Dysphagia-Induced Dehydration: Causes, Symptoms and Impacts

Dysphagia (difficulty swallowing) is common among patients in hospitals and residents in aged care homes, and is associated with a number of medical conditions, including malnutrition and dehydration.

Unfortunately, the risk of dehydration – which is just as common as the risk of malnutrition, and potentially more serious – is often overlooked during staff training [1]. Nurses and other clinical staff either aren’t aware of the risk itself, or aren’t familiar enough with the symptoms of dehydration, resulting in up to 45% of hospital admissions becoming dehydrated [2].

Keep reading to find out how to identify dehydration, its potential consequences, the relationship between dehydration and dysphagia, and how to prevent dysphagia-induced dehydration.

What is dysphagia?

Dysphagia, or difficulty swallowing, affects an estimated one million Australians [3]. It is particularly common in hospital patients and older adults, impacting roughly half of Australia’s residential aged care population [3].

People with dysphagia may have difficulty chewing and moving the food around their mouth or down their throat, and may cough, choke or even inhale food or fluid particles into their lungs as a result [4].

What is dehydration?

Dehydration is clinically defined as “the loss of body water, with or without salt, at a rate greater than the body can replace it” [5]. It can be quantified as the loss of 1% or more of body mass due to fluid loss [2]. Like dysphagia, dehydration is particularly common in older Australians, affecting between 20–30% of older adults [6].

There are two main types of dehydration [6]:

Hypertonic dehydration, defined by a serum osmolality level greater than 300 mOsm/kg. Hypertonic dehydration occurs when the body attempts to balance its fluid-electrolyte ratio, and, in doing so, draws water from intracellular fluid, resulting in cell shrinkage and dehydration.
Isotonic dehydration, defined by a serum osmolality level between 285 and 295 mOsm/kg. Isotonic dehydration occurs in roughly 80% of dehydration cases, and is typically caused by fluid loss – electrolytes and fluid are depleted in equal measure.

Signs and Symptoms of Dehydration

Although dehydration is difficult to positively identify without a biochemical (osmolality) analysis, there are a number of different signs and symptoms that can help you screen patients or residents who might be at risk.

These include [5, 6]:

Headaches
Thirst
Fatigue
Muscular weakness
Dizziness
Lethargy
Psychosis and hallucinations
Unconsciousness
Confusion and impaired cognitive function
Dry mouth and other oral problems
Sunken eyes
Reduced urination (urine also becomes darker)
Reduced food intake
Fever-like symptoms (high temperature)
Dry mucous membranes in the nose
Dry tongue (the tongue may often be furrowed)
Dry armpits
The use of drugs, such as diuretics
Rapid heart rate (tachycardia)
Decreased skin turgor (elasticity of skin)
Reduction of 4% or more in body weight over seven days [11]

Not all dehydration is equal. Mild dehydration (loss of 1% of body weight due to fluid loss) may only present itself as headaches, dry mouth, and thirst, but these signs can be a useful way to stop progression to moderate or severe dehydration [5].

Effects of Dehydration

Dehydration is a serious medical condition that can cause potentially fatal complications. Multiple studies have found that hospital patients who are dehydrated are, on average, six times more likely to die in hospital than non-dehydrated patients [2, 7].

Acute kidney injury (AKI) is also a result of dehydration. Approximately 25% of hospital patients who become dehydrated will also suffer an AKI, which can be reversed if treated quickly [7]. Your patient or resident could have an AKI if they are urinating less than 400 mL/24 h, or if they are not urinating at all [2, 8].

If AKI is not identified and treated quickly, it can result in acute renal failure, which can be fatal. A systematic review spanning studies of over 71,000 patients found that the mortality rate for patients with a risk of AKI was 18.9%, 36.1% for those with an AKI, and 46.5% for those with kidney failure; this was compared to a mortality rate of 6.9% for patients without AKIs [9].

In both older Australians and hospital patients, dehydration can cause a number of other problems, including increased risk of falls, confusion, heat stress, constipation, urinary tract infections, kidney stones, drug toxicity, stroke, and poor wound healing [6].

Dry mouth, also known as xerostomia, can be caused by both short- and long-term dehydration. If it occurs chronically, dry mouth can contribute to conditions like gum disease [16]. Xerostomia can also impact on a patient or resident’s ability to taste, chew and swallow food safely, which may mean they eat less food [17].

Long-term dehydration can, in addition to its physical effects, cause anxiety, panic attacks, and agitation [5]. If you’re caring for a patient or resident with pre-existing cognitive conditions (like dementia), don’t dismiss changes in temperament as a result of the condition worsening – instead, consider whether they might be suffering from dehydration. Even in young, healthy people, dehydration causes worsened moods, increased perception of task difficulty and lower concentration [10].

How does dysphagia cause dehydration?

Now we’ve explored the symptoms and effects of dehydration, it’s time to examine the relationship between dysphagia and dehydration.

For people who have trouble swallowing, consuming both food and fluid can be difficult, time-consuming, and potentially dangerous. Choking is a serious hazard, as is aspiration (inhaling material such as food or liquid particles into the lungs). Food and fluids can dribble from the mouth or be regurgitated, which can be embarrassing and off-putting for the affected person.

As a result, people with dysphagia may drink and eat significantly less than their non-dysphagic counterparts, particularly in hospital or aged care settings. When lower fluid intake is combined with additional requirements due to old age and increased expenditure due to sickness, the result is a recipe for dehydration [11].

Preventing Dehydration in People with Dysphagia

Early identification of dysphagia is very important to ensure that patients or residents receive the support they need. If you think one your patients or residents could have dysphagia, refer them to a speech pathologist.

For many people with dysphagia, low-viscosity liquids like water can be difficult to manage and drinking them may result in coughing or aspiration. Speech pathologists may recommend changes to the fluid viscosity (thickened fluids), and provide rehabilitation strategies and exercises to help your patients or residents swallow safely.

In many Australian hospitals and aged care homes, thickened fluids are often used by healthcare professionals as a simple and cost-effective solution to dehydration. A 2014 study surveying Australian speech pathologists, nurses, dietitians, and other related staff found that, in 98% of the facilities where the participants worked, patients and residents used thickened fluids to hydrate safely [12]. Of this number, 82% used pre-packaged drinks like Flavour Creations’ Thickened Water [12].

Despite their convenience, thickened fluids may not be the right solution for every patient. The goal of thickening water and other fluids is to help patients and residents safely drink more, but many people dislike the taste and texture of thickened fluids, and actually end up drinking less. One study found that post-stroke patients with dysphagia who drank thickened fluids only drank an average of 781 millilitres a day – half of what they should have been consuming [13].

Free water protocols – allowing people with dysphagia and residents to sip water between meals – can help those people who dislike thickened fluids to drink more. Recent research has indicated that aspiration of pure water is less likely to cause aspiration pneumonia than aspiration of other liquids; in fact, small amounts of pure water can actually be absorbed into the bloodstream via the lungs without complications [14, 15].

This doesn’t mean that water protocols should be applied to every person with dysphagia, nor should free water protocols be implemented without directly consulting a speech pathologist. Gillman et al set out a useful summary of water protocol principles [14]:

Patients are allowed to drink pure thin water between meals and only at least 30 min after eating/drinking
Thorough oral care must be completed before water is consumed
Only thickened fluids can be consumed at meal/snack times
Ice chips may be permitted as a ‘thin fluid’
Medications must not be provided with thin water
Recommended compensatory swallowing strategies may still be applied
Supervision is required if patients are impulsive and/or cannot adhere to recommended strategies
Patients and relevant family members are educated on how to implement the protocol and the rationale behind it
Interdisciplinary training and interdisciplinary teamwork are required for successful implementation of the protocol
Patients should be excluded from free water protocols if they have:
- Medical instability
- Respiratory compromise
- Degenerative neurological conditions
- Immobility and/or inability to sit fully upright
- Strong cough reflex to water
- Impaired cognition, like impulsivity or memory impairment impacting on the patient’s ability to safely implement the protocol
- Oral or dental infection

With those recommendations in mind, here’s a bullet-point guide for preventing dehydration in the people with dysphagia under your care.

Be aware that people with dysphagia are much more likely to be at risk of dehydration, especially if they are older or have other health conditions.
Once you have identified at-risk patients or residents, familiarise yourself with the signs and symptoms of dehydration.
Check daily for signs of dehydration, and pay attention to complaints of headaches, dizziness, thirst, or drowsiness.
Monitor patient/resident intake of fluid, especially over the course of a day.
If a patient or resident on thickened fluids is regularly refusing to drink their fluid, consider implementing a free water protocol in consultation with a speech pathologist
Be especially mindful of reduced skin elasticity, dry armpits and dry tongues – these are all fairly reliable signs of dehydration.
If you suspect a patient with dysphagia may be dehydrated, immediately refer them to a specialist like a speech pathologist for assessment and treatment

Conclusion

People with dysphagia are significantly more at risk of dehydration than people without dysphagia, especially if they are older or have other health conditions. People with dysphagia in hospitals and aged care residents with dysphagia both fall into this category, so it’s important for nursing staff, clinicians and family members to be aware of both the risk and the ways to prevent it.

Implementing a good fluid intake regime that takes into account the specific requirements and preferences of patients or residents is a good start. Familiarity with the symptoms of dehydration is also important – if a patient or resident does become dehydrated, they need to be referred to a specialist for treatment as soon as possible.

If you believe a patient or resident under your care could be at risk of dehydration or dysphagia, consult a speech pathologist or Accredited Practising Dietitian immediately.

Medical information on FlavourCreations.com.au is merely information and is not the advice of a medical practitioner. This information is general advice and was accurate at the time of publication. For more information about nutrition and your individual needs, see your GP, an Accredited Practising Dietitian, or a speech pathologist.

References

[1] Reber, E., Gomes, F., Dähn, I. A., Vasiloglou, M. F. & Stanga, Z. (2019) Management of Dehydration in Patients Suffering Swallowing Difficulties. Journal of Clinical Medicine. 8(11), 1923. DOI: 10.3390/jcm8111923

[2] Shells, R. & Morrell-Scott, N. (2018) Prevention of dehydration in hospital patients. British Journal of Nursing. 27(10), 565–569. DOI: 10.12968/bjon.2018.27.10.565

[3] Speech Pathology Australia (2021, February 8) Swallowing Awareness Day. Speech Pathology Australia. Retrieved from: https://www.speechpathologyaustralia.org.au/SPAweb/whats_on/Swallowing_Awareness_Day/SPAweb/What_s_On/SAD/Swallowing_Awareness_Day.aspx

[4] Triggs, J. & Pandolfino, J. (2019) Recent advances in dysphagia management. F1000 Research. 8. DOI: 10.12688/f1000research.18900.1

[5] Thomas, D. R., Cote, T. R., Lawhorne, L., Levenson, S. A., Rubenstein, L. Z., Smith, D. A., Stefanacci, R. G., Tangalos, E. G. & Morley, J. E. (2008) Understanding Clinical Dehydration and Its Treatment. Journal of the American Medical Directors Association. 9(5), 292–301. DOI: 10.1016/j.jamda.2008.03.006

[6] Miller, H. J. (2015) Dehydration in the Older Adult. Journal of Gerontological Nursing. 41(9), 8–13. DOI: 10.3928/00989134-20150814-02

[7] El-Sharkawy, A. M., Watson, P., Neal, K. R., Ljungqvist, O., Maughan, R. J., Sahota, O., & Lobo, D. N. (2015) Hydration and outcome in older patients admitted to hospital (The HOOP prospective cohort study). Age and Ageing. 44(6), 943–947. DOI: 10.1093/ageing/afv119

[8] Chen J. & Zeng R. (2020) Oliguria, Anuria and Polyuria. In: Wan XH., Zeng R. (eds) Handbook of Clinical Diagnostics. Springer, Singapore. DOI: 10.1007/978-981-13-7677-1_25

[9] Makris, K. & Spanou, L. (2016) Acute Kidney Injury: Definition, Pathophysiology and Clinical Phenotypes. The Clinical Biochemist Reviews. 37(2), 85–98.

[10] Armstrong, L. E., Ganio, M. S., Casa, D. J., Lee, E. C., McDermott, B. P., Klau, J. F., Jimenez, L., Bellego, L. L., Chevillotte, E. & Lieberman, H. R. (2011) Mild Dehydration Affects Mood in Healthy Young Women. The Journal of Nutrition. 142(2), 382–388. DOI: 10.3945/jn.111.142000

[11] Hooper, L., Bunn, D., Jimoh, F. O. & Fairweather-Tait, S. J. (2014) Water-loss dehydration and aging. Mechanisms of Ageing and Development. 136-137, 50–58. DOI: 10.1016/j.mad.2013.11.009

[12] Murray, J., Doeltgen, S., Miller, M. & Scholten, I. (2014) A survey of thickened fluid prescribing and monitoring practices of Australian health professionals. Journal of Evaluation in Clinical Practice. 20(5), 596–600. DOI: 10.1111/jep.12154

[13] Murray, J., Miller, M., Doeltgen, S. & Scholten, I. (2013) Intake of thickened liquids by hospitalized adults with dysphagia after stroke. International Journal of Speech-Language Pathology. 16(5), 486–494. DOI: 10.3109/17549507.2013.830776

[14] Gillman, A., Winkler, R., & Taylor, N. F. (2016) Implementing the Free Water Protocol does not Result in Aspiration Pneumonia in Carefully Selected Patients with Dysphagia: A Systematic Review. Dysphagia. 32(3), 345–361. DOI: 10.1007/s00455-016-9761-3

[15] Murray, J., Doeltgen, S., Miller, M. & Scholten, I. (2016) Does a Water Protocol Improve the Hydration and Health Status of Individuals with Thin Liquid Aspiration Following Stroke? A Randomized Controlled Trial. Dysphagia. 31(3), 424–433. DOI: 10.1007/s00455-016-9694-x

[16] Xu, F., Laguna, L. & Sarkar, A. (2018) Ageing related changes in quantity and quality of saliva: Where do we stand in our understanding? Journal of Texture Studies. DOI: 10.1111/jtxs.12356

[17] Lee, K. A., Park, J.-C. & Park, Y. K. (2020) Nutrient intakes and medication use in elderly individuals with and without dry mouths. Nutrition Practice and Research. 14(2), 143–151. DOI: 10.4162/nrp.2020.14.2.143

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