Nutrition, Fluid, and Electrolyte Management
Nutrition fundamentals
Understand protein-energy wasting in kidney disease and the balance between adequate protein and controlling nitrogenous waste. In hemodialysis, protein needs are higher because of losses during treatment; in peritoneal dialysis, glucose absorption adds calories. Restrict sodium, potassium, and phosphorus as indicated, but avoid over-restriction that causes malnutrition. Review phosphate sources (processed foods, additives) and the role of binders taken with meals. Understand that potassium restriction depends on residual function and medications, not on a universal rule.
Fluid and electrolyte management
Assess volume status by weight trends, blood pressure, edema, and intradialytic findings. Set fluid limits based on urine output and dialysis ultrafiltration capacity. Recognize hyperkalemia and its treatment: stabilize the myocardium with calcium, shift potassium intracellularly with insulin and glucose or beta-agonists, and remove potassium with binders or dialysis. Understand hyponatremia and hypernatremia correction limits, and the risks of overly rapid correction.
Traps
Do not recommend a fixed fluid restriction for every patient. Do not assume a low-potassium diet is needed for all CKD stages. Do not forget that salt substitutes often contain potassium. Do not overlook hidden phosphorus in processed foods and colas. Do not treat hyperkalemia with a shifting agent alone when removal is needed.
Worked example and rule of thumb
A dialysis patient gains 4 kg between sessions and reports eating canned soup and using a salt substitute. Address sodium and potassium sources and review the fluid goal with the team. Rule of thumb: sodium drives thirst and fluid gain, so control sodium first; then individualize potassium and phosphorus limits using labs and diet history.