Category: Commentary

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Free Onconephrology text book

Awesome, current resource on onconephrology from the ASN. Nineteen chapters with everything you need to be a superior consultant nephrologist

Chapters

  1. Onco-Nephrology: Growth of the Kidney-Cancer Connection
    Mark Perazella, MD, and Mitchell Rosner, MD
  2. Why Do We Need an Onco-Nephrology Curriculum?
    Mark Perazella, MD, and Mitchell Rosner, MD
  3. AKI Associated with Malignancies
    Amit Lahoti, MD, and Benjamin Humphreys, MD, PhD
  4. Tumor Lysis Syndrome
    Amaka Edeani, MD, and Anushree Shirali, MD
  5. Electrolyte and Acid-Base Disorders and Cancer
    Anushree Shirali, MD
  6. Glomerular Disease and Cancer
    Divya Monga, and Kenar Jhaveri
  7. Hematologic Diseases and Kidney Disease
    Ala Abudayyeh, MD, and Kevin Finkel, MD, FACP, FASN, FCCM
  8. Clinical tests for Monoclonal Proteins
    Nelson Leung, MD
  9. Hematopoietic Stem Cell Transplant-Related Kidney Disease
    Sangeeta Hingorani, MD, and Joseph Angelo, MD, MPH
  10. Radiation Nephropathy
    Amaka Edeani, MBBS, and Eric Cohen, MD
  11. Chemotherapy and Kidney injury
    Ilya Glezerman, MD, and Edgar Jaimes, MD
  12. Pharmacokinetics of Chemotherapeutic Agents in Kidney Disease
    Sheron Latcha, MD, FASN
  13. CKD as a Complication of Cancer
    Laura Cosmai, MD, Camillo Porta, MD, and Maurizio Gallieni, MD, FASN
  14. Hereditary Renal Cancer Syndromes
    Katherine Nathanson, MD
  15. Work-up and Management of Small Renal Masses
    Susie Hu, MD Anthony Chang, MD
  16. Cancer in Solid Organ Transplantation
    Mona Doshi, MD
  17. Cancer Screening in ESRD
    Jean Holley, MD
  18. Ethics of RRT, Initiation and Withdrawal, in Cancer Patients
    Michael Germain, MD
  19. Palliative Care in Patients with Kidney Disease and Cancer
    Alvin H. Moss, MD, FACP, FAAHPM

The more you learn the cheaper that ASN membership looks.

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What books or resources should I use to learn nephrology?

I received this DM today (my DMs are open. I was nervous about opening DMs but a year later I would rate the experiment as a delightful success. It has opened up Twitter to many new discussions that otherwise would not have occurred).

Hi Dr. Topf, I’m a final year medical student from the UK. I’ve been following you for a while due to my interest in renal medicine. Are there any books/online resources that you would recommend to learn renal physiology? I feel that I lack fundamental principles and concepts which I’d like to improve. Thanks!

Arnav

This is actually a relatively common question and I am going to attempt to write this post so I can link to it in the future.

The answer depends on the goals of the student

Preclinical medical student.

Vander’s Renal Physiology

Slim, readable. Good choice.

The Acid-Base Haggadah

This is designed to be part of a workshop but it can be read on its own.

Medical student or resident on a clinical rotation

This list is for the learner who is looking to know what to do.

Nephrology Secrets

Of course I’m one of the authors and I edited every single word in this book but a year later I still am amazed at how well this review book walks the tightrope of being concise without over simplifying complex topics. I may be biased, but I think this is an excellent book.

NKF Nephrology Primer

Before Secrets this was my go to recommendation, but this book is getting long. I’m beginning to think this may be too long for a student resident on a one month nephrology rotation. That said you can’t find better renal educators that editors than Gilbert and Weiner.

The learner really wants (or needs) to have a mechanistic understanding of why we do what we do then…

Fluid, Electrolyte and Acid Base Companion

It is strange that one of the things I am most proud of in my entire career is a book I wrote as a resident but it is no exaggeration to say this book for transformative for my life. I poured five years of work into this project and i think it stands up. However you should skip the tremendously outdated and overly complex section on the treatment hyponatremia and instead read the European Clinical Practice Guidelines.

Burton Rose’s Clinical Physiology of Acid Base and Electrolyte Disorders.

People look at the copyright on Rose’s electrolyte book and conclude the book is out of date.
It is.
It doesn’t matter.
Rose excels at providing the reader a cohesive mental model of how the kidneys work so that things make sense. Then if you need to learn more and get a more up to date and nuanced view of how the kidney works it is pretty simple to plug those updates into your mental model of the kidney.

The nephrology fellow

Use the following:

  • Nephrology Secrets
  • Burton Rose’s electrolyte book
  • Daugirdas’ Handbook of Dialysis
  • All of the KDIGO clinical practice guidelines
  • A subscription to UpToDate
  • A subscription to Nature Reviews Nephrology
  • Attend every NephJC

Read the first three cover-to-cover and then cover-to-cover again. The KDIGO Guidelines will give you the state-of-the-art for many of the important issues in Nephrology and the full guidelines provide a solid scientific rational for why the guideline are the way they are. You should have more than a superficial familiarity with the guidelines. Use UpToDate and Nature Reviews to go deep on every weird, rare, or interesting patient. Use the last one to stay up to date with clinical research. That’ll do. That’ll do quite nicely.

What did I miss? What are your favorites. Hit me up on #MedTwitter or slide into my DMs.

Some good updates from Twitter

And Mir Tariq Ali reminded me of major omission to my list. I forgot Daugirdas’ Handbook of Dialysis. This is the third book that every nephrology fellow should read cover to cover and then read again.

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Medical management of hyperkalemia

My team was consulted for acute kidney injury (AKI) and hyperkalemia. Before we saw the patient they had already been given the standard, calcium, bicarb, and insulin/glucose cocktail. This had no effect. Potassium went from 6.4 to 6.4.

The patient was still making urine. The AKI was due to emergency surgery with an impressive estimated blood loss (translation: blood loss measured in liters). We gave a liter of NS, 80mg of IV furosemide and 0.2 mg of oral fludrocortisone. Potassium went from 6.4 to 3.4 despite a further increase in the serum creatinine.

Remember to use the kidney for treating hyperkalemia. Even in AKI you can get impressive results.

Renal clearance of potassium is entirely dependent on the cortical collecting duct, specifically the principal cells. It is a multi-step process:

  1. reabsorption sodium down its chemical gradient through eNaC
  2. The chemical gradient to allow sodium resorption is generated and maintained by the Na-K-ATPase
  3. Movement of sodium without an anion(or a cation going in the opposite direction creates a negative charge in the tubular fluid which pulls potassium down an electrical and chemical gradient from the cells into the tubule. This occurs through ROMK and BIGK.

That is how potassium is excreted but, how is potassium regulated? There are two primary components to regulation:

  1. Aldosterone stimulates the transcription of all three transporters (ENaC, Na-K-ATPase, and ROMK) as well as transcribing versions of the proteins which are more active.
  2. Tubular flow. Increased distal sodium delivery provides plenty of sodium to be reabsorbed into the principal cell providing the negative charge, as well as washes away any secreted potassium to maintain the chemical gradient favoring potassium excretion.

The medical management we provided takes care of both aspects of potassium regulation, the furosemide and saline makes sure there is a robust supply of sodium delivered distally and the fludrocortisone makes sure there is ample aldosterone activity to assist with potassium clearance.

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Things we do for no reason (#TWDFNR ) in AKI

Last week I wrote this tweetorial

I had been thinking about this for a long time.

When you hear #TWDFNR talks about AKI the two things that are usually hammered are:

  1. The uselessness of the FENa and other urinary excretion indices.
  2. The low yield of the kidney ultrasound.

I actually like both of those tests, despite the pundit class dumping on them.

The FENa is vilified because in trials that look at its ability to separate out purely hemodynamic decreases in GFR from acute tubular necrosis it does poorly. This is especially disappointing because all of the board exams and med student level lectures on FENa says this is just what the test is all about. I concede that FENa in isolation is a bad test to determine the etiology of AKI. But as part of the global assessment of the patient, getting a FENa can be incredibly powerful.

Saying the FENa is useless is like testing to see if a blinded physician given only an aucultory exam could diagnose community acquired pneumonia. I think there is a good chance auscultation would fail that hurdle. But that doesn’t mean we should abandon our stethoscopes. The auscultory exam is one of a number of studies we do when assessing a patient who may have pneumonia. It is a valuable part of the global patient assessment.

Similarly, the FENa is part of my global assessment of a patient.

For example, I have a patient with cirrhosis and acute kidney injury. I look at the urine and see a mixture of hyaline casts and granular casts. Now, you need to be careful about granular casts in cirrhosis. As the bilirubin climbs, it can stain innocent hyaline casts to look brown, and they can start to look somewhat like muddy-brown casts. I don’t think that is what is happening on this slide, because I can see simultaneous dirty brown and hyaline casts. Then we checked the urine sodium and it was 50. This is off diuretics. This is remarkably high for a patient with cirrhosis and ascites. But there it is. The urine sodium is high and in agreement with U/A findings. I make a diagnosis of acute tubular necrosis.

Not the patient’s urine, but those are some nice muddy brown casts.

It’s an N of 1, but that’s all we have in clinical medicine, one N of 1 study after another.

The kidney ultrasound story is a much simpler than the FENa story. The argument that kidney ultrasound is of low yield and low cost effectiveness is due to the exrtemely low yield of U/S to find obstruction. In almost every case that you find obstruction, you suspected obstruction, and using it in cases without a clinical suspicion is like Acestes aiming at a non-existent target.

But the thing is, the treatment of obstruction is not dialysis, and if you fail to identify and correct the obstruction, no mixture of IV fluids, avoiding nephrotoxins, and regulating blood pressure will fix the obstruction. That obstruction will lead to renal failure and dialysis. In a world of $60,000 a month maintenance therapies, I refuse to miss even one easily correctable (but otherwise irreversible) cause of kidney failure.

The real #TWDFNR in AKI are:

  • Urinary protein to creatinine ratio
  • Intact PTH

The fallacy of the Protein Creatinine ratio was the subject of the afore mentioned tweetorial.

Some great comments and discussion from the tweetorial:

The problem with PTH in AKI is that it is useless. I see fellows and attendings ordering this and I have no idea what to do with it. Some people try to use the KDIGO PTH guidelines for ESKD. This seems to be totally evidence-less. PTH is an acute phase reactant in AKI. Part of the AKI syndrome is a drop in calcium, and after that PTH rises, just like it is supposed to. I don’t see any reason to suppose this secondary hyperparathyroidism is pathologic. I have seen some people order it to try to distinguish acute from chronic CKD. The reasoning being, that chronic kidney disease would have a high PTH and acute would not. This is not the case both acute and chronic kidney disease can have secondary hyperparathyroidism.

Stop ordering PTH in AKI. Stop checking urinary protein to creatinine ratio and start doing urinalysis and microscopy.

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What is the role of UpToDate in medical education?

I wrote the following tweetorial last week and the response was amazing. Seems like everyone had an opinion.

The poll at the end of the tweetorial had over 1,500 votes with 90% split between “Definitive source” and “Equivalent to other textbooks”

A recurring thought among commenters was that textbooks are great for providing overviews and UpToDate is a more practical reference that will be both up-to-date and provide specific recommendations for your clinical question. I remember talking to Burton “call me Bud” Rose when he was hawking a still incomplete UpToDate in the halls of ASN Renal Week in the 90s. One thing he drilled in on was that his cards (a card is a single entry in UptoDate) always finish with a specific recommendation. He viewed this as a critical differentiator for UpToDate. He made his writers not just provide the data but pick a side.

One great comment was by Poonam Sharma

I think this might be the source of some physicians distaste for UpToDate. When we have a resident give a presentation to teach the rest of the team or residency, or fellowship program we want people to dig deeper than summarizing UpToDate.

Additionally people kept commenting on the importance of going to the primary literature. This is great in principal, but in practice the volume of primary literature is overwhelming. The KDIGO 2012 blood pressure recommendations have 453 references on blood pressure alone. If you seek to be an expert, going down the rabbit hole of primary literature is essential, but if you want to put all of that training to use taking care of patients, it is best to stick with guidelines, review articles, and, yes, UpToDate.

One final note, the villain of the initial tweet, Dustyn Williams, contributed to the conversation.

This is a model with how to deal with this type of hullabaloo. He avoided any ad-hominem defensiveness. He stated that this was a long time ago and he is no longer the same person. His thoughts on the topic have evolved. Nicely done. God knows what inappropriate and emotional things I have typed out in the past. And I am sure most of us will, in the future, need to deal with years-old statements returning zombie-like to chase us down. Dr. Williams provides an admirable model to follow.

COI: I am the author of a medical textbook.

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The social media and medical education talk at Vanderbilt

Earlier this year I got the opportunity to speak at Brigham and Women’s Nephrology division. I had spent a lot of time and thought in updating my Social Media and Medical Education talk. For the first time I added Podcasts and Tweetorials, two of the most exciting developments in social media medical education.

Then on the day of my presentation I had “technical problems” connecting my MacBook Air to BWH’s projector (what is this 2003?). So I logged into iCloud and ran an older version of the presentation from iCloud using the online version of Keynote on the PC connected to the projector. The idea that I can run my presentation, with fonts, images, animations on a browser version of Keynote on a PC is truly amazing. Hats off to the Apple engineers.

But that meant the newest version of the talk was still “unpublished.” So I was delighted to get a generous invitation from Vanderbilt to speak at medicine grand rounds.

So this past Thursday I traveled to Nashville and I was able to present this presentation. And now that it is “published”, I am offering the presentation for you to present, edit and repurpose in any way you desire (no permission required, go at it):

  • Keynote (this is the native format) (1.16 gb)
  • Powerpoint (this is an exported version of the native Keynote, so it has questionable fidelity) (744.7 mb)
  • PDF (317 mb)

And what an amazing nephrology department. Holy moly what a deep bench. Loved getting a chance to talk with Ray Harris, Anna Burgner, Tom Golper, Jay Bhave, Kerri Cavanaugh, Alp Ikizler, Julie Lewis, Be a Concepcion, Davika Nair, Leslie Gewin. and Edward Gould.

If you are applying to nephrology fellowship and don’t have Vanderbilt on your list, you are doing it wrong.

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#NKFClinicals: The Social Media Session

Matt and I had the honor of putting together a session on social media for the NKF. We did not want to do intro to social media. The beginning of social media in medicine is over. We are in the beginning of the middle, and we wanted to deeper look than intro lectures can provide.

We had three talks.

  • Matt and I tag teamed for a NephMadness 7 year retrospective. Keynote | PDF
  • Teresa Chan spoke about the future of medical education online. Amazing Powerpoint | PDF
  • Macey Henderson spoke about using social media in transplant, specifically about finding living donors. PowerPoint | PDF
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KIDNEYcon 2019 was awesome

KIDNEYcon is the answer to my post about how ASN’s Kidney Week is facing an existential crisis. John Arthur, Shree Sharma, and Matt Sparks have put together a brilliant two-day conference that offers hands-on work shops, an inspirational keynote, trainee Jeopardy, and state of the art clinical lectures.

The night before the conference a bunch of people met for bowling. Very fun. One of many events organized by Samira Farouk.

You can see the entire schedule here.

This was my third year participating in KIDNEYcon and this year I was invited to re-run the acid-base, fluid, and electrolyte workshop from last year. This year I teamed up with Roger Rodby of Rush (do more people anyone identify Rodby with Rush or ASN Communities, Twitter, ASN Board Review Course, or #NephMadness Blue Ribbon Panel?).

The workshop started with my favorite electrolyte gimmick, the IV fluid tasting party.

University of Arkansas provided 0.9% NS, 3% saline, lactated ringers, and D5W for our gustatory enjoyment. I then presented three cases:

  1. A case of toluene toxicity and how it looks like a distal RTA (non-anion gap metabolic acidosis), smells like a distal RTA (hypokalemia), and quacks like a distal RTA (positive urinary anion gap), but it’s not a distal RTA (lots of urinary ammonium).

Then I went over a case of hypernatremia and drilled down on how to calculate a water prescription that will actually correct hypernatremia.

And then a case of hypotonic hyperosmolar hyponatremia.

My slides, including a case of hyperkalemia that we didn’t use, are here:

Keynote | Powerpoint | PDF

(I include the Powerpoint for the unenlightened who still use that ancient technology. I do not check if the transitions, animations or images look decent. Use at your own risk)

Then Roger took over and went through a case of MDMA induced hyponatremia.

Then he went through a case of cerebral injury and polyuria. No, it was not a case of cerebral salt wasting. He then presented a really practical case of hyponatremia. Too many electrolyte problems are made up and you can feel the fiction when you hear them. This case of hyponatremia had integrity. Loved it.

Which was a great entry for Ure-Na tasting.

This led to a totally off label discussion of buying food-grade urea from Amazon and making home UreNa. This is not standard of care. Your mileage may vary. Talk to your lawyer before proceeding.

Roger concluded with a great discussion of DKA in an anuric dialysis patient.

After that I finished the workshop by presenting an unknown case of hypokalemia. And then then we tried to simulate those findings by drinking a sample of sodium zirconium cyclosilicate, Lokelma.

After lunch (dosed with extra mentoring, again thanks to Samira Farouk), Roger and I ran it all again.

That night was a dinner. There was an entertaining game of Jeopardy for the trainees. Jeopardy was put together by Samira Farouk (who, if you haven’t noticed is building a compelling case for NephJC Kidney MVP). Steven Coca found a mistake in the otherwise brilliant Jeopardy board.

Then Michelle Rheault gave an inspiring keynote speech about her journey through academic medicine. It was really good.

Saturday was a day of didactic sessions. The best way to catch up on all the tweets is to take a look at the amazing live tweeting by Brent Wagner…

It started with a review of social media and medicine by Sayna Norouzi and Sri Lekha. It was a breakfast session so it was called Hashtags and Hash-browns. Unfortunately no hash-browns were available.

This was followed by a session on hypertension put together by Swapnil which was amazing. Four lectures:

  • Office, Automated, Home, or Ambulatory? Which One and Why? by Mathew Luther
  • BP Variability: What is It and Why Should We Care? by Jordana Cohen
  • Drugs and Devices That Lower BP: A 2019 Update by Steven Coca
  • Debate: BP in CKD: How Low Should We Go? Tara Chang and Scott Brimble

The debate might have been the best medical debate I have ever seen. Dr. Chang’s slides were gorgeous and Scott did a beautiful, funny and humble job poking holes in the generalizability of SPRINT.

It was followed by a session on AKI

  • Urine Sediment Microscopy to Diagnose and Phenotype AKI: Should We Bother? by Juan Carlos Velez
  • TIMP2/IGFBP7 as a Predictor of AKI Outcomes: Are We There Yet? by Nithin Karakala
  • Genomic Predictors in AKI by Kevin Rogers
  • Using Proteomics to Identify AKI Biomarkers by John Arthur

After lunch there was a session on pediatrics

  • C3GN: Pathogenesis and Treatment by Carla Nester
  • Pediatric Kidney Stone Disease, Including Genetic Forms by David Sas
  • Kidney Development and APOL1 by Kimberly Reidy
  • Non-Adherence in Pediatric Kidney Transplant-Practical Strategies for the Pediatric and Adult Nephrologist by Vikas Dharnidharka
Love this on brand pic of Vikas!

The last session of the weekend was on clinical research.

  • Fellow Case Report on euglycemic DKA from an SGLT2i
  • A Telehealth Study to Improve Outcomes in Patients with CKD by Manisha Singh
  • Perplexed About Pragmatic Trials? The Ins and Outs of Different Trial Designs in Clinical Research by Swapnil Hiremath (who has generously made his presentation available)
  • SGLT2 Inhibitors: Discovering Their Role in Slowing Progression of Diabetic Nephropathy by myself
  • Tolvaptan for ADPKD: From Mechanisms to Treatment by Frederic Rahbari Oskoul

Here is the presentation I gave:

Keynote | Powerpoint | PDF

(I include the powerpoint for the unenlightened who still use that ancient technology. I do not check if the transitions, animations or images look decent. Use at your own risk)

After the lecture the conference moved to John Arthur’s house for a party with delicious hand crafted martinis and gourmet meatballs.

KIDNEYcon is a special conference. It is a great place for trainees. The workshops allow hand-on experiential learning that you can’t get from YouTube. It gives people the opportunity to really drill down and develop biopsy skills, pathology skills, early career development. In the past they have done point of care ultrasound and cooking classes. It is amazing. If you haven’t been it’s time to make a trip to Little Rock.

Here is a sharp top ten list from KIDNEYcon