Sodium (renal III) Flashcards
Major physiologic trigger for release of ADH? Sensed by what?
plasma osmolality (VERY low E
sensed by hypothalamus
released by posterior pituitary
Symptoms of hyponatremia?
malaise, stupor, coma, nausea
What are situations that you may see high serum osmolality along with hyponatremia?
hyperglycemia or mannitol
What are situations that you may see hyponatremia with normal serum osmolality? ?
hyperlipidemia
hyperproteinemia (multiple myeloma)
common causes of SIADH?
drug induced (carbamazepine, cyclophosphamide)
paraneoplastic (small cell lung cancer)
CNS
pulmonary disease
Special treatment of SIADH?
demeclocycline
(tetracycline antibiotic) - ADH antagonist
Symptoms of hypernatremia?
irritability, stupor, coma
Common causes hypernatremia?
- water loss
- diabetes insipidus
- acquired: hypercalcemia, hypokalemia, lithium, amphoteracin B
Treatments for nephrogenic DI?
thiazide diuretics (incrase proximal Na/H20 reabsorption)
NSAIDS (inhibit prostaglandins, which are ADH antag)
“ultrafiltrate” is composed of what substance?
water, electrolytes, glucose, amino acids
The epithelium in the glomerulus is composed of what cell type?
podocyte
What are filtration layers to the glomerulus?
- Endothelium (fenestrated)
- only small molecules (<40nm) can pass through
- repels RBC, WBC, platelets
- basement membrane
- negatively charged (type IV collagen wrapped in heparan sulfate)
- repels (-) charged molecules like albumin
- epithelium (podocytes)
- food processes that wrap around capillaries
- slitsbetween foot processes filter - further size barrier
General difference between nephritic & nephrotic syndromes?
- nephritic
- RBC casts
- mild proteinuria (< 3.5)
- renal failure
- nephrotic syndrome
- massive proteinuria
- hyperlipidemia
- protein in urine (< 3.5)
What are the two mechanisms that lead to edema in nephrotic syndrome?
decreased plasma oncotic pressure d/t loss of albumin
the decrease in ECV causes a decrease in GFR which stimulates the RAAS and leads to Na/H20 retention
why do you see hyperlipidemia in patients with nephrotic syndrome? This leads to what?
the loss of albumin causes the liver to become to be active as it tries to replace it (but it cannot)
however, b/c the increased liver metabolic activity, you will see hyper lipidemia (high levels total cholesterol & HDL)
fatty casts & oval fat bodies in the urine (maltese cross)
Why can patients with nephrotic syndrome develop a pulmonary embolism?
losing anti-thrombin III in the urine
causes a hypercoaguable state that predisposes patients thrombosis
Why do patients with nephritic syndrome excrete less protein in their urine than patients with nephrotic syndrome?
Nephritic syndrome decreases GFR, which decreases the amout of protein they are able to excete per day
this is also why you see an increase in the BUN/Cr ratio, oliguria, and increased hydrostatic pressure (which can cause hypertension & edema)
What is the condtion that is basically IgA nephropath with extrarenal involvement?
Henich-Schonlein Purpura
MC childhood systemic vasculitis
Focal segmental glomerulosclerosis is associated with what conditions?
HIV
Sickle Cell Patients
Heroin users
massive obesity
pts. on interferon treatment
What are the respective findings in renal biopsy of membranous nephropathy for each of the following methods:
light microscopy
electron microscopy
immunofluorescence
- light microscopy
- capillary / BM thickening
- electron microscopy
- subepithelial deposits
- immunofluorescence
- granular IgG/C3
What are the 3 secondary causes of membranous nephritis?
tumor
hepatitis
rheumatoid arthritis
MPGN type 1 is associated with what conditions?
hepatitis C & B
What antibody is commonly seen in patients with MPGN type II?
C3 nephritic factor
C3 convertase (activates alternative pathway) stabilizing antibody
