Final answer:
Persistent diarrhea in a 3-month-old hospitalized with gastroenteritis represents an ineffectiveness of the current treatment regimen, signaling the need to reassess and potentially adjust the treatment approach.
Step-by-step explanation:
The correct answer to which assessment finding indicates ineffectiveness of treatment for a 3-month-old with gastroenteritis is Persistent diarrhea.
Gastroenteritis treatment aims to prevent dehydration and alleviate symptoms. An increased urine output (a) and decreased vomiting (b) are both signs that the rehydration therapy is effective and the body is recuperating. Moist mucous membranes (c) signify good hydration.
However, persistent diarrhea indicates that the treatment is not effectively managing one of the primary symptoms of gastroenteritis. During a gastrointestinal illness like gastroenteritis, the presence of diarrhea, especially if it lasts more than 3 days, can further dehydration and indicate that the patient's condition isn't improving as expected. This finding could warrant an evaluation of the current treatment strategy, including the possible need for stool analysis, and an adjustment to the treatment plan.