Final answer:
The nurse would monitor the client undergoing hemodialysis for signs of disequilibrium syndrome, which include headache and restlessness.
Step-by-step explanation:
The nurse would monitor the client undergoing hemodialysis for signs of disequilibrium syndrome, which include headache and restlessness. Disequilibrium syndrome is a neurological condition that can occur during the first few hemodialysis sessions when there is a rapid reduction in blood urea nitrogen levels. The sudden decrease in urea can cause fluid shifts in the brain, leading to symptoms such as headache, restlessness, nausea, and vomiting.