes, especially in the case of a urinary tract infection (UTI), a sudden onset of confusion in someone is the first sign of the infection. Next is Rx drugs for the letter R. Just as in Diane’s case, her pain medications had significantly contributed to her confusion. The next I refers to injury, pain, and stress. These things lead to poor sleep/rest, which can then translate to confusion.

U is for unfamiliar environment. Diane’s family stayed with her throughout the day to remind her that she was in the hospital and just to be a familiar face for her to see. This goes such a long way in someone who is at risk for delirium or already experiencing delirium. And finally, M is for metabolic. Blood work is done to rule out the accumulation of certain things in the blood that can lead to delirium. For instance, when one’s ammonia level becomes significantly elevated, it leads to altered mental status. In the hospital setting, these things are often able to be ruled in or out and quickly treated. Once someone does have delirium, it can often take a while (days or even weeks) for this to improve. If it does not improve after all the possible causes are ruled out, then that would lead to further testing. 

Seeing a loved one experience delirium can be unsettling and scary for most of us. More often than not, this does improve. If your loved one is at home when this begins, it is important to have them evaluated by a physician. If this occurs in the hospital, be proactive in making it known that he or she is not at baseline in terms of cognition and behaviors so that necessary steps can be taken to determine any underlying cause. 

(Related blog post: Taking Care Of Elderly Parents At Home)

Is your aging parent struggling with delirium? Share your questions in the Comments section. Or reach out to me directly for a personalized care strategy.

© 2021 Jessica Kluetz, DO