The results from my Adequacy Test (more on this nomenclature later on) and my labs in general are in. As you can view in the lead graphic, my Kt/V, captured by the Urea Index, has significantly increased to 2.29, or as my local Fresenius clinic would report, 2.3 rounding the number to one decimal place. While on the surface this would appear to be “good,” to me it raises the question “How much Kt/V is “enough?” or “What value is medically indicated?”
This is where “medicine” is all over the place. Let me explain. The Nurse practitioner who recently visited with me last week stated the “government’s” criteria is 1.4 or better. My local Fresenius clinic sets a minimum of 1.7 as do several other entities. From the graph above, you can see the lab sets a minimum of 2.0 with no upper bound as do several other entities. I have to live with the environment where I am so as long as I am above 1.7 I may have discussions with my team, and if I’m above 2.0 get atta boys. But this still begs the issue of how much is enough.
My copious research turned up this statement: “The updated January 2020 ISPD guidelines reflect the changes mentioned above including a shift in terminology used to describe the proper amount of dialysis attained from “adequate” to “goal directed,” including multiple aspects to meet optimal “goal directed” care, including residual kidney function, nutritional status, and patients’ sense of well-being and satisfaction with their treatment. The effect of the burden of time spent fulfilling their dialysis prescription on their ability to carry out normal day-to-day tasks and their psychosocial status are now included as important factors in assessing if dialysis prescriptions are adequate. Finally, it is now mentioned that there is no specific target for clearance to meet to ensure PD prescriptions are satisfactory (15). … Finally, we have seen a growth in the field of nephrology in which the term “adequacy” has developed from a synonym for clearance of a single small solute to a term for a holistic assessment of the patient. We have learned that in PD, there is such a thing as too much of a good thing. Link to source for quotes above.
OK, so instead of “Adequacy Tests” we should be goal-directed based on patients’ input. It still begs a response to the question “How much Kt/V is enough? which we may attack through the question “What harm, if any, results from higher Kt/V?” I turned to Perplexity with this question with the following results:
For peritoneal dialysis patients, what is really good kt/v
Answer
For peritoneal dialysis patients, a Kt/V of 1.7 or higher per week is generally considered good. This target value has been recommended by guidelines from organizations like the International Society for Peritoneal Dialysis (ISPD) and the Kidney Disease Outcome Quality Initiative (K/DOQI). However, it’s important to note that the relationship between Kt/V and clinical outcomes is not straightforward. Some studies have shown that achieving higher Kt/V values may not necessarily lead to better survival rates. The ISPD in 2020 stated that there was a lack of high-quality evidence to prove the impact of Kt/V on survival and mortality, and reaching Kt/V > 1.70 may not bring additional survival advantages. Recent research suggests that the Kt/V reach rate – the percentage of Kt/V measurements that reach the target threshold – may be a more representative index to assess clinical status. Patients who consistently achieve the target Kt/V (3/3 times) or intermittently achieve it (1/3 or 2/3 times) have been shown to have better clinical outcomes than those who never reach the target. Ultimately, while a Kt/V of 1.7 or higher is considered good, it’s essential to consider other factors such as how the patient feels, their overall health status, and their residual kidney function when assessing dialysis adequacy.
SourcesKt/V reach rate is associated with clinical outcome in incident …tandfonline·1Kt/V reach rate is associated with clinical outcome in incident … – NCBIncbi.nlm·2Peritoneal dialysis adequacy: a paradigm shiftkrcp-ksn·3
Rather than ask “How high should Kt/V be,” perhaps we should ask Perplexity another question “What are the risks associated with higher Kt/V targets in PD patients?”
Answer
While higher Kt/V targets are often considered beneficial for peritoneal dialysis (PD) patients, there are some potential risks and considerations associated with pursuing higher Kt/V values:
- Increased peritoneal exposure: Achieving higher Kt/V may require more frequent exchanges or larger volumes of dialysate, which can lead to increased exposure of the peritoneal membrane to glucose and other potentially harmful substances.
- Peritoneal membrane damage: Over time, excessive exposure to dialysis solutions can cause structural and functional changes in the peritoneal membrane, potentially leading to ultrafiltration failure.
- Loss of residual renal function: Aggressive pursuit of higher Kt/V targets might inadvertently accelerate the decline of residual kidney function, which is crucial for PD patients’ overall health and survival.
- Diminishing returns: Studies have shown that achieving Kt/V values above 1.7 may not provide additional survival benefits. This suggests that there might be a point of diminishing returns where the risks outweigh the potential benefits.
- Quality of life impact: More frequent or longer dialysis sessions to achieve higher Kt/V targets can negatively affect a patient’s quality of life and daily activities.
- Increased risk of complications: More intensive dialysis regimens may increase the risk of peritonitis, exit-site infections, or mechanical complications related to the PD catheter.
- Nutritional issues: Overzealous removal of uremic toxins might lead to the loss of essential nutrients, potentially affecting the patient’s nutritional status.
It’s important to note that the relationship between Kt/V and clinical outcomes is complex, and individual patient factors should be considered when determining optimal dialysis prescriptions.
So the bottom line here is there isn’t one.
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