The fluid balance calculator computes net 24-hour fluid balance by subtracting total output from total intake across all fluid sources. Accurate fluid balance monitoring is a fundamental nursing responsibility for patients with heart failure, sepsis, post-operative status, renal impairment, and any condition where fluid overload or dehydration is a clinical concern. A positive balance above +500 mL warrants monitoring for oedema and pulmonary congestion; a negative balance below −500 mL warrants monitoring for dehydration.
| Balance | Interpretation |
|---|---|
| > +500 mL | Positive — monitor for fluid overload, oedema, pulmonary congestion |
| −200 to +500 mL | Roughly balanced — normal range for most patients |
| < −500 mL | Negative — monitor for dehydration, hypotension, reduced urine output |
Target urine output: 0.5–1.0 mL/kg/hr in adults (≈ 30–50 mL/hr for average adult).
A balance of roughly −200 to +500 mL is considered broadly normal for most adult patients. The target depends heavily on the clinical context — patients with heart failure may require a negative balance, while post-operative patients often need a slight positive balance to maintain perfusion.
No. Insensible losses (approximately 500–1000 mL/day via respiration and perspiration) cannot be measured and are therefore not included in standard nursing fluid balance documentation. Clinicians account for them separately in overall fluid management planning.