Dehydration

What is it?

Dehydration occurs when the body loses more water than it takes in, resulting in a deficit of body water.

It can result from:

• Inadequate fluid intake.
• Vomiting or diarrhea.
• Fever and excessive sweating.
• Increased urine production.
• Illness or difficulty accessing fluids.

Older adults are at increased risk because they may experience reduced thirst, mobility limitations, or difficulty obtaining and drinking fluids.

How does it work?

Significant fluid loss can reduce circulating blood volume and venous return.

This may decrease Cardiac Output and Blood Pressure, reducing blood flow to organs.

Severe dehydration can contribute to circulatory instability, kidney dysfunction, and changes in mental status.

Why does it matter clinically?

Dehydration may increase the risk of:

• Dizziness and falls.
• Weakness and reduced activity tolerance.
• Low blood pressure.
• Reduced urine output.
• Confusion or other changes in mental status.
• Serious complications when fluid loss becomes severe.

Recognition and Assessment

Possible Warning Signs

• Thirst or dry mouth.
• Reduced fluid intake.
• Darker or decreased urine output.
• Dizziness, weakness, or unusual fatigue.
• Increased heart rate.
• Recent vomiting, diarrhea, or fever.

Important: Older adults may not experience pronounced thirst. No single symptom reliably establishes or excludes dehydration.

Urgent Warning Signs

• New confusion or significant change in alertness.
• Fainting or loss of consciousness.
• Absent or markedly reduced urination.
• Rapid breathing or heartbeat accompanied by concerning symptoms.
• Severe weakness, collapse, or suspected shock.
• Inability to drink safely or ongoing substantial fluid loss with clinical deterioration.

These findings require immediate nursing assessment or activation of the facility’s emergency response protocol, depending on severity.

Care Considerations

CNA Responsibilities:

1. Observe and accurately record fluid intake when assigned.
2. Assist with drinking and hydration according to the resident’s care plan.
3. Respect fluid restrictions and swallowing precautions.
4. Observe and report changes in urine output, alertness, mobility, and activity tolerance.
5. Report vomiting, diarrhea, fever, poor intake, or other factors contributing to fluid loss.
6. Promptly notify the nurse of suspected dehydration or significant changes.
7. Activate emergency response for severe symptoms according to facility policy.

Scope & Safety:

• Do not independently diagnose dehydration.
• Do not change ordered fluid goals or restrictions.
• Do not offer oral fluids to residents who cannot safely swallow or have restrictions prohibiting intake.
• Do not assume that all residents need increased fluids; some have conditions requiring fluid restriction.
• Follow nursing direction for further monitoring and care.

Connections

• Fluid Balance
• Blood Pressure
• Cardiac Output
• Blood Loss
• Hypotension
• Orthostatic Hypotension
• Measuring Intake & Output

Sources

• MedlinePlus — Dehydration
• MedlinePlus — Dehydration Medical Encyclopedia
• Hooper et al. — Diagnostic Accuracy of Dehydration Signs in Older Care Home Residents
• Facility hydration, fluid-restriction, and intake/output monitoring procedures (verify at clinical site)

Flashcards

What is dehydration?01-foundations / diseases-conditions

Answer

A deficit of body water.

Which symptoms may suggest dehydration?01-foundations / diseases-conditions

Answer

Thirst, dry mouth, weakness, dizziness, or reduced urine output.

Why can dehydration occur without noticeable thirst in older adults?02-mechanisms / diseases-conditions

Answer

The thirst response may become less reliable with age.

What symptoms suggest dehydration may require urgent escalation?03-application / diseases-conditions

Answer

New confusion, fainting, absent urination, or signs of shock.