6.2 Intake, Output, and Measurement

Key Takeaways

  • Measure fluids in milliliters and record exactly according to facility policy.
  • Intake includes oral fluids and other ordered fluid sources; output includes urine, emesis, drainage, and liquid stool when measured.
  • Use eye-level measurement on a flat surface for graduates.
  • Report low urine output, dark urine, new incontinence, or signs of dehydration.
  • California skills tasks may require urine output and meal/fluid intake calculations.
Last updated: April 2026

Intake And Output

Intake and output, often called I&O, tracks fluid balance. This is important for residents with dehydration risk, heart failure, kidney problems, fever, vomiting, diarrhea, or urinary issues.

What Counts

IntakeOutput
Water, juice, milk, coffee, teaUrine
Soup or gelatin if policy counts itEmesis
Ice chips converted to fluid amountDrainage
Tube feeding if assigned to recordLiquid stool when ordered
IV fluids are usually nurse-documentedWound or tube drainage

Measurement Habits

Use milliliters. A common conversion is 1 ounce equals about 30 mL. Always follow facility cups and conversion charts.

For urine in a graduate:

  1. Place graduate on a flat surface.
  2. Read at eye level.
  3. Record in mL.
  4. Empty and rinse equipment as directed.
  5. Perform hand hygiene.
  6. Report unusual findings.

Meal Intake

Meal intake may be recorded as a percentage. Estimate how much of the total meal was eaten: 0%, 25%, 50%, 75%, or 100% are common values.

On California skills, meal/fluid measurement must be close to the evaluator's calculation. Practice reading cups and estimating solids.

What To Report

Report:

  • Very low output.
  • Blood in urine or stool.
  • Burning urination.
  • New incontinence.
  • Strong odor with symptoms.
  • Repeated vomiting.
  • Signs of dehydration: dry mouth, confusion, dizziness, poor skin turgor.

Exam Tip

If the question asks for output measurement, choose the answer with eye-level reading, correct units, and prompt reporting of abnormal findings.

Test Your Knowledge

A CNA measures urine output in a graduate. How should the CNA read it?

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B
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D
Test Your Knowledge

Which finding should be reported?

A
B
C
D