A nurse is caring for a group of clients on a pediatric unit. Which of the following clients is most at risk for insufficient vascular perfusion?

A. Receiving IV fluids is important but it doesn't typically put a child at risk for insufficient vascular perfusion unless there are complications like fluid overload or infiltration. B. A spica cast can restrict movement and potentially impair circulation to the affected limb, increasing the risk of insufficient vascular perfusion. C. A urinary tract infection primarily affects the urinary system and doesn't directly impact vascular perfusion. D. Otitis media is an ear infection and does not typically affect vascular perfusion.