Intake and Output (I&O)
Intake and Output (I&O) is a nursing measurement that tracks all fluids entering (intake) and leaving (output) a patient's body over a specified period, typically 24 hours. Accurate I&O monitoring is essential for assessing fluid balance, kidney function, and hydration status.
Exam Tip
Minimum acceptable urine output = 30 mL/hr for adults. Ice chips = 50% of volume as fluid. 1 gram of wet diaper = 1 mL of urine. Report output less than 30 mL/hr or significant fluid imbalance to the RN immediately.
What Is Intake and Output (I&O)?
Intake and Output (I&O) monitoring is a fundamental nursing responsibility that involves measuring and recording all fluids a patient consumes and all fluids the patient excretes. This data helps the healthcare team assess fluid balance, detect fluid overload or dehydration, and guide treatment decisions.
What Counts as Intake
| Source | Examples |
|---|---|
| Oral fluids | Water, juice, coffee, soup, ice chips (count as 50% volume) |
| IV fluids | Normal saline, lactated Ringer's, D5W, IV medications |
| Tube feedings | Enteral nutrition via NG tube or PEG tube |
| Blood products | Packed RBCs, FFP, platelets |
| Irrigation fluids | Bladder irrigation (record separately) |
What Counts as Output
| Source | Examples |
|---|---|
| Urine | Voided, catheter drainage |
| Emesis | Vomited material |
| Drainage | Wound drains (Jackson-Pratt, Hemovac), NG suction, chest tube |
| Stool | Liquid or semi-liquid stools (estimate volume) |
| Blood loss | Estimated blood loss during procedures |
| Perspiration | Estimated for febrile patients |
Normal Values
| Measurement | Normal Range |
|---|---|
| Daily intake | 2,000-2,500 mL |
| Daily urine output | 1,500-2,000 mL (approximately 0.5-1 mL/kg/hr) |
| Minimum acceptable urine output | 30 mL/hr (adults) |
| Fluid balance | Intake should approximately equal output (within 200-300 mL) |
Key Nursing Considerations
- Measure and record all intake and output accurately
- Report urine output less than 30 mL/hr (may indicate renal insufficiency)
- Calculate fluid balance at the end of each shift and per 24 hours
- Report significant positive balance (fluid overload) or negative balance (dehydration)
- Ice chips = approximately 50% of their volume as fluid
- Weigh diapers for incontinent patients (1 g = 1 mL)
Exam Alert
I&O monitoring appears in the Basic Care & Comfort and Reduction of Risk Potential categories on the NCLEX-PN. Know that minimum acceptable urine output is 30 mL/hr for adults, ice chips count as 50% of their volume, and always report significant imbalances to the RN.
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Indwelling Catheter (Foley)
An indwelling catheter (Foley catheter) is a flexible tube inserted through the urethra into the bladder to continuously drain urine. It is held in place by an inflated balloon and connected to a closed drainage system. Proper catheter care is essential to prevent catheter-associated urinary tract infections (CAUTIs).
Nursing Process
The nursing process is a systematic, five-step problem-solving framework used by nurses to provide patient-centered care: Assessment, Diagnosis, Planning, Implementation, and Evaluation (ADPIE). It is the foundation of all nursing practice and the organizing framework for the NCLEX.
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