Which PN strategy may benefit patients on fat-free PN?

• A. Hypercaloric PN
• B. Normocaloric PN
• C. Hypocaloric PN
• D. PN with added insulin

Answer: (C)

When PN is given without any fat, the body loses a major non-protein energy source. The remaining energy must come from carbohydrate and amino acids. If you push a high total caloric dose in fat-free PN, most of those calories come from glucose, which can lead to hyperglycemia, increased hepatic fat production, and excessive CO2, while still not providing the fat-related energy that was missing. Setting a lower total caloric target—hypocaloric PN—helps keep carbohydrate intake from being overbearing, reduces the risk of metabolic complications, and preserves some calories for protein utilization to support healing. This approach also buys time to reintroduce lipids once tolerance is established, so overall energy needs can be met without overfeeding carbohydrates. While adding insulin to PN can help control blood glucose when hyperglycemia occurs, the foundational strategy in fat-free PN is to limit total calories from non-fat sources.