CNSC Practice Questions (2026) — Free Sample Questions with Answers

Answer: C

240 g/day: This uses actual weight (2.0 × 120 kg); in obesity the recommendation is based on ideal body weight.

88 g/day: This uses 1.2 g/kg IBW, the general range for non-obese critically ill adults, not the higher obesity target.

146 g/day: Correct. For BMI 30–40, ASPEN/SCCM recommends 2.0 g protein/kg IBW: 2.0 × 73 kg = 146 g/day.

120 g/day: This uses 1.0 g/kg of actual weight, which underestimates needs for hypocaloric high-protein feeding.

Critical illness with obesity: high-protein, hypocaloric feeding. Protein is 2.0 g/kg IBW (BMI 30–40) or up to 2.5 g/kg IBW (BMI 40 or more); energy is 11–14 kcal/kg actual weight (BMI 30–50).

Answer: B

Moderate malnutrition in the context of acute illness: Moderate acute-illness criteria are 1–2% weight loss in 1 week or intake below 75% for more than 7 days; this patient exceeds both thresholds.

Severe malnutrition in the context of acute illness: Correct. Weight loss of 2.8% in 1 week (more than 2%) and intake of 50% or less for at least 5 days meet two severe criteria for acute illness or injury.

Severe malnutrition in the context of chronic illness: Pancreatitis with a 1-week course is an acute illness, and chronic-illness criteria use longer time frames (e.g., intake ≤75% for at least 1 month).

Not yet malnourished, since less than 5% weight was lost: A 5% threshold applies over 1 month; in acute illness, more than 2% in a week is already severe.

ASPEN/Academy criteria need two of six characteristics. In acute illness, severe = more than 2% weight loss in 1 week (more than 5% in 1 month, more than 7.5% in 3 months) or intake of 50% or less for at least 5 days.

Answer: B

Hold EN for 4 hours and recheck the residual: Holding EN for GRVs below 500 mL without other signs of intolerance reduces delivery without lowering aspiration risk.

Continue EN at the current rate: Correct. ASPEN/SCCM advises against holding EN for GRVs under 500 mL when there are no other signs of intolerance.

Change the patient to PN immediately: There is no indication for PN; the patient is tolerating EN clinically.

Cut the infusion rate by 50%: Reducing EN for an isolated GRV of 300 mL lowers delivery without benefit.

GRV is a poor marker of intolerance. Don't hold EN for GRVs under 500 mL; instead assess the abdomen, vomiting, distension and stool, and use aspiration-prevention measures.

Answer: C

2,100 kcal: This counts dextrose at 4 kcal/g; IV dextrose monohydrate provides 3.4 kcal/g.

1,695 kcal: This counts the 20% lipid at 1.1 kcal/mL (the 10% value) rather than 2 kcal/mL.

1,920 kcal: Correct. Dextrose 300 g × 3.4 = 1,020; amino acids 100 g × 4 = 400; 20% ILE 250 mL × 2 = 500; total 1,920 kcal.

1,520 kcal: This leaves out amino acid calories; PN total energy includes protein (4 kcal/g).

PN energy: dextrose 3.4 kcal/g, amino acids 4 kcal/g, 20% ILE about 2 kcal/mL (10% about 1.1 kcal/mL; 30% about 3 kcal/mL).

Answer: C

As final percentage concentrations, such as D20/AA 5%: Percentage concentrations make doses volume-dependent and are linked to errors; ASPEN discourages them.

As the volume of each stock solution to be added: Volumes of stock solutions are compounding instructions, not prescriptions, and invite calculation errors.

As the amount of each component per day: Correct. ASPEN recommends ordering adult PN components as amount per day (e.g., g/day, mEq/day), and pediatric PN as amount per kg per day.

As the amount of each component per liter: Per-liter ordering makes the delivered daily dose depend on volume changes and is discouraged.

PN safe practice: standardized electronic orders that express adult components per day (pediatric per kg per day), with labels that match the order format.

Answer: D

25: This confuses the relative risk reduction (25%) with the NNT.

5: This is the absolute risk reduction expressed in percentage points, not the NNT.

4: This is 1 ÷ 0.25, which uses the relative risk reduction instead of the absolute risk reduction.

20: Correct. ARR = 0.20 − 0.15 = 0.05, and NNT = 1 ÷ ARR = 1 ÷ 0.05 = 20.

NNT = 1 ÷ absolute risk reduction (as a decimal). Relative risk reduction = ARR ÷ control event rate (here 0.05 ÷ 0.20 = 25%).