This is the 15313th most frequent Russian word.
пострадавшую
"Пострадавшую" means "injured" or "affected" (feminine, accusative case).
In this sentence, 'пострадавшую' is in the accusative case as it refers to the woman who is the object of the action of helping.
Мы помогли пострадавшую женщину.
We helped the injured woman.
Here, 'пострадавшую' again describes someone affected by an incident, in the accusative case due to the direct object role.
Медики обследовали пострадавшую на месте происшествия.
Medics examined the injured person at the scene of the incident.
In this use, 'пострадавшую' remains accusative case as it is the object of the preposition 'о' which governs this form with specific meaning.