A nurse in an emergency department is assessing a client who has a basilar skull fracture and serosanguineous nasal discharge following a motor vehicle crash. Which of the following findings should the nurse identify as reliable for determining that the discharge is cerebrospinal fluid?
A.
Papilledema.
B.
Halo sign.
C.
Racoon’s eyes.
D.
Elevated WBCs.
The Correct answer and Explanation is:
The correct answer is B. Halo sign.
A basilar skull fracture involves the bones at the base of the skull and can lead to a tear in the dura mater, which may cause cerebrospinal fluid (CSF) to leak from the nose (rhinorrhea) or ears (otorrhea). Identifying whether the discharge is CSF is crucial, as it indicates a breach in the barrier protecting the brain from infection and injury. One reliable method for determining if nasal discharge is CSF is observing the halo sign.
Explanation of the Halo Sign
The halo sign is a diagnostic test that helps differentiate CSF from other types of fluid, such as blood or serous fluid. To perform the test, a sample of the fluid is collected on a piece of gauze or a clean surface. If CSF is present, the fluid will separate into concentric rings—blood or serosanguineous material will collect in the center, while the clear CSF forms a halo or ring around it. This sign indicates that the discharge is likely CSF and not just nasal mucus mixed with blood.
Other Answer Options
- A. Papilledema refers to swelling of the optic disc due to increased intracranial pressure. While it can occur with conditions affecting the brain, it is not a reliable method for identifying CSF leakage.
- C. Raccoon’s eyes (periorbital ecchymosis) indicate a possible skull fracture and are a sign of trauma, but they do not directly confirm the presence of CSF leakage.
- D. Elevated WBCs (white blood cells) suggest infection or inflammation but are not specific to diagnosing CSF leakage.
In summary, the halo sign is a reliable and simple bedside test to determine the presence of CSF in serosanguineous nasal discharge following a basilar skull fracture. Early detection of CSF leakage is essential to prevent complications such as meningitis.