Is it safe to administer PNSS (Parenteral Nutrition Support Solution) at 40 cc per hour?

Administering PNSS at 40 cc/hour

Yes, you can safely administer parenteral nutrition at 40 cc/hour, but this rate must be individualized based on the patient's total daily nutritional requirements, clinical status, and risk of complications such as refeeding syndrome. 1

Rate Calculation Framework

The infusion rate depends on several critical factors:

• Total daily volume: If the patient requires 1000-1500 mL of PN per 24 hours (a typical range for adult patients), then 40 cc/hour would deliver 960 mL/day, which falls within acceptable parameters 1

• Continuous 24-hour infusion is recommended: Optimal nitrogen sparing and metabolic stability are achieved when all PN components are administered simultaneously over 24 hours rather than cycling 1

• Osmolarity considerations: Central venous access is required for high-osmolarity solutions (>850 mOsm/L), which is standard for complete PN formulations 1. Peripheral access can only be used for solutions <850 mOsm/L 1

Critical Safety Considerations

Initiation Protocol

• Start low and advance gradually: PN should be initiated with a low-calorie regimen and built up step-by-step over 2-3 days to avoid metabolic complications 1

• Initial energy targets: During the acute phase (first 72-96 hours), provide 20-25 kcal/kg/day, which may require lower initial infusion rates 2

• Refeeding syndrome prevention: In malnourished patients or those at risk, increase PN gradually over the first 3 days with close monitoring of phosphate, potassium, and magnesium 1

Monitoring Requirements

• Glucose control: Blood glucose should be maintained between 140-180 mg/dL (7.8-10 mmol/L), with monitoring for hyperglycemia (>10 mmol/L) which contributes to mortality 1, 2

• Triglyceride monitoring: When lipids are included, maintain triglyceride levels <12 mmol/L (<400 mg/dL), temporarily discontinuing lipid infusion if levels exceed this threshold 1

• Electrolyte surveillance: Daily monitoring of phosphate, potassium, magnesium, and calcium is essential, particularly in the first 72 hours 1, 3

Common Pitfalls to Avoid

• Overfeeding: Avoid exceeding 30 kcal/kg/day as this is detrimental to cardiopulmonary and hepatic function 1. In patients with SIRS or MODS, limit to 15-20 kcal/kg/day 1

• Abrupt discontinuation: Sudden cessation can cause rebound hypoglycemia; taper gradually when transitioning to enteral nutrition 1

• Missing micronutrients: All PN prescriptions must include daily multivitamins and trace elements, which are omitted in up to 50% of cases 1

Route and Access

• Central venous access is preferred: The catheter tip should be positioned between the lower third of the superior vena cava and upper third of the right atrium 1

• Dedicated lumen recommended: Use a dedicated lumen for PN administration to reduce infection risk 1