An older adult client has been treated for stage 4 left-sided heart failure for several days. New laboratory

An older adult client has been treated for stage 4 left-sided heart failure for several days. New laboratory results indicate serum sodium of 130 mEq/L (130 mmol/L), TCO2 36 mEq/L (36 mmol/L), and potassium 3.4 mEq/L (3.4 mmol/L). The nurse suspects these results are related to one of the client’s medications prescribed to treat heart failure and its complications. The nurse prioritizes assessing what systems prior to contacting the healthcare provider about reassessing the medication?