intake and output

in·take and out·put

(I&O) (intāk owtput) Notations on a patient's hospital chart showing how much liquid was consumed and how much was eliminated as urine.

intake and output

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I and O

Measurement of a patient's fluid intake by mouth, feeding tubes, or intravenous catheters and output from kidneys, gastrointestinal tract, drainage tubes, and wounds. Accurate 24-hr measurement and recording is an essential part of patient assessment. See: Intake and Output