The nurse is caring for an elderly patient who was admitted with renal insufficiency.An expected laboratory finding for this patient may be

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The most important renal physiological change that occurs with aging is a decrease in the GFR.After age 40,renal blood flow gradually diminishes at a rate of 10% per decade.With advancing age,there is also a decrease in renal mass,the number of glomeruli and peritubular density.Serum creatinine levels may remain the same in the elderly patient,even with a declining GFR,because of decreased muscle mass and hence decreased creatinine production.Tubular changes include a diminished ability to excrete drugs,including radiocontrast dyes used in diagnostic testing,which necessitates a decrease in drug dosing to avoid nephrotoxicity.Many medications,including antibiotics,require dose adjustments as kidney function declines.Age-related changes in renin and aldosterone levels also occur,which can lead to fluid and electrolyte abnormalities.Renin levels are decreased by 30% to 50% in the elderly,resulting in less angiotensin II production and lower aldosterone levels.Together these can cause an increased risk of hyperkalemia.The aging kidney is also slower to correct an increase in acids,causing a prolonged metabolic acidosis and the subsequent shifting of potassium out of cells and worsening hyperkalemia.

The Nurse Is Caring for an Elderly Patient Who Was