The Weekend is (Still) Killing patients

First, I want to apologize to The Weeknd in case the title of this blog got anyone confused. I promise this is not about the celebrity. The Weeknd does not kill dialysis patients.

Normalized Risk

Now, for the serious part.

I want to talk about something terribly dangerous that we have accepted as normal in U.S. dialysis. Something that increases mortality significantly for our patients, but is so codified into our practice that it has become the unquestioned standard of care.

I am talking about the weekend.

The two-day gap. In the US and most of the world, in-center hemodialysis patients are prescribed 3-4 hours of treatment, 3 times per week, which creates two standard schedules:

• Monday, Wednesday, Friday (MWF)

• Tuesday, Thursday, Saturday (TTS)

Clinics are typically closed Sundays. So, patients have a built-in “weekend” break from dialysis.

The two-day gap created by the standard schedule (from Friday to Monday for the MWF and from Saturday to Tuesday for the TTS shift) is the build-up to the highest mortality period for dialysis patients. In this NEJM article, the first treatment day following a weekend had a mortality rate of 22.1 deaths per 100 patient years, compared with a mortality rate of 18.0 on other days of the week. A relative increase.

Since it’s easy to read over how awful this actually is, let me make that clearer.

• MWF patients were 23% more likely to die on Monday.

• TTS patients were 23% more likely to die on Tuesday.

We know. Other studies have repeatedly shown the same pattern since Bleyer et al first observed it in 1999—27 years ago. Still, the status quo dictates the “culture” of dialysis. Change is hard, even when there is knowledge. Even though many clinicians are aware of the danger. Even when we see it happen.

The worst part for me is that most patients have never been told.

Wouldn’t you want to know when your life is most at risk? It feels to me like we’re keeping a dirty secret from patients. Unlike dialysis, physiology doesn’t pause for the weekend.

The 2-day Gap

The first dialysis session after the 2-day gap remains the most dangerous time of the week for patients on a standard schedule. Multiple studies have shown that interdialytic gaps are dangerous:

1. Foley et al looked at 32,065 dialysis patients between 2004 and 2007 and compared rates of death and cardiovascular-related hospital admissions after the 2-day gap versus other days of the week. After the 2-day gap, they found patients had:

• 23% higher overall mortality

• 36% higher cardiac mortality

• 30% higher risk of death from cardiac arrest

• 43% higher risk of death from heart attack

Also, after the 2-day gap, patients had spikes in hospitalizations:

• 77% higher hospitalization rate for congestive heart failure

• 52% higher rate of stroke hospitalization

• 90% higher hospitalization rate for dysrhythmia

Re-read all of that. Let it sink in.

A 90% higher rate of dysrhythmia admissions. That is WILD. That almost makes it sound like to me that electrolyte balance matters. Or something.

2. Fielding-Singh et al looked at the outcomes of 1,147,828 surgical procedures on 346,828 Medicare patients with ESKD. They found that the longer the interval from last dialysis to surgery, the greater the mortality risk.

Patients who had surgery:

• 2 days after dialysis had a 14% higher mortality risk

• 3 days after dialysis had a 25% higher mortality risk

Risk increased relative to the length of the interdialytic interval. This interval matters. The 2-day gap was created by a schedule, not by physiology. The 2-day gap is not a harmless weekend.

It is a cumulative physiologic stress. If you want more sources, let us know—we’re happy to provide them.

Physiology of the Weekend (wink, wink)

Let’s recap some simple facts: dialysis removes fluid and some toxins, but only when the patient is actively on treatment. When a dialysis patient is not actively receiving dialysis, nothing is replacing kidney function. There is no “carry over.” I know this sounds like the most obvious “duh” ever. But I genuinely think basic physiology can get lost in the routine.

Physiology doesn’t stop until we’re dead.

Even when a person is “hooked up,” we are only temporarily and minimally correcting for a body system that is already in a state of failure. When treatment stops, after a brief rebound period, the physiological trajectory of kidney failure is resumed.

When I was a new nurse, one of my mentors said, “the patient is a closed system!” and that really stuck with me. It’s true in a very real way. The patient is a closed system accumulating a toxic metabolic burden from eating, drinking, breathing, and just…generally being a living creature with a strict biologic requirement for homeostasis.

Many patients report feeling well on the off days. But feeling well is not the same as being stable. Dialysis patients’ bodies compensate, constantly.

Homeostasis is underappreciated to begin with. In dialysis patients, it’s extremely fragile.

During the weekend:

• Fluid accumulates

• Metabolism continues

• Protein degradation goes on

• Electrolyte shifts occur

• All uremic toxin levels rise

• Acidosis intensifies

• Phosphate rises

• Inflammation increases

• Cardiac stress builds

But most concerning of all? Potassium. We like to talk about potassium as if its only purpose is to exist within bananas and tomatoes and kiwis much to the dismay of kidney patients, but potassium is the electrolyte that stops the heart. Any time potassium is out of balance, the heart is electrically unstable.

I’ll let you in on another dark secret. This isn’t abstract chemistry. Potassium chloride is the 3rd drug used in lethal injection protocols. The first two are an anesthetic and a paralytic—to prevent movement. Potassium is then given specifically because it causes cardiac arrest. For right, wrong, or indifferent, even our criminal justice system knows what potassium can do.

Now, to be fair, potassium doesn’t spike all at once in dialysis patients like it does in the execution chamber. It merely accumulates over the weekend. But the mechanisms driving the heart are the same. The heart ultimately doesn’t care whether the rise is fast or slow. The electrical conductivity is unstable. And dialysis patients already have many co-morbid cardiovascular risk factors that can push them easily over an edge they don’t even know exists.

When we bring them back into the clinic after a weekend, we run their hyperkalemic blood against dialysate, causing a steep gradient of change in a short time while simultaneously removing twice the amount of accumulated fluid as usual. In short, we are playing with fire.

So, it shouldn’t surprise anyone that sudden cardiac death clusters happen to patients on their return treatment after the 2-day gap. The system is set up that way.

The weekend is not neutral. And it is certainly not natural. The weekend is dangerous. Patients ought to know this because I am not sure everyone consents to the risk that is scheduled into their lives. More on that later.

Cognitive Dissonance

Cognitive dissonance is the psychological discomfort we feel when our beliefs, values, or behaviors are in conflict with each other. For example, it makes us uncomfortable when someone says one thing, but then does another. This sends mixed signals, which creates a tension that can be difficult to identify or articulate.

In dialysis, we tell patients:

• It is critical to never skip treatments

• Leaving treatment early can be deadly

• Fluid gains are dangerous

• Potassium kills

Yet, we normalize a 72-hour treatment gap. Every. Single. Week.

We talk to patients until our voices are gone about fluid restriction—but the system is set up for convenience, not human necessity. We are basically guaranteeing the extra accumulation.

We police bananas, tomatoes, kiwis, and orange juice while forcing patients to live in a system that focuses more on what they can’t have than on how to manage what they want. And we allow for extra time for electrolytes to become even more deranged over the gap.

We tell patients dialysis keeps them alive.

Then, we structure care in a way that withholds treatment—right when they’re thinking about spending time with family and friends, maybe eating some normal food, or being less diet conscious.

This is cognitive dissonance. And patients feel it. Even if they don’t have the words for it, they feel the Monday/Tuesday wash-out. They cramp from the higher UFR. They feel the longer recovery time.

Then they ask, “Why do I feel so bad after dialysis?” And that’s the wrong question. The problem isn’t so much the dialysis as it is the weekend. The time. The lack of correction for kidney failure over a gap that is even more unphysiological than dialysis itself!

The Non-Blame Game

I am not here to blame nurses. Or nephrologists. Or administrators. This is a systemic problem. A historic one. In brief:

The dialysis system was built in the 1960s-1970s when dialyzers and machines and know-how were scarce. It was still a miracle that any patients could chronically survive past kidney failure. A revolutionary concept. The question then was not about optimization as much as it was about access to treatment for the masses. Home dialysis existed, but all access to care was limited.

When Medicare expanded coverage to patients in 1972, dialysis clinics rapidly expanded and facilities opened that used business models to handle the volume of patients. The thrice weekly schedule is efficient from an operations standpoint. It allows for large numbers of people who require dialysis to receive it and survive.

But is survival the only or best benchmark?

The schedule was never about replacing kidney function well. It was about saving lives. As many as possible. And it worked, thank heavens. But over time, reimbursement structures reinforced the status quo with justifications needed for patients who dialyze more than thrice weekly. And businesses reinforced it with staffing models, facility hours, and training programs.

A survival-driven schedule evolved into our permanent infrastructure. It’s “how dialysis works” but it’s not how kidneys work. It’s not a schedule worth defending, in my opinion. We know it is not optimal for patients.

Home Dialysis is NOT a Luxury

Home treatments are one of very few ways to receive more physiologic treatment. We have lots of information about that on this website. Some clinics offer more frequent or longer treatments, though this is rare in the U.S. But this is where home dialysis truly changes the conversation for patient survival and quality of life.

There is no reason for home patients to have a long no-treatment gap. In fact, they really shouldn’t. Every 72-hour metabolic cut off is dangerous. Every weekly potassium challenge is dangerous. Every aggressive UFR to “get back to baseline” after a heavy few days is dangerous.

We know that more frequent, more gentle, and longer dialysis:

• Stabilizes balance

• Maintains potassium at relatively stable levels

• Improves BP control

• Reduces the risk of left ventricular hypertrophy

• Reduces organ stunning

• Reduces recovery time

• Reduces symptom burden

• Improves quality of life

This isn’t trendy medicine. This isn’t hippy-dippy medicine. It’s physiology. Dialysis 3 times a week is not and will never be physiologic. Working kidneys provide continuous clearance. The more we mimic continuous clearance, the more stable a person becomes.

Home dialysis is not a luxury. It is the best tool we have to respect how the human body actually works in dialysis under the constraints of the medical system we are beholden to. If you want physiologic treatment in the U.S., the most reliable way to accomplish this is to do it yourself. At home.

The Consent Question

As I said before, the lack of patient consent is what bothers me most. Do dialysis patients truly consent to the risks incurred during the 2-day gap? Are patients explicitly told that, after the weekend gap, their:

• Risk of death is 23% higher?

• Risk of cardiac death is 36% higher?

• Risk of arrhythmia requiring hospitalization is 90% higher?

• Surgical mortality rises the longer they go without treatment?

Informed consent requires absolute transparency about material risk—just like we provide when patients miss a treatment or leave early. We give them AMA forms that explain the risks of hyperkalemia, of heart failure, or death.

But, we may not explain the identical risks that are built into and normalized by the schedule itself.

Patients deserve to know when their lives are most at risk. Not to frighten them, but to give them the chance to empower their own futures. Some people may choose to stick with the standard of care—and that’s fine if they understand. That’s their right.

The beauty of truly informed decision-making is that, armed with this information, some people would find this schedule-based risk unacceptable and rescind their “consent” to the gap, choosing instead to take matters into their own hands.

My Reflection

I don’t want to villainize in-center dialysis. One of my best friends, Mandy, is a two-time transplant recipient. She is constantly telling people online to “stop knocking the treatment” because she realizes that dialysis does save lives. It is still the miracle treatment it has always been.

But can’t we do better than survival?

We have an obligation to be honest about the pitfalls of our abilities. The standard in-center hemodialysis schedule was born in a time that focused on mass survival and access. It was revolutionary. It has saved countless lives. But, we now have the infrastructure to support volumes of patients.

We also have data showing the inter-dialytic gap carries serious preventable risk. We know that our practice is in conflict with physiology. The CMOs of every major dialysis company know and collaborated on a letter to this effect—in 2014. And, therefore, we should pause. We should think. We should ask better questions and find better answers.

Conclusion

In dialysis, the weekend is not neutral. It’s not natural. It’s not a welcome reprieve even when it feels like it is. The 2-day weekend treatment gap is counterintuitive to how patients’ bodies function. And, it is not person-centered to leave patients blind to the risks of long interdialytic intervals. We need to be honest, because the weekend is still killing dialysis patients.

Acknowledging that there is a problem is the first step toward changing it.

The weekend is not a break from dialysis. It’s a break from kidney replacement. That is the problem.