Yesterday:
- My first patient had SIADH and a sodium of 125
- My last patient had nephrogenic diabetes insipidus and a sodium of 150
musings of a salt whisperer
This post really resonates with me: The Ten Commandments of PowerPoint and I wish that I had included it in my lectuer from last week on how to give a lecture.
The chief resident at St John Hospital and Medical Center asked me to do morning report on giving better presentations. It was an interesting project. I have been pretty busy and didn’t have enough time to put together a really polished presentation, but this is what I came up with.
Here is a link to the PDF and Keynote file (130 mb)
iWork documents are a little wonky if you are not using Safari. So the videos I embedded in the lecture are below if you are having trouble looking at them.
Steve Jobs tells it how it is regarding Microsoft
The birth of a morning report:
Screen captures with command-shift-4:
Smart builds
Highlight text:
Mask an image
Improve a crappy figure:
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In my clinical experience as the GFR approaches zero the creatinine goes up between 1 and 2 mg/dL everyday.
However I was working out a story problem for an acute renal failure and when I calculated how much the creatinine would rise it was 3.3 per day. Here is how I calculated this:
Did I do my calculation wrong? The total body creatinine calculation of 420 mg seems awfully low, especially if muscles create 1400 mg of new creatinine everyday.
Picture by The Doctr
I promised a full examination of the renal biopsy in pregnancy.
This is the longest post I have ever done and so I have segmented it into two parts:
My conclusions:
The renal biopsy is as safe in pregnancy as it is outside of pregnancy. Ultrasound guidance and modern understanding of coagulopathy paired with aggressive use of antihypertensives makes this an acceptable risk in pregnancy. This is a field of medicine that accepts risk to the fetus to in the name of better diagnostic data, see amniocentesis.
As long as the blood pressure is controlled, and the patient is not coagulopathic, if you need the biopsy, get the biopsy.
However, I have not been fully satisfied that the diagnostic data is that useful in most situations. The therapeutic options in pregnancy seem pretty narrow:
Given those options, a biopsy will not make a difference in many situations.
Timing becomes critical as a therapeutic abortion and delivery of the infant both have narrow windows of opportunity. The decision to use symptomatic treatment will not be influenced by histologic findings.
That leaves IV methylprednisolone. In every case report I read where methylprednisolone +/– azathioprine was used I thought the decision to use it coud have been made solely from the patient’s symptoms and that the biopsy results didn’t really influence that decision. In every case the mother had increasing blood pressure, creatinine and proteinuria 20+ weeks into the pregnancy. It was too early to deliver the baby and steroids were used to buy time for the fetus to grow prior to delivery.
Here are the situations I would recommend doing a biopsy:
In the survey I presented I had 6 different clinical scenarios, they are summarized below:
from Google Analytics |
The thing that confuses me is why the percent of people that want a biopsy at 12 weeks seems to fall as the patient gets sicker: 49% in case 1 to 34% in cases 3 and 5. What happened to 8 of the pro-biopsy doctors?
The same puzzling trend held for the 24 week gestational age with the biopsy rate being highest, 81%, in the healthiest and as the patient developed decreased renal function and hypertension it fell to 64% and 57%.
I broke down the data for attendings versus fellows:
And now you can see where those missing biopsies for the patient at 12 weeks went. Over half the fellows were willing to biopsy the asymptomatic nephrotic syndrome at 12 weeks. But the bravado disappeared if you added a bit of hypertension (scenario 3) with the biopsy rate falling below 20%.
The attendings were more likely to biopsy the patient in just about every scenario with an overall biopsy rate of 59% versus 49% for fellows.
In the U.S. versus the world:
Also don’t forget the review of renal biopsy in pregnancy I did a week ago. I reviewed this article.
…the outcome of repeated pregnancies in patients with MGN is good with 90% live births. Repeated pregnancies do not influence the course of MGN.
The incidence of obstetric complications varied with the presence or absence of risk factors. Women with low proteinuria (≤2.5 g/24 hours), without hypertension or renal failure had a low complication rate: 2.8% (one still birth). In the nephrotic syndrome, obstetric complications reached 33% of the pregnancies (pre-term), the same as with moderate renal failure (33% abortion, pre-term) and lower than women with hypertension (62% of the pregnancies, abortion, pre-term).
The high fetal survival rate and the lack of repercussions of pregnancy on maternal nephropathy in the majority of women reported here indicate that pregnancy in patients with primary glomerulonephritis, glomerulosclerosis without hypertension, or significant renal function impairment should not be advised against. On the other hand, it should be kept in mind that coexistent hypertension worsens the prognosis, and the nephrotic syndrome increases the incidence of pre-term deliveries and low birth weight infants, although fetal viability is not markedly affected.
The graph on the left is pregnancy outcome, on the right is the long-term follow-up for the mothers.
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Thus the observations of most investigators is that women with IgA nephropathy who are normotensive and have preserved renal function should anticipate few problems and that there is no convincing evidence linking gestation to progression of their disease.
I was listening to the Slate Cultural Gabfest on my way to work this morning and Julia Turner asked the audience to defend the epigraph, the quotations that some authors use to lead off a book or chapter.
The Fluid and Electrolyte Companion used an epigraph that I thought was perfect and communicated the mood I wanted readers in as they read the book:
The quotation is from Dr. Strangelove and General Ripper (the man with the cigar) says it in the scene captured in the picture at the top of PBFluids.com. If you haven’t seen the movie you really should. It is one of Stanely Kubrick’s masterpieces and possibly the funniest movies I have ever seen.
What touched me was how similar I am to General Ripper. Here was a man who spent all of his time thinking about precious bodily fluids and every time he captured someone in his vacinity and started to explain how wonderful and important they are, the other person just got nervous, uncomfortable and wanted to squirm away. In the header picture, imagine me as General Ripper talking about pseudohyponatremia and imagine Group Captain Mandrake being played by an unsuspecting innocent medical student who is randomized to one of my medicine teams.
The mood I wanted to establish was that this text book was lighter than Guyton’s physiology, we would poke fun at medicine and you could unbutton the white coat and relax a little while reading this text. I think the epigraph absolutely nailed this mood.
By the way if you downloaded the book before this week, re-download it. I just added the leading 10 pages which include the introduction, dedication, colophon, table of contents and epigrpah.
It seems that Blogger, the service that hosts PBFluids and a number of other nephrology blogs including the Renal Fellow Network, usually gets disregarded and most serious bloggers elect to go with WordPress. I have been delighted with Blogger since beginning PBFluids almost three years ago and have been impressed with the regular updates they have introduced. Today, though they really blew me away. Take a look at the new Blogger Dynamic Views:
I am still researching and writing up a monster post on membraous nephropathy and pregnancy (2,300 words and 7 images so far and I still have a handful of references to go). Researching this topic is like archeology. All the literature is from the early 90’s and 80’s. Almost none of the data is available as full text on the web. No PDFs. Its all scans of photocopies.
But I think the topic is important and having and the fact that the primary data is locked up in paper makes a comprehensive review indexible by google, all the more important.
The survey is also gaining data. So far it is showing definite equipoise on the questions. I am still looking for some more participants.