Final answer:
It is true that if a patient with a head injury has a runny nose or a salty taste in their throat, the fluid should be assumed to be cerebrospinal fluid (CSF), which requires immediate medical attention for confirmation and treatment.
Step-by-step explanation:
If a patient with a head injury has what looks like a runny nose or reports a salty taste at the back of the throat, you should assume that the fluid is cerebrospinal fluid (CSF). This is true because a salty tasting fluid or clear fluid leaking from the nose or ear can be indicative of a skull fracture that has torn the meninges, leading to the leaking of CSF. In a clinical setting, this assumption must be confirmed with additional testing, such as a beta-2 transferrin assay, which is highly specific to CSF. Immediate medical attention is imperative since CSF leaks can lead to serious complications like infections of the central nervous system, including meningitis.