A 72-year-old male with a history of heart failure and atrial fibrillation is admitted to the ICU with septic shock. He is receiving continuous norepinephrine infusion, mechanical ventilation, and total parenteral nutrition (TPN). The TPN order is being reviewed by the pharmacist: 2.5 L per day, containing concentrated dextrose 25%, amino acids 10%, lipids 20% at 50 mL/hr. Labs: Na 138 mmol/L, K 3.5 mmol/L, Cl 102 mmol/L, Cr 110 µmol/L, Glucose 9.8 mmol/L. What is the most critical immediate concern for the pharmacist regarding this TPN order?

Question: A 72-year-old male with a history of heart failure and atrial fibrillation is admitted to the ICU with septic shock. He is receiving continuous norepinephrine infusion, mechanical ventilation, and total parenteral nutrition (TPN). The TPN order is being reviewed by the pharmacist: 2.5 L per day, containing concentrated dextrose 25%, amino acids 10%, lipids 20% at 50 mL/hr. Labs: Na 138 mmol/L, K 3.5 mmol/L, Cl 102 mmol/L, Cr 110 µmol/L, Glucose 9.8 mmol/L. What is the most critical immediate concern for the pharmacist regarding this TPN order?

Answer options:

• The concentration of dextrose may be too high, leading to hyperglycemia.
• Lipid infusion rate is too fast given the patient's critical condition.
• Electrolyte abnormalities are likely with this TPN formulation. ✅ The TPN infusion rate (50 mL/hr) does not align with the daily volume (2.5 L over 24 hours).

Correct answer: The TPN infusion rate (50 mL/hr) does not align with the daily volume (2.5 L over 24 hours).

Explanation: 2.5 L over 24 hours equates to an infusion rate of approximately 104 mL/hour (2500 mL / 24 hours). The ordered rate of 50 mL/hr would result in only 1.2 L of TPN being infused per day, significantly underdosing the patient and not matching the ordered daily volume. This discrepancy requires immediate clarification to prevent severe undernutrition.