Dialysis Unplugged: “It will be alright in the end”

This line, most recently used in the recent movie “Best Exotic Marigold Hotel”, is emblematic of some of what’s wrong with dialysis.

Take the following story from a patient I saw the other day.  She is a 76-year-old retired Armenian pediatric neurologist. She has stable chronic kidney disease and was seeing me after approximately 6 months. She told me that she had lost her husband a few months ago.

“I lost my husband with whom I was married for 40 years. We loved each other every one of those great years and I miss him so much”.

I asked her how he died.

 “Well, you know, he was on dialysis, dialyzed three times a week. Around 4 am, on the night he died, he woke up suddenly complaining of an inability to breathe. He asked me to take him to the ER in the car rather than calling 911. But, as we were leaving the house he collapsed in the hallway and stopped breathing. I performed CPR on him, called 911, but we weren’t able to revive him.”

What was the cause of death?

“The autopsy didn’t really provide any answer; his heart was fine, but the lungs were filled with fluid. They said he died from pulmonary edema."

She went on: “He had stopped eating months before he died. He just lost his appetite. I think that the dialysis doctors didn’t realize that he had lost muscle. They just kept dialyzing him to the same weight, and I think he filled up with fluid until he couldn’t take it anymore”

As I reflect on this conversation, I am sad for my profession. In the 25 years I have been looking after dialysis patients our tools to assess the dry weight remain rudimentary. 

Establishing the patient’s dry weight is also usually done empirically by volume challenging the patient. It’s not easy to get the patient to their dry weight. There is a risk of hypotension and cramps, and I’ve seen patients pass out when we’ve been too aggressive. But the truth is that we don’t have a fancy assay like the BNP to tell us if a patient is wet or dry. We still rely on taking a history and performing a physical examination. Some of the signs of volume expansion are unreliable and a physical exam is usually hard to do in an open dialysis unit with patient’s hooked to a machine in a dialysis chair.

Here is an excerpt from a superb article by Jack Jaeger and Ravi Mehta in JASN from 1999.

“Missing Changes in Lean Body Mass. There is also the occasional patient who has achieved their so-called dry weight, but over time subtle negative changes in lean body mass occur due to inadequate dialysis prescription, inadequate dialysis delivery, comorbid illness, depression, or other causes. This change might not be reflected in serum albumin or urea kinetics studies, and failure to adjust dry weight results in a greater proportion of their body weight becoming ECF. An increase in BP with recognition of lean body mass change and consequent adjustment of dry weight may occur. Alternatively, there may be no BP response to this ECF expansion, a failure to adjust dry weight downward, and henceforth failure to identify this subtle change in nutritional status. Such small changes in nutritional status might be significant for the patient.”

They continue: “it is evident that contemporary management of fluid in the dialysis patient is largely dependent on a clinically derived estimate of dry weight. Clinical assessment of dry weight inevitably leads to both overestimation and underestimation of dry weight. Overestimation of dry weight leads to hypertension, stroke, and congestive heart failure, which are the main causes of excess death in dialysis. Underestimation leads to persistent hypotensive episodes, alienating dialysis patients from their caretakers, and affecting delivery of prescribed dialysis. Moreover, the current focus on Kt/V as an index for adequacy of dialysis in terms of solute removal ignores the contribution of volume as an independent factor influencing outcome.”

The bottom-line is that we need to develop better ways to assess dry weight. For the husband of my patient, it really wasn't alright in the end and for our patient's not knowing precisely their dry weight isn't good enough.