Renal - Amboss Flashcards
Amboss Renal
How do you calculate an anion gap?
Anion gap = Na⁺ + K⁺ - (Cl⁻ + HCO₃⁻)
Amboss Renal
How can renal plasma flow be estimated using PAH?
RPF = (UPAH * Urine flow rate) / PPAH
Amboss Renal
After calculating renal plasma flow (UPAH * urine flow rate / PPAH), how can you figure out what the total renal blood flow is?
RBF = RPF / (1 - hematocrit)
Amboss Renal
If you calculate the renal blood flow in a healthy individual, how can you determine cardiac output?
CO = Renal blood flow / 0.2
(The kidneys get 20 - 25% of cardiac output.)
Amboss Renal
Treatment is initiated in a patient with prostate cancer. Initially, there is an increase in serum testosterone and DHT, followed by a sustained decrease in both serum hormone levels.
He is being treated with what?
Leuprolide
(flutamide would result in a chronically elevated serum testosterone)
(finasteride would result in an elevated serum testosterone but no increase in DHT)
Amboss Renal
Whether sporadic or familial, renal cell carcinomas have an association with deletions in which gene?
VHL
Amboss Renal
A patient presents with fever, flank pain, hematuria, and a maculopapular rash. Urinalysis shows eosinophilia, WBCs and RBCs. He reports frequent meloxicam use over the past two weeks for back pain.
Kidney biopsy will likely show interstitial infiltration of what cell type?
T cells
Amboss Renal
A patient presents with fever, flank pain, hematuria, and a maculopapular rash. Urinalysis shows eosinophilia, WBCs and RBCs. He reports frequent meloxicam use over the past two weeks for back pain.
Is this renal papillary necrosis?
No, this is allergic interstitial nephritis.
RPN usually results from chronic analgesic use; eosinophilia and maculopapular rash are inconsistent with RPN.
Amboss Renal
Which medication types are contraindicated in patients with bilateral renal artery stenosis?
(Why?)
ACE inhibitors; ARBs
(inhibition of efferent arteriole constriction –> decreased GFR)
Amboss Renal
A patient presents with a benign tumor in the superior pole of the kidney. Histology shows epithelial cells characterized by an excessive amount of mitochondria, resulting in an abundant acidophilic, granular cytoplasm.
What is the likely diagnosis?
Oncocytoma
Note: the large, eosinophilic, granular cells in the image are called ‘oncocytes.’
Amboss Renal
The uremia seen in ESRD is associated with what changes (if any) in pH, serum bicarbonate, anion gap, and pCO2?
Anion-gap metabolic acidosis
(low pH, low HCO3-, mildly low pCO2 — a buildup of acids leads to the pH, bicarb, and anion-gap changes and a subsequent respiratory compensation)
Amboss Renal
A normal GFR is in about what range?
90 - 125 mL/min
Amboss Renal
Urothelial cancers are strongly linked with exposure to what compound(s)?
Aromatic amines (e.g. benzidine - (rubber production, oil refineries, dye-making, etc.), nicotine, arsenic, cisplatin (and other platinum chemotherapeutics), cyclophosphamide
Amboss Renal
As ACE inhibitors cause a dilation of the efferent arteriole, what effect do they have on GFR, renal plasma flow, and filtration fraction?
GFR - decreased
RPF - increased
FF - decreased
Amboss Renal
What is the earliest diagnostic sign of diabetic nephropathy?
Microalbuminuria
Amboss Renal
What are the two major signs of Goodpasture syndrome?
Hematuria + hemoptysis
(+ other signs of nephritic syndrome)
Amboss Renal
True/False.
Hematuria and hemoptysis are the major signs of granulomatosis with polyangiitis.
False.
Hematuria and hemoptysis are the major signs of Goodpasture syndrome.
Granulomatosis with polyangiitis is initially associated with rhinosinusitis, otitis media, ocular lesions, mucocutaneous granulomas, and vasculitic purpura.
Amboss Renal
Goodpasture syndrome is caused by what main etiology?
Anti-GBM antibodies
Amboss Renal
Crescents in Bowman’s space (due to fibrin-deposition) are associated with which generic cause of nephritic syndrome?
Rapidly progressive glomerulonephritis
Amboss Renal
Which diuretic category is calcium-sparing?
Thiazides
Amboss Renal
Why are serum lipids elevated in nephrotic syndrome?
Secondary to the hypoalbuminemia
(hepatic lipoprotein synthesis increases to maintain oncotic pressure)
Amboss Renal
What disorder is associated with recurrent UTIs, bilateral flank masses, hypertension, and elevated serum creatinine?
ADPKD
Amboss Renal
A patient with sudden, possibly painful urges to urinate followed by frequent, small-volume voids likely has what condition?
What is the cause?
Urge incontinence;
detrusor muscle spasms
Amboss Renal
Name one of the more common causes of stress incontinence in multiparous women.
Urethral hypermobility
Amboss Renal
Name the main defective location in the kidney for each of the following:
Fanconi syndrome
Bartter
Gitelman
Liddle
‘Fans Bartter and Gitel Liddle back’
PCT
Ascending LoH
DCT
CD
Amboss Renal
Fanconi syndrome, a defect in the PCT, causes what main serum changes?
Type 2 tubular acidosis (normal anion gap)
+
Hypokalemia
+
Hypocalcemia
Amboss Renal
Bartter syndrome, a defect in the ascending limb of the Loop of Henle, causes what main effects?
Polyuria and muscle cramps; hypo-everything in early childhood
- hyponatremia
- hypochloremia
- hypokalemia
- hypocalcemia
- hypomagnesemia
- metabolic alkalosis
Amboss Renal
Gitelman syndrome is caused by a defect in the ______ __________ in the distal convoluted tubules.
Gitelman syndrome is caused by a defect in the Na+-Cl- cotransporters in the distal convoluted tubules.
Amboss Renal
Gitelman syndrome, a defect in the descending convoluted tubule, causes what main effects?
Fatigue, muscle cramps, polyuria, chondrocalcinosis in late-childhood
- hyponatremia
- hypomagnesemia
- hypokalemia
- hypocalcemia
- hypocalciuria
- metabolic alkalosis
Amboss Renal
Liddle syndrome is caused by a defect in the ______ in the collecting duct.
Liddle syndrome is caused by a defect in the ENaCs in the collecting duct.
Amboss Renal
Liddle syndrome, a defect in the collecting duct ENaCs, causes what main effects?
Hypokalemia, metabolic alkalosis, and hypertension in childhood
(all explained by a compensatory increase in sodium and water reuptake)
Amboss Renal
Name the effect of DKA on each of the following in a patient’s urine:
pH
HCO3-
NH4+
K+
Low (ketones)
Low (HCO3- reabsorbed)
High (NH4+ excreted)
High (lost in urine due to osmotic diuresis)
Amboss Renal
A patient with some history of infection(s) presents with RBC casts in their urine. What is the first pathology on your differential to be considered?
IgA nephropathy
(Berger’s disease)
Amboss Renal
What type of urinary cast is seen in patients with minimal change disease?
Fatty casts
Amboss Renal
RBC casts are associated with what three disease categories?
Nephritic syndromes;
glomerular ischemia;
malignant hypertension
Amboss Renal
Identify the shape of each of the following crystal types on urinalysis:
Calcium phosphate
Struvite
Uric acid
Cystine
Wedge
Coffin-lid
Rhomboid or needle
Hexagonal
Amboss Renal
True/False.
Urine alkalinization is an acceptable prophylaxis for urate nephropathy.
True.
Amboss Renal
In addition to adequate hydration, which of the following is(are) most useful in preventing calcium nephrolithiasis?
A. High-oxalate diet
B. Vitamin C supplementation
C. Low-protein diet
D. Low-calcium diet
E. High-sodium diet
C. Low-protein diet
(The rest are risk factors: A., B., and D. all increases urinary oxalate levels; E. dehydrates the patient.)
Amboss Renal
Which nerves innervate the detrusor muscle?
The pelvic splanchnic nerves
(damage may lead to atonic bladder)
Amboss Renal
How can one prevent formation of all forms of nephrolithiasis?
Adequate hydration
Amboss Renal
True/False.
Caffeine, coffee, and tea are all useful in decreasing the recurrence rate of nephrolithiasis.
True.
(Caffeine increases urinary flow; coffee and tea have antioxidant properties.)
Amboss Renal
True/False.
Urinary acidification is useful in the prevention of all types of nephrolithiasis.
False.
It is useful in preventing struvite and calcium phosphate stones but not calcium oxalate.
Amboss Renal
What are the two locations in which abdominal bruits from renal artery stenosis can be auscultated?
The epigastrium (2-3 cm lateral);
over the costovertebral angles
Amboss Renal
True/False.
Nephrolithiasis typically results in a normal finding in all of the following:
Serum Ca2+
Serum uric acid
Urine Ca2+
Urine pH
Urine cystine
False.
Urine calcium will be increased and urine pH decreased.
Amboss Renal
What are the effects of amphotericin B as a result of the nephrotoxicity it sometimes has?
Type 1 renal acidosis;
hypercloremic, hypokalemic, normal anion-gap metabolic acidosis
Amboss Renal
Which naturally occurring substance combines with calcium in the urinary tract to prevent calcium stone formation?
Citrate
Amboss Renal
True/False.
Vitamin C is excreted in the urine as citrate, which decreases risk of calcium stone formation.
False.
Vitamin C is excreted in the urine as oxalate, which increases risk of calcium stone formation.
Amboss Renal
What substance commonly found in high concentrations in energy drinks can increase risk of calcium nephrolithiasis?
Oxalate
Amboss Renal
Cystinuria is characterized by decreased reabsorption of cystine, orthinine, lysine, and arginine in what location(s)?
The kidneys;
the small intestine
Amboss Renal
Patients with cystinuria and cystine nephrolithiasis have a positive urinary sodium ________________ test.
Patients with cystinuria and cystine nephrolithiasis have a positive urinary sodium cyanide nitroprusside test.
Amboss Renal
In treating a spastic neurogenic bladder, one should administer a muscarinic ____gonist.
In treating a spastic neurogenic bladder, one should administer a muscarinic agonist.
Amboss Renal
What medication type increases urinary glucose excretion?
SGLT-2 inhibitors
(-flozins really get the glucose flowin’)
Amboss Renal
What effect will dehydration have on the following:
Glomerular filtration rate
Renal plasma flow
Filtration fraction
Decreased (< RPF)
Decreased (large decrease)
Increased (FF = GFR/RPF)
(Basically, RPF decreases due to decreased blood volume; GFR decreases due to RAAS efferent arteriole constriction. Since GFR decreases less than RPF, FF actually increases.)
Amboss Renal
Name a normal urine osmolality (in mOsms) in each of the following locations:
PCT
Descending LoH
Ascending LoH
DCT (100)
CD (600)
300
1200
200
100
600
Amboss Renal
Name a normal urine osmolality (in mOsms) in each of the following locations:
PCT (300)
Descending LoH (1200)
Ascending LoH
DCT
CD
300
1200
200
100
600
Amboss Renal
True/False,
PAH clearance decreases as plasma [PAH] increases.
Plasma [PAH] can saturate the organic acid transporters, inhibiting clearance of PAH from the remaining RPF
Amboss Renal
Renal cell carcinomas typically arise from which portion of the nephron?
The PCT
Amboss Renal
Why are the cells in renal cell carcinomas typically clear on microscopy and yellow on gross appearance?
High lipid and glycogen content
Amboss Renal
Describe the effect of a renal NaCl transporter blocker in the DCT on serum levels of the following:
pH
Potassium
Calcium
Sodium
Increased (increased H+ exchange for Na+)
Decreased (increased K+ exchange for Na+)
Increased (unknown mechanism)
Decreased (NaCl reuptake blockage)
Amboss Renal
Desmopressin increases collecting duct permeability to what two substances via the V2 receptors?
Water (aquaporin2)
Urea (UT-A1)
Amboss Renal
Presence of WBC casts on urinalysis indicates inflammation of the renal ___________.
Presence of WBC casts on urinalysis indicates inflammation of the renal interstitium.
Amboss Renal
Long-term use of drugs like aspirin, tylenol, opioids, etc. coupled with hematuria is indicative of what?
Renal papillary necrosis
Amboss Renal
Which segments of the nephron are most affected by ischemia?
The straight PCT
+
the distal straight tubule (aka the thick ascending limb)
Amboss Renal
A neonate with Potter sequence shows evidence of periportal fibrosis and portal hypertension.
Identify which of the following is the most likely precipitating cause of the presentation:
A. Bilateral renal hypoplasia
B. Mutation of the short arm of chromosome 16
C. Vesicoureteral reflux
D. Nondisjunction of chromosome 18
E. Nondisjunction of chromosome 13
F. Cystic dilation of the collecting ducts
F. Cystic dilation of the collecting ducts
(ARPKD - mutation of the fibrocystin gene on the short arm of chromosome 6)
Amboss Renal
What is the mechanism of atrial natriuretic peptide?
Afferent arteriole dilation
Efferent arteriole constriction
Decreased sodium reabsorption
Amboss Renal
The level of ANP is proportional to ________ stretch.
The level of BNP is proportional to ________ volume and pressure overload.
The level of ANP is proportional to atrial stretch.
The level of BNP is proportional to ventricular volume and pressure overload.
Amboss Renal
True/False.
Post-renal acute kidney injury and hydronephrosis causes renal damage that is typically irreversible.
False.
Post-renal acute kidney injury and hydronephrosis causes renal damage is typically reversible with medical intervention.
Amboss Renal
Identify the congenital renal syndromes associated with Wilms tumor that are caused by each of the following:
WT1 deletion
WT1 mutation
WT2 mutation
WAGR
Denys-Drash
Beckwith-Wiedemann
Amboss Renal
Muscarinic agonists ___________ bladder contraction.
Muscarinic antagonists ___________ bladder contraction.
Muscarinic agonists increase bladder contraction.
Muscarinic antagonists decrease bladder contraction.
Amboss Renal
A patient with oliguria due to short-term hypovolemia (precipitating prerenal ATN in the long-term) is most likely to have what urinalysis results as far as sodium and casts are concerned?
Low sodium
+
hyaline casts
Amboss Renal
A heterogenous mass arising from the renal pelvis is most likely (90%) to be what kind of tumor?
Urothelial carcinoma
Amboss Renal
True/False.
Creatinine is freely filtered at the glomerulus, with no passive reabsorbtion or active secretion.
False.
Creatinine is freely filtered at the glomerulus, minimally passively reabsorbed, and small amounts are actively secreted.
Amboss Renal
Which overestimates renal clearance, creatinine or inulin?
Creatinine
(10 - 20% actively secreted)
Amboss Renal
True/False.
Inulin is freely filtered at the glomerulus, with no passive reabsorbtion or active secretion.
True.
Amboss Renal
What are the renal effects seen with tacrolimus-induced injury?
Tubular vacuolization
+
possible glomerular scarring and focal segmental glomerulosclerosis
Amboss Renal
What are the renal effects seen with sirolimus-induced injury?
None.
There are no renal effects of sirolimus use.
Amboss Renal
The levator ani are innervated by which nerve roots?
S3 - S4
Amboss Renal
Which type of diuretic is useful in preventing calcium stones?
Thiazides
(calcium-sparing)
Amboss Renal
True/False.
Inermittent catheterization can be useful as treatment for patients with neurogenic bladder.
True.
Amboss Renal
Describe the difference in etiology between the two forms of renal arteriolosclerosis shown in the image.
The left image shows hyperplastic arteriolosclerosis due to acute-onset hypertensive emergency;
the right image shows hyaline arteriolosclerosis due to chronic hyperglycemia
Amboss Renal
In a pregnant patient with gonorrhea, what is the treatment plan?
IM ceftriaxone + oral azithromycin
(The pregnancy does not alter treatment.)
Amboss Renal
What drug is a second-line agent used to inhibit uric acid reabsorption in the PCT?
Probenecid
Amboss Renal
Cigarette smoking and chronic ergotamine use are both risk factors for what?
Retroperitoneal fibrosis
(abdominal irradiation, retroperitoneal surgeries, and IgG4-related systemic diseases are also risk factors)
Amboss Renal
Name some of the potential treatments for nephrogenic diabetes insipidus.
Indomethacin
Thiazides
Amiloride (if lithium-induced)
Amboss Renal
Bilateral, irregular areas of dilation and constriction in the renal arteries is characteristic of what form of autoimmune condition causing transmural inflammation and fibrinoid necrosis of the arteries?
Polyarteritis nodosa
List the main features of type 1 renal tubular acidosis.
(Main issue, pH changes, potassium changes, other issues, etc.)
Distal RTA
Impaired H+ secretion
Elevated urine pH
Hypokalemia
Nephrolithiasis
List the main features of type 2 renal tubular acidosis.
(Main issue, pH changes, potassium changes, other issues, etc.)
Proximal RTA
Impaired HCO3- reabsorption
Initially high but decreasing urine pH
Hypokalemia
List the main features of type 4 renal tubular acidosis.
(Main issue, pH changes, potassium changes, other issues, etc.)
Hyperkalemic RTA
Impaired aldosterone action (either due to resistance or decreased secretion)
Low urine pH
Hyperkalemia
