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Crazy numbers: lowest creatinine

The consult team is now taking care of a patient with what I think is the lowest creatinine I have ever seen: 0.29 mg/dL. I’m not a bench nephrologist but I think that is a pretty typical mouse creatinine.

Update: some commenters asked about the BUN: 6 mg/dL. FYI today the Cr is down to 0.28 and the BUN fell to 3!

The patient has SIADH and low creatinines are a usual finding. She also has a crazy low uric acid of 1.4. Not quite Uricase low but getting close. Her admission sodium was 108, her urine sodium today was a whopping 156 with a urine potassium of 34. So if you calculate her electrolyte free water clearance (the amount of her urine which is electrolyte free water):

You get a negative 826 mL. A negative electrolyte free water is not unusual in SIADH and distinguishes it from the hyponatremia seen with heart failure (or other conditions of decreased effective circulating volume).
In this case the negative clearance means that for every liter of urine this patient makes it is as if she drank 826 mL of fluid. The very act of urinating lowers the sodium further by diluting the plasma sodium.
This throws a wrench in the standard plan of adding the urinary output to the insensible losses and setting the fluid restriction to be 200-500 mL below that. This works in conditions like heart failure where the electrolyte free water is positive but with a negative free water clearance you need to account for the negative free water clearance by adding it to the water intake, not the renal losses.
See this presentation on electrolyte free water clearance for further details.
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Highest creatinine in chronic renal failure

Mr. S., a 38 y.o. African American male, came to the hospital with nausea, vomiting and fatigue. Initial creatinine was 36.2 mg/dl. After hydration overnight it came back at 38 mg/dl.

Update: one of the comments asked about the patients body habitus, rhabdo and BUN.

  • Mr S. is muscular but no body builder
  • He was not in rhabdo. I would not include an elevated creatinine due to muscle breakdown under the crazy numbers tag as it essentially represents a lab error, in that the creatinine is no longer a measure of severity of the renal failure or the chronicity but rather a measure of the aggregate muscle damage.
  • His BUN was 139 mg/dL

This patient had a remote diagnosis of hypertension but had been out of any medications for months. The computer showed a 2 year old creatinine of 2 but the patient denied any memory of being told he had CKD.

One of my co-fellows, Rajiv Poduval, used to call this acute ESRD. Chronic kidney disease that goes unrecognized until the patient rolls into the ED in need of dialysis.
Tragic
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Consult service: electrolyte free water

Yesterday I started on the consult service mid-month. We are experimenting with having the atendings rotate from the dialysis floor to the consult service every two weeks. I am skeptical because of the lack of continuity but in the spirit of 80-hour weeks we are trying it out.

Yesterday I lectured on electrolyte free water clearance and tea and toast syndrome.

Here is the lecture on Electrolyte free water:

The online version doesn’t look great. Download the file and then try it.

The lecture on tea and toast syndrome is below:

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Great article in the New Yorker summarizing books on obesity


See XXXL

Elizabeth Kolbert reviews the current crop of what she calls obesity books

Though weight-loss books will doubtless always be more popular, what might be called weight-gain books, which attempt to account for our corpulence, are an expanding genre.

It is very good. Nothing on uric acid or fructose or an infectious etiology but a lot of interesting thoughts on our expanding wastlines.
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My first two lectures to the IM Intern Class of 2012

On July first I gave a lecture on IV fluids, total body water and hyponatremia. This handout is similar to the lecture I give to the medical students titled sodium and water. It adds a half baked section on potassium but this handout really needs to have th sodium section tightened up and shortened, the potassium section finished and short sections on the treatment of phos, magnesium and calcium disorders.

  • Here is the PDF
  • Here is the native Pages documentin case you use Pages and are interested in finishing this work in progress.

On July 9th I gave a lecture on acute renal failure. The handout is 28 5.5 x 8.5 pages. The book is designed as a workshop with questions and points for discussion throughout.

  • Here is the PDF of the 28 page handout. It is very readable and one of the best handouts I have put together.
  • Here is the native Pages document in case you use Pages and are interested in editing my masterpiece.
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Happy July 1st, and don’t worry about the July phenomenon. All myth.

According to this article in Newsweek from last July:

the July medical-training period is associated with between 1,500 and 2,750 accelerated deaths every year. In a study of the July phenomenon from which initial findings were released in 2005 by the National Bureau of Economic Research, Harvard Business School health-care economists Robert Huckman and Jason Barro compared mortality rates in teaching and non-teaching hospitals around the country. They found that there are 4 percent more incidences of accelerated death in average-sized teaching hospitals in July and August.

They also found length of stay increased 2%. It is not clear from the above paragraph but the 1,500 to 2,750 deaths is also part of the same study by Huckman and Barro. A good review of the paper is found on this blog, A New Start. Here is a link to the abstract, full article costs $5.

A study done on hospitals in Ohio found no increase in mortality in ICU patients admitted in July through September. It looks like a massive study with rigorous methodology and it is more recent by nearly a decade.

In analyses of over 48,000 patients admitted to ICUs in 5 major teaching hospitals, using a validated method of adjusting for admission severity of illness, several important findings emerge. First, in-hospital mortality and LOS were similar in patients admitted to intensive care units from July through September and during later months of the academic year. Moreover, results were consistent when July, August, and September were analyzed separately, and there was no discernible pattern of variation when examining outcomes for individual months over the entire year. Furthermore, we were unable to detect differences when individual academic years, surgical and nonsurgical patients, and individual hospitals and ICUs were examined separately. These results were all similar in analyses of roughly 108,000 patients admitted to minor teaching and nonteaching hospitals.

With its unremarkable findings and disruption of the common wisdom is it any wonder that it is given short shift in the Newsweek article.

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Cool article on Hippocratics Aphorisms

The authors describe aphorisms as:

…terse and trenchant, facilitating maximum comprehension in minimum expression. The Hippocratic aphorisms are just that: concise, often pithy, and memorable statements of literal truths and frequently obvious wisdoms.

Sounds like Hippocrates would have had a ton of followers on Twitter.


This aphorism is probably the first description of casts associated with ATN.

Here is the article