Upon initiation of home parenteral nutrition, within how many hours should laboratory data be obtained?

• A. 72 hours
• B. 48 hours
• C. 96 hours
• D. 24 hours

Answer: (B)

Early laboratory monitoring after starting home parenteral nutrition is essential to catch metabolic shifts quickly and guide adjustments to the formula. When PN is initiated, the body can experience rapid changes in electrolytes, glucose control, and liver function as nutrients begin circulating intravenously. Obtaining labs within the initial couple of days provides a baseline and helps detect issues such as electrolyte disturbances (for example, low phosphorus or magnesium), electrolyte imbalances affecting calcium or bicarbonate, and changes in hepatic enzymes and triglycerides. With these results, clinicians can promptly tailor energy and protein delivery, electrolyte supplementation, and lipid tolerance to prevent complications and ensure the patient tolerates the regimen. Delaying this check risks undetected abnormalities that could lead to refeeding problems, intolerance, or other adverse effects, whereas checking too soon may not reflect how the PN will stabilize once the patient adapts.