A nurse in an emergency department is assisting a provider who is assessing a client who has suspected appendicitis. Which of the following findings should the nurse expect?

A. Positive leukocyte esterase is a laboratory finding typically identified during a urinalysis to screen for the presence of white blood cells. While this may indicate a urinary tract infection or renal calculi, it is not a diagnostic marker for an inflamed appendix. In appendicitis, the primary biochemical changes are systemic rather than localized to the urinary excretion system. The nurse would not expect this specific finding to confirm a diagnosis of appendiceal inflammation.

B. Increased pain upon the sudden release of deep abdominal palpation is known as rebound tenderness or Blumberg sign. This clinical phenomenon occurs when the parietal peritoneum is irritated due to the inflammatory process of the adjacent appendix. It is one of the most reliable physical examination findings for identifying peritoneal irritation associated with acute appendicitis. The nurse should expect this reaction during the provider's assessment of the right lower quadrant.

C. A white blood cell (WBC) count of 9,500 mm3 falls within the standard physiological reference range for a healthy adult. In a client with acute appendicitis, the nurse would instead expect to see significant leukocytosis, typically exceeding 10,000 to 18,000 mm3. This elevation in the leukocyte count reflects the body's systemic inflammatory response to the localized infection. A normal count like 9,500 mm3 would be atypical for a client with an actively inflamed appendix.

D. Pain from flexion of the left thigh while lying on the right side is not a characteristic sign of appendicitis. The psoas sign, which is associated with appendicitis, involves pain upon extension or flexion of the right thigh, as the appendix sits in the right iliac fossa. Flexing the left thigh does not cause the anatomical tension required to irritate an inflamed appendix. This finding would suggest a different pathology or involve an unaffected anatomical region.