Types of Delirium
Delirium is a common and very serious neuro-psychiatric syndrome. Typically it affects older patients with multiple medical problems, in fact up to half of all elderly patients in the hospital will have an episode of delirium at some point, but being said it could affect anyone – even children, even though that’s much less common.
So what is delirium exactly? Here’s a quick example.
Let’s say there is an elderly man with diabetes and heart disease, who comes into the hospital with pneumonia. He might be slowly recovering, even about to go home, and then one evening things change all of a sudden. He might get hyperactive, and by that, I mean that he may be agitated or aggressive with the staff, mumble or say things incoherently, and have disorganized thoughts or even delusions, perhaps talking about things that haven’t happened or things that happened years ago. He might even hear or see things like hallucinations, and not know where he is or what he’s doing there.
We would call this an episode of delirium, and it can be really scary for him or someone who is taking care of him, especially the first time it happens because it can come out of the blue. These are the symptoms of what we call hyperactive delirium.
But there’s also hypoactive delirium which is like the flip side of the coin. As an example, you might have a woman with a history of chronic constipation which has recently come out of back surgery. If she has hypoactive delirium, she might feel suddenly sluggish and drowsy, less reactive and sullen, and might look withdrawn, perhaps because she’s scared of having hallucinations. These symptoms of both hyperactive and hypoactive delirium can start pretty suddenly and can happen off and on over the course of a few hours to a few days, with some patients having what they call mix state delirium where they are sometimes having hyperactive symptoms, and sometimes having hypoactive symptoms.
As you might guess, delirium symptoms can be tiresome for a patient and can make them sleepy during the day, and keep them up at night – all of which causes massive disruption to a person’s life and the lives of their friends and family. Even though this sounds pretty hard to miss, delirium can often go unnoticed or confused with other conditions like dementia, which has some similarities.
Delirium vs Dementia
To help distinguish delirium from dementia, there are some key differences to keep in mind. Unlike delirium where the symptoms can start pretty suddenly, patients with dementia typically have a slow mental decline over months to years. Early on, dementia patients are also generally alert, oriented, have normal behavior, and don’t have hallucinations. The good news is that unlike dementia, delirium is usually temporary, resolving when the underlying cause is addressed promptly. Delirium can sometimes resolve within hours to days. But in other cases, it takes weeks or months to resolve fully.
So what causes delirium? The exact mechanism is not well understood, and unlike a lot of diseases, there probably is no single cause. But we do have a lot of clues, and these come from understanding the risk factors for getting delirium in the first place. Patients who have had recent surgery are often at risk for delirium, and it might be related to the effects of certain medications such as narcotic pain medication, benzodiazepines, hypnotics, and anticholinergics as well as the underlying diseases and chronic fatigue from not sleeping well in the hospital. Since delirium can also cause trouble sleeping, losing sleep can turn into a dangerous cycle that can worsen the symptoms.
There are some risk factors related to the person’s general health as well, for example, elderly patients with multiple medical problems, especially ones like dementia, constipation, pneumonia, and urinary tract infections are at high risk for having delirium. But even though we know these risk factors, there isn’t a specific pathophysiologic mechanism that explains delirium that we know of – currently we only have theories. One theory is looking at whether the overall level of neuro transmitters like acetylcholine, dopamine, norepinephrine, and glutamate might cause delirium.
Another theory is about how the neuronal membrane may not be able to depolarize properly in delirium, and therefore can’t transmit an action potential from one neuron to another.
A third theory suggests that it might also have to do with inflammatory cytokines that are released during an infection or trauma that might interfere with the neuron’s ability to do its job. There are other theories as well, and ultimately one or maybe all of these may be involved in the neuropsychiatric changes that we call delirium. The good news is that there are things that can be done to help prevent delirium from happening in the first place, and many of these things can also help calm a patient down when they are experiencing delirium as well.
The biggest key is identifying people at risk, and this is usually done with the multiple members of the team that interacts with the patient in different ways. As a quick example from before, a nurse might notice that a patient hasn’t been sleeping well, a pharmacist might notice that they are on multiple opiates for pain control, and a physician might notice that they have a history of delirium in their medical record. Taken together this is a high-risk patient, and recognizing these high-risk patients often requires perspectives from various members of the medical team.
Once you identify patients at risk for delirium, it’s really important to help them feel as oriented and comfortable as possible. You can do that creating an environment similar to their home environment. Basic things like reducing extra noise and stimulation by turning off the TV so that they can feel calmer, and making sure that they have their glasses on and that their hearing aids are working.
Maintaining a good daily routine really helps as well – so that means allowing them to eat healthy meals, stay well hydrated, stool regularly to avoid constipation, stay mobile and as active as possible, and maintain healthy sleep habits. This is, of course, applies to everyone but becomes even more important with patients who are at risk for delirium.
Since we know that many patients with multiple medical problems develop delirium after having surgery, it’s ideal to manage their pain using non-opiate pain medications, as well as avoiding the other medications that we know can cause problems.
Finally, it’s always ideal to let patients feel like they are in control and avoid using restraints or putting them in unfamiliar situations. This becomes particularly tricky when it seems like a patient might be unsafe, but there are medications like Haloperidol or second generation antipsychotics that can be used to help with patients with really severe symptoms. There are also some serious long-term effects of thinking about – one of the most important ones is related to falling. When patients are feeling disoriented, agitated, and confused, they can easily stumble and fall- in fact, some studies show that patients with delirium are up to 6 times more likely to fall. These falls can lead to all sorts of painful consequences including broken bones, head injuries, as well as bruises and bleeds. Unfortunately, this is why patients with delirium often end up having longer hospitalizations, more medical complications, and ultimately higher mortality rates.