Final answer:
A positive Brudzinski's sign observed by a nurse when assessing a client suspected of having meningitis indicates meningeal irritation, symptomatic of meningitis.
Step-by-step explanation:
When assessing a client suspected of having meningitis, the nurse noted a positive Brudzinski's sign. This is when neck flexion in a supine patient induces reflex flexion of the hips and knees. This sign indicates meningeal irritation, which is a characteristic symptom of meningitis. Meningitis is a potentially life-threatening inflammation of the membranes (meninges) that cover the brain and spinal cord, and it can be caused by viruses, bacteria, or fungi, with bacterial meningitis being particularly serious.