research

Movement and the Brain ⇒

A very interesting case study came out recently, looking at the neurological function of a particularly active 93-year-old woman named Olga Kotelko (she died in 2014 at age 95) . She became an athlete in her sixties playing softball, then started track and field at age 77. Exercise benefits are often assumed to apply to our physical state, and it also seems to be associated more and more with good mental health. This study took things a step further and looked at her overall brain function to see if her routine exercise had any impact on both the brain itself as well as cognition.

“In general, the brain shrinks with age,” [University of Illinois Beckman Institute postdoctoral researcher Agnieszka] Burzynska said. Fluid-filled spaces appear between the brain and the skull, and the ventricles enlarge, she said.

“The cortex, the outermost layer of cells where all of our thinking takes place, that also gets thinner,” she said. White matter tracts, which carry nerve signals between brain regions, tend to lose their structural and functional integrity over time. And the hippocampus, which is important to memory, usually shrinks with age, Burzynska said.

Previous studies have shown that regular aerobic exercise can enhance cognition and boost brain function in older adults, and can even increase the volume of specific brain regions like the hippocampus, Kramer said.

Kotelko’s brain offered some intriguing first clues about the potentially beneficial effects of her active lifestyle.

Though it wasn't strongly emphasized in the article, something else really grabbed my attention:

“During dinner after the long day of testing, I asked Olga if she was tired, and she replied, ‘I rarely get tired,’” [Beckman Institute director Art] Kramer said. “The decades-younger graduate students who tested her, however, looked exhausted.”

It really does seem that our culture has a problem with sleep. I'm as guilty of not getting enough sleep as anyone. I have a bad habit of getting only around 6-7 hours of sleep per night. I blame the amount of things I have on my plate at any given time for this, but the likelier truth is that if I would get enough rest, I could probably manage all of these things with greater efficiency.

In any case, one of my goals since transitioning settings has been to both increase the amount of sleep I get and also start to exercise more. Forming new habits is hard, but watching Olga herself on video shows that it's clearly worth it.

★ Cognitive Dysfunction in ICU Patients

Every month a group of #SLPeeps blogs about research. For formation, you can find more out about it here.

For my previous post, I talked about mild TBI resulting from electrical injury. That was an article focusing on a general disorder resulting from a specific injury. This month, I found an article that was something of an extension of this idea: general disorder(s) resulting from general illness. I spend a good deal of time in the intensive care unit, and my current rotation is focused on medicine patients. I work in both the medical ICU as well as the medicine sub-acute units. I work every day with a population who we don't typically think of as being our target audience.

One of the challenges of acute care, as I've mentioned previously, is that the intensity of patients' illness prevents doing any meaningful therapy. This isn't a bad thing; we're taught in school to start therapy immediately, but I've learned that there's a caveat to this. Starting therapy early is helpful only once a patient is medically stable. Without that last component, therapy is bound to be anything but effective.

The article I selected this month is not a study itself, but rather a "narrative review". The authors noted that unlike other clinical outomes, "cognitive function in critical care survivors has not been deeply studied."

The Study

The primary medical diagnosis discussed in the study was acute respiratory distress syndrome (ARDS). ARDS can be associated with a number of other diagnoses, such chronic obstructive pulmonary disease (COPD) or sepsis, but the requirement of mechanical ventilation was emphasized in the review.

The authors wanted to compare cognitive impairment at time of hospital discharge and then again later on, all in the context of acute illness (i.e. other than neurological injury, which are more widely studied). "At hospital discharge, 70% to 100% of patients were determined to have cognitive impairment... At 1- and 2-year follow-up, the prevalence of cognitive impairment was 46% to 78% and 25% to 47%, respectively." Though there is a decline observed in prevalence, it's interesting that there is cognitive impairment at all; these are patients we often receive consults for as primarily swallowing patients due to prolonged intubation. What's even more interesting: "the domains of cognitive function most commonly affected were attention and concentration, memory, and executive function." The caveat is that the severity of deficits rated across studies, but it is interesting to note that these are all areas in which speech pathologists work with other patients.

Factors Associated with Cognitive Impairment

The authors note that pre-existing cognitive impairment is difficult to rule out, and that a certain amount of pre-existing cognitive impairment may be prevalent especially in elderly ICU patients. Conditions such as genetic predisposition to Alzheimer's dementia (apolipoprotein E4, or APOE4) demonstrate a "stronger association with duration of elirium than age, severity of illness score, sepsis, or benzodiazepine use". Other factors to consider are pre-existing psychiatric impairment, such as depression. The authors also note that 10-58% of survivors of critical illness suffer from depression.

The above risk factors may indicate an increased likelihood for developing cognitive impairment. "The pathogenesis of cognitive impairment following critical illness is not fully understood but may represent an accelerated neurodegenerative process tht develops in in vulnerable hosts." Delirium is becoming more widely understood to not simply be "confusion" related to illness, but rather something that can have more significant and long-lasting effects. "[P]atients who suffered a longer duration of delirium had greater overall brain atrophy and ventricular enlargement as well as smaller superior frontal lobes and hippocampal volumes 3 months following hospital discharge." There were further findings of loss of white matter in the corpus collosum and internal capsule.

Clinical Variables

The first variable listed is hypoxia, which is not foreign to SLPs. We often consider hypoxic injuries relevant, and that consideration transcends area of expertise. An additional component the others discuss is hypotension; while we so often recognize hypertension as a risk factor for such things as stroke or aneurysm (heck, hypertension even earns itself the casually tossed about HTN shorthand), hypotension could be seen as a red flag for possible anoxic injury.

Other variables noted included sepsis, dysglycemia, delirium, and sleep efficiency. Patients with sepsis were observed to have "cognitive and functional decline... [and had] deficits in verbal learning and memory and were seen to have significant reductions in left hippocampal volume compared with healthy controls." Even EEG results showed changes, reflecting more low-frequency activity, "indicating a nonspecific brain dysfunction." Dysglycemia refers to fluctuations in blood sugar levels. The authors noted that "patients with a highest blood glucose level (>153.5 mg/dL) and those with with greater fluctuations in blood glucose had three times the odds of being cognitively impaired at 1 year compared with patients who did not experience either glycemic condition." Associated impairment with dysglycemia and hyperglycemia included deficits in visuo-spatial skills.

As I mentioned above, delirium is becoming more widely acknowledged as a relevant condition that can have lasting effects. I've been noticing it being discussed more frequently on rounds among more and more medical teams. Deliriums is defined as "an acute change in mental status that is characterized by inattention and a fluctuating course... [and] it is associated with longer lengths of stay, increased duration of mechanical ventilation, and higher risk of death." The link between delirium, which was once considered temporary (and still is, in some ways), and cognitive impairment is "hypothesized to be mediated directly or indirectly through a systemic inflammatory response," leading to chronic neuroinflammation and neurotoxicity.

Finally, sleep is a large component of cognitive well-being. A common theme among many of my patients is how hard it can be to get good sleep. It's easy to see why this is: patients are frequently woken for vital signs throughout the night, carted away for tests, or simply get restless (being stuck in bed for days, weeks or even months on end is astonishingly hard on the body). Though the studies found didn't report cognitive outcomes, they did note that "sleep fragmentation (quantified by actigraphy) was associated with a nearly 1.5-fold increased risk of incident Alzheimer disease after controlling for demographics, total daily rest time, chronic medical conditions, and the use of medications."

Moving Forward

Though we often concern ourselves initially with swallowing safety when we first begin working with ICU patients, it would behoove us to not look too lightly at cognitive status. Early on, I developed a habit of monitoring cognition from the moment I start working with a patient so that I could monitor their progress. I used to think of it as a way to really see (and document) how my patients are doing, but now I have even more reason to do so. Sure, I might shrug off confusion as "par for the course", but I will be watching closely to see how long it takes patients to really clear.

I attended a lecture recently that discussed delirium, and one of the most interesting points discussed was how easing sedation, spontaneous breathing trials daily, and early mobilization were helpful in reducing length of time for mechanical ventilation as well as reducing delirium. If these ideas pan out as they're hypothesized to, perhaps cognitive function may be more spared. The authors also point out that improving sleep efficiency can impact recovery. With that in mind, I found myself this week advocating for a patient with sleep apnea to be able to use his CPAP (no order had been written, and though he had his machine, it had not yet been cleared for use); he was so exhausted he kept falling asleep during my evaluation. Not only do patients perform better with rest; it may also help prevent further cognitive deficits down the road.

As I learn more about delirium and its long-term effects, I see potential for how SLPs can be assets to multidisciplinary teams. I'm learning to see how duration of delirum is as important, if not more important, than the "severity" of the delirium. This new information may begin to shed light on why we encounter patients who present with cognitive deficits (especially "frequent flyer" patients) with unclear etiology; we may be seeing early markers of cognitive decline resulting from chronic illnesses that lend themselves to chronic delirium.

Article Citation

Wilcox, M. Elizabeth, MD, MPH, et al. (September 2013.) Cognitive Dysfunction in ICU Patients: Risk Factors, Predictors, and Rehabilitation Interventions. Critical Care Medicine, vol. 41, #9, S81-S98.

★ Oral Cares For Days

SLP colleague and #SLPeeps twitter friend Rachel Wynn recently rallied the community of SLP bloggers to write about research. The mission? Taking the time once a month to read a research article and then write a review about it.

Having recently attended ASHA’s Dysphagia in Older Adults online conference, I have had a lot of research on my mind. As with any good continuing education, I walked away from the conference with far more questions than I had when I started it. Since then, I have found myself thinking often about different presentation topics, and how they fit into my professional life.

One topic that stands out to me, in particular, is that there is a lack of adequate research in acute care. And it seems that my conference wasn’t the only one during which this topic arose.

I’m finding myself in an interesting position, profesionally speaking. It has been now two years since I earned my CCCs, and at the moment I feel like all I want to do is pause, pull out all my textbooks and notes, and re-learn everything I ever studied in school. My perspective has shifted so significantly since I was a student; I find myself thinking about everything on a much larger scale than I ever imagined, and there’s so much I want to know.

Having a goal in mind is always nice, so it was timely that Rachel suggested this blogging endeavor. It’s given me a little bit of direction, something I think I sorely needed.

An Article: Nay, a Review

One of the presentations from the online conference was called Oral Hygiene in Older Adults: Complications, Assessment, and Care, and was presented by John R. Ashford, PhD, CCC-SLP. In 2012, I joined two Special Interest Groups, and when looking for articles for this project, I happened to perusing the “Perspectives” resources for SIG 13 (Swallowing and Swallowing Disorders). John Ashford had published an article in 2012 called Oral Care Across Ages: A Review.

Personal Bias

As an acute care SLP, I find that many of the patients I work with have, for lack of a better descriptor, disgusting mouths. This could be do to any number of factors: alcohol or drug abuse, prolonged intubation, and radiation therapy for cancer, to name just a few. When I work in the ICU, I have a tendency to start working with patients early. That is, I like to evaluate them before they might be ready to start eating. Not only have I found it beneficial in terms of being able to really gauge patients’ progress, but it also allows me to do my part to help advance them to feeding readiness.

I can’t quite recall when I started to say it, but I noticed recently that I have a little catch phrase I seem fond of sharing with patients and families: “If your mouth doesn’t feel good, then the rest of you doesn’t feel good.” It’s a simple observation, but I feel it’s a powerful one. It occurred to me at one point when I was sick; the combination of mouth-breathing and that filmy yet dry coating of my tongue and palate seemed to compound my illness.

The Mouth At Work

How does the mouth really work? It turns out, it’s not all that different from the rest of our GI tract. We’re very fond of probiotics these days, and we often discuss the idea that within our bodies lies a veritable ecosystem of bacteria. Our oral cavity, as the “beginning” of our GI tract, has its own ecosystem. John Ashford breaks it down nicely: “the oral cavity is covered by a protective mucous membrane, serous fluids, and mixtures of microorganisms, or flora, comprised of bacteria, viruses, and fungal species.”

The fancy term for this is biofilm, and it covers the surfaces of the oropharynx and teeth. “These coatings benefit the oropharynx by stimulating the immune system to protect surfaces against colonization and infection from invading microbes and to stimulate certain nutritional and digestive functions.” It’s like a naturally-occurring vaccine: a little bit of exposure keeps our immune system on the ball. The flora also function, as they do in our intestines, to help break down nutrients so that our bodies can extract them and use them accordingly.

Breakdown

While we are able to manage exposure to bacteria when healthy, illness of any kind leads to susceptibility. Poor oral health coupled with illness can leave one with greater colonization of bacteria and fungi, which, if aspirated, has the potential to cause pneumonia.

Many of the patients I encounter have poor oral care at baseline, which results in lost and broken teeth, and many of them have full or partial dentures. “[T]he acrylic and silicone materials used in denture and denture-lining construction provide ample surfaces for bacterial attachment.” As a result, proper denture cleaning is a must in addition to oral cares. Another point to consider, which I hadn’t before, is that “dentures that fit closely to mouth surfaces reduce salivary cleaning” (emphasis mine). We swallow routinely throughout the day, so basically the flora in our mouths are not permanent residents.

In his presentation for the Dysphagia in Older Adults Conference, John Ashford explained that saliva contains certain sugars, and it is those sugars (rather than oxygen) which the pathogens in our flora live on. Saliva, in a sense, acts as both an incubator (maintainer of moisture to provide an environment for flora to thrive, relatively speaking) and a lubricant. The “serous fluid [found in saliva] is rich in antimicrobial substances… [which prevent oral pathogens] from attaching to and colonizing the oropharyngeal surfaces, thus preventing oral infections.”

Oral Cares

Where does this leave us as SLPs? There are different schools of thought: some feel that oral cares responsibility lays with nurses and techs. It makes sense, given that they are usually the ones present 24/7, while we SLPs can only be present intermittently. Any SLP who has worked in a medical setting, be it acute, LTAC, SNF, etc., is likely aware that oral cares are often neglected in the face of other, seeming more pressing, issues. I’ve also found that my emphasis and perspective of the importance of good oral care is not always shared by others; this isn’t a bad thing, necessarily, but I think the nature of increasing specialization. It’s why being part of an inter-disciplinary team is so important: I can develop a plan, emphasize its importance, and encourage the team to follow the plan to ensure the best patient care.

Ashford cites a number of studies which show that “tooth brushing is strongly supported over use of foam swabs with hospitalized and nursing care patients”, as “toothbrushes were substantially better at removing plaque”. When I provide oral cares, I often begin with a swab, as I have found it more effective to remove dry oral mucosa that may be coating the tongue, teeth, and palate. Once I am able to clear the oral cavity, I then go back to brush properly. In the event that someone’s mouth is particularly messy, I like to provide thorough cleaning before initiating any PO trials. It has the benefit of not only helping the patient feel better (and optimize their chances for success), but it can also serve as a nice way to increase level of arousal in somnolent patients.

Moving Forward

I appreciated this article, as well as the conference lecture, as an excellent starting point. I have been looking into further into tools like the Oral Health Assessment Tool (OHAT) and educational tools like “KISS” (Keep it simple, staff) Basic Oral Care for caregivers.

I hope to increase my knowledge and plan to implement oral care plans as part of my recommendations. I hope to help my department increase awareness of the importance of oral care and how it can benefit patients. I hope to increase the availability of artificial salivas (such as Mouth Kote) for critically ill patients suffering from xerostomia.

I would also love to start collecting more informal data so that I can monitor patient progress compare efficacy of the treatments I may provide.

As I wrap up this post, I’m struck by how much I still want to know. Many of the resources Ashford provided in his article are from outside professions, such as dentistry and other medical publications. I am reminded that, while we have wonderful resources available within our own organization, sometimes collaboration with other professions can yield a whole other world of applicable information.

I look forward to continuing to explore new territory. I hope to keep finding reasons to question what I know, and to always work to broaden my horizons.

Article Citation: Ashford, John. (March 2012.) Oral Care Across Ages: A Review. Perspectives on Swallowing and Swallowing Disorders (Dysphagia), vol. 21, pp. 3-8.

(Aside: Comments are open. I welcome dialogue, new ideas, and cool ways to rethink all these things. Thoughts?)