Which sign on a dressing indicates CSF leakage when drainage is bloody?

Which sign on a dressing indicates CSF leakage when drainage is bloody?

• A. Glucose strip testing positive
• B. Halo sign on a white dressing
• C. Clear drainage
• D. Blood-tinged drainage without halo sign

Answer: (B)

The main idea being tested is recognizing a CSF leak by a distinctive dressing change sign. When drainage from a cranial wound is bloody, a halo sign—a ring of clear fluid surrounding the bloodstained area on a white dressing—strongly indicates CSF leakage. CSF contains glucose, and as it seeps onto the dressing, it separates from the surrounding blood to form that clear halo, making the ring a specific bedside clue that CSF is escaping rather than just blood. While clear drainage might suggest CSF, and simple blood-tinged drainage is common with postoperative bleeds, the clear halo around the blood is more specific for CSF leakage. Glucose testing of the drainage could support the suspicion, but blood contamination can affect the result, so the halo sign provides a more reliable visual cue at the bedside.

The main idea being tested is recognizing a CSF leak by a distinctive dressing change sign. When drainage from a cranial wound is bloody, a halo sign—a ring of clear fluid surrounding the bloodstained area on a white dressing—strongly indicates CSF leakage. CSF contains glucose, and as it seeps onto the dressing, it separates from the surrounding blood to form that clear halo, making the ring a specific bedside clue that CSF is escaping rather than just blood.

While clear drainage might suggest CSF, and simple blood-tinged drainage is common with postoperative bleeds, the clear halo around the blood is more specific for CSF leakage. Glucose testing of the drainage could support the suspicion, but blood contamination can affect the result, so the halo sign provides a more reliable visual cue at the bedside.