The nurse working on a medical unit is assigned to care for four clients. Which client should the nurse assess first?

A. A fever with a pressure ulcer indicates possible infection, but this is not the most urgent finding compared to a life-threatening neurological emergency. B. Right-sided weakness after a stroke is expected and not an acute change unless new or worsening. C. Constipation requires attention but is not urgent. D. A severe headache in a quadriplegic client is correct to assess first because it may indicate autonomic dysreflexia, a medical emergency that can cause dangerously high blood pressure, stroke, or death if not treated immediately.