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How to make a cool clinic diagnosis

I had a great case yesterday in clinic.

The patient was a 55 year old woman with HIV and a chief complaint of gradually climbing creatinine. Among her medications were Truvada and Norvir.

Truvada is one of three brand name drugs that contains tenofovir:

  1. Viread: tenofovir
  2. Truvada: emtricitabine-tenofovir
  3. Atripla: efavirenz-emtricitabine-tenofovir
Tenofovir rarely causes renal failure through proximal tubule toxicity. One of its hallmarks is a Fanconi syndrome, though the renal failure can occur without Fanconi’s. Fanconi’ syndrome is generalized dysfunction of the proximal tubule, so metabolites normally reabsorbed in the proximal tubule are wasted in the urine. Patients have amino aciduria, bicarbonaturia (RTA type II), inappropriate phosphaturia and glucosuria. Because of the increased phosphaturia, hypophosphatemia is a surprisingly sensitive indicator of tenofovir toxicity (20/20 cases).
This patient’s creatinine rose from 1.4 in March of ’09 to 1.7 in November. The primary care doctor that handles this patient’s HIV had checked an ultrasound (9 and 10 cm kidneys), and albuminuria (400 mcg/min).
Here are the results of his U/A we did in the clinic:
I focused on the glucosuria and concluded that if her blood sugars are normal then she must have proximal tubular dysfunction and likely tenofovir toxicity.
Her blood sugar was 87. The Tm for glucose is roughly 200, so a serum glucose of 87 should not cause any glucosuria.
The Truvada was stopped. The patient is also on ritonovir (Norvir). Ritonovir is found in 72% of patients with tonofovir induced Fanconi’s syndrome, so it maybe an important co-factor in the development of this condition. We did not stop the Norvir, should we?

 I will follow up with the patient in the month. Hopefully she will do well.

Here is a talk I gave on HIV and the Kidney:
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Great web service for making booklets

My favorite way to lecture is to pass out a personally written chapter on the subject and then collectively read the hand-out. I call this lecturing “Seder-style” named after the ritualistic dinner of the Jewish holiday Passover.

The booklets have four pages on each sheet of paper but you need a computer program to reorder the sheets so the booklets come out right. I used to have a print service that did this for me but it stopped working when I upgraded to Snow Leopard. I found this web service BookletCreator which does a great job with this.

Here are the original PDFs I uploaded:

Here are the bookletized PDF the website created:

Perfect.

UPDATE: No longer free.

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PubMed on Tap for the iPhone: the NLM in your pocket

Last week at the end of a morning conferance there was an impromptu discussion of the problem of residents ordering IV contrast for patients with acute kidney injury. The residents see a patient on dialysis and feel that its open season for contrast.

As part of the discussion one of the attendings mentioned this is also a problem with his PD patients with residual renal function and the residents need to know that contrast should be avoided in these patients to preserve residual renal function. I mentioned that actually the data doesn’t support the common sense notion that contrast accelerates the loss of residual renal function. Immediately all eyes were on me and the consensus was that no one else had seen that data and that I was way off the reservation. Pretty uncomfortable place to be.

I had buttoned holed Paul Palevsky at the 2006 ASN Renal Week after a talk on contrast nephropathy and in that hallway conversation he had mentioned that he had just finished research on this vary question. he only reason I remember it was that the results were so counter intuitive. Contrast has no measurable affect on residual renal function. I had actually never seen the article but now I had put up or shut up.

After the conference I had to run to an outside hospital but I stopped at a Tim Hortons (the best thing to come out of Canada since Douglas Coupland) and fired up PubMed on Tap (PMT).

PMT is an app dedicated to adapting the PubMed database to the constraints of a mobile platform. I used an app by the same name on my old Treo. Adding Palevsky as author, and then contrast and residual renal function as text words.

Bingo! One article:

You can pull up the abstract:
The PDF:
 :
and the PubMed listing:

I then did a less specific search by dropping the author name and found a higher quality study:

I was able to send the references to my colleagues right from the application. Sweet.

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What are the top nephrology stories of the last decade?

As we come to the end of the naughts, we naturally reflect back and think about how far we have come from in the last ten years. Here is my quick list:

  1. MYH9 gene for ESRD
  2. The failure of the normalization of hemoglobin and the wholesale reevaluation of ESAs
  3. The rise of aldosterone and its importance in hypertension and renal disease
  4. the failure of dialysis dose to improve out come in both chronic (HEMO) and acute dialysis (ATN).
  5. FGF-23, hey a whole new hormone and a major advancement in renal physiology
  6. Re-emergence of home dialysis
  7. Problems with the definition of CKD and the problems with eGFR
  8. discovering the antigen in idiopathic membranous nephropathy
I want to do a longer article about this but I’m sure I’m missing some stuff. I don’t have a transplant subject, seems like vitamin D belongs up there, what about the phos binder wars? Bundling? What about MMF in lupus nephritis and every other GN?
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week-end call and a pair of crazy numbers: Glucose and Calcium

Glucose
I saw the highest glucose I can remember in a patient without ESRD. I have seen the glucose go over 2,700 in a patient with the misfurtune to have both DKA and anuric ESRD. Without the osmotic diuresis to lower the glucose the glucose can shoot the moon. This patient had HyperOsmolar Non-Ketotic Coma (or HONK as my fellow calls it, love that) and baseline Cr of 0.83 and a peak glucose of 1,600 mg/dL.
I love the twin graphs showing the falling glucose and the simultaneous resolution of the pseudohyponatremia. The patient had enough pre-existing osmotic diuresis to cause hypernatremia which was masked by the hyperglycemia. As the glucose comes down the sodium goes up from 136 to 162.

Calcium
The other crazy number was the most severe hypercalcemia I have ever seen. The calcium was 18 mg/dL with an albumin of 3.7 g/dL. The patient is a kidney transplant recipient who was recently seen in the outpatient clinic with hypocalcemia. His calcium was 6.5 and his calcitriol was increased from 0.5 mcg to 1 mcg twice daily. He was also continued on his calcium carbonate.

Admission labs:

The other pertinent calcium labs:

  • PTH: 3.2 pg/mL
  • Vit D 1,25 dihydroxy: 36 pg/mL
  • SPEP/UPEP: unremarkable
  • PTHrp: pending
I think this is milk-alkali syndrome from the calcium carbonate exacerbated by the calcitriol. One supporting string of evidence supporting this is the fact that his calcium came down and has not reoccurred. If it was hypercalcemia of malignancy I would have expected his calcium to be resistant to conservative therapy.  
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Cast Nephropathy and plasmapheresis

Does removal of the light chains with plasmapharesis reduce the severity of cast nephropathy? We know that renal failure is a terrible prognostic factor in multiple myeloma so fixing acute renal failure is important.

Renal failure comes in many different flavors with myeloma:

  • Light chain deposition disease
  • Heavy chain deposition disease that I have never seen but Steve Rankin had a case as a fellow.
  • Amylloidosis
  • Hypercalcemia
  • Cast nephropathy
Only the last is amenable to plasmapheresis. Whether it works has been the subject of three prospective randomized studies:

  1. Zucchelli 1988
  2. Johnson 1990
  3. Clark  2005 (PDF)
UPDATE

Though not randomized this recent article from KI should be of interest (Thanks Kyste):

Leung et al. Improvement of cast nephropathy with plasma exchange depends on the diagnosis and on reduction of serum free light chains. Kidney Int (2008) vol. 73 (11) pp. 1282-8.

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Fellow talk on sodium

I was scheduled to give a talk on disorders of sodium and water to the fellows yesterday. We have a particularly clever cohort of fellows this year and I really couldn’t give them a warmed over version of my resident and student sodium lecture so I put together this talk which looks five different issues with hyponatremia and some data regarding them:

  1. mannitol induced pseudohyponatremia
  2. TURP syndrome
  3. uremia and propensity for myelinolysis
  4. exercise induced hyponatemia
  5. differentiation of salt delpetion from SIADH with FENa, FEUrea and FE Uric acid with a couple of slides on treating SIADH with saline

Remember, downloading the native Keynote file will give you animations and a better  looking experience.

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Engage with Grace Blog Rally

Last Thanksgiving weekend, many bloggers participated in the first documented “blog rally” to promote Engage With Grace – a movement aimed at having all of us understand and communicate our end-of-life wishes.

It was a great success, with over 100 bloggers in the healthcare space and beyond participating and spreading the word. Plus, it was timed to coincide with a weekend when most of us are with the very people with whom we should be having these tough conversations – our closest friends and family.

The original mission – to get more and more people talking about their end of life wishes – hasn’t changed. But it’s been quite a year – so we thought this holiday, we’d try something different.

A bit of levity.

At the heart of Engage With Grace are five questions designed to get the conversation started. We’ve included them at the end of this post. They’re not easy questions, but they are important.

To help ease us into these tough questions, and in the spirit of the season, we thought we’d start with five parallel questions that ARE pretty easy to answer:

Silly? Maybe. But it underscores how having a template like this – just five questions in plain, simple language – can deflate some of the complexity, formality and even misnomers that have sometimes surrounded the end-of-life discussion.

So with that, we’ve included the five questions from Engage With Grace below. Think about them, document them, share them.

Over the past year there’s been a lot of discussion around end of life. And we’ve been fortunate to hear a lot of the more uplifting stories, as folks have used these five questions to initiate the conversation.

One man shared how surprised he was to learn that his wife’s preferences were not what he expected. Befitting this holiday, The One Slide now stands sentry on their fridge.

Wishing you and yours a holiday that’s fulfilling in all the right ways.


To learn more please go to www.engagewithgrace.org. This post was written by Alexandra Drane and the Engage With Grace team. If you want to reproduce this post on your blog (or anywhere) you can download a ready-made html version here