Final answer:
A nurse should monitor a polycythemia vera patient for increased blood pressure due to elevated blood viscosity and for decreased oxygen saturation due to potential impairments in oxygen delivery.
Step-by-step explanation:
Polycythemia vera is a condition characterized by an overproduction of red blood cells, which leads to an increase in blood viscosity and elevated hematocrit levels. This elevated blood viscosity can raise blood pressure and make it harder for the heart to pump blood, potentially leading to circulatory complications.
Hence, a nurse should closely monitor the client for increased blood pressure. Increased viscosity may also impair oxygen delivery despite the increase in red blood cells, so monitoring for decreased oxygen saturation is also necessary. However, polycythemia vera would not typically cause changes in urinary output or a significant decrease in respirations directly.