Renal FA (Physiology and Pathology) Flashcards
1
Q
Kidney embryology
A
- Pronephros (up till wk4)
- Mesonephros (first trimester)
- Metanepros (appears in wk 5)
2
Q
Ureteric bud
A
derived from mesonephric duct
gives rise to ureter, pelvises, calyces, collecting ducts
3
Q
Metanephric mesenchyme
A
gives rise to glomerulus through to DCT
4
Q
Ureteropelvic junction
A
Last to canalize
Most common site of obstruction (hydronephrosis)
5
Q
Potter sequence- POTTER
A
Pulmonary hypoplasia Oligohydramnios Twisted face (low set ears, overbite, flattened nose) Twisted skin Extremity defects Renal failure
Due to failure of ureteric bud formation
Can be cause by ARPKD, bilateral renal agencies, chronic placental insufficiency
6
Q
Horseshoe kidney
A
Inferior pole of the kidneys fuse
Gets trapped under INFERIOR MESENTERIC ARTERY (IMA)
Kidneys function normally
7
Q
Associations/ complications with horseshoe kidney
A
hydronephrosis, renal stones, infection, renal cancer
See more commonly in Turner and trisomies
8
Q
Unilateral renal agenesis
A
ureter bud (pelvix, calyx, collecting duct ureter) fails to develop metanephric mesenchyme (glomerulus and DCT) also does not develop Causes complete absence of kidney and ureter
9
Q
Multicystic dysplastic kidney
A
Ureteric bud develops
UB fails to induce differentiation of metanephric mesenchyme
Causes non-functional kidney with cysts and connective tissue
10
Q
Duplex collecting system
A
bifurcation of one ureteric bud (or just two) before entering the metanephric mesenchyme causes Y-shaped bifid ureter
Associated with vesicoureteral reflux/ obstruction
Increase UTI risk
11
Q
Congenital solitary functioning kidney
A
Born with only one functioning kidney
Generally asymptomatic with compensatory hypertrophy of contralateral kidney (which also may have some anomalies)
12
Q
Left kidney
A
Longer renal vein- so generally taken for donor transplantation
13
Q
Renal blood flow
A
Renal artery –> Segmental artery –> Interlobar artery –> arcuate artery –> interlobular artery –> afferent arteriole –> glomerulus –> efferent arteriole –> vasa recta/ peritubular capillaries –> venous outflow
14
Q
Components of the glomerular filtration barrier
A
Podocytes, basement membrane, and endothelial cells (around the arterioles)
15
Q
Mesangial cells of the glomerulus
A
Remove trapped residues and aggregated protein from the basement membrane
16
Q
Afferent vs. Efferent arterioles
A
Afferent: arriving
Efferent: exiting
17
Q
Ureters
A
Pass Under the uterine artery or under the vas deferent (water under the bridge)
Ligation of the uterine (cardinal ligament) or ovarian vessels (suspensory/ infundibulopelvic ligament) may damage ureter
18
Q
Fluid compartments (60-40-20)
A
60% total body water (40% ICF + 20% ECF); 40% non water mass
19
Q
ECF vs. ICF
A
kg –> L (since density of H2O is 1)
For a 70kg person (42kg of TBW; 28kg of non water mass)
1/3 ECF- 14 kg (Interstitial fluid (10.5 kg) and plasma (3.5 kg))
2/3 ICF- 28kg (RBCs (3 kg) and Cells (25 kg))
20
Q
Plasma volume- measurement
A
Radiolabeling albumin
21
Q
Extracellular volume- measurement
A
Innulin or Mannitol
22
Q
Osmolarity
A
285-295 mOsm/kg H2O
23
Q
Glomerular filtration barrier
A
Filters based on SIZE and net CHARGE
Composed of:
Fenestrated capillaries: size barrier
BM with heparan sulfate: negative charge and size barrier
Epithelial layer consisting of podocyte foot processes: negative charge
Albumin: negatively charged, and therefore repelled by negative charges on BM and epithelium
24
Q
Charge barrier compromised
A
Lost in nephrotic syndrome
Causes albuminuria, hypoproteinemia, generalized edema, and hyperlipidemia
25
Renal clearance
Clx = Ux * V/ Px where
Px: plasma concentration (mg/mL)
Ux: urine concentration (mg/mL)
V: urine flow rate
26
Filtration vs. Secretion
Filtration: First pass dump into BC
Secretion: Second pass dump (material from interstitium/ capillaries to tubular lumen to be removed)
Reabsorption: Moved from lumen to capillaries/intersititium
27
Clearance Rate
Equal to: Filtration Rate - Reabsorption Rate + Secretion Rate
28
Clearance vs. GFR
If Clx = GFR: indicates no net secretion or absorption of X
If Clx > GFR: indicates net tubular secretion of X
If Clx < GFR: indicates net tubular reabsorption of X
29
Calculating GFR
Use GFR = Cl = UV/P for INNULIN
Innulin is freely filtered and neither reabsorbed nor secreted
30
Creatinine Cl vs. GFR
Creatinine is secreted so CrCl slightly overestimates GFR (assumes all that is cleared is filtered- when in reality some is also secreted)
vs. urea (which is reabsorbed, so Urea clearance slightly underestimates what is filtered (since some of it is reabsorbed))
31
Normal GFR
Around 100 mL/min
32
Effective renal plasma flow
Can be estimated using PAH (because nearly 100% cleared (via filtration and secretion))
eRPF = U(PAH) * V/ P (PAH) = Cl (PAH)
eRPF slightly underestimates true renal plasma flow
33
Renal Blood Flow
RBF = RPF/ (1-Hct)
34
Plasma
1 - hematocrit
| Hct (refers to percentage of blood volume comprised of RBCs/ RBC volume in blood)
35
GFR vs. RPF
GFR: Amount that is filtered by the kidney at the glomerulus per unit time
RPF: Amount of plasma that flows into the kidney per unit time
36
Filtration fraction (FF)
```
Filtration fraction (FF) = GFR/RPF
Normal is 20%
```
37
Filtered load (mg/min)
Filtered load = GFR * Plasma concentration
38
Glomerulus- Afferent arteriole (things that constrict vs. dilate)
Afferent:
Constrict: NSAIDs (Decreases GFR and RBF)
Dilate: Prostaglandins (Increases GFR and RBF)
No change in filtration fraction
39
Glomerulus- Efferent arteriole (things that constrict vs. dilate)
Efferent:
Constrict: Angiotensin II (Increases GFR, Decreases RBF); Increases FF
Dilate: ACE-Inhibitors (Decreases GFR- less residence time in pipe due to big exit, Increases RBF); Decreases FF
Memory pearly: ACE-Is are good for diabetic nephropathy, because it opens up the constricted efferent arterioles
40
Glomerular dynamics- protein concentration, ureter constriction, and dehydration
Protein concentration: As protein conc increases, GFR decreases, RPF doesn't change, so FF decreases
Ureter constriction: As ureter gets constricted, less can be filtered (enter the tubular lumen), so GFR decreases, RBF stays the same, FF decreases
Dehydration: As body gets dehydrated, protein/ solute concentration increases, GFR decreases, RPF decreases (because of RAAS activation), and FF stays the same
41
Reabsorption calculation
Reabsorption = Filtered load - Excretion/Clearance rate (assuming no secretion) = GFR*Px - Ux*V
42
Secretion calculation
Secretion = Excretion/Clearance Rate - Filtered load (assuming no reabsorp) = Ux*V - GFR*Px
43
Fractional excretion of sodium- FE (Na)
Na+ excreted/ Na+ filtered = U (Na) * V/ (GFR * P (Na))
Assuming GFR can be estimated by CrCL = U (Cr) * V/ (P (Cr)):
FE Na = U (Na) * P (Cr)/ (U (Cr) * P (Na))
44
Glucose clearance
Under normal plasma level (60-120 mg/dL), should be completely reabsorbed in PCT via Na+/glucose transport
Glucosuria begins at a P (glucose) of 200 mg/dL and at a filtered load of 375 mg/min all transporter get saturated (and no more glucose is reabsorbed)
45
Splay: glucose clearance
concentration difference between maximal renal absorption and concentration in urine
46
Nephron physiology- PCT
Reabsorbs all glucose and AAs (as well as most ions- bicarb, Na+, Cl-, etc)
Generates and secretes ammonia and H+
PTH- acts here to cause increase phosphate (PO4 3-) excretion
Acetazolamide- acts here to inhibit carbonic anhydrase and increase bicarb excretion
Angiotensin II- Stimulate Na+/H+ exchange in low blood volume states (Na+ and HCO3- reabsorbed, H+ excreted)
60-80% Na+ reabsorbed here
47
Thin descending loop of Henle
Passively reabsorbs H2O
48
Thick ascending loop of Henle
reabsorbs Na+, K+, and Cl-
paracellularly absorbs Ca2+ and Mg2+
Loop diuretics act here (and therefore can cause loss of K+, Ca2+, NOT Mg2+)- LOOps LOSE Ca2+
10-20% of Na+ absorbed here
49
Early DCT
reabsorbs Na+ and Cl-
PTH- acts here to increase Ca2+/Na+ exchange to retain Ca2+ and excrete Na+
Thiazides- act here and inhibit Na+/Cl- cotransproter
5-10% of Na+ reabsorbed here
50
Collecting tubule
Reabsorbs Na+ in exchange for secreting K+ and H+
Aldosterone- Acts on MC receptor --> mRNA --> increases ENaC activity
ADH- acts on V2 receptor; inserts aquaporin H2O channels on apical side
3-5% Na+ absorbed
Therefore- diuretics that act here (amiloride, triamterene, and aldosterone antagonists) will be K+ sparing (as they excrete Na+)
51
Renal tubular defects (Fanconi first and all others in alphabetical order)
Fanconi SYNDROME
Bartter syndrome
Gitelman syndrome
Liddle syndrome
SAME- Syndrome of Apparent Mineralocorticoid Excess
52
Fanconi SYNDROME
Fanconi SYNDROME- PCT defect (caused by biochemical hereditary defects, drugs, lead poisoning, etc.)- can cause metabolic acidosis
53
Bartter syndrome
Bartter syndrome- Ascending LOH defect (AR)- (looks like people who use loop diuretics chronically)
54
Gitelman syndrome
Gitelman syndrome- DCT defect (AR)- (looks like people who use thiazides chronically- less severe than Bartter)
55
Liddle syndrome
Liddle syndrome- Gain of function; increased Na+ reabsorption in CT (AD)- looks like hyperaldosteronism, but does aldosterone is nearly undetectable; tx with Amiloride (inhibits ENaCs)
56
SAME- Syndrome of Apparent Mineralocorticoid Excess
SAME: Cortisol tries to be the SAME as aldosterone
Deficiency of 11-B hydroxysteroid dehydrogenase (can be induced by black licorice)
Normally converts cortisol (active) to cortisone (inactive on MR receptors)
Excess cortisol cross-reacts with MR and causes symptoms of hyperaldo
Tx: corticosteroids (suppress endogenous cortisol prodn)
57
RAAS System
Angiotensinogen converted to Angiotensin I by renin
Angiotensin I converted to Angiotensin II by ACE in pulmonary endothelial cells
Angiotensin II causes systemic effects (Increases aldo production in adrenal cortex (glomerulosa), vasoconstricts- vasculature and efferent arteriole of glomerulus, increases ADH secretion by posterior pituitary, increases PCT Na+/H+ activity, stimulates thirst)
58
Renin
Secreted by JG cells
59
ATII
Maintains blood volume and pressure; affects baroreceptor function
60
ANP and BNP
released from atria (ANP) and ventricles of heart (BNP) when increase volume/ stretch is detected
dilates afferent arteriole and constricts efferent to promote filtration/ natriuresis
61
ADH
Regulates osmolarity, responds to low blood volume states
62
Aldosterone
Regulates ECF and Na+ content;
63
Juxtaglomerular apparatus
SECRETE renin in responses to decreased renal blood pressure and increased sympathetic tone (B1)
Beta-blockers: inhibit renin release (by inhibiting N1 receptors of the JGA)
(as opposed to macula densa- which only sense decreased Na+)
64
Macula densa
SENSE decreased NaCl delivery to DCT --> talk to JGA --> increase renin release --> constrict efferent arteriole --> GFR increases, but RPF decreases
65
Kidney endocrine functions
Erythropoietin
Calciferol
Prostaglandins
Dopamine
66
Erythropoietin
Release by interstitial cells in peritubular capillary bed
Stimulate RBC proliferation in bone marrow
Supplemented in CKD
67
Calciferol
PCT- activates Vit D (calcitriol- active form)
| converts 25-OH Vit D3 to 1, 25- (OH)2 Vit D3 via 1 alpha hydroxylase
68
Prostaglandins
Vasodilate the afferent arterioles to increase RBF
69
NSAIDs
Constrict afferent arteriole (may result in acute renal failure)
70
Dopamine
```
Also secreted by the PCT
Promotes natriuresis (increases RBF)
At high doses- vasoconstrictor
```
71
Potassium shifts- out of the cell (HYPERkalemia)
DO LABS
```
Digitalis
hyperOsmolarity
Lysis of cells
Acidosis (H+/K+ "exchanger")
Beta blocker
high blood Sugar (insulin deficiency)
```
72
Potassium shifts- into the cell (HYPOkalemia)
INsulin (shifts K+ INto the cells)
| Opposite of the things above (alkalosis, beta agonist, hypo-osmolarity)
73
Presentation of Hyponatremia
Nausea and malaise, stupor, coma, seizures
74
Presentation of Hyperkalemia
Similar to hypo: stupor, coma, + irritability
75
Presentation of Hypokalemia
U wave, flattened T wave
| Arrhythmias, muscle cramps, spasm, weakness
76
Presentation of Hyperkalemia
Wide QRS, peaked T waves
| Arrhythmias, muscle weakness
77
Presentation of Hypocalcemia
Tetany, seizures, QT prolongation, twitching (Chvostek sign- lip twitches when tapping facial nerve), Trousseau sign- spasm/ curvature of hand with BP cuff, tingling of lips and mouth
78
Presentation of Hypercalcemia
Stones (renal), bones (pain), groans (abdominal pain), thrones (increased urinary frequency), and psychiatric overtones (anxiety, altered mental status)
Do not necessary have increased Ca2+ urinary excretion
79
Presentation of Hypomagnesemia
Tetany, torsades de pointes, hypokalemia
80
Presentation of Hypermagnesemia
Decreased deep tendon reflexes, lethargy, bradycardia, hypotension, cardiac arrest, hypocalcemia
81
Presentation of Hypophosphatemia
Bone loss, osteomalacia (adults), rickets (kids)
82
Presentation of Hyperphosphatemia
Renal stones, metastatic calcifications, and hypocalcemia
83
Henderson-Hasselbach equation
pH = 6.1 + log ([HCO3-]/ .03*P (CO2))
84
Metabolic Acidosis- increased anion gap
Increased anion gap: MUDPILES
```
Methanol (formic acid)
Uremia
DKA
Propylene glycol
Isoniazid and iron supplements
Lactic acidosis
Ethylene glycol (oxalic acid)
Salicylates (late)
```
85
Metabolic Acidosis- normal anion gap
```
Normal anion gap- HARDASS
Hyperalimentation (IV nutrition overdose)
Acetazolaminde
Renal tubular acidosis
Diarrhea
Addison disease
Spironolactone
Saline infusion
```
86
Metabolic Alkalosis
Loop diuretics
Vomiting
Antacids
Hyperaldosteronism
87
Respiratory Acidosis
```
Things that keep CO2 in: hypoventilation
Airway obstruction
Acute and chronic lung disease
Opioids, sedatives
Weakening of muscles
```
88
Respiratory Alkalosis
```
Things that get too much CO2 out: hyperventilation
Hysteria
Hypoxemia
Salicylates (early)
Tumor
Pulmonary embolism
```
89
Renal Tubular Acidosis
```
3 types:
Type I (distal): Too little H+ is being secreted, therefore too much K+ being excreted (hypokalemia)- Urine pH > 5.5
```
Type II: Too little bicarb being absorbed (hypokalemia)- Urine pH < 5.5
Type IV: Hypoaldosteronism --> Na+ wasted and K+ retained (hyperkalemia)- Urine pH < 5.5
90
Casts
Indicate that hematuria/pyuria is of glomerular or renal tubular origin
(Casts will not be present in bladder cancer, kidney stones, cystitis, etc.)
91
RBC casts
GN, malignant HTN
92
WBC casts
Tubulointerstitial inflammation, acute pyelo (bacterial in kidneys), transplant rejection, UTIs (specifically in diabetes)
93
Fatty casts
Nephrotic syndrome
| Associated with maltese cross sign
94
Granular (muddy brown casts)
ATN
95
Waxy casts
End stage renal disease, chronic renal failure
96
Hyaline casts
Aka Tamm-Horsefall mucoprotein
| Non-specific; can be normal
97
Nephritic syndrome
Characterized by:
1. No proteinuria (<3.5 g/day)
2. Azotemia (high levels of nitrogenous compounds)
3. HTN
4. RBC casts in urine (Hematuria)
5. Oliguria
It is an Inflammatory process
98
Nephrotic syndrome
Characterized by:
1. Proteinuria (> 3.5 g/day)
2. Edema
3. Hyperlipidemia
4. Hypoalbuminemia
Hyper coagulability can be seen due to wasting of antithrombin III
99
Kidney stones
Presents with unilateral flank tenderness, colicky pain radiating to groin, and hematuria
100
Stones- calcium
Calcium oxalate (envelope) more common than calcium phosphate (wedge shaped)
Radiopaque on X-ray and CT
Causes: Ethylene glycol ingestion, Vit C abuse, hypocalcitraturia, Malabsorption (Crohns)
Tx: thiazides
101
Stones- Ammonium magnesium phosphate (struvite)
Most common cause of staghorn calculi
Caused by infection from urease + organisms (e.g. Proteus, Staph saprophyticus, Klebsiella)
Radiopaque on X-ray and CT
Tx: Tx underlying infection, surgery to remove stone
102
Stones- Uric acid
About 5% of all stones
Risk factors: decreased urine volume, arid climates, and acidic pH
Rhomboid or rosette shape
Radiolucent on X-ray; visible on ultrasound
Strong association with hyperuricemia (gout), and seen in disease with high cell turnover (leukemia)
Tx: alkalization of urine, allopurinol
103
Stones- Cystine
Cystinuria: Hereditary condition causing defects in absorption of COLA (cysteine, ornithine, lysine, and arginine)
Sodium cyanide nitroprusside test +
Urine crystal is hexagonal in shape (SIXteine stones have SIX sides)
Tx: low sodium diet, alkalization agent if needed, chelation if refractory
104
Hydronephrosis
Distention/ dilation of renal pelvis and calyces
Caused by obstruction (stones, BPH, cancer, ureter injury); vesicoureteral reflux
Raised Cr only seen if bilateral involvement
Can cause atrophy of renal cortex and medulla
105
Renal cell carcinoma (Hypernephroma)
Most common primary tumor of the kidney
RCC associated with VHL (also show hemangioblastoma (brain tumor) and pheochromocytoma)
Originates from PCT cells filled with accumulated lipids and carbs
106
RCC risk factors
Men ages 50-70
Smoking
Obesity
107
RCC- S&S
hematuria, palpable mass, polycythemia, flak pain, fever weight loss
Mets to lung and bone
Often associated with paraneoplastic syndrome (ectopic EPO, ACTH, PTHrP, renin)
108
RCC- Tx
Resection, if localized
Immunotherapy (aldesleukin) or targeted therapy
Often resistant to chemo and radiation
109
Renal oncocytoma
Benign
| Tumor of the epithelial cells- arising from collecting ducts
110
Renal oncocytoma histology
Abundant eosinophils
| No perinuclear clearing (as opposed to RCC)
111
Renal oncocytoma- S&S
Painless hematuria, flank pain, and abdominal mass
112
Renal oncocytoma- Tx
Often resected to exclude malignancy
113
Wilms tumor
Most common renal malignancy of early childhood (2-4yr)
114
Wilms tumor- S&S
Presents with large, palpable, unilateral flank mass and/ or hematuria
115
Wilms tumor- genetics
Associated with mutations of tumor suppressor genes: WT1 and WT2 on chromosome 11
116
Wilms tumor- associated syndrome
1. WAGR: Wilms tumor, Aniridia, Genitourinary malformations, and mental Retardation (WT1 deletion)
2. Denys-Drash: nephrotic syndrome, male pseudohermaphroditism (WT1 mutation)
3. Beckwith-Wiedemann: Wilms tumor, macroglossia, organomegaly, hemihypertrophy (WT2 mutation)
117
Transitional cell carcinoma- S&S
Generally affects urinary tract system (but can also affect calyces, pelvis, ureter, and bladder)
Painless hematuria with NO CASTS
118
Transitional cell carcinoma- risk factors (Pee SAC)
Pee SAC
| ```
Phenacetin
Smoking
Aniline dyes
Cyclophosphamide
and Diabetes
```
119
Squamous cell carcinoma of the bladder pathogenesis
Chronic irritation --> Squamous metaplasia --> dysplasia --> carcinoma
Presents with painless hematuria
120
SCC of the bladder- risk factors
Schistosoma hematobium infection
Chronic cystitis or nephrolithiasis
Smoking
121
Stress incontinence
Weak outlet (urethral hyper mobility or intrinsic sphincter deficiency)- leak with increased abdominal P (STRESS)
Tx: Kegels, weight loss, pessaries
122
Urgency incontinence
Overactive bladder (Detrusor instability)- leak with urge to void immediately
Tx: Kegels, anti-muscarinics (oxybutynin), bladder training (distraction or relaxation techniques)
123
Mixed incontinence
Features of stress and urgency incontinence
124
Overflow incontinence
Incomplete emptying (due to detrusor under activity or outlet obstruction)
Leak with overfilling
Dx: via increased post-void residual urine volume
Tx: catheterization, relieve obstruction (e.g. via alpha blockers for BPH)
125
Urinary tract infection- S&S
Inflammation of bladder
Suprapubic pain, dysuria, urinary frequency, urgency
Systemic sign (fever, chills) generally not present
126
UTI- Risk factors
```
female (short urethra)
sexual intercourse
indwelling catheter
diabetes mellitus
impaired emptying
```
127
UTI- common causes
E.coli (most common)
Staph saprophyticus
Klebsiella
Proteus mirabilis (urine has ammonia scent)
128
UTI- lab findings
+ leukocyte esterase
| + nitrites (indicates gram - infection- specifically E.coli)
129
N. gonorrhea and Chlamydia urethritis presentation
Sterile pyuria and - urine cultures
130
Pyelonephritis
Acute pyelo- neutrophils (affects CORTEX ONLY); presents with fevers, flank pain (CVA tenderness), n/v, chills; WBCs seen in urine
Chronic pyelo- recurrent pyelo (often due to vesicoureteral reflux, neurogenic bladder, or chronically obstructing kidney stones), affects CORTEX and MEDULLA, blunted calyx; tubules can contain eosinophilic casts (resemble thyroid)
131
Xanthogranulomatous pyelonephritis
Characterized by widespread kidney damage due to granulomatous tissue containing foamy macrophages
132
Diffuse cortical necrosis
Cortical infarction of BOTH kidneys
Due to vasospasm and DIC; associated with obstetric catastrophes, septic shock
133
Renal osteodystrophy
Hypocalcemia, hyperphos, and failure of Vit D hydroxylation associated with chronic renal disease
Causes secondary hyperparathyroidism
Low calcium causes subperiosteal thinning of bones
134
Acute kidney injury
Abrupt decline in renal function (increased creatinine and BUN)
135
Prerenal azotemia
Increased BUN/Cr, decreased FENa
Due to decreased RBF; BUN retained to conserve volume but Cr is excreted
Urine osmolality >500
Urine Na+ <20
FENa <1%
Serum BUN/Cr >20
136
Intrinsic renal azotemia
Decreased BUN/Cr, increased FENa
Due to acute tubular necrosis or ischemia/toxins
Urine osmolality <350
Urine Na+ >40
FENa >2%
Serum BUN/Cr <15
137
Postrenal azotemia
Variable BUN/Cr and FENa (more severe if value is higher)
Urine osmolality <350
Urine Na+ >40
FENa >1% (mild); >2% (severe)
Serum BUN/Cr varies
138
Consequence of renal failure- MAD HUNGER
Inability to get rid of nitrogenous wastes can cause:
Metabolic Acidosis
Dyslipidemia (especially higher triglycerides)
Hyperkalemia
Uremia (increased BUN causes cause, pericarditis, asterixis, encephalopathy, platelet dysfunction)
Na+/H2O retention
Growth retardation and developmental delay
Erythropoietin failure (anemia)
Rrenal osteodystrophy
139
Acute interstitial nephritis- the 5 P's
Pyuria (pus in urine) and azotemia after administration of drugs
```
Penicillins and cephalosporins
Pain-free (NSAIDs)
Pee (diuretics) & sulfonamides
Proton pump inhibitors (-prazoles)
RifamPin
```
140
Acute tubular necrosis (ATN)- presentation
Most common cause of AKI in hospitalized patients
Spontaneously resolves
Can see increased FENa (makes sense because this is a intrinsic renal prob)
Can also see muddy brown casts in urine
141
ATN- stages
1. Inciting event
2. Maintenance phase (oliguric): 1-3 wks
3. Recovery phase (polyuric)
142
ATN causes (ischemic and nephrotoxic)
Ischemic vs. Nephrotoxic
Ischemic: secondary to decreased RBF; tubular cells may slough off into tubular lumen; PCT highly susceptible to injury
Nephrotoxic: secondary to toxic substances, crush injury, etc.
143
Renal papillary necrosis- SAAD papa with papillary necrosis
Gross hematuria and proteinuria (sloughing of necrotic renal papillae)
```
SAAD
Sickle cell disease or trait
Acute pyelonephritis
Analgesics (NSAIDs)
Diabetes mellitus
```
144
Renal cyst disorder
1. ADPKD
2. ARPKD
3. Medullary cystic disease
4. Simple vs. complex renal cysts
145
ADPKD- autosomal dominant polycystic kidney disease
Cysts in cortex and medulla
Mutation in PKD1 (more common) or PKD2
Associated with berry aneurysms, mitral valve prolapse, and hepatic cysts
146
ADPKD- tx
ACE inhibitors (for hypertension)
147
ARPKD
Cystic dilation of collecting ducts
Presents in INFANCY
Associated with congenital hepatic fibrosis
Renal failure in utero can lead to Potter sequence
148
ARPKD complications
HTN, progressive renal insufficiency, portal HTN (due to hepatic fibrosis)
149
Medullary cystic disease
Causes tubulointerstitial fibrosis and progressive renal insufficiency with inability to concentrate urine
Medullary cysts are not visualized, but shrunken kidneys are see on US
150
Simple vs. Complex cysts
Simple: filled with ultra filtrate (anechoic)- generally asymptomatic and very common
Complex: separated or have solid components- require removal due to increased risk of RCC
