The nurse is caring for a client receiving total parenteral nutrition (TPN). The nurse understands that the best explanation for utilizing TPN is to:

C. Costovertebral tenderness, which is tenderness over the costovertebral angle (where the ribs meet the vertebral column) on palpation, is more indicative of acute pyelonephritis rather than cystitis. In acute pyelonephritis, inflammation of the kidney parenchyma and surrounding tissues can lead to tenderness in this area.

A. Both acute pyelonephritis and cystitis can present with urinary urgency, as it is a common symptom of urinary tract infections (UTIs) in general.
B. Increased WBCs in urinalysis: While an increased number of white blood cells (WBCs) in the urinalysis can indicate a urinary tract infection, it is not specific to either acute pyelonephritis or cystitis.
D. Hematuria can occur in both acute pyelonephritis and cystitis.

C. TPN does provide all of the client's nutritional needs, including carbohydrates, proteins, fats, vitamins, minerals, and electrolytes, in a hypertonic solution. The hypertonicity of the solution is necessary to prevent fluid overload and ensure compatibility with the vasculature. The hypertonic solution allows for higher nutrient concentrations to be delivered without exceeding vascular capacity.
A. TPN is indicated for clients who are unable to tolerate enteral nutrition (feeding through the gastrointestinal tract) or have impaired absorption, digestion, or utilization of nutrients despite having active GI function.
B. TPN may be used temporarily after a surgical procedure if the client is unable to tolerate oral or enteral feeding or if enteral nutrition is contraindicated due to the surgical site or condition. However, TPN is not limited to short-term use after surgery and may be required for an extended period in clients with chronic conditions or prolonged inability to tolerate enteral nutrition.
D. TPN may be used in some cases after a laparotomy for a bowel obstruction, particularly if enteral nutrition is contraindicated or if the client is unable to tolerate oral intake. However, TPN is not primarily used to prevent complications after surgery but rather to provide nutritional support when enteral feeding is not feasible or sufficient.