Renal Flashcards
What are the most common causes of acute bacterial prostatitis? What is the MOST common the U.S.?
Same as UTI: E coli, Klebsiella, Proteus, Pseudomonas, Enterobacter, Serratia, Enterococcus, Staphylococcus
In the U.S. - E coli
What pathogenic attribute do uropathogenic strains of E coli share?
P-pili = pyelonephritis-associated pili (pilus adhesins)
What metabolic acid-base disturbance does acute renal failure lead to?
Metabolic acidosis (increased H+ and decreased HCO3- in the blood)
What are the three things recommended in a diet for renal failure patients?
- Low protein
- Restrict salt and fluid
- High carbohydrate - provides body with exogenous glucose so prevents gluconeogenesis which also prevents protein catabolism and nitrogen production
For the loop of Henle (medullary thin descending, medullary thick ascending, cortical thick ascending), which parts are permeable to water? List them in order of osmolality.
Thin descending is permeable to water while both the medullary and cortical thick ascending are impermeable to water
MOST hypoosmolalic: cortical thick ascending > medullary thick ascending > medullary thin descending (i.e. the tubular fluid gets more hypotonic as it travels through the loop)
How do you calculate changes in body osmolality due to urine loss?
(total body osmoles - urine osmoles) / (total body water - urine volume)
What are the presenting symptoms of ADPKD?
- HTN - from decreased renin
- renal failure (with elevated BUN and Cr)
- anemia - from decreased epo
Patients typically in their 40s
When is spironolactone contraindicated? How would you be able to tell this on EKG?
Spironolactone is potassium sparing so it is contraindicated in patients with hyperkalemia who are at increased risk of arrhythmia. Hyperkalemia on EKG shows absent P waves, tall peaked T waves.
What is a dangerous renal complication of aortic dissection and how does it present?
The dissection may run distally and occlude the renal arteries causing bilateral renal infarction. It presents with flank pain and hematuria.
What is the signature histologic finding in diabetic nephropathy?
Kimmelstiel-Wilson lesion - nodular (ovoid) PAS+ deposits of mesangial matrix and thickened basement membrane in the periphery of the glomerulus
What is the characteristic histologic feature of post-streptococcal glomerulonephritis?
Subepithelial electron dense humps
What is the characteristic histologic finding of Goodpasture syndrome?
Linear deposits of IgG (antibodies against the basement membrane)
How do you calculate the filtered load of a substance?
FL = GFR x plasma concentration
Bilateral renal agenesis is typically caused by a malformation of what?
ureteric buds
When is diffuse cortical necrosis typically seen?
DIC
What are the most common causes of papillary necrosis?
Diabetes, analgesic abuse, urinary tract obstruction, sickle cell disease
What is pseudomonas known to cause?
PSEUDO: pneumonia, sepsis, external otitis (swimmer’s ear), UTI, diabetic osteomyelitis
also: hot tub folliculitis
How might large kidney stones present?
Can be clinically silent for a while until the present with microhematuria and recurrent episodes of pyelonephritis
Describe the two mechanisms by which PAH reaches the tubular fluid and their regulatory mechanisms.
- Freely filtered - this is a constant fraction
- Secreted by the PCT cells - this is a carrier mediated process so it can be saturated with increasing blood concentration of PAH
What part of the nephron contains the most dilute tubular fluid? What is this value?
DCT - around 100 mOsm/L
What are the characteristic IF and LM findings in Goodpasture Syndrome?
Goodpasture is a type I RPGN.
IF - linear deposits of IgG and C3 along the basement membrane
LM - glomerular crescent formation
What induces the development of the metanephros which will go on to form the definitive kidney?
Ureteric buds
What are the common causes of drug-induced interstitial nephritis?
NSAIDs (ibuprofen and indomethacin), beta lactam antibiotics, sulfonamides, diuretics, phenytoin, cimetidine, methyldopa
What is the only diuretic that acts solely upstream of the macula densa?
Acetazolamide (which acts on PCT) because thiazides and loops both act on transporters that are also located in the DCT thus interfering with the macula densa’s sensing of NaCl delivery