Feasibility of adequate solute clearance in obese patients on peritoneal dialysis: a cross-sectional study

It is widely assumed that obese patients are poorly suited for peritoneal dialysis (PD). Mathematical models predicting weight limits to achieve adequate solute clearance in anuric patients on continuous ambulatory PD therapy do not apply to the majority of obese patients on PD therapy.

To define the extent to which obesity or large body size interferes with successful PD, the feasibility of achieving adequate solute clearance, defined by the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines, was studied. We reviewed prospectively recorded data for 25 obese patients (body mass index > or = 29) from a group of 58 prevalent PD patients treated in an inner-city ambulatory dialysis center. Adequacy of solute clearances was assessed by comparing weekly Kt/V and weekly creatinine clearance (WCC) with those recommended by the K/DOQI. Adequacy also was examined separately for large patients, defined as those with total-body water (TBW) by the Watson and Watson equation of 48 L or greater. Similar analyses were performed separately for 10 anuric obese patients.

Eighty four percent and 88% of the 25 obese patients achieved K/DOQI targets for weekly Kt/V and WCC, respectively. Among the 10 anuric obese patients, 90% and 70% achieved these targets. Only 60% of those with TBW of 48 L or greater met the Kt/V target.

PD remains a viable option for obese patients with end-stage renal disease. It is possible for the majority of obese patients on PD therapy to achieve solute clearances recommended by the K/DOQI.