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Nephrotic Syndrome

Nephrotic syndrome presents with protein in the urine. The most common story would be somebody between one and 12. So a three-year-old would be the peak age. Mom wakes up, sees the baby wake up at six in the morning with swollen shut eyes. Itís a panic call that you get, but until you see the kid on examination, around noon, the boys is found to have no periorbital edema but has 3+ pitting edema of the legs and impressive scrotal edema and ascites. So thatís, as I mentioned, dependent edema; gone down. He had had small amounts of diarrhea the previous day, but mom doesnít know if he has had his usual amount of urine as well, because she didnít know to look for that. And itís also diarrhea and pee-pee at the same time so itís hard to tell. So thatís the story, and then you see them and the blood pressure is, if anything, on the low side or normal and the heart rate is a bit on the high side. Liver is palpable and there are decreased breath sounds bilaterally, and dullness on percussion. Normal or low blood pressure is because the basic status of this patientís volume is hypovolemic intravascularly, because itís low oncotic pressure, the fluids are outside in the interstitium and the intravascular volume is depleted. So usually, nephrotics are hypotensive or normotensive. Very rarely are they hypertensive from some other cause. And the heart rate is high because itís like a dehydrated patient. Liver is already palpable; yes or no depends on how long itís been going on, and the decreased breath sounds are of pleural effusions that this kid can have.

Next, on lab exam, urine shows 4+ protein. There is no blood. Then he gets blood tests and the serum albumin is 1.6. I donít want to scare you with 0.8 or 0.6, but that you can also find. Low albumin levels, cholesterol can be as high as 500, 600. Those are the cholesterols we see with nephrotics. And the sodium is low, 127. The sodium either because itís really low or itís pseudohyponatremia more likely from the hyperlipidemia. So thatís not always the real sodium, but you get electrolytes because this kid with the low volume can already have some degree of renal failure. Most nephrotics donít but they could, so they could have hyperkalemia, acidosis, and other cause things. Creatinine is actually lower than you usually see and that is because the proteinuria increases the excretion of creatinine. So the creatinine is low, lower than normal. On the x-ray, the chest x-ray, the heart is a drop-shape that is smaller because of the low intravascular volume and there are small bilateral pleural effusions.

Heís admitted to the hospital, not necessarily but in this case, to get IV albumin followed by Lasix once a day; 1 per kg of the albumin and 2 per kg of the Lasix and over the next three days the patient has a very good diuresis, pleural effusions and scrotal edema resolves and the mom is taught how to dipstick the urine and he is discharged home. After a week she comes or calls and the edema in the legs, abdomen, everything has disappeared. The urine dipstick was still 4+ at home. Itís gone down to 3+, 2+ and after another week is negative.

So this is a typical story of a kid with minimal change nephrotic syndrome. We donít have to biopsy this child to know that itís minimal change. The diagnosis is by the age, the response to treatment, and the relapse that will happen more than likely, after Ö we donít know exactly when but more than likely in the next few months this kid will have a relapse. Thatís minimal change. You donít have to biopsy to make the diagnosis.

So the treatment Ö I think we have all realized what the definition of nephrotic syndrome with proteinuria and the hypoalbuminemia, edema and hypercholesterolemia and the causes; most commonly, minimal change. There is a minimal change that now is not completely minimal. I mean, it is still minimal but not no findings at all, but there is on immunofluorescence something thatís IgM deposits. We are not sure whether it is an entity in itself. Itís still called minimal change with IgM deposits, but it seems like these patients donít respond as well as pure minimal change. The other causes are much less common; focal segmental glomerular sclerosis, MPGN, membranous and congenital nephrotic syndrome, which is a whole different story of no response to immune suppressive medications. Nephrotic syndrome within the first year of life. Anybody below one-year-of-age or above whatever age you want to choose, 12, 10, 13, is not necessarily minimal change and needs a biopsy. But between one and whatever is the age for minimal change and you do the treatment first. Nephrotic syndrome can also accompany other multi-system diseases. Weíve already mentioned all of them; systemic lupus erythematosus, HSB, Hodgkinís lymphoma, all these can present with nephrotic syndrome as well as the disease.

I talked about this, clinical presentation. I didnít mention that they can have such bad edema that there can be skin breakdown with oozing of fluid, such as in the scrotal area, the vulvar area in girls, and that would require admission and IV albumin to try and mobilize the fluids a little bit, out of the interstitium back into the vascular tree. Blood pressure is normal or low. We talked about it. The diarrhea, I mentioned because they can have intestinal edema, intestinal mucosal edema. The same as they have edema everywhere else, and they have those little diarrheal stools. Thatís why I mentioned it in the case. Primary peritonitis is the most common, maybe not the most common complication, but a common complication, infectious complication of nephrotics. So whenever a nephrotic comes to the ER with abdominal pain, thatís first thing to rule out. Primary peritonitis. And for the Boards - I think they ask this quite a few times - the most common cause of primary peritonitis in nephrotic syndrome is pneumococcus. They can have E. coli or other causes as well, but if there is a question and thatís one of the answers, thatís the one to mark.

Okay, another common complication, perhaps the most common nowadays, is thrombotic events, thrombosis. They are very hyper-coagulable, nephrotics, and they can have thrombotic emboli or just deep vein thrombosis. Any nephrotic shouldnít have deep vein sticks or arterial sticks. They have a very high incidence of thrombotic events. The urine has massive proteinuria and we donít have to do a 24-hour collection because we can just dipstick; 4+ equals nephrotic range proteinuria. You donít really have to do a 24-hour collection to waste time. You start treatment, so this will be our indication of nephrotic range. And even in minimal change, there is a percentage of kids who have hematuria. Donít forget that. It doesnít mean that itís not minimal change if you do find hematuria, but itís much much more common in FSGS. So hematuria in a kid who is suspect for minimal change, I kind of put it on the back burner in case they donít respond as well or have hypertension. So that would seem more that it is showing FSGS and not minimal change. I would really watch their response to therapy much more with worry.

Blood tests, we already talked about. Now I talked about pseudohyponatremia but also there is hypocalcemia in the calcium that is measured, only because the albumin that the calcium is bound to is low. So there is this calculation. For every 1 gram of albumin below normal, to increase the calcium by 0.8. You know that calculation? Say an albumin is 4 and in the child it is 1, so ití 3 below normal; 3x0.8 is 2.4. add that to the, say, 7.6 calcium that you got and really the calcium is 10. So those are things to remember. Because of the hypoalbuminemia or the hypercholesterolemia. Usually their hematocrit, hemoglobin and platelets are increased because they are very very concentrated.