Blood Chemistries



Analysis of serum chemistries reveals a variety of abnormalities in patients with ESRD. The BUN and creatinine are increased to a variable degree Since the blood level attained reflects not only the impairment in filtration function of the kidney but also the rate of generation of these substances, the development of “uremic” symptoms may not correlate directly with blood values. Metabolic acidosis is commonly observed and is usually a hyperchloremic acidosis. In faradvanced renal failure, the acidosis may be associated with an increased anion gap. Hyperkalemia is observed when renal failure is far-advanced or in patients with coexisting deficiency or tubular insensitivity to aldosterone. Patients with ESRD are “potas­sium adapted” and tolerate mild degrees of hy­perkalemia with no clinical se­quelae. In faradvanced renal failure, the serum concentration of phosphate is increased. Bone-de­rived alkaline phosphatase increases over time in the ESRD patient and can be used to follow the development of uremic osteodystrophy. Serum concentrations of uric acid and magnesium are often elevated.