Final answer:
The nurse should be alerted to a possible acute subdural hematoma in a patient who develops a decreased level of consciousness and a headache within 48 hours of a head injury.
Step-by-step explanation:
The nurse should be alerted to possible acute subdural hematoma in a patient who develops decreased level of consciousness (LOC) and a headache within 48 hours of a head injury. In an acute subdural hematoma, bleeding occurs between the dura mater and the surface of the brain. The symptoms associated with a hematoma may not be apparent immediately following the injury, but if untreated, blood accumulation will exert increasing pressure on the brain and can result in death within a few hours.