Final answer:
A normal serum albumin level is the best indicator that a client's nutritional needs are being met while receiving total parenteral nutrition after surgery, as it is a specific marker of protein nutritional status.
Step-by-step explanation:
The best indicator that a client's nutritional needs are being met after abdominal surgery and while receiving total parenteral nutrition (TPN) would be a normal serum albumin level. The response that the client's serum albumin level is 3.5 mg/dL indicates that their protein needs are likely being met initially. Albumin levels are a good marker for nutritional status because albumin is a protein made by the liver and its concentration decreases in malnutrition and hepatic disorders. A level within normal range (approximately 3.5 to 5.0 g/dL) can be indicative of proper nutrition. In comparison, while the healing of the surgical incision is a positive sign, it is not as specific as albumin in assessing nutritional status, and the same goes for balanced fluid intake and output and blood glucose levels. While necessary for monitoring, blood glucose could be regulated through insulin administration and is not as direct a measure of nutrition status as albumin. Additionally, while balanced fluid intake and output are important in patient management, they don't specifically assess nutrition status.