Final answer:
The nurse should assess for underlying conditions that might have caused secondary polycythemia, especially evidence of lung disease and impaired renal function which could lead to elevated RBC production. Assessing for a history of venous thromboembolism also may be relevant due to increased clotting risks, whereas assessing for recent blood donation would not be related.
Step-by-step explanation:
If a patient has a history of treatment for secondary polycythemia, it's important for the nurse to assess for underlying conditions that could cause an elevated red blood cell (RBC) count. Secondary polycythemia can be due to high-altitude living, chronic lung disease, or tumors that produce erythropoietin, among other causes. Specifically, the nurse should assess for evidence of lung disease, which can lead to hypoxia and secondary polycythemia as the body attempts to increase oxygen-carrying capacity to compensate for low oxygen levels. Assessing the patient for impaired renal function is also important, as kidney diseases can result in the overproduction of erythropoietin, leading to polycythemia. While a history of venous thromboembolism (VTE) could be relevant due to the increased risk of clotting associated with polycythemia, this is not a cause of polycythemia itself and might not be the primary focus of assessment in this context. Assessing for recent blood donation would not be relevant here, as this would be more likely to lower hematocrit levels, not raise them.