I rewrote large sections if the IVF and Sodium handout. I added Tea and Toast syndrome, more on SIADH and a lot of interactivity. Overall a huge improvement. I used it today with the Beaumont Hospital Family Practice residents and was really pleased. Find the update in the handouts tab.
Patient list
P less than 0.05
Lecture on how to give a lecture
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:
When the GFR is zero how fast does the creatinine rise?
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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:
- Total body creatinine: 420 mg
- This assumes that creatinine is equally distributed through out total body water. So 42 liters (60% of 70kg) times 1 mg/dl times 10 dL per liter
- New creatinine: 1400 mg
- 20 mg of creatinine generation per kg body weight, 70 kg body weight
- New total total body creatinine 1820 mg
- add the first two figures
- New creatinine: 4.33 mg/dL
- Divide the total body creatinine (1820 mg) by total body water (420 dL):
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
Index of my posts on membranous nephropathy, renal biopsy and pregnancy
- The Question: When do you biopsy pregnant patients? A review of Clara Day’s NDT article on renal biopsy in pregnancy.
- The Survey: Request for doctors to share their practice patterns on decision making regarding pregnant patients with renal disease.
- The Plea: Request for more participants in the survey practice patterns.
- The Research: a long, somewhat unstructured, bibiography of the literature.
- The Conclusions: A summary of my findings and conclusions. This includes the results of the survey.
Membranous nephropathy and pregnancy
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 along with discussion of the survey of clinical decision making
- The supporting data, which is structured as a detailed annotated bibliography.
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:
- IV methylprednisolone with or without azathioprine
- Therapeutic abortion
- Delivery of the infant prematurely
- Symptomatic therapy
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:
- First trimester with early signs that the patient may be in for a rocky pregnancy due to renal disease. There are three risk factors: nephrotic range proteinuria, renal failure with a creatinine over 1.5 and hypertension. Getting a pathologic diagnosis at this point could allow termination of the pregnancy if any frightening diagnosis are made, i.e. lupus nephritis, scleroderma, crescentic GN, possibly MPGN. Outside of those findings I doubt the biopsy will actually change your therapy. I am sympathetic to the argument that each of these diagnosis has pretty good serologic tests that could decrease the need for the biopsy. That said the decisions are weighty enough that I would prefere a tissue diagnosis.
- The only other situation would be a patient with symptoms suggestive of scleroderma presenting late in pregnancy, 20+ weeks with high blood pressure. The right choice here is probably terminating the pregnancy. The mother’s life is in danger and the condition will not respond to steroids, the only therapeutic option available. I would like to get a tissue diagnosis to confirm prior to proceeding down that road.
In the survey I presented I had 6 different clinical scenarios, they are summarized below:
- Gestational age 12 weeks, nephrotic syndrome, normal BP, normal Cr
- Gestational age 24 weeks, nephrotic syndrome, normal BP, normal Cr
- Gestational age 12 weeks, nephrotic syndrome, normal BP, elevated Cr
- Gestational age 24 weeks, nephrotic syndrome, normal BP, elevated Cr
- Gestational age 12 weeks, nephrotic syndrome, elevated BP, elevated Cr
- Gestational age 24 weeks, nephrotic syndrome, elevated BP, elevated Cr
from Google Analytics |
- Gestational age 12 weeks, nephrotic syndrome, normal BP, normal Cr.
I voted BIOPSY, the community: - Gestational age 24 weeks, nephrotic syndrome, normal BP, normal Cr.
I voted NO biopsy, the community: - Gestational age 12 weeks, nephrotic syndrome, normal BP, elevated Cr.
I voted BIOPSY, the community: - Gestational age 24 weeks, nephrotic syndrome, normal BP, elevated Cr.
I voted NO biopsy, the community: - Gestational age 12 weeks, nephrotic syndrome, elevated BP, elevated Cr.
I voted BIOPSY, the community: - Gestational age 24 weeks, nephrotic syndrome, normal BP, elevated Cr.
I voted NO biopsy, the community:
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:
Renal Disease in Pregnancy, an annotated bibliography
Also don’t forget the review of renal biopsy in pregnancy I did a week ago. I reviewed this article.
- Intrauterine growth retardation (that’s a stretch since the kid was small for gestational age)
- Suppression of fetal adrenal glands
- Periventricular leukomlacia
- Fetal loss at 37 weeks associated with pre-eclampsia in the first pregnancy
- Spontneous abortion prior to 22 weeks with the second pregnancy
- Live-birth complicated by prematurity, pre-eclampsia and cesarean sections. Infant with low birthweight.
- Live-birth complicated by prematurity, pre-eclampsia and cesarean sections. Infant with low birthweight.
…the outcome of repeated pregnancies in patients with MGN is good with 90% live births. Repeated pregnancies do not influence the course of MGN.
- Abe S et al. The influence of antecedent renal disease on pregnancy Am J Obstet Gynecol 1985; 153: 508-514.
- Jungers Membranous glomerulobephritis and Pregnancy. Clin Nephrol 1988; 29: 106-107
- Surian M et al. Glomerular disease in patients with primary and secondary glomerular diseases Nephron 1984; 36:101-105.
- MPGN 16
- FSGS 13
- IgA 10
- MGN 7
- Focal nephritis 2
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.
- 17 women initially presented during pregnancy
- 7 women had the diagnosis ante-partum
- 8 pregnancies resulted in fetal death (24%)
- 6 occurred in the first trimester
- 3 spontaneous abortions (1 at 14 weeks, 2 in the first 12 weeks)
- 4 therapeutic abortions
- 1 still birth at 22 weeks
- 14 pregnancies resulted in premature infant (32-36 weeks)
- 60% of pregnancies that went beyond the first trimester had premature delivery
- 2 babies were born before 32 weeks
- Two congenital abnormalities
- hydrocephalus (one of the therapeutic abortions)
- hare lip
- three patients had decrease in renal function
- 1 lost half of her kidney function, the loss persisted after delivery but remained stable on azathioprine and warfarin. The patient ultimatly stopped those drugs and progressed to ESRD
- 1 mother had a twin pregnancy and was diagnosed with mild membranous in the first trimester. At 34-weeks she developed ARF, severe hypertension. She was induced and after delivery went for a repeat kidney biopsy which demonstrated crescentic GN. The patient was treated with cyxlophosphamie and had a good outcome with stable renal function.
- 1 mother had worsening renal function at 14 weeks. Her biopsy revealed fibrinoid crescents. She later spontaneously aborted the fetus. Renal function later normalized.
- Hypertension occurred in 15 (46%) of the pregnancies.
- usually in the third trimester
- resolved after delivery in all but 3 women.
- women with renal disease but ony mild decreases in renal function and normal blood pressure at conception will do well and the pregnancy does not adversly affect their renal prognosis. They specifically exclude lupus, MPGN, scleroderma and pariarteritis from this conclusion.
- If the patient has a creatinine ≥1.5 and >3 mg/dl or hypertension at conception about a third of patients will lose further renal function during pregnancy and have further loss of function post-partum.
- Women with a creatinine ≥3 mg/dl are frequently infertile and when they do conceive the liklihood of a successful outcome is low with high maternal morbidity.
The graph on the left is pregnancy outcome, on the right is the long-term follow-up for the mothers.
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- 121 pregnancies
- 5 still births
- 6 neonatal deaths
- 91% success rate
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.
- 16.7% gross hematuria
- 4.4% perirenal hematomas
- one maternal death
- sudden deterioration of renal function before 32 weeks
- symptomatic nephrotic syndrome before 32 weeks
- proteinuria alone, with normal blood pressure and normal renal function.
- hematuria alone, with normal blood pressure and normal renal function.
- basic metabolic profile
- BUN
- albumin
- fasting lipid profile
- 24-hour urine for:
- creatinine
- protein
- uric acid
- AST/ALT, LDH
- PT, PTT, INR
- CBC d/p
In defense of the epigraph
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.
Way to go Blogger
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: