Renal Flashcards
ACE Inhibitors Names Uses Toxicity Contraindications
Captopril, Enalapril, Lisinopril
CHF, HTN, Diabetes, Renal Disease
Cough, Angioedema, Teratogen, Cr Increase, Hypotension, HyperK
Do not use in Renal Artery Stenosis
How are ATII Receptor Blockers Different from ACEI?
Do not cause cough or angioedema because they do not affect inhibit Bradykinin degradation
How do diuretics affect urine NaCl
Increased. Serum NaCl may decrease
How do diuretics change urine [K]?
All diuretics increase urine K except for KSD.
Serum K may decrease
Which Diuretics cause Acidosis?
CAI (decreased bicarb reabsorption) and KSD (hyperK –> H leaving cells)
Which diuretics cause alkalemia?
Loop and Thiazide
Decreased Vol –> ATII –> Na/H exchanger –> bicarb reabsorption (contraction alkalosis)
Decreased K –> H entering cells
Decreased K –> H (instead of K) exchanged for Na in CT
K Sparring Diuretics Names Use MoA Tox
Spironolactone, Eplerenone, Amiloride, Triamterene
Increased Ald, Decreased K, CHF
S –/ Ald R, T and A –/ Na Channels
Increased K –> Arrhythmias, S –> gynecomastia + anti androgen
Which diuretics affect urine Ca?
Urine Ca increases with LD and decreases with Thiazide
Thiazide Diuretics
Uses
MoA
Toxicity
–/ NaCl reabsorption in DT
HTN, CHF, Increased Ca in Urine, Nephrogenic Diabetes Insipidus
Hyper Glucose, Lipids, Uric Acid, Ca
(HICC the GLUC)
Ethacrynic Acid
Like Furosemade for people allergic to Sulfur
Loop Diuretics Name Use Inhibited by MoA (2) Tox
Furosemide
–/ NaK2Cl pump, –> PGE –> AA dilation
Inhibited by NSAIDs
Edema (CHF, cirrhosis, Nephrotic Syndrome, Pul Edema), HTN, Hypercalcemia
Ototoxic, HypoK, Mg and Ca, Dehydration, Alergy, Alkalosis, Interstitial Nephritis, Gout
CAI
Names
Use
Tox
Acetazolamide Glaucoma, Make Urine Basic, Alkalosis, Altitude Sickness, Pseudotumor Cerebri Met Acidosis (with increased Cl), Paresthesia, NH3 toxicity, Sulfa allergy
Mannitol Uses MoA Tox Contras
Shock, OD, ICP, IOP
Osmotic Diuretic
Pul Edema, Dehydration
Contraindicated in CHF, anuria
Urea transport in the Kidney
PT: reabsorbed, Descending LoH: secreted, CD: Reabsorbed or stays in lumen depending on ADH
ADH and Urea
ADH –> UT1 in medullary collecting to increase Urea reabsorption which adds to corticopappillary osmotic gradient
Where is Vit D made in the Kidney?
What stimulates its production?
PT
PTH –> 1 alpha hydroxylase (which converts 25 vit D to 1, 25 vit D)
How does Vit D promote bone mineralization?
Vit D –> Osteoblasts –> alkaline phasphatase
AP hydrolyzes Pyrophasphate and other inhibitors of Ca-PO4 crystallization.
Functions of Vit D
GI reabsorption of Ca and PO4
Bone mineralization
Maintains serum [Ca]
–> monocytes to become osteoclasts
Drugs associated with Hematuria
Anticoagulants (warfarin and heparin)
Cyclophasphamide –> hemorrhagic cystitis and increased risk for transitional cell carcinoma
Tests for Protienuria
Dipstick for albumin
SSA (sulfosalicylic acid) for albumin and globins
Urea and GFR
Increased GFR –> Decreased Urea reabsorption
Functional Proteinuria
Not associated with rena disease
fever, exercise, CHF, Orthostatic
Overflow Proteinuria
LMW proteinuria
Multiple Myeloma, Hemoglobinuria, Myoglobinuria
Tubular Proteinuria
Defect in PT reabsorbing LMW proteins
Hg or Pb poisoning
Fanconi Syndrome
Hartnup Disease
When would BUN Decrease?
Increased Volume
Decreased Urea Synthesis
Decreased Protein intake
BUN/Cr > 15
Prerenal azotemia
Early postrenal azotemia
Bilateral Renal Agenesis
What does it lead to?
What are the signs of this?
Causes Potter Syndrome
Extremity deformities, Facial deformities, Pulmonary hypoplasia
Incompatible with life
If the renal artery is narrowed, what is the kidney’s response?
JG apparatus releases Renin and undergoes hypertrophy and hyperplasia (in order to secrete more renin)
What makes up the JG apparatus?
JG cells = modified smooth muscle cells of AA and EA
Macula Densa = tall, narrow cells in DT
The MD responds to [Cl] (via NaK2Cl pump) and transmits this information to JG cells which respond by secreting Renin
Path of K reabsorption in the Kidney
2/3 reabsorbed in PT
20% in LoH
Secreted in CD unless in a low K state –> Intercalated cells reabsorb K (K/H exchanger)
Factors that Increase K secretion in CD
High K diet, Aldosterone, Alkalosis (K/H exchanger), Diuretics (except KSD)
Renal angiomyolipomas
What are they?
How are they diagnosed?
What are they associated with?
Benign tumor made of blood vessels, SM, and fat
Diagnosed with abdominal CT because of low density of fat
Associated with Tuberous Sclerosis
What kind of Hypersensitivity Rxn is PSGN?
Describe the PathoPhys?
Describe appearance in Immunofluorescence and EM?
Type III: Immune Complex Mediated
After GAS infection, IC formed against bacterial antigens cross react w/ GMB and deposit in subepithelial portion of the glomerulus.
Lumpy Bumpy on IF and electron dense humps on EM
Horseshoe Kidney cannot ascend because it is trapped behind …
IMA
List 3 factors that increase PT Na Reabsorption
Increased Luminal Flow
ATII (decreased cAMP)
NE (via PKC)
List 2 factors that decrease PT Na Reabsorption
DA
PTH (increased cAMP)
When does the Pronephros form and degenerate?
Week 4
When does the Mesonephros function as the kidney?
1st Trimester
When does metanephros first appear?
Until when does nephrogenesis continue?
Week 5
Nephrogenesis continues through week 32-36
Fate of Mesonephros
Male: Mesonephros –> Wolffian duct –> ductus deferens and epididymis
Female: –> Gartners ducts
Kidney derived from Ureteric Bud
Fully canalized by week..
Collecting Duct, Calyces, Pelivs, Ureter
Fully canalized by week 10
Metanephric mesoderm gives rise to…
Glomerulus through collecting tubule
Last part of kidney to canalize?
Ureteropelvic junction
What is the most common site of obstruction and cause of hydronephrosis in the fetus?
Ureteropelvic Junction
Causes of Potter’s Syndrome?
ARPKD, Posterior Urethral Valves, Bilateral Renal Agenesis
Horseshoe kidney associated with…
Turners Syndrome
Multicystic Dysplastic Kidney Due to... Leads to... Kidney consists of... Uni or Bi? Symptoms? Diagnosed by...
Due to abnormal interaction bet ureteric bud and metanephric mesenchyme
Leads to non functional kidney
Kidney consists of cysts and connective tissue
Unilateral
Asymptomatic
Diagnosed by prenatal US
Which Kidney is taken from a living donor? Why?
Left because of longer renal vein
Ureter re uterine artery and ductus deferens?
Ureter goes Under uterine artery and ductus deferens
water under the bridge
% of total body weight that is water? extracellular? plasma? interstitial?
60% water –> 2/3 intracellular, 1/3 extracellular
1/4 plasma, 3/4 interstitial
What substance measures plasma Vol?
radiolabeled albumin
What substance measures extracellular vol?
Inulin
Osmolarity of the body?
290 mOs/L
Glomerular filtration barrier composed of:
Fenestrated capillaries (size) Fused BM with heparin sulfate (neg charge barrier) Podocyte foot processes (epithelium)
In Nephrotic Syndrome, what happens to the charge barrier in the Glomerulus?
Lost
Clearance formula
C = UV/P
C<GFR
Reabsorption
C>GFR
Secretion
Using Cr to estimate GFR
Slight overestimation because Cr is secreted
Normal GFR
100ml/min
Calculating GFR (2 formulas)
C inulin, C creatinine, or K[(Pgc-Pbs)-(Pigc-Pibs)]
What substance is used to measure ERPF? Why?
PAH because it is filtered and actively secreted. All PAH that goes in goes out
ERPF calculation
C pah
RBF calculation
RPF/(1-Hct)
By how much is ERPF different from RPF
ERPF underestimates RPF by ~10%
Filtration Fraction
GFR/RPF
Filtered Load
GFR x Px
How do NSAIDs affect RPF, GFR and FF?
NSAIDs –/ Prostaglandins (which normally dilate AA)
NSAIDs –> Decreased RPF and GFR –> no change in FF
How do ACEI affect RPF, GFR, and FF
ACEI –/ ATII (which normally constricts EA)
ACEI –> Increased RPF, Decreased GFR –> Decreased FF
How does AA constriction affect RPF, GFR, and FF?
RPF: Decreases
GFR: Decreases
FF: NC
How does EA constriction affect RPF, GFR, and FF?
RPF: Decreases
GFR: Increases
FF: Increases
How does increased plasma [protein] affect RPF, GFR, and FF?
RPF: NC
GFR: Decreases
FF: Decreases
How does decreased plasma [protein] affect RPF, GFR, and FF?
RPF: NC
GFR: Increases
FF: Increases
How does Constriction of the Ureter affect RPF, GFR, and FF?
RPF: NC
GFR: Decreases
FF: Decreases
Excretion rate?
V x U
Net Reabsorption Calculation
Filtered - excreted
Net Secretion Calculation?
Excreted - Filtered
At what [Glucose] does Glucosuria begin
160mg/dL
Tm of Glucose
350mg/dL
Normal Pregnancy can alter reabsorption of certain solutes in the PT. Which ones?
Can reduce reabsorption of Glucose and AA
Hartnups Disease
Cause
Results in…
Deficiency of neutral AA (Tryptophan) transporter in PT
Leads to Pellagra
What is secreted by the PT? Why?
NH3 as a buffer for secreted H+
PTH on PT
MoA
Inhibits Na/PO4 cotransporter –> PO4 excretion. Will also decrease Na reabsorption in PT
–> cAMP and IP3
ATII on PT
MoA
What can it lead to?
ATII –> Na/H exchanger –> increased Na, H2O and Bicarb reabsorption
ATIIR –/ cAMP, ATiiR –> IP3
Can lead to contraction alkalosis
PTH on DT
PTH –> Na/Ca exchanger in basal membrane –> Increased Ca Reabsorption
Receptor for ADH
Type of cell responsive to ADH?
V2 receptor on Principal Cells
[Inulin] along PT
Increases in Concentration by not Amount because of water reabsorption
Cl reabsorption in PT
What proteins reabsorb Cl
Occurs at a slower rate than Na reabsorption in the proximal 1/3 and then matches Na distally –> [Cl] increases then plateaus
Reabsorbed by Cl/Base exchanger
What stimulates Renin release?
Decrease in BP, Decreased Na(Cl) delivery to DT, Increased Sympathetic tone (β1 Receptors)
What does ACE do?
Converts AT1 to AT2
Degrades Bradykinin
Main Functions of ATII
- -> AT1 receptor –> Vascular SM constriction
- -> EF constriction
- -> Adrenal Cortex –> Aldosterone
- -> Post Pituitary –> ADH
- -> PT –> Na/H exchanger
- -> DT –> Na/Cl cotransporter
- -> Hypothalamus –> Thirst
ATII and Baroreceptors
ATII affects baroreceptors function to limit reflex bradycardia which would normally accompany its pressor effects
ANP Released by... In response to... MoA How does it affect Na? Net Effect:
Released by atria in response to increased volume
ANP –> cGMP –> vascular smooth muscle relaxation –> increased GFR –> decreased renin release
Increased GFR –> Increased Na filtration (w/o compensatory Na reabsorption distally)
Net effect is Na and volume loss
ADH primarily regulates:
Will also respond to:
Which one takes precedence?
ADH primarily regulates: Osm
Will also respond to: Vol
Which one takes precedence –> vol
Aldosterone primarily regulates:
Volume
How do Beta Blockers affect RAA System?
BB –/ Beta1R in JGA
Thereby BB –/ Renin release
Where is Erythropoietin made?
What stimulates its production?
EPO released by interstitial cells in the peritubular capillary bed in response to hypoxia
Prostaglandins and the kidney?
Paracrine secretion vasodilates the AA to Increase GFR
PTH
Released in response to:
Leads to:
Released in response to Decreased Ca, Increased PO4, or Decreased VitD
Leads to Increased Ca reabsorption (DT), Decreased PO4 reabsorption (PT), and Increased VitD production
What stimulates Aldosterone production?
Decreased Vol (ATII) Increased K
What ions does Aldosterone affect?
Increased reabsorption of Na
Increased secretion of K and H
What shifts K out of cells (HyperK)?
DO Insulin LAB
Digitalis, HyperOsmolarity, Insulin deficiency, Lysis of cells, Acidosis, Beta Antagonists
What shifts K into cells (HypoK)?
“Insulin shifts K into cells”
Hypo-osmolarity, Insulin, Alkalosis, Beta agonists
Low [Na] presents with:
Nausea, Malaise, Stupor, Coma
High [Na] presents as
Irritability, stupor, coma
Low [K] presents as
U wave, Flat T wave, Arrhythmias, muscle weakness
High [K] presents as
Wide QRS and peaked T waves, Arrhythmias, muscle weakness
Low [Ca] presents as
Tetany, seizures
High [Ca] presents as
Stones (renal stones), Bones (pain), Groans (abdominal pain), Psychiatric overtones (anxiety, altered mental status), but not necessarily calcinuria
Low [Mg] presents as
Tetany, arrhythmias
High [Mg] presents as
“Lazy DR. Better Hike/Cram Ca”
Lethargy, decreased deep tendon reflexes, bradycardia, hypotension, cardiac arrest, hypocalcemia
Low [PO4] presents as
Bone loss, osteomalacia
High [PO4] presents as
Renal stones, metastatic calcifications, hypocalcemia
Metabolic Acidosis: pH, PCO2, [HCO3], Compensatory response?
Low pH, Low PCO2, Low [HCO3], Immediate hyperventilation
Metabolic Alkalosis: pH, PCO2, [HCO3], Compensatory response?
High pH, High PCO2, High [HCO3], Immediate hypoventilation
Respiratory Acidosis: pH, PCO2, [HCO3], Compensatory response?
Low pH, High PCO2, High [HCO3], Delayed increase in bicarb reabsorption
Respiratory Alkalosis: pH, PCO2, [HCO3], Compensatory response?
High pH, Low PCO2, Low [HCO3], Decreased renal bicarb reabsorption
Kidney Henderson-Hasselbalch Equation for Kidney
pH = 6.1 + log ([HCO3]/.(.03 x PCO2))
How does one predict the compensation for a simple Met Acidosis? What if actual PCO2 is different from predicted?
Winters Formula: PCO2 = (1.5 x [Bicarb]) + 8) +/- 2
If not as predicted: Mixed acid/base disorder
Anion Gap Calculation
Normal Anion Gap?
Na - (Cl + HCO3)
Normally 8-12 mEq/L
Causes of Resp Acidosis?
Hypoventilation due to Obstruction, Disease, Opioids or Sedatives, Muscle weakness
Causes of Anion Gap Met Acidosis
MUDPILES Methanol (formic acid), Uremia, Diabetic ketoacidosis, Propylene glycol, Iron tablets or INH, Lactic acidosis, Ethylene glycol (Oxalic Acid), Salicylates (late)
Causes of Non Anion Gap Met Acidosis
HARD ASS
Hyperalimentation, Addisons Disease, Renal Tubular Acidosis, Diarrhea, Acetazolamide, Spironolactone, Saline infusion
Causes of Resp Alkalosis?
Hyperventilation (i.e. altitude sickness)
Salicylates (early)
Causes of Met Alkalosis?
Loop Diuretics, Vomiting, Antaacids, Hyperaldosteronism
Type 1 Renal Tubular Acidosis Location of defect Defect Urine pH Associated with Increased risk for
Defect in DT ability to excrete H
Urine pH > 5.5
Associated with HypoK
Increased risk for CaPO4 kidney stones because of increased urine pH and bone resorption
Type 2 Renal Tubular Acidosis Defect in Defect Seen in what disease? Urine pH Associated with Increased risk for
Defect in PT HCO3 reabsorption Seen in Fanconi Syndrome Urine pH < 5.5 Associated with hypoK Increased risk for hypophosphatemic rickets
Mechanism of Type 4 Renal Tubular Acidosis
Low Aldosterone or lack of response to aldosterone –> hyperK –> impaired ammoniagenesis in PT –> PT loses buffering capacity –> urine pH decreases
What do Casts in Urine indicate?
Renal (vs. Bladder) origin
RBC Casts Indicate
Glomerulonephritis, Ischemia, MalHTN
WBC Casts indicate
Tubulointerstitial inflammation, acute pyelonephritis, transplant rejection
Fatty Casts
Appearance
Indication
Oval Fat Bodies
Indicate Nephrotic Syndrome
Granular (Muddy Brown) Casts Indicate
ATN
Waxy Casts indicate
Advanced renal disease, Chronic renal failure
Hyaline casts indicate
Non-specific. Can be a normal finding
Causes of hematuria without casts
Bladder Cancer or Kidney Stones
Causes of pyuria without casts
Acute Cystitis
Definition of Focal Glomerular Disorder
<50% glomeruli involved
Definition of Diffuse Glomerular Disorder
> 50% glomeruli involved
Definition of Proliferative Glomerular Disorder
Hypercellular glomeruli
Definition of Membranous Glomerular Disorder
Thickening of glomerular BM
Definition of Primary Glomerular Disorder
Only glomeruli involved
Definition of Secondary Glomerular Disorder
Glomeruli + other organ involved
Names of Nephritic Syndromes
“PARIS”
PSGN, RPGN, Berger’s IgA Glomerulonephrtopathy, Alport Syndrome
(DPGN and MPGN can also be nephrotic)
(SLE can also cause a nephritic syndrome)
“PIG ARMS” includes Goodpastures and MPGN
Names of Nephrotic Syndromes
“F. SAM M.D.”
Focal Segmenting Glomerulosclerosis, Amyloidosis, SLE, Membranous Nephropathy, Minimal Change Disease, Diabetic Glomerulonephropathy
(DPGN and MPGN can also be nephritic)
Presentation of Nephrotic Syndrome
Casts
Associated with
Increased risk for
“Protein LEACHs out”
Proteinuria > 3.5 g/day, ↑Lipids, Edema, hypoAlbuminia, ↑Cholesterol, HTN (Na retention)
Fatty Casts
Associated with Thromboembolism (hypercoagulable state due to ATIII loss)
Increased risk for infection (from loss of gamma Igs)
FSGS LM EM Rate Associated with diseases? drug use? lifestyle? medicines?
LM: segmental sclerosis and hyalinosis
EM: effacement of foot processes
Most common nephrotic syndrome in adults
Associated with HIV, Heroin, Obesity, Interferon treatment, Chronic kidney disease (due to congenital absence or removal)
Membranous Nephropathy Mechanism LM EM IF What diseases present this way? Rate Caused by
"MP" Subepithelial IC deposition LM: Diffuse capillary and BM thickening EM: "Spike and Dome" with subepithelial deposits IF: Granular (IgG and C3) SLE's presentation 2nd most common Nephrotic in adults Causes: idiopathic, drugs, infections, SLE, tumors
Minimal Change Disease Pathogenesis LM EM Describe the Proteinuria Triggered by Most common in Treatment
T Cell Cytokines
LM: normal
EM: foot process effacement
Selective loss of albumin, not globins, because of BM polyanion loss
Triggered by recent infection or immune stimulus
Most common in children
Responds to corticosteroids
Amyloidosis
LM
Associated with…
LM: congo red stain shows apple-green birefringence under polarized light
Associated with chronic conditions like Multiple Myeloma, TB, and RA
MPGN Type I Mechanism IF Appearance Associated with
Subendothelial IC deposits
IF: Granular
Tram-Track appearance due to BM splitting caused by mesangial ingrowth
HBV, HCV
MPGN Type II
Mechanism
Appearance
Associated with
Intramembranous IC deposits
AutoAb –/ degradation of C3 convertase which leads to low levels of C3
“Dense deposits”
Associated with C3 nephritic factor
Diabetic Glomerulonephropathy
Mechanism
Nonenzymatic Glycosylation of BM –> ↑ permeability to proteins + ↑ thickness
NEG of EA –> hyaline arteriolosclerosis –> ↑GFR –> hyperfiltration –> damage to mesangial cells –> mesagnial expansion
Osmotic damage to glomerular capillary endothelial cells (Glucose –> sorbitol which is osmotically active and leads to swelling and cellular damage)
ATII receptor MoA
ATIIR –> IP3
ATIIR –/ cAMP
In Nephrotic Syndrome, what is the glomerular injury due to?
Cytokines damage podocytes causing them to fuse and destroy - charge of GBM
Which diabetes causes Diabetic Glomerulonephropathy?
Both. 1 (40%) > 2 (20%)
Diabetic Glomerulonephropathy
LM
LM: Mesangial expansion, BM thickening, eosinophilic nodular glomerulosclerosis (Kimmelstiel-Wilson Lesion)
Nephritic Syndrome
What kind of process?
What is it mediated by?
Inflammatory Process mediated by neutrophils
Nephritic Syndrome Presentation
"PR HOZ" Proteinuria (<3.5g/day) RBC casts Hematuria, HTN (due to salt retention) Oliguria aZotemia
PSGN
Presentation
Treatment
“Throat, Bloat, Coke”
Child w/ previous infection (GAS), peripheral + periorbital edema, HTN, and dark urine
Resolves Spontaneously
PSGN
LM
EM
IF
LM: Glomeruli enlarged and hypercellular. Neutrophils, “lumpy bumpy”
EM: Subepithelial IC humps
IF: Granular appearance due to IgG, IgM and C3 deposition along BM and mesangium
RPGN (crescentic)
LM
IF
What are in the crescents?
LM + IF: crescent moon shape
Crescents = fibrin + plasma proteins (C3) with glomerular parietal cells, monocytes, and macs
RPGN prognosis
Poor (days to weeks)
Diseases that result in RPGN
Markers for them?
Goodpasture’s (hematuria + hemoptysis), Wegener’s (cANCA), Microscopic polyangiitis (pANCA)
How Goodpasture’s –> RPGN
What kind of Rxn?
Mechanism
Type II Hypersensitivity Rxn
Abs to GBM + alveolar BM
Goodpasture’s IF
Linear pattern
DPGN Mechanism What diseases cause it? LM EM IF
Subendothelial IC mediated SLE + MPGN cause it LM: wire looping of capillaries EM: subendothelial and sometimes intramembranous IgG-based IC often with C3 deposition IF: granular
Most common cause of death in SLE
DPGN
Which diseases can cause concurrent nephrotic and nephritic syndromes?
SLE and MPGN
Berger's Disease (IgA Nephropathy) Related to what other disease? LM EM IF
"AM" Think Mesangium Related to Henoch-Schonlein Purpura LM: mesangial proliferation EM: mesangial IC deposits IF: IgA based IC deposits in mesangium
When does Berger’s disease often presents/flares?
Often presents/flares with URI or acute gastroenteritis
Henoch-Schonlein Purpura Kind of vasculitis? Most common vasculitis in... Classic Presentation Disease Mediated by Associated with Age of lesions?
Small vessels Most common vasculitis in children "NAPA" Child following URI with Nephropathy, Abdominal pain (melena), Purpura, Arthralgia Mediated by IgA complex deposition Associated with IgA nephropathy Multiple lesions of same age
Wegener's Granulomatosis (Granulomatosis with Polyangiitis) Kind of vasculitis? Presentation Histo Blood CXR Treatment
Small vessels Upper Respiratory Tract: Perforated nasal septum, sinusitis, otitis media, mastoiditis Lower RT: Hemoptysis, Cough, Dyspnea Renal: Hematuria, RBC Casts Focal Necrotizing vasculitis + Necrotizing granulomas in the lung and upper airway + Necrotizing glomerulonephritis c-ANCA Large Nodular Densities Cyclophosphamide and corticosteroids
Alport Syndrome
Mechanism
Genetics
Presentation
“Imagine the V in IV splitting the BM”
Mutation in IV collagen –> split basement membrane
X linked
Glomerulonephritis, deafness, eye problems
Treat and prevent Kidney Stones with
Fluid intake
Ca Kidney Stones
Frequency
Precipitates at what pH
XR
80%
CaPO4 –> ↑pH
CaOxalate –> ↓pH
Radiopaque
Oxalate crystals can result from
Ethylene glycol or VitC abuse
Treatment for recurrent kidney stones
Thiazide and citrate
Most common kidney stone presentation Re: Kind of Kidney stone, Urine, and Blood?
CaOxalate stone in pt with hypercalcinuria and normocalcemia
Ammonium MgPhosphate Kidney Stones (struvite)
Frequency
Precipitates at pH
XR
15%
Precipitates at ↑pH
Radiopaque
Ammonium MgPhasphate Kidney Stones
Caused by
Mechanism
What can they form?
Caused by infection with urease+ bugs (proteus mirabilis, Staph, Klebsiella)
The bugs hydrolyze urea to ammonia and this alkalizes urine
Can form staghorn calculi that can be a nidus for UTIs
Uric Acid Kidney Stones
Frequency
Precipitates at pH
XR
5%
Precipitates at ↓pH
RadiolUcent
Uric Acid Kidney Stones Visible on Associated with Often seen in what kind of diseases? Treatment
Visible on CT and US but not XR
Associated with hyperuricemia (gout)
Often seen in diseases with high cellular turnover (leukemia)
Treat w/ alkalinization of urine
Cystine Kidney Stones Frequency Precipitates at pH XR Usually Secondary to Appearance of stone Treatment
1% Precipitates at ↓pH Radiopaque Secondary to cystinuria Hexagonal crystals Treat w/ alkalinization of urine
Hydronephrosis What happens? Can be caused by Leads to May result in
Backup of urine into the kidney
Caused by urinary tract obstruction or vesicoureteral reflux
Leads to dilation of renal pelvis and calyces
Results in parenchymal thinning
ATN
Frequency?
Reversible?
When does death most frequently occur?
Most common cause of intrinsic renal failure
Self reversible in some cases but can be fatal if untreated
Death most often occurs during oliguric phase
ATN
What causes it?
Renal ischemia (from shock, sepsis) Crush injury (myogloniburia) Drugs, toxins
Acute Tubular Necrosis Stages
Initiation: Ischemic injury. Usually unnoticed
Maintenance
Recovery:
ATN Maintenance Stage Urinating/Quality of urine Edema? GFR? Electrolytes (K and Na) pH Casts Duration
Oliguria. Low Urine Osm. Fluid overload (edema) Increased Cr/BUN, Increased K. High Na excretion. Anion Gap Met Acidosis (because of retention of H and anions). Muddy Brown Casts. Last 1-3 days
ATN Recovery Stage
Urinating/Quality of urine
Electrolytes
Diuresis, Hypotonic urine, Low K, Mg, PO4, and Ca
Renal Papillary Necrosis What is happening? Urine? Triggered by Associated with
Sloughing of renal papillae
Gross hematuria and proteinuria
May be triggered by a recent infection or immune stimulus
Associated with DM, Acute Pyelonephritis, Chronic Phenacetin Use (acetaminophen)
Sickle Cell Anemia
Acute Renal Failure (Acute Kidney Injury)
Definition
Abrupt decline in renal function with ↑ Cr and ↑ BUN over several days
Prerenal azotemia
Result of
BUN/Cr ratio
↓RBF –> ↓GFR
BUN/Cr ↑
Intrarenal azotemia Generally due to Less commonly due to Mechanism Casts BUN/Cr
Generally due to ATN or ischemia/toxins
Less commonly due to acute glomerulonephritis
Necrosis –> debris obstructing tubule –> fluid back flow –> ↓GFR
Epithelial/granular casts
BUN/Cr ↓
Post Renal azotemia
What causes obstruction?
Develops only when obstruction is?
Due to outflow obstruction (stones, BPH, neoplasia, congenital abnormalities)
Develops only with bilateral obstruction
Prerenal Azotemia Urine Osm (mOsm/kg) Urine Na (mEq/L) FENa BUN/Cr
Urine Osm (mOsm/kg) > 500
Urine Na (mEq/L) < 20
FENa < 1%
BUN/Cr > 20
Intrarenal Azotemia Urine Osm (mOsm/kg) Urine Na (mEq/L) FENa BUN/Cr
Urine Osm (mOsm/kg) < 350
Urine Na (mEq/L) > 40
FENa > 2%
BUN/Cr < 15
Postrenal Azotemia Urine Osm (mOsm/kg) Urine Na (mEq/L) FENa BUN/Cr
Urine Osm (mOsm/kg) < 350
Urine Na (mEq/L) > 40
FENa > 2%
BUN/Cr > 15
Consequences of Renal Failure Na/Water K pH Urea Blood Bones Lipids Growth
Na/Water retention --> CHF, Pul Edema, HTN) HyperK Met Acidosis Uremia Anemia (low EPO) Renal Osteodystrophy Dyslipidemia (↑ Tris) Growth retardation and developmental delay (children)
Uremia
Blood work
Presentation
↑BUN and ↑Cr
Nausea, anorexia, Pericarditis, Asterixis, Encephalopathy, Platelet dysfunction
Renal Osteodystrophy
Pathogenesis
Low VitD + Kidney dysfunction –> ↓Ca and ↑PO4 –> ↑PTH –> bone resorption (subperiosteal thinning of bone)
Adult PKD Gross presentation of kidney Presentation Genetics w/ chromosome Death from Associated with
Multiple, large, bilateral cysts
Flank pain, hematuria, HTN, Urinary infections, Progressive renal failure
Autosomal Dominant in PKD1 or 2 on chromosome 16
Death from chronic kidney disease or HTN (↑ Renin)
Associated with Berry Aneurysm, MVP, Benign Hepatic cysts
AR PKD Genetics Associated with Significant renal failure in utero leads to Concerns beyond neonatal period
Autosomal recessive
Associated with hepatic fibrosis
In utero –> Potters
Beyond neonatal concerns –> HTN, Portal HTN, Progressive renal insufficiency
Medullary Cystic Disease Genetics What does it lead to Inability to Visualization? On US Prognosis
Autosomal dominant Leads to tubulointerstitial fibrosis and progressive renal insufficiency with inability to concentrate urine Medullary cysts usually not visualized US: shrunken kidney Poor prognosis
Renal Cell Carcinoma Originates from what kind of cells? Histo Most common in Risk ↑ w/ Presentation How does it spread Metastasizes to
Originates from PT cells
Polygonal clear cells (accumulated lipids and Carbs)
Most common in Men 50-70
Risk ↑ w/ smoking and obesity
Hematuria, palpable mass, polycythemia, flank pain, fever, wt loss
Renal vein –> IVC
Lung and Bone
Renal Cell Carcinoma Frequency Genetics Tumors secrete? When is it usually detected? Treatment
Most common renal cancer
Gene deletion in chromosome 3 (sporadic or von Hippel Lindau)
Paraneoplastic (EPO, ACTH, PTH)
Silent cancer because retroperitoneal. Usually detected b/c of metastases
Resection. Resistant to Chemo and Radiation
Wilms' Tumor (Nephroblastoma) Frequency Contains what kind of structures Presentation Genetics Associated with what Syndrome?
Most common renal malignancy of early childhood (2-4)
Contains embryonic glomerular structures
Presents with huge palpable flank mass and/or hematuria
Deletion of tumor suppressor WT1 on chromosome 11
May be part of Beckwith-Wiedemann Syndrome
Components of Beckwith-Wiedemann Syndrome
WARG
Wilms, Aniridia, Genitourinary malformations, Retardation
Transitional Cell Carcinoma Frequency Can occur in Presentation Associated with...
Most common tumor of urinary tract system
Can occur in Calyces, pelvis, ureters, bladder
Painless hematuria (no casts)
“problems in the Pee SAC”
Phenacetin, Smoking, Aniline dyes, Cyclophosphamide
Acute Pyelonephritis
Which part of kidney affected?
Presentation
Urine?
Affects cortex with sparing of glomeruli and vessels
Fever, CVA tenderness, nausea, vomiting
White cell casts in urine
Chronic Pyelonephritis Result of Requires Histo Tubules contain
Result of recurrent episodes of acute pyelonephritis
Requires predisposition to infection (vesicoureteral reflux, chronic kidney stones)
Coarse, asymmetric corticomedullary scarring and blunted calyx
Tubules can contain eosinophilic casts (thyroidization of kidney)
Drug-Induced Interstitial Nephritis (tubulointerstital nephritis) Presentation Urine MoA Time course and drugs
Azotemia, fever, rash, hematuria, CVAT. Can be asymptomatic
Pyuria (eosinophils)
Drugs act as haptens –> hypersensitivity
1-2 weeks: Diuretics, penicillin, sulfonamide, rifampin
Months: NSAIDs
Diffuse Cortical Necrosis
What is it?
Due to
Associated with
Acute generalized cortical infarction of both kidneys
Combination of vasospasms and DIC
Associated with obstetric catastrophe (abruptio placentae) and Septic Shock
Which Nephrotic/Nephritic Syndromes have Subepithelial IC deposits
PSGN
Membranous
Which Nephrotic/Nephritic Syndromes have Subendothelial IC deposits
MPGN I
DPGN
Charges in the Tubule of the Kidney
PT: -4
LoH: +7
DT: -10
CT: -50