What is the role of residual renal function in PD clearance, and which actions help preserve it?

• A. Residual renal function contributes to clearance and should be preserved by avoiding nephrotoxins, controlling blood pressure, and maintaining hydration.
• B. Residual renal function is not involved in PD clearance.
• C. Preservation requires increasing dialysate glucose.
• D. Preservation is achieved by reducing fluid intake only.

Answer: (A)

Residual renal function adds to PD clearance by providing extra solute and water removal beyond what the dialysate and peritoneal membrane achieve. Preserving even small amounts of kidney function improves overall clearance, helps with fluid balance, and can reduce morbidity as PD therapy progresses.

Avoiding nephrotoxins (like certain NSAIDs or contrast agents), keeping blood pressure well controlled to protect kidney perfusion, and maintaining adequate hydration to prevent volume depletion are the key actions to preserve RRF. These steps help sustain glomerular filtration and urine output, which in turn contribute to clearance.

The other ideas don’t support preservation of residual function: RRF does participate in clearance, so saying it isn’t involved is inaccurate; increasing dialysate glucose is a dialysis prescription adjustment, not a preservation strategy for kidneys; and reducing fluid intake alone ignores other protective measures that help sustain kidney function.