Questions About PD
There is no clear answer to your answers specifically even in literature. Adequacy is a state of well-being, not specifically defined by one number. (A minimum total Kt/Vurea of 1.7 if you require a number). It is determined by both patient & provider.
Some centers advocate for a target Kt/V of 2.0 (the prior KDOQI guideline) to achieve an ‘adequate’ dose of peritoneal dialysis, as defined by small solute clearance. There are many factors that determine clearance for PD patients. Some of these include factors not changeable via prescription (body size, peritoneal transport characteristics, residual renal function) and those changeable via prescription (frequency of exchanges, dwell volume, tonicity of solutions, day versus night dwells).
Most data suggest residual renal function (RRF) is a better survival indicator than the kt/v or adequacy ( ADEMEX, Canusa, Hong Kong trial). However adequacy will give some guide in term of prescribing your patients’ PD regime.
All measurements of peritoneal solute clearance should be obtained when the patient is clinically stable and at least 1 month after resolution of an episode of peritonitis. More frequent measurements of either peritoneal urea clearance or RRF should be obtained when clinically indicated. (AJKD Vol 48, No 1, Suppl 1 (July), 2006: p S131)
We thank you for your question and would like to add the following information to the excellent response above. The whole focus on PD adequacy (Kt/Vurea – small solute clearance) and how frequently this should be measured has been debated for a long time. Our understanding is that in the U.S. you have to follow the latest recommendations from CMS (U.S. Centers for Medicare & Medicaid Services) (1). Our understanding also is that most PD units in the U.S. perform adequacy testing on their PD patients once every 3 months. You will need to be aware of your local regulations and comply with them.
You may be interested to know that PD units in different countries have different approaches to monitoring adequacy of PD. For example, in the U.K., following the recommendations of the U.K. Renal Association clinical practice guidelines, PD adequacy is usually measured every 6 months, more frequently only if clinically indicated (2). Most important, today, there is a general concern among nephrology health care professionals that only focusing on the one measure of small solute clearance (Kt/Vurea) to determine PD adequacy is insufficient, and that a more multi-dimensional approach (including quality of life, cardiovascular health, and how a patient feels on dialysis) should be taken into account to quantify an optimum dialysis (3). Measuring small solute clearance forms a basic building block for determining the provision of PD; however, there is much more research that needs to be conducted to determine the best measures for a more multi-dimensional approach.
- Centers for Medicare & Medicaid Services Center for Clinical Standards and Quality CMS ESRD Measures Manual for the 2018 Performance Period / 2020 Payment Year (2018). Available at: https://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/ESRDQIP/Downloads/ESRD-Manual-v30.pdf
- Woodrow G, Fan SL, Reid C et al. Renal Association clinical practice guideline on peritoneal dialysis in adults and children. BMC Nephrol. 2017; 18:333 Available at: https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-017-0687-2
- Perl J, Dember LM, Bargman JM, Browne T, Charytan DM, Flythe JE, et al. The Use of a Multidimensional Measure of Dialysis Adequacy-Moving beyond Small Solute Kinetics. Clin J Am Soc Nephrol. 2017; 12(5): 839-47 Available at https://cjasn.asnjournals.org/content/12/5/839