CDR Enteral and Parenteral Nutrition 3

Question 1

Which formula characteristic makes semi-elemental formulas preferable to standard polymeric formulas in a patient with pancreatic insufficiency?

Accepted Answer

Pre-hydrolyzed protein and medium-chain triglycerides (MCTs) requiring less digestion

Answer

Semi-elemental formulas contain partially digested (hydrolyzed) proteins and MCTs that require minimal pancreatic enzyme activity, making them ideal for pancreatic insufficiency where enzyme secretion is impaired.

Question 2

A patient on home parenteral nutrition develops line sepsis. What is the MOST common causative organism?

Accepted Answer

Staphylococcus epidermidis (coagulase-negative staphylococci)

Answer

Coagulase-negative staphylococci (primarily S. epidermidis) are the most common cause of catheter-related bloodstream infections in home PN patients due to biofilm formation on catheter surfaces.

Question 3

In calculating the non-protein calorie-to-nitrogen ratio (NPC:N) for a PN formulation, how many grams of nitrogen are in 100 g of amino acids?

Accepted Answer

16 g

Answer

Proteins and amino acids contain approximately 16% nitrogen by weight, so 100 g of amino acids contains approximately 16 g of nitrogen (used as the standard conversion factor in PN calculations).

Question 4

Which clinical sign indicates INTOLERANCE to enteral nutrition and should prompt evaluation and possible rate reduction?

Accepted Answer

Abdominal distension, pain, and high gastric residuals consistently above 500 mL

Answer

Consistent gastric residuals above 500 mL combined with abdominal distension and pain indicate significant intolerance; ASPEN recommends holding tube feeds and reassessing rather than tolerating persistently high residuals.

Question 5

What is the metabolic complication associated with excessive glucose infusion rates in parenteral nutrition?

Accepted Answer

Hepatic steatosis and elevated liver enzymes due to lipogenesis

Answer

Excessive carbohydrate delivery in PN promotes hepatic de novo lipogenesis (conversion of glucose to fat), leading to hepatic steatosis, elevated transaminases, and contributing to PNALD.

CDR - Commission on Dietetic Registration Exam Practice Test

CDR - Commission on Dietetic Registration Exam Practice Test

CDR Enteral and Parenteral Nutrition 3