Custom dialysate solutions

I get nervous when I need to dialyze someone who is severely hyponatremic. Dialysis has the power to change the sodium concentration very fast. Patients with chronic, compensated hyponatremia need their sodium corrected slowly. Experts recommend increasing the sodium by less than 12 mEq/L/day and to actually undertarget only 6 mEq/L/day to give you some margin for error.

Over the week-end we were consulted on a patient with a sodium of 106 and acute renal failure. By the time we were forced to dialyze the patient the sodium was up to 112. To do this safely we selected CVVHD and then diluted our dialysate down to 120 mEq/L.

Here is a Keynote (100 mb), PDF (155 kb) and a narrated version of that presentation (118 mb) where I walk through the algebra on how to mix a dialysate of any final sodium concentration.

The movie available for download is very high quality. Below is a YouTube conversion of that video to save you the 118 mb download.

This is some serious Sodium Jujitsu and I awarded my team the first Nephrology Merit Badge: Sodium Ninja (pages | pdf). Designed for Avery 5163 2×4 labels.

Nephrology Merit Badge, updated for the 21st century as a sticker for your iPad

PBFluids breaks into the medical literature.

The first time PBFluids was referenced in the medical literature was in Matt Sparks’ article on nephrology internet resources.

Today I received an e-mail from Tom Oates. Apparently, when he is not researching the unique genetic predisposition of the WKY rat to crescentic glomerulonephritis he is an avid reader of both Hemodialysis International and PBFluids. He sent me this article in Hemodialysis International regarding the highest creatinine ever. The key sentence in the article:

Extremely high levels of serum creatinine have been reported in the literature.3 The highest level of serum creatinine reported was 37 mg/dL.3

So what is the highest previous creatinine reported in the literature? Well according to the author, Said Abuhasna, it’s 37 from this post at PBFluids. Nice to see blogs being included in the canon of medical literature. Though it would be even nicer if they spelled my name right.

The death of MobileMe and a whole mess of broken links at PBFluids–Updated

One of the best stories about Steve Jobs was his tirade is response to the MobileMe disaster.

He gathered the MobileMe team together and asked,

“Can anyone tell me what MobileMe is supposed to do?”
Having received a satisfactory answer, he continues,
“So why the f*** doesn’t it do that?”

He then picked another executive to run the project on-the-spot. Ultimately, this resulted in the service being shuttered and replaced with iCloud.

I never had any problems with MobileMe; it always worked fine for me. However, I foolishly relied on it to host files for PBFluids. This includes all of the presentations and handouts that are the highest trafficked pages of the site. Well, MobileMe stopped accepting new subscriptions a year ago and as of June 30th the hosted files are no longer accessible. I have downloaded all of the material and will start re-uploading the files to DropBox.  The problem is rewiring all of the past links to the new file locations. This will take some time.

As I looked through the collection of files that used to be hosted at MobileMe I found a lot of journal articles and other copyrighted works. I have no idea how popular these links were but I remember when I uploaded them, PBFluids was a lonely backwater, where I was the sole source of traffic. I put the files the files online for my own use in teaching and on rounds. I don’t plan on replacing these files.

Update: 
7/3/12 Lecture tab is ported to DropBox
7/3/12 Handout tab is ported to DropBox through Adventures in Renal Imaging
7/5/12 Handout and Book tabs ported to DropBox

July 3, first lecture of the year

For the past few years I have had the honor of giving the July 1st morning lecture for the internal medicine residents at St John Hospital and Medical Center. Unfortunately, July 1st was a Sunday and Monday mornings are dedicated to a formal sign out rounds in our division. So July 3rd was my first lecture.

I gave my Fluids, Diuretics and Sodium for the Terrified Intern lecture. You can down load it here:

Bet he has Gitelman’s syndrome

This post on BuzzFeed makes me so glad I never suffered the indignity of on-line dating. My favorite is this guy:

What are the odds he has Bartter’s or Gitelman’s. Every patient I have encountered with Bartter’s or Gitelman’s has admitted to drinking pickle juice, so it’s sensitive but I don’t know how common this is among norms so its specificity has yet to be determined.

eAJKD: integrated care

I interviewed Allen Nissenson for eAJKD. He wrote a great review of his knowledge and experience with accountable care organizations and how they will affect nephrology. The best part of his article was when he discussed his experience working on a pilot project for CMS demonstrating benefits to dialysis patients using an integrated care model. This project showed a survival benefit not by changing the dose of dialysis, or giving additional drugs. The improved outcomes came simply from better communication and organized, systematic care. Eye-opening stuff.

Uric acid and hypertension, a unique study

I have written and presented quite a bit about uric acid, fructose and the link to hypertension and chronic kidney disease. Last month’s Kidney International published an interesting take on this subject.

The question that the investigators were examining was, “Is uric acid a cause of hypertension?” The data supporting this is largely epidemiologic, with a smattering of interventional trials. The largest criticism of the epidemiological trials has been the issue of causality and directionality, i.e. does the hypertension cause the high uric acid or does high uric acid cause the hypertension?

this is how I show the directionality debate in my presentation

Previous interventions involved using allopurinol to decrease uric acid. However there are questions of whether allopurinol may have some magical anti-hypertensive effect outside of its ability to lower uric acid. The investigators discovered a cohort of Amish with a variant of GLUT9, a urate transporter. This variant, an ILE for VAL at amino acid 259, lowers the uric acid level by about 0.5 mg/dL in women and 0.25 in men. The lowered uric acid is likely due to enhanced renal clearance.

The authors used Mendelian Randomization to see what the effect of a lower uric acid has on developing hypertension.

Mendelian randomization (MR) is a concept I had not come across before. Here is a video of Wayne State University researcher, Dr Anthony Ference, who used MR to study LDL. He does a nice job of describing the concept.

The authors of the uric acid acid trial describe mendelian randomization thusly:

The mendelian randomization principle relies on the tenet that alleles, and hence genotypes, are randomly assigned during gamete formation. The main advantage of this method is that gamete formation occurs before birth and is therefore unaffected by traditional confounders that occur after conception, such as diet, socioeconomic status, access to healthcare, and all other environmental factors. Because relationships between genotypes and outcomes have only limited susceptibility to confounding and are not subject to reverse causality, genetic variation may be used to establish directionality and infer causality between a certain gene product and a specific outcome. Therefore, Mendelian randomization is akin to a randomized trial design, inheritance of the GLUT9 ILE allele would be analogous to randomly being assigned probenecid, a uricosuric agent, from birth, whereas inheritance of the wild-type genotype would be analogous to receiving placebo.

The cohort was a group of 868 participants of the HAPI (Hereditary and Phenotype Intervention) study. Ninety-eight of these people had GLUT9 variants. Patients’ blood pressures recorded in clinic on a liberal (standard) diet and then checked with 24-hour ambulatory monitoring following a week on a high-sodium diet (280 meq/day) and again after a week on a low-sodium diet (40 meq/day). The diets had fixed carbohydrates and potassium.

The blood pressure spread is impressive and statistically significant in both the high- and low-sodium diets. The authors summary was for every 1 mg/dl decrease in uric acid the systolic blood pressure fell by 3-5 mmHg.
I thought this study was an original approach to the question of fructose and uric acid. They found an experimental method that allowed them to look at different levels of uric acid without confounding the results with the pleiotropic effects of allopurinol.

The nephrologist’s guide to Twitter

Twitter is the second largest social network after Facebook. But, though they are often grouped together this is not a Coke and Pepsi type of pairing. Twitter and Facebook are different animals.

The difference stems from a fundamental difference in the construction of the networks. In Facebook, both parties must agree on the relationship. Once you have “friended” each other, you are on roughly equal footing. This mutual agreement to exchange information gives people a sense of privacy that Facebook is repeatedly jeopardizing as they lurch from dorm room experiment to world changing company.

Twitter, on-the-other-hand promises neither privacy nor mutuality. People sign up to “follow” your updates and you can choose to follow them, or not. This changes everything. It allows celebrities to use twitter to broadcast to a wide audience. It also thrives at allowing people to communicate with people they have never met.

It has been said: Facebook allows you to connect with people you already know, Twitter allows you to meet people you want to know.

A more cynical version of this is:

Facebook is where you lie to people you know. Twitter is where you’re honest with strangers. @Berci, author of a great Prezi on Twitter in Medicine

The best part of Twitter is that it highly flexible and each user has complete power to customize her experience.

The three fundamental things anyone needs to know to get started on Twitter are:

  1. Who to follow
  2. What to do
  3. What to say

Who to follow
I would categorize who to follow in various slots. I will highlight people I think are important to follow, not because I believe in what they say but because they illustrate an angle to Twitter that helps the neophyte understand the medium. Favstar.fm is a service which tracks the most popular tweets. It is a good tool to see the best of what a person is capable of Tweeting.

@BurbDoc (FavStar) provides a few lessons. The first he is the quintassential example of unprofessional behavior on Twitter. Burb is a primary care doc who has been driven over the edge by the inanity of suburban America and a primary care system disrespected by clueless patients, arrogant specialists, absurd insurance companies, immoral drug companies, and meddling bureaucrats.

Typical NSFW Tweet from @BurbDoc

BurbDoc does not use his real name on his Twitter account. There is no way he could use his real name and Tweet with the style he uses. There are long debates on the merits of anonymous tweeting. I’m a firm believer of tweeting with your name, it will remind you that you aren’t scrawling graffiti behind the high school but posting a permanent billboard on the road called Google. Sign your name and you will be more careful with what say. And you never are as anonymous as you think you are.

@DrVes (FavStar) is a professional medical blogger. He is an Assistant Professor at the University of Chicago and blogs at Casesblog.blogspot.com. He is a prolific tweeter covering a broad swath of medical news each day. DrVes is broadly followed and well respected among Twitter doctors. Typical tweet:

@KidneyNews (favstar)is the primary twitter account of KidneyNews, the magazine of the American Society of Nephrology. It may seem similar to @DrVes as it is a continuous stream of kidney stories. The primary difference is that DrVes custom crafts each tweet. KidneyNotes is a bot that automatically posts links to every post from a host of kidney focused blogs. If you want to keep a finger on the pulse of the renal blogosphere this is an easy way to keep up. Pacale Lane, a Pediatric Nephrologist, runs the KidneyNews twitter feed. She also has an individual twitter account at @PHLane (favstar)

Similar to KidneyNews is @TheKidneyGroup (favstar). This nephrology group has established an exemplary social media presence in nephrology. They have active Facebook and Twitter feeds. The tweets usually contain stories about transplant or quirky stories of scientific advancement. The feed doesn’t seem to be managed by a doctor, but rather an enthusiastic employee (spouse?) of the group.

If you want to skip the ASN middleman you could follow the top renal blogs directly:

Also you can consider following the blog authors personal accounts:

There are other nephrologists who use Twitter as their only online presence. Two examples I like are:

@BrianLee is a nephrologist in Hawaii. He is not a high volume tweeter with a tweet or two every few weeks. He uses Twitter to comment on blogs, spread news stories or celebrate his victories.


He always comes across as professional and well informed. A nephrologist could do worse than model his use of Twitter after Brian Lee.

In this same vein is @KnittingNephron (favstar). She is much more prolific than Brian but since most of the tweets are @ replays they will not show up in your stream, until she drops a bit of renal wit.

Two final twitter accounts that you should consider following. @Skepticscalpel (favstar) is a surgeon who tweets about evidence based medicine, trauma, and medical education. Sharp wit.

Shad Ireland is an athlete on dialysis who is training to swim/bike/run the IronMan Triathlon. He does home hemo and is an inspiring example of what you can do despite dialysis. @IronShad

What to do

Example of a twitter conversation. Read from the
bottom up, click to get a larger, readable copy.

There are three ways to interact on twitter, a reply, a retweet and a favorite. That order is in descending order of engagement. Meaning, if you want a meaningful, interactive Twitter experience, be quick to reply and worry less about favorites.

The simplest to understand is the reply. You see a tweet you appreciate, and you acknowledge it by engadging with it. You direct the message to the author by starting the tweet with their user name: @Kidney_boy to reply to me.


If the reply begins with the twitter handle only people following both parties will see the tweet. This clears out a lot of private chats from your Twitter stream. People that follow just BurbDoc or just me will not see the tweet. People sometimes add a period before the @ so everyone will see the tweet.  

A retweet is a way of saying “I like this.” It amplifies the writer’s message. Favstar tracks retweets as a way of measuring the popularity or impact of a tweet.

Tweets I have starred

Favorites are a way to honor tweets that you like and it also marks them and collects them so you can review them later. There is no reaction on the public timeline when you favorite a tweet, however people can see what you have favorited by going to your profile page. Stars are not private. Sarah Palin got a bit of heat by making this mistake.

In Twitter for the Mac, each of the interaction functions are just a click away.





Medical Twitter Chats
In addition to the above methods of interaction I suggest exploring some of the regular medical chats that happen a few times everyday.

I like three chats, though I don’t participate that often, I always enjoy them when I do. To participate in the chats, search for the HashTag for the chat (#TwitJC, or #HCSM, etc). When you want to add your 144 characters, make sure to append the hashtag so other people can find your comment.

On every second or third Sunday there is the Twitter Journal Club. It is an innovative combination of a website and twitter chat. The organizers post an article and an introduction in the week leading up to the chat. Then during the appointed time the organizers ask pointed questions to tease out the complete story of the article. The discussion uses the hastag #TwitJC. Every other Sunday at 3 pm EST. (7 pm GMT)

Sunday Night from 7-8 pm EST is health care and social media chat. This is the oldest medical twitter chat. It started in 2009. If you want to use twitter to talk about twitter, this is the place for you. The hashtag is #HCSM.

Thursday at 9 pm EST is the MedEd chat. This is one of my favorites. The discussion is lively and generally the people are interesting. Hastag #MedEd.

What to Say
Everyone needs to find his own voice on Twitter. That said, I have a bit of advice. Firstly, remember that everything you say will be permanent and associated with you. Staying quiet initially and watching is a good way to get started. Find people you like and respect and see how they interact on Twitter. Like anything in medicine, imitating respected mentors is a good way to learn.

Probably the best pithiest advice and on how physicians should behave on Twitter comes from the Mayo Clinic and their twelve word social media policy:

Don’t Lie, Don’t Pry
Don’t Cheat, Can’t Delete
Don’t Steal, Don’t Reveal

What I love about nephrology and the kidneys

A month ago the board of the eAJKD blog met to discuss plans for the blog. One topic, was what we wanted to do for World Kidney Day and decided that we should each write about what nephrology meant to each us. So for the last month I had been noodling about that and on World Kidney Eve I created the following video of my feelings.



I got into nephrology, like a lot of people get into it. I just went crazy for the chemistry. I loved fixing the numbers. I loved the inherent logical nature of nephrology. But as I have been doing it for a number of years my enjoyment of the field has matured and I now look at the field in a new way.
All of my life I have been an environmentalist. My very earliest childhood memories are populated by hiking and canoeing trips in the North Woods. Environmentalism has been an important part of my moral compass for as long as I can remember. I now see a connection between environmental awareness and appreciation of nephrology. When I look around, everywhere, I see examples of humans being poor stewards of the earth; however when I’m at work I see the kidneys, at least when they are functioning properly, being perfect stewards of their internal environment. Eternally maintaining a stable ecosystem for growth.

To a large extent I don’t blame humans. Our ability to affect the earth’s environment is so new, that we can’t see the consequences of our actions. We don’t have the benefit of a million generations of evolution that aid the kidney’s in there mission to establish and stabilize the internal environment. The kidneys have perfected their ability to maintain homeostasis. They maintain the body’s atmosphere and oceans in perfect balance.

The way the kidneys maintain this idyllic state is both simple and extraordinary. The kidneys simply track every atom that is absorbed and then make sure those same atoms are excreted. This happens in perfect balance. Atom in. Atom out. At the most fundamental level the kidneys are incredibly finely-tuned, atomic balancing-machines. And when I realized that this is what the kidneys were, I was just overwhelmed with their beauty and perfection.