All patients undergoing long-term renal replacement therapy (RRT) develop accompanying metabolic and other disorders. These disorders require appropriate attention and adjunctive treatment. Approach varies by patient but typically includes nutritional modifications and management of multiple metabolic abnormalities (see also Nutrition).
(See also Overview of Renal Replacement Therapy.)
Diet
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Anemia of renal failure
The anemia that occurs in renal failure should be treated with recombinant human erythropoietin and iron supplementation (see Anemia and coagulation disorderserythropoietin therapy and thereafter every other month. Iron deficiency is the most common reason for erythropoietin resistance. However, some dialysis patients who have received multiple blood transfusions have iron overload and should not be given iron supplements.
Coronary artery disease
Risk factors for coronary artery disease must be managed aggressively because many patients who require RRT have hypertension, dyslipidemia, or diabetes; smoke cigarettes; and ultimately die of cardiovascular disease. Continuous peritoneal dialysis is more effective than hemodialysis in removing fluid. As a result, hypertensive patients require fewer antihypertensive drugs. Hypertension can also be controlled in about 80% of hemodialysis patients by filtration alone. Antihypertensive drugs are required in the remaining 20%. Treatment of dyslipidemia, diabetes management, and smoking cessation are very important.
Hyperphosphatemia
Hyperphosphatemia, a consequence of phosphate retention due to low glomerular filtration rate (GFR), increases risk of soft-tissue calcification, especially in coronary arteries and heart valves, when calcium (Ca) × phosphate (PO4) >
acute kidney injury and very high serum phosphate concentrations) require addition of aluminum-based phosphate binders, but these drugs should be used short-term only (eg, 1 to 2 weeks as needed) to prevent aluminum toxicity.
Hypocalcemia and secondary hyperparathyroidism
Aluminum toxicity
Toxicity is a risk in hemodialysis patients who are exposed to aluminum-contaminated dialysate (now uncommon) and aluminum-based phosphate binders. Manifestations are osteomalacia, microcytic anemia (iron-resistant), and probably dialysis dementia (a constellation of memory loss, dyspraxia, hallucinations, facial grimaces, myoclonus, seizures, and a characteristic electroencephalogram [EEG]).
≥ 50 mcg/L suggests toxicity. Aluminum-related osteomalacia can also be diagnosed by needle biopsy of bone (requires special stains for aluminum).
Pearls & Pitfalls
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Bone disease
Renal osteodystrophy is abnormal bone mineralization. It has multiple causes, including , elevated serum phosphate, secondary hyperparathyroidism, chronic metabolic acidosis, and aluminum toxicity. Treatment is of the cause.
Vitamin deficiencies
Calciphylaxis
× PO4 product has resulted in considerable improvement.
