For a 70‑kg adult without cardiac disease receiving a continuous Jevity 1.5 kcal/mL (enteral nutrition) tube feed, how many milliliters of plain water per hour should be added to meet maintenance fluid requirements?

Free Water Requirements for Continuous Jevity 1.5 Tube Feeding

Direct Answer

For a 70-kg adult without cardiac disease receiving continuous Jevity 1.5 tube feeding, provide approximately 30-40 mL of plain water per hour (720-960 mL per 24 hours) to meet maintenance fluid requirements. 1, 2

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Calculating Total Fluid Needs

Baseline Maintenance Fluid Calculation

• Use 30-35 mL/kg/day as the baseline for adults, which equals 2,100-2,450 mL/day for a 70-kg patient 1, 2
• The Holliday-Segar formula (100 mL/kg for first 10 kg, 50 mL/kg for next 10 kg, 25 mL/kg for remaining weight) yields similar results: approximately 2,050 mL/day for 70 kg 2
• Older adults (>60 years) should target the same 30-35 mL/kg/day range 1

Fluid Content of Jevity 1.5

• Jevity 1.5 is a high-calorie formula (1.5 kcal/mL) that contains approximately 75-80% water by volume 1
• If providing full nutritional needs at 30 kcal/kg/day for 70 kg = 2,100 kcal/day = 1,400 mL of Jevity 1.5 1
• This 1,400 mL of formula provides approximately 1,050-1,120 mL of water 1

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Free Water Supplementation Protocol

Calculating the Water Deficit

• Total fluid needs: 2,100-2,450 mL/day 1, 2
• Water from formula: ~1,050-1,120 mL/day 1
• Additional free water needed: 1,000-1,330 mL/day (approximately 40-55 mL/hour) 1

Practical Administration Schedule

• Flush with at least 30 mL of water before starting feeds and after completion 1
• For continuous feeding, flush with 30-50 mL of water every 4 hours 1
• This 4-hourly flushing schedule (6 times per 24 hours × 30-50 mL) provides 180-300 mL additional water for tube maintenance 1
• Add an additional 30-40 mL/hour of free water boluses to reach total supplementation of 720-960 mL/24 hours 1, 2

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Critical Adjustments Required

Conditions Requiring Increased Free Water

• Fever: Add 2-2.5 mL/kg/day for each 1°C rise above 37°C 2
  • For 70 kg with 38.5°C fever: add 210-263 mL/day (9-11 mL/hour)
• Hyperventilation or increased respiratory losses require additional 200-400 mL/day 1
• Excessive gastrointestinal losses (diarrhea, high-output ostomy, vomiting) necessitate replacement of measured losses 1
• Hot environmental temperatures increase insensible losses requiring additional 200-500 mL/day 1

Conditions Requiring Reduced Free Water

• Heart failure would require 50-60% reduction in calculated maintenance volume 2
  • This patient has NO cardiac history, so standard volumes apply 1, 2
• Renal failure or hepatic failure mandate 50-60% reduction 2
• Mechanical ventilation in temperature-controlled environments reduces requirements 1

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Monitoring Requirements

Essential Daily Assessments

• Monitor daily fluid balance, serum sodium, and clinical status 2
• Check urine output (target ≥0.5 mL/kg/hour = ≥35 mL/hour for 70 kg) 2
• Assess for signs of dehydration: decreased skin turgor, dry mucous membranes, concentrated urine 1
• Watch for fluid overload: peripheral edema, pulmonary crackles, weight gain 2

Electrolyte Considerations

• Standard enteral feeds contain adequate electrolytes (1-3 mmol Na and K per 100 kcal) when meeting full energy needs 1
• Serum sodium is the most sensitive marker for fluid balance: hyponatremia suggests excess free water, hypernatremia indicates inadequate free water 1, 2

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Critical Pitfalls to Avoid

Common Errors in Free Water Administration

• Never use hypotonic maintenance fluids if IV supplementation is needed – use isotonic crystalloids to avoid hospital-acquired hyponatremia 2
• Avoid fluid overload, which independently predicts prolonged complications and increased mortality 2
• Do not forget tube flushing – inadequate flushing is the primary cause of tube obstruction 1
• Flush tubes with at least 30 mL water before and after medication administration 1

Special Medication Considerations

• Crushing medications through feeding tubes increases occlusion risk – use liquid formulations when possible 1
• Separate medication administration from feeding by pausing feeds and flushing adequately 1

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Practical Implementation Algorithm

Step 1: Calculate Total Daily Fluid Needs

• 70 kg × 30-35 mL/kg = 2,100-2,450 mL/day 1, 2

Step 2: Determine Water from Formula

• Jevity 1.5 at 1,400 mL/day provides ~1,050-1,120 mL water 1

Step 3: Calculate Free Water Deficit

• 2,100-2,450 mL minus 1,050-1,120 mL = 1,000-1,330 mL additional free water needed 1

Step 4: Distribute Free Water Administration

• Routine tube flushing: 30-50 mL every 4 hours = 180-300 mL/day 1
• Additional free water boluses: 30-40 mL/hour = 720-960 mL/day 1, 2
• Total supplementation: 900-1,260 mL/day meets calculated needs 1, 2

Step 5: Adjust for Clinical Factors

• Increase for fever, hyperventilation, or excessive losses 1, 2
• No reduction needed in this patient without cardiac/renal/hepatic disease 2