Renal Flashcards
What patient characteristic indicates poorer long-term prognosis in PSGN?
Adult onset. Kids completely recover, but adults have risk of chronic HTN and renal insuff
Kidney biopsy: mesangial IgA deposits on IF
IgA nephropathy (Berger disease) = recurrent self-limited, painless hematuria w/in 5 days of URI
Kidney biopsy: thin basement membrane
type IV collagen disorder - asymp microscopic hematuria (benign)
Kidney biopsy: lamellated BM with irregular thinning and thickening (basket-weave appearance)
Alport syndrome
Type IV collagen disorder –> renal failure, hearing loss, ocular abnormalities
Kidney biopsy: coarse/granular IgG, IgM and C3 deposits on IF
PSGN
Kidney biopsy: Cresent formation (EM) with linear IgG deposits (IF)
Antiglomerular basement membrane ab disease (goodpasture’s disease) - rapidly progressive glomerulonephritis
Kidney biopsy: Effacement of podocytes (EM)
Minimal change, focal segmental glomerulosclerosis
Urinary incontinence: leaking with cough, sneezing, laughing, lifting is due to what
Stress incont
Loss of urethral support
Intraabdominal pressure> urethral sphincter pressure
Urinary incontinence: sudden overwhelming or freq need to empty bladder
Urge incont
Detrusor overactivity
Urinary incontinence: Constant involuntary dribbling of urine and incomplete emptying
Overflow
Impaired detrusor contractility, bladder outlet obstruction
CHRONIC bronchial obstruction causes what acid base disturbance?
Compensated Respiratory acidosis
eg. pH 7.34 (low normal), CO2 70, HCO3 36
DKA causes what acid base disturbance?
Metabolic acidosis
eg low pH, low HCO3, low pCO2 (resp comp via hyperventilation or Kussmaul breathing)
Overuse of diuretics or vol loss causes what acid base disturbance?
Metabolic alkalosis
eg high pH, high HCO3, high PCO2
Aldosterone: retains Na and H20, losses K and H+
Panic attacks (hyperventilation) cause what acid base disturbance?
Respiratory alkalosis
high pH, low PCO2, slightly low HCO3 (no compensatory response bc acute)
Heroin overdose causes what acid base disturbance?
Acute Respiratory acidosis
eg low pH, high pCO2, normal HCO3
Where is the lowest osmolarity of tubular fluid in the setting of high ADH?
EARLY DCT (relatively impermeable to water) Note: ascending limb of loop of henle is impermeable to H2O regardless of serum ADH
MUDPILES stands for what and is assoc with what acid base disturbance?
methanol, uremia, DKA, propylene glycol, Iron tablets/INH, lactic acidosis, ethylene glycol, salicylates (late)
metabolic acidosis with INCREASED anion gap
HARDASS stands for what and is assoc with what acid base disturbance?
hyperalimentation, addison disease, RTA, diarrhea, acetazolamide, spironolactone, saline infusion
metabolic acidosis with NORMAL anion gap
early salicylate excess causes what acid base disturbance?
respiratory alkalosis
PE causes what acid base disturbance?
respiratory alkalosis
Hypoxemia
Bicarb is normal acutely, but metabolic compensation w/renal bicarb loss occurs in 48 h
Vomiting causes what acid base disturbance?
metabolic alkalosis
opioids, sedatives cause what acid base disturbance?
respiratory acidosis (hypoventilation)
Classic condition that causes mixed acidosis (metabolic and resp acidosis) is what?
cardiopulmonary arrest
When cr clearance decreases two-fold, what must happen to plasma cr concentration?
Increase two fold
What is in the crescent in RPGN?
Glomerular parietal cells, monocytes, macrophages, and fibrin.
C3 and IgG are in the BM in type 1 RPGN (goodpasture syndrome)
Most RCC (also known as clear cell carcinomas) originate from what part of the kidney?
epithelial cells of the proximal renal tubules.
High lipid content on histo
Vasopressin and desmopressin cause a V2 receptor mediated increase in what 2 substances in the inner medullary collecting duct?
water
urea
Aspirin toxicity initially presents with what acid-base disturbance? Then what acid base disturbance?
- Primary respiratory alkalosis (<12h)
2. Mixed respiratory alkalosis and AG metabolic acidosis (>12h)
UA: Leukocyte esterase positive, nitrite negative indicates what UTI?
Enterococcus (does not produce nitrite from nitrate)
Key characteristic of inulin?
Freely filtered by not reabsorbed or secreted
Ie % filtered = % excreted
Key characteristic of PAH?
Filtered and secreted by proximal tubule. >100% of filtered load excreted
Note: carrier protein-mediated process - secretion of PAH can be saturated at high blood conc
Autoregulation of GFR and RBF = constant GFR and RBF with changes in blood pressure
Glomerular vascular resistance dictates GFR and RBF by providing effector mechanism for autoregulation
What factors affect glomerular capillary permeability in terms of
- diameter
- charge
- inc in molecular weight/diameter –> less likely to pass
2. Charge - neg charged less likely filtered compared to neutral molecules. This is bc membrane is neg charged.
What diuretic works synergistically with furosemide?
Synergist = total effect combined is greater than independently.
HCTZ inhibits Na/Cl transporter in the early DCT. Furosemide acts proximally in the loop of henle
Goodpasture syndrome - pulm hemorrhage and glomerulonephritis; assoc with what HLA?
HLA-DR7
Most approp therapy for Goodpasture syndrome?
Renal failure is the MCC of death from this syndrome. PLASMA EXCHANGE to remove circulating anti-GBM antibodies and inflammatory mediators is the best treatment
CD55 decay accelerating factor is unable to inactivate COMPLEMENT, causing hemolysis in what condition?
Paroxysmal nocturnal hemoglobinuria.
Note: chronic hemolysis can cause Fe deposition int he kidney (hemosiderosis)
Describe K absorption in the kidney
PCT - 2/3 K reabsorbed
TAL - 25-30% reabsorbed
Collecting duct - primary mediator of K regulation (hypok stim reabsorption, hyperk stim excretion)
Kidney biopsy: spike and dome appearance of GBM on methenamine silver stain
Membranous glomerulopathy (nephrotic) SLE causes this (but diffuse glomerulonephritis is more common)
Kidney biopsy: tram-track appearance
membranoproliferative glomerulonephritis (nephritic or nephrotic)
What drug acts on the descending thin loop of Henle and PCT?
Osmotic diuretics like mannitol
High altitude results in what acid base disturbance?
Respiratory alkalosis (dec PaO2, inc pH, dec pCO2) After a few days --> compensated renal compensation (dec HCO3)
Where is the highest osmolarity in the setting of low ADH?
Tubular fluid would be most concentrated at the junction bw the descending and ascending limbs of the loop of Henle.
Proximal ureter and distal ureter get its blood supply from what arteries?
Proximal (near kidney) - renal artery
Distal (near bladder) - superior vesical artery
Stages of ATN
Initiation - ischemic injury
Maintenance - dec urine output, fluid overload, inc Cr/BUN, hyperkalemia
Recovery - inc urine output –> high vol diuresis –> hypoK, hypoMg, hypoPO4, hypoCa
How does ibuprophen used concurrently with loop diuretics decrease diuretic response?
Loop diuretics inhibit Na-K-2Cl and stim PROSTAGLANDIN release. NSAIDs inhibit PG synth
UA in DKA? pH, HCO3, PO4
Metabolic acidosis
pH - dec (inc excretion of H+, NH4, PO4)
HCO3 - dec (completely reabsorbed)
PO4 - inc (acidic)
Fever, maculopapular rash, and sx of acute renal failure 1-3 weeks after beginning tx w/B-lactam abx or quinolones suggest what?
Acute interstitial nephritis.
Peripheral eosinophila and eosinophiluria are clues.
Goodpasture syndrome is caused by autoantibodies against what?
Anti-GBM antibodies - autoantibodies against the alpha 3 chain of TYPE IV COLLAGEN in glomerular and alveolar BM
Antibodies against neutrophil myeloperoxidase is what?
this is ANCA
p-ANCA - eosinophilic granulomatosis with polyangiitis = Churg Strauss
c-ANCA = Wegener’s
MC part of nephron affected by ATN?
Proximal tubules and thick ascending limb of Henle.
muddy brown casts
How can you test for metabolic alkalosis cause?
Determine the patient’s volume status and measure urinary CHLORIDE conc
Vomiting/NG suctioning and thiazide/loop diuretics cause vol and Cl- depletion: saline responsive
Hyperaldosteronism is saline-unresponsive.
MC small vessel vasculitis in kids? Sx?
HSP - IgA mediated leukocytoclastic vasculitis
Preceded by viral or strep URI
GI bleeding, inc risk of intussusception, IgA nephropathy (Berger dz), palpable purpura, migratory arthralgias and arthritis
Abrupt-onset gross hematuria, passage of tissue fragments in urine in an otherwise healthy patient with a family hx of sickle cell disease suggests what?
Renal papillary necrosis due to underlying sickle cell trait.
Note: analgesic nephropathy, DM, pyelonephritis can also cause this.
What is a frequently observed paraneoplastic finding in renal cell carcinoma?
Polycythemia resulting from increased EPO production by the tumor.
Other classic sx of RCC: painless hematuria, flank pain, abd mass, wt loss.
Renal artery stenosis results in hyperplasia of what cell type?
Modified smooth muscle cells of the afferent arteriole (juxtaglomerular apparatus)
Hypoperfusion –> inc renin secretion by JG cells. Long-term hypoperfusion–> hyperplasia of JG cells
What segment of the nephron would see the greatest decrease in Na resorption if perfused with a mitochondrial inhibitor
PCT - reabsorbs 66% of the filtrate
TAL, DCT, PCT and collecting ducts all are assoc with ATP.
TAL provides 15-20% of Na resorption
DCT - 5-10%
Deficiency of carbonic anhydrase in ERYTHROCYTES would result in higher concentration of what substance?
Chloride
chloride shift – CA in the RBCs makes bicarb from CO2 and H2O and then the HCO3/Cl antiporter on the RBC membrane trades HCO3 from inside the RBCs for chloride in the venous blood – thus an inhibition of RBC carbonic anhydrase would increase chloride content in venous blood since it would inhibit the chloride shift.
How does ADPKD cause renal failure?
Bilateral cystic dilation ultimately destroy renal parenchyma. Enlarged Kidneys, presents w/ flank pain, hematuria, HTA, UTIs, Progressive Renal failure.
Death complications of chronic kidney disease or HTA due to increase renin px.
A/W Polycystic liver disease, Berry Aneurysms, diverticulosis, MVP
Labs: Increase creatinine and BUN.
DI: What will be tubular osmolality compared with serum osmolality in the proximal tubule, juxtaglomerular apparatus, and medullary collecting duct?
PCT - isotonic
JGA (distal tubule) - hypotonic
CT - hypotonic
What is a significant predisposing risk factor for transitional cell carcinoma of the urinary tract system?
2-Naphthylamine
It is an aromatic amine, used to make azo dyes.
Aniline dyes…aromatic amine
2-Naphthylamine is found in cigarette smoke and suspected to contribute to the development of transitional cell carcinoma of urinary tract system
(It is activated in the liver but quickly deactivated by conjugation to glucuronic acid. In the bladder, glucuronidase re-activates it by deconjugation, which leads to the development of bladder cancer.)
Why is the PO2 in the renal vein relatively high compared with venous PO2 from most other organs?
The ratio of O2 consumption to blood flow is lower in the kidneys than in other organs.
Serologic studies showing presence of antibodies against proteinase 3 indicates what?
Wegener granulomatosis
Proteinase 3 is found in neutrophils
Kidney exposed to 100% nitrogen instead of oxygen. What area of the kidney shows signs of anoxic injury first?
Proximal tubule
When you hear ischemia immediately thing about the TUBULE - Acute tubular necrosis can be caused by ischemic or nephrotic injury
Ischemia secondary to decreased renal blood flow hypotension, shock, sepsis, hemorrhage, CHF, results in death of tubular cells that may slough into tubular lumen proximal tubule and thick ascending limb are highly susceptible to injury.
Chronic pyelonephritis presents how on US?
Small asymmetric kidneys with broad scars and BLUNTED CALYCES.
What can trigger renal papillary necrosis?
Renal Papillary necrosis triggered by sickle cell disease, DM, pyelonephritis and chronic acetaminophen
is a rare form of chronic pyelonephritis, especially associated with Proteus infection. Tumor-like growth, upper urinary tract infection, and (this is key) lipid-laden foamy macrophages make this neither acute pyelo nor cancer.
Xanthogranulomatous pyelonephritis (XGP)
