Final answer:
The finding that requires further intervention is the increased wheezing in the left lung, indicating potential respiratory complications that can be serious during a sickle cell crisis.
Step-by-step explanation:
Among the findings provided, the one that requires further intervention during the assessment of a client in a sickle cell crisis is b. Increased wheezing in left lung. This indicates possible respiratory complications which can be serious in sickle cell disease due to the decreased ability of the sickle-shaped cells to transport oxygen and their tendency to obstruct capillaries. The nurse should prioritize addressing this concern as sickle cell crises are often precipitated by infections, including pneumonia. Interventions may include administration of additional oxygen, respiratory support, and potentially antibiotics if an infection is present.