oxemia due to chronic kidney disease oxemia refers to decreased levels of red blood cells (RBCs). Patients of chronic kidney disease (CKD) gradually develop oxemia, which worsens as the disease progresses. Since the kidneys partially but permanently lose their functions in CKD, there is not enough erythropoietin formation. This hormone promotes RBCs production by the bone marrow. As a result, production of RBCs is affected, leading to fewer RBCs than normal.