How to Measure Pediatric Intake and Output

It’s almost the end of the shift and you are asked by your clinical instructor to measure the intake and output of the patient assigned to you. However, it is your first day of duty and you are still a bit confused of what to do. You have read about it, but aren’t quite sure how to do it. To add to your so-called “burden”, you are assigned to a pediatric patient. How do you do this? Is measuring I& O of adults the same with pediatric patients?

Monitoring a patient’s fluid balance to prevent dehydration or overhydration is a relatively simple task, but fluid balance recording is notorious for being inadequately or inaccurately completed (Bennett, 2010).

According to the Nursing and Midwifery Council (2007), record keeping is an integral part of nursing care, not something to be “fitted in” where circumstances allow. It is the responsibility of the nurse caring for a patient to ensure observations and fluid balance are recorded in a timely manner, with any abnormal findings documented and reported to the nurse in charge (Scales and Pilsworth, 2008).

Smith and Roberts (2011) said that all fluid intake and output, whatever the source, must be documented using quantifiable amounts.


Below are the steps on measuring intake and output.

  1. Use a calculation sheet, which should be provided by the doctor. All sheets may differ with each physician, but always, there’s an intake column and an output column, which are further divided into “routes”–which are how the fluids are taken in or how they come out. Intake routes are oral (by mouth through drinking or feeding tubes that provide liquid nutrition), IV (intravenous catheter fluids and IV medications), rectal (enemas or rectal medications). Output routes are urine (foley catheters, bed pan, diaper), emesis (vomit), liquid stools, or drainage or suction tubes (nasogastric, closed wound drainage or chest). Use one sheet for every 24-hour period.
  2. Measure intake. All intake is measured in units called milliliters (mls or ccs). All fluid that is taken into the body, regardless of the route, is considered intake. Ice chips are calculated at half measurement. Measure all intake before giving it to the child with a milliliter measuring device, which the nurse may find at a medical supply store or provided by the child’s doctor.
  3. Measure output. All output is measured in units called milliliters (mls or ccs) and can be measured in graduated measuring devices marked with milliliter measurements, usually given by the child’s physician. Documenting the route of output is important: Knowing if 30 mls of output is urine or vomit can be useful information. For accurate measurements, keep toilet paper out of the urine.
  4. Measure urine output in a diaper. If a child cannot use a bedpan or other measuring device for urinating, a diaper can be weighed. Zero an empty scale that uses gram measurements. Place a dry, new diaper on the scale, zero the scale again, remove the diaper and use it. The scale is now ready to measure a wet diaper. To measure the wet diaper, place it on the scale that has been zeroed with that diaper, and measure the grams. Grams translate to milliliters (1 gram = 1 ml) for your I & O chart.
  5. Calculate I& O. Write down all intake and output as it occurs; don’t count on remembering numbers. With suction or drainage tubes or foley catheters, measure the output every four hours unless otherwise indicated. To calculate a 24-hour I & O, add up all intake numbers, then add up all output numbers. Subtract the input from the output. If the number is positive, the child has a positive I& O. If the number is negative, the child has a negative I& O. This positive or negative number is then used by the child’s doctor or nurse to determine further care.



Liane Clores, RN MAN

Currently an Intensive Care Unit nurse, pursuing a degree in Master of Arts in Nursing Major in Nursing Service Administration. Has been a contributor of Student Nurses Quarterly, Vox Populi, The Hillside Echo and the Voice of Nightingale publications. Other experience include: Medical-Surgical, Pediatric, Obstetric, Emergency and Recovery Room Nursing.

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