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I guess PBFluids is part Dr. Boring and part Dr. Didactic.

From A Cartoon Guide to Becoming a Doctor

Crazy

I just received the following e-mail the ASN

On Tuesday, March 22, 2011, your HighWire sites began receiving a flood of unusual requests for PDFs. What we observed was that a single click to request a PDF of an article would result in multiple requests for the PDF being sent to your sites. In some cases a single request was being multiplied more than 100 times. This caused an overload on the systems responsible for serving PDFs. Early impacts, around 5:00 to 6:00 AM (PDT), were felt as slow response for PDF serving but as the day moved on and traffic on the sites rose the impacts increased until the whole sites were slow as the PDF requests backed up, in the 8:00-9:00 AM (PDT) hours.

Our first response was to turn off access to the PDFs so that the sites would continue to serve other pages well. This was effective and allowed us the breathing room to analyze the traffic more carefully, and we were able to localize the large majority of these multiple requests as coming from users of the most recent version of Google’s Chrome browser, which was just updated in the last few days.

At approximately noon on Tuesday we blocked the use of the most recent version of Chrome from all H20 sites. We regretted taking this action (I use Chrome as my browser, too) but it was the way we could restore full service to more than 90 of your users and still allow the other 10 the option to choose a different browser and receive full service as well. Chrome was blocked from approximately noon until 5:15 PM, when we were able to deploy a fix for the Chrome bug.

During the time that Chrome was blocked we were able to perform diagnosis and to determine that for many PDFs, Chrome was requesting the file 32Kbytes at a time. What this mean is that for some large PDFs a single click of the mouse was generating 11,000 requests for the PDF. We were also able to determine how to prevent Chrome from making these requests and we built a fix that was deployed t0 all H20 sites at 5:15 PM.

At the time of this writing all sites have been restored to full function and all users are receiving full service. We have no reason to believe this problem will recur and we deeply regret the impact that the Chrome update had on you and your readers.

Wow, that’s cool. Both that they fixed it so fast and that they cared enough to send a note. Go Team ASN!

Nephron Power has a fine post on the top ten reasons the kidney’s are the best organs. Here is my riff:

1. A lot of organs can secrete hormones. The kidneys can turn water into stone.
2. Other organs have epithelial cells. Kidneys have podocytes.
3. Orthopods can cast bones. The kidneys can cast red cells, white cells, brown mud and hyalin!
4. Acute renal success!
5. Recombinant EPO causes thrombotic complications, erythropoietin from the kidney, pure gold.
6. The adrenal gland looks like a hat!
7. The lack of randomized controlled data means that all of the kidney’s secrets are still, secret.
8. Technology can not duplicate the function of any other organ as well as the kidney. 
9. They are the key part of the machine that turns “the red wine of Shiraz into urine“
10. They have the best diss, “You got a problem with ‘dis? Well you can just piss off.”

The lungs serve to maintain the composition of the extracellular fluid with respect to oxygen and carbon dioxide, and with this their duty ends. The responsibility for maintaining the composition of this fluid in respect to other constituents devolves on the kidneys. It is no exaggeration to say that the composition of the body fluids is determined not by what the mouth takes in but what the kidneys keep: they are the master chemists of our internal environment. Which, so to speak, they manufacture in reverse by working it over some fifteen times a day. When among other duties, they excrete the ashes of our body fires, or remove from the blood the infinite variety of foreign substances that are constantly being absorbed from our indiscriminate gastrointestinal tracts, these excretory operations are incidental to the major task of keeping our internal environments in the ideal, balanced state.

I just added my third and last (?) tab to the blog. Books. It just has two items, The Fluid and Electrolyte Companion and the Michigan Hypertension Core Curriculum. Both are complete texts available as free PDFs. Check’em out.

The Immortal Life of Henrietta Lacks is about the HeLa cells and the woman they came from. I’ve just started it but it is really interesting.

One of the most striking parts of the story is hearing how Jim Crow laws and segregation affected medicine. Rebecca Skloot discusses sick black patients coming to a hospital and being turned away to go to a “Colored” hospital and then dying in the parking lot without ever receiving therapy. Hard for me to imagine.

The other interesting story was that of Alexis Carrel the winner of the  1912 Nobel Prize for medicine. His Nobel was for his work in creating a surgical technique for sewing blood vessels together. He is important in the HeLa story as he claimed to have created the first immortal tissue cell culture. This was embryonic chicken heart cells. The heart tissue long outlived the lifetime of the chicken and even outlived Carrel himself but the book states that Carrell faked his results by adding fresh embryonic cells periodically. The book also discredits him as a Nazi sympathizer and a eugenics proponent.

The book is good. I recommend it.

I spoke on the openning day in one of the big rooms. This was my first talk at a national meeting (though I did do an oral presentation to a small room for the American Society of Hypertension but the room held only about 50 people. This felt like a thousand.

To see the room before it filled you will need to go to the old blogspot site (and see how small video from an iPhone was in 2010).

Here is the talk.

My camping club, Aggressive Deer Adventures had a great trip to Kings Canyon National Park. The group consisted of 7 men, all 40-something who lived at around 600 feet above sea level. The whole trip took place between eight thousand and twelve thousand feet.

Every one started on low dose acetazolamide (125 mg bid) 36 hours before we left home.

Not one of us developed anything more than a small headache on travel day. Complete success.

The patient had SIADH due to viral encephalitis. We started tolvaptan 30 mg and his SIDAH rapidly reversed with the sodium rising from 124 to 128 overnight and up to 136 in the following week. Along with his improved sodium the patients mental status improved. I attribute that more to improvement in the encephalitis than the normalized osmolality but the association is there.

I stopped the Tolvaptan after 8 days and the next morning here are his urine chemistries:

Urine sodium 20, urine osmolality was 614. Somehow, I got a urine chloride rather than the urine potassium I ordered. The sodium nudged up to 137 off the tolvaptan. It looks like the SIADH has resolved with the urine sodium falling from 148 prior to the drug to 70 after the first dose to 20 off the drug completely.
Also note that even though the urine osmolality (614) is greater than serum osmolality, the serum sodium can still rise. This is because the electrolyte free water is still positive, despite a negative solute free water.


– Posted using BlogPress from my iPhone and edited on my 15 inch MacBook with a big dent in the corner.

I gave the patient from yesterday 30 mg of tolvaptan. The repeat sodium was 128, up from 124 and urine sodium was down to 70, from 148 and the potassium was 40, down from 48. Urine output rose to 3425 mL.

The electrolyte free water clearance went from negative 1,364 to positive 481 mL.

Tolvaptan FTW.

The SIADH is due to West Nile Virus induced encephalitis.

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Check out that urine sodium. The guys pissing normal saline. That’s the highest urine sodium I have ever seen.

Urine sodium 148
Urine potassium 48
Serum sodium 124
Urine output 2350

Electrolyte free water clearance:
-1364 mL

Interpretation: with those urine electrolytes, when urinates 2,300 mL it is as if he actually drank nearly a liter and a half of tap water. And that is why fluid restriction fails in dense SIADH.

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