Final answer:
The laboratory finding that should be reported to a health care provider immediately is a white blood cell count of 22.8/mm, which is indicative of a strong immune response and requires urgent attention.
Step-by-step explanation:
The laboratory finding that should be reported to the health care provider immediately for a client reporting right lower quadrant abdominal pain is a white blood cell (WBC) count of 22.8/mm. This result is significantly higher than the normal WBC range of 3.5 to 11 x 10⁹ cells/L and indicates a strong immune response, possibly due to an infection or inflammation. In the context of abdominal pain, it may suggest conditions such as appendicitis or another serious infection that requires prompt attention.
Other lab values provided, such as the red blood cell count, serum potassium level, and serum sodium level, are within the normal ranges and would not typically warrant immediate concern. An elevated WBC count, especially in the setting of acute abdominal pain, would need urgent evaluation to determine the cause and appropriate treatment.