What results would be expected in a prothrombin time (PT) and activated partial thromboplastin time (APTT) test for a patient with polycythemia?

For a patient with polycythemia, the expected results for prothrombin time (PT) and activated partial thromboplastin time (APTT) tests would be considered in the context of the disease's impact on blood properties. Polycythemia leads to an increase in blood viscosity due to the higher number of red blood cells, which can influence coagulation factors and overall hemostatic balance.

In this scenario, prolonged PT and APTT can occur because the increased viscosity can affect the flow of blood and may result in a disturbance in the normal function of clotting factors. This can potentially lead to slower clot formation and a longer time for the coagulation process to occur. The activation of the coagulation cascade involves various factors that may become less efficiently activated due to the altered dynamics of the blood in polycythemia.

Thus, while both tests may show prolonged results, it is essential to understand that the increased blood viscosity is a significant factor influencing these clotting times. Normal PT and normal APTT would suggest that the coagulation pathways function effectively despite the increased cell counts, which does not align with the expected findings in polycythemia. Hence, prolonged times are more likely in this condition.