A patient with bloody nasal drainage is suspected of a CSF leak. Which finding supports CSF presence?

• A. Clear nasal drainage along with the bloody discharge
• B. A halo sign on the nasal drip pad
• C. Decreased blood pressure and urinary output
• D. A positive reading for glucose on a Test-tape strip

Answer: (B)

The main idea is recognizing CSF leakage from nasal drainage. CSF is a clear fluid, and when it leaks along with blood on a pad, it often creates a halo: a ring of clear fluid surrounding the bloody center. This halo sign is a classic bedside clue that the drainage is CSF rather than just blood, because pure blood would be red and opaque without a surrounding clear ring. While CSF does contain glucose, using a glucose test strip to confirm CSF is less reliable and can be influenced by contamination or other factors, so it’s not as definitive as the halo sign. The other options don’t fit because they aren’t specific indicators of CSF leakage, whereas the halo sign directly reflects the presence of CSF in the drainage.