When do you start an intake and output chart?

Intake and output (I&O) charts are generally started when a patient is:

1. Critically ill or unstable.

2. Receiving intravenous (IV) fluids or medications.

3. Experiencing fluid imbalances or electrolyte abnormalities.

4. At risk of developing complications related to fluid balance.

The frequency of charting intake and output depends on the patient's condition and may range from every hour or two to every 12 to 24 hours.