Cyclic Parenteral Nutrition Infusion: Considerations for the Clinician

Parenteral nutrition (PN) is typically administered as a 24 hour infusion in acutely ill patients and those requiring only short term PN. Stable patients who require long term or home PN, however, may benefit from a cyclic infusion regimen. Cyclic PN infusion involves daily interruption of PN, allowing patients periodic freedom from infusion equipment. Daily starting and stopping of PN infusion may increase the risk of hyperglycemia and hypoglycemia, respectively. Symptomatic post-infusion hypoglycemia is uncommon in adults, but infusion tapering may be warranted in children < 2-3 years old to limit risk. Critically ill, mechanically ventilated patients may not be candidates for cyclic PN infusion based on increases in energy expenditure and carbon dioxide elimination, among other considerations. Metabolic consequences of cyclic PN infusion are reviewed here.