TPN Infusion Rate via Central Line
For central line TPN administration, use cyclic infusion over 10-14 hours (typically overnight) rather than continuous 24-hour infusion, with infusion rates typically ranging from 80-125 mL/hour depending on total daily volume requirements of 25-35 mL/kg/day. 1, 2
Standard Infusion Protocol
Cyclic Administration (Preferred Method)
- Cyclic infusion over 10-14 hours is the recommended approach for central TPN, allowing patients freedom from the infusion pump during daytime hours and improving quality of life 1
- For a typical 2-3 liter daily TPN volume, this translates to infusion rates of approximately 80-125 mL/hour during the cycling period 2
- The use of infusion pumps is strongly recommended to ensure accurate delivery and prevent complications 1
Calculating Individual Infusion Rates
- Total daily fluid requirements are 25-35 mL/kg/day, which determines your total TPN volume 2
- Divide the total daily volume by your intended infusion duration (10-14 hours) to determine the hourly rate
- Example: For a 70 kg patient requiring 30 mL/kg/day = 2,100 mL total volume ÷ 12 hours = 175 mL/hour
Gradual Initiation in High-Risk Patients
Refeeding Syndrome Prevention
- In severely malnourished patients, start with reduced caloric loads (15-20 kcal/kg/day) and increase gradually over 3 days to prevent refeeding syndrome 1, 3
- Monitor phosphate, potassium, and magnesium levels closely during initiation 3
- Administer thiamine (Vitamin B1) prior to starting glucose infusion to reduce risk of Wernicke's encephalopathy 4, 3
Standard Patients
- For non-malnourished patients, target 25-30 kcal/kg/day initially, with maximum caloric load not exceeding 30 kcal/kg/day 1
- In patients with SIRS or multi-organ dysfunction, reduce to 15-20 kcal/kg/day 1
Glucose Administration Limits
Critical Rate Threshold
- Glucose administration should not exceed 7 mg/kg/min to avoid hyperglycemia and associated complications 1
- This translates to approximately 10 g/kg/day of glucose maximum
- Continuous 24-hour TPN infusion is considered a risk factor for liver complications; cyclic administration mitigates this risk 1
Monitoring During Infusion
Essential Parameters
- Daily blood glucose monitoring is critical, with target levels below 180 mg/dL 1
- Daily electrolyte monitoring in high-risk patients during initiation 4
- Regular inspection of the central line site for signs of infection or complications 1
Common Pitfalls to Avoid
Overfeeding Complications
- Avoid all forms of overfeeding, particularly in patients with liver disease or at risk for hepatic complications 1
- The fat/glucose energy ratio should not exceed 40:60, with lipids comprising no more than 1 g/kg/day 1
- Glucose administration exceeding 7 mg/kg/min increases risk of hyperglycemia, infections, and metabolic complications 1
Infusion Rate Errors
- Never administer TPN as a rapid bolus or at rates exceeding calculated requirements 5
- Do not use continuous 24-hour infusion when cyclic administration is feasible, as this increases risk of hepatic complications 1
- Avoid abrupt discontinuation; taper infusion rates at the end of the cycle to prevent rebound hypoglycemia 1