A patient has the following lab results on a chronic basis:…

A patient has the following lab results on a chronic basis: Lab April  July October Reference Ranges: Hgb  7.3 g/dL 7.6 g/dL 7.2 g/dL Normal: 12-16 g/dL Hct  22% 24.1% 21.6% Normal: 38-48% Creatinine clearance  60 mL/min 45 mL/min 40mL/min Normal: 90-120 mL/min The creatinine clearance has been trending down in the last three results. Which of the following interventions would be indicated?