Understanding and Preventing Dehydration in the Older Adult

Kim Valentine, BSN, RN

When thirsty, most of us inevitably go to the tap or refrigerator for a drink of water or some other refreshing beverage. In most cases, we all take this simple task for granted. Our receptors will signal when thirsty, so we drink. Hydration can be relatively simple for most of us but it's especially challenging for the older population over the age of 65.

The average person needs 6-8 glasses of water per day to maintain a healthy balance. 50% to 70% of your body weight is comprised of water, so any disruption to that equilibrium can produce either minor side effects or precipitate a medical emergency or even death.

(Please note: There are certain conditions such as heart failure, end-stage kidney disease and renal dialysis that have specific fluid restrictions ordered, so the "average" amounts of water recommended per day do not apply to them.)

The Facts

Because 40% of older adults have chronic "underhydration", they have an increased susceptibility to viral or bacterial infection if exposed.¹
After age 60, older adults have the highest percentage of emergency room visits which increases progressively as they age.²
Adults over age 75 have the highest incidence of hospital admissions with dehydration listed as the admitting diagnosis.³
Several diagnoses have dehydration recorded as a comorbid condition in the older adult patient.⁴

How does an older adult present with dehydration?

Fatigue
Headache
Fever
Irritability
Dizziness
Constipation
Poor skin turgor
Dry mouth and lips
Sunken eyes
Hypotension
Tachycardia
Decreased urine output/concentrated urine
Confusion

What are some of the lab results that can support the diagnosis of dehydration?

Elevated creatinine and blood urea nitrogen (BUN)
Elevated Serum osmolality
Elevated sodium levels
Elevated potassium levels
Elevated urine specific gravity

What are some of the medical conditions that could be caused by the lack of adequate hydration?

Urinary tract Infection
Delirium
Acute Kidney Injury
Hypernatremia and other electrolyte imbalances
Orthostatic hypotension
Falls and fractures I.e., Fractured hip
Renal Calculi
Seizures

What are some contributing factors to dehydration?

Lower amounts of body water with aging

From 80% as a child to 40-50% after age 60

Medications

diuretics or medications that cause diaphoresis

Previous gastric surgeries that reduce water absorption

I.e., Roux-en-Y surgery

Incontinence, diarrhea, vomiting

From any number of causes such as viral infection, medication reaction, etc.

Decreased sense of thirst

As we age the sense of thirst diminishes due to changes in the physiological control systems for thirst

Fear of incontinence

Intentional decrease of fluid intake to avoid going to the bathroom so often

Chronic illness

Adults with diabetes, kidney disease and adrenal gland disorders are at higher risk for dehydration

Decreased mobility

Conditions such as arthritis or other chronic conditions can cause someone to find it to be too difficult to get up for a drink

Maintaining water balance in the tissues decreases with age

This increases the vulnerability to acute kidney injury referred to as Hemodynamic Frailty.⁵

Could something as "simple" as adequate hydration reduce admissions and or severity of illness? The data confirms this, but dehydration often goes unnoticed in the older population. The challenge to have intentional strategies to address prevention needs prioritization.

How can dehydration be prevented in the older adult?

Provide and offer drinks often including water

Roughly 60% of our water consumption comes from the fluids we drink
Caregivers need to offer drinks on a regular basis and have them within reach to enable accessibility. Setting a timer or keeping a chart of fluid intake is helpful

Offer water-rich foods for meals and snacks

Foods such as soup, watermelon, Jello, and other moist foods count for 30% of our water intake. Using juice may be appropriate in moderation, but due to sugar content it can be problematic for adults with diabetes or prediabetes

Avoid caffeinated drinks such as coffee, tea, or cola

Caffeinated drinks can produce a slight diuretic effect that may increase fluid loss. Use flavor additive drops to water thereby improving the taste (ie Mio)
Older adults often don't like the taste of plain water, plus taste sensation decreases with age

It is paramount to recognize the signs of dehydration early! Continuing education for caregivers at home, in long-term care and in hospitals, needs prioritization to ensure appropriate care planning for prevention. Maintaining fluid equilibrium can reduce minor side effects and reduce the risk of serious illness. If dehydration is suspected, positive outcomes depend on early recognition and interventional strategies.

References

^1,3Salivary Osmolality, Function, and Hydration Habits in Community-Dwelling Older Adults

²Emergency Department Visits Among Adults Aged 60 and Over: United States, 2014–2017

⁴DEHYDRATION IN THE ELDERLY: A REVIEW FOCUSED ON ECONOMIC BURDEN

⁵Haemodynamic frailty – A risk factor for acute kidney injury in the elderly

Water: How much should you drink every day?