I&O Balance: Multi-Source Conversion & Net Calculation
Marcus must total intake & output for a post-op patient. Negative balance > 500 mL triggers a fluid bolus order.
- I&O flowsheet
- Graduated urinal
- IV pump readout
- Cup conversion chart
- 1
Convert every input to mL
1 oz = 30 mL. A 6 oz jello cup = 180 mL. IV pumps already read in mL.
- 2
Sum intake (PO + IV + tube)
Add by hour. Example shift: 1,200 mL PO + 800 mL IV = 2,000 mL in.
- 3
Sum output (urine + drain + emesis)
Example: 1,400 mL urine + 100 mL drain = 1,500 mL out.
- 4
Net balance
In − Out = 2,000 − 1,500 = +500 mL. Document and report.
End-of-shift charting: patient consumed 8 oz juice, 6 oz broth, 1 cup ice chips (count as ½ volume), got 500 mL D5W IV, voided 850 mL urine, lost 150 mL emesis, and 200 mL via NG suction. Convert everything to mL, total intake vs output, and flag if net balance crosses ±500 mL — a clinical alert threshold.
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Shift fluid balance
Given: PO: 8 oz juice + 6 oz broth; IV: 500 mL; urine: 850 mL; emesis: 150 mL
- 1
Convert PO to mL (×30)
(8 + 6) × 30 = 420 mL