Final answer:
Cyanosis is the clinical manifestation indicating an unconscious victim is having trouble breathing.
Step-by-step explanation:
The clinical manifestation that indicates an unconscious victim is having trouble breathing is cyanosis. Cyanosis refers to a bluish discoloration of the skin and mucous membranes, which occurs due to lack of oxygen in the blood. It is a sign that the victim is not getting enough oxygen and needs immediate medical attention.
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