TOPIC DISCUSSION: Residual renal function???

We often associate this term:- residual renal function(RRF) with Peritoneal dialysis and how important that is for fluid management. Why is this not that emphasized in Hemodialysis??? 
Does residual renal function matter in any dialysis modality? The short answer is yes!!
A recent paper in NDT looked at mortality in 1800 haemodialysis (HD) and peritoneal dialysis (PD) patients in 1996-2006.  The investigators estimated a hazard ratio (HR) corresponding to the effect of the full loss of GFR on mortality, as compared to not having fully lost GFR, of 1.50 [95% confidence interval (CI) 1.09-2.07]. The HR corresponding to the effect of GFR when GFR is not (yet) fully lost on mortality was 0.97 (95% CI 0.92-1.02) (per mL/min/1.73m(2)). They found no significant difference in the effect of GFR on mortality between patients starting on PD and HD. They concluded that preventing or delaying the full loss of GFR can improve survival in dialysis patients. This supports the importance that is given to the effect of treatment options for patients with ESRD on the rate of decline of the residual renal function.
Another study found that patients without RRF were older, had lower baseline serum albumin levels and spent 18.6 more days in hospital per year than those with RRF. Mean survival time was significantly lower in patients without RRF (p = 0.027). In a Cox proportional hazards model, only RRF remained as a significant independent predictor. 
Another study in CJASN found a strong relation between RRF and improved phosphate and anemia control in HD patients. 
Given these recent studies, it appears that RRF is very important in HD patients as well. Perhaps holding ACE-inhibitors and/or angiotensin-receptor blockers, limiting the use of nephrotoxic drugs, avoiding dialysis associated hypotension, avoiding contrast media procedures, adequate control of blood pressure might help preserve that RRF. All three studies are listed below!


Ref:
http://www.ncbi.nlm.nih.gov/pubmed/21242677
http://www.ncbi.nlm.nih.gov/pubmed/21317411
http://www.ncbi.nlm.nih.gov/pubmed/21030579