Exam 6 Flashcards
(195 cards)
1
Q
Roles of kidney (3)
A
Eliminate waste
Drug metabolism/excretion
Regulate body fluids
2
Q
3 layers of glomerular capillaries
A
Endothelium (don’t allow blood cells to pass)
Basement membrane (best barrier, allows solute and fluid to pass)
Epithelium (fenestrated foot processes, limit what filters out)
Negative charge to repel large, negatively charged molecules
3
Q
Mesangial cells
A
Structural cells in the glomerulus, don’t participate in filtration
4
Q
Bowman’s space
A
Filtered fluid collects here, the filtrate
5
Q
GFR
A
Filtrate formed per minute by both kidneys combined
Depends on starling forces
6
Q
Cockcroft fault equation
A
(140-age)/Cr, x .9 in a female
7
Q
GFR can also be calculated from…
A
BUN or Cr
8
Q
Main mechanism for modifying GFR?
A
Diameter of afferent and efferent arterioles
9
Q
A positive sodium balance will…
A
Increase ECF volume
Intake>excretion
10
Q
A negative sodium balance will…
A
Decrease ECF volume
Excretion > intake
11
Q
Under normal conditions, almost all Na is…
A
Reabsorbed
12
Q
Proximal convoluted tubule
A
Isosmotic reabsorption of water (and other things)
Most of Na is absorbed here
13
Q
Thin descending limb
A
Water and sodium permeable
14
Q
Thin ascending limb
A
Water impermeable, but sodium permeable
15
Q
Thick ascending limb
A
Water impermeable
Active reabosorbing of sodium
16
Q
Countercurrent multiplication
A
Blood flows through vasa recta in opposite flow of tubule
Bottom of loop concentrates blood
Water diffuses from descending limb back into bloodstream
17
Q
ADH effects on collecting duct
A
Up regulates aquaporin channel insertion, H2O absorption
18
Q
Polyuria, oliguria, anuria
A
Polyuria- >2500
Oliguria- <500
Anuria- <50
19
Q
Hyaline cast
A
Normal OR
Fever, concentrated urine, exercise
20
Q
RBC casts
A
Glomerulonephritis
21
Q
WBC casts
A
Pyelonephritis
Interstitial nephritis
22
Q
Renal tubular cell casts
A
Acute tubular necrosis
Interstitial nephritis
23
Q
Broad waxy casts
A
Chronic kidney disease
24
Q
Serum sodium reference range
A
135-145
25
Serum osmolality reference range
285-295
26
Osmolality equation
2(Na) + glucose/18 + BUN/2.8
27
If spot urine is <10, suggests...
Extrarenal salt loss
Kidneys trying to hold onto all of the salt that they can
28
After determining volume status for hyponatremia, determine...
Osmolality
29
Hypotonic hypovolemic hyponatremia
Extrarenal salt loss
Dehydration from vomiting, diarrhea or sweating
Fluid replaced with hypotonic liquid
Free water retained to maintain intravascular volume
30
Hypotonic hypovolemic hyponatremia
Renal salt loss
Excess excretion of sodium into the urine
Could be diuretics, ACE inhibitors, renal tubular epithelial dz
31
Euvolemic hypotonic hyponatremia
Could be hormonal, like hypothyroid or adrenal insufficiency
Post op
HIV
32
ADH
Secreted from posterior pituitary
Released based on extracellular osm and BP- if >280 then secretion of ADH
**arterial vasoconstriction
33
SIADH
Euvolemic hypotonic hyponatremia
Small cell lung CA one of principal causes
Water retention stimulated natriuresis
34
SIADH presentation
Clinical diagnosis- hyponatremia, decreased Osm, no other diseases, >20 urine sodium
Signs of volume loss rule this out
35
Psychogenic polydipsia causes...
Euvolemic hypotonic hyponatremia
Excess free water intake, excretion of sodium keeps them euvolemic
Eventually the sodium will drop
36
Hypervolemic hypotonic hyponatremia
States of edema, such as...
```
HF
Cirrhosis
Nephrotic syndrome
Hypoalbuminuria
ESRD
```
Increased RAAS and ADH secretion
37
Isotonic hyponatremia
Pseudohyponatremia can result with marked excess of substance that reduces plasma volume in blood like protein or triglycerides
38
Hypertonic hyponatremia
Intracellular water pulled into hypertonic ECF
Mannitol administration or hyperglycemia
Something other than sodium is the osmolalite
39
Emergent hyponatremia and treatment goals
Acute hyponatremia with any symptoms
Rapidly increase serum sodium by 4-6 over several hours
**do not exceed 8-10 in 24 hours
40
Osmotic demyelinating syndrome
Overzealous correction of hyponatremia, reversible if caught early and sodium re-lowered
Mexican hat sign on CT
41
If acute, hyperacute or severe with sx, treatment...
IV hypertonic saline
Watch rate of rise
42
Nonemergent, chronic with minimal sx treatment...
Fluid restriction
43
Hypernatremics all have...
Hyperosmolality
44
Causes of hypernatremia
Free water loops
| Iatrogenic
45
Manifestations of hypernatremia
Dehydration, tachycardia, tenting
Neuro symptoms, variable and not very different than hyponatremia
46
Hyperaldosteronism
Causes hypertension
Generally mild, sometimes hypokalemia
47
Osmolar diuresis
Diuresis due to nonabsorbed, nonelectrolyte solute (like mannitol, glucose and urea)
Water loss in excess of sodium loss
48
If urine osmolality is <250, suggests...
Diabetes insipidus
Dilute or low specific gravity
49
Diabetes insipidus
ADH deficiency or resistance
Not released with increasing Osm
Polydipsia, polyuria, hypernatremia
50
Central DI
Primary- autoimmune, genetic
Secondary- hypophyseal damage
51
Nephrogenic DI
Acquired ADH resistance
Variety of reasons
52
DI workup
24 hour urine volume and Cr
Desmopressin challenge- central DI patients will have reduced thirst and urination, but no change if nephrogenic
53
Potassium main driver of...
Cells and sets resting potential for excitable cells
Mostly inside cells
54
Insulin and sodium/potassium ATPase function
Pushes potassium into cells, can cause hypokalemia
55
Metabolic acidosis and potassium
Hyperkalemia
In an acidotic state, protons outside of the cell need to go inside, and the antiporter pushes potassium out of cells
56
Potassium mainly absorbed in...
Proximal convoluted tubule
57
Potassium secretion in the kidney
Largely in distal tubule
Insulin pushes K into cells and causes excretion
Aldosterone causes K excretion
58
Hypokalemia and excitability
Hyperpolarization, tougher to trigger action potential
59
Hyperkalemia and excitability
Depolarization, easier to trigger action potential
60
Hypokalemia general causes
Increased entry into cells
Increased GI losses
Increases urinary losses
Increased sweat loss
Dialysis
Plasmapheresis
61
Trauma and epinephrine will cause...
Hypokalemia
62
Magnesium deficiency
Must be considered in refractory hypokalemia!!
Mg inhibits K secretion, so decreased Mg allows greater K secretion
63
Hypokalemia and HTN?
Aldosterone excess
64
Severe hypokalemia symptoms
Paralysis
Decreased DTR
Tetany
Rhabdo
65
Hypokalemia EKG changes
Flattened and broadened T waves
U waves
PVTs
ST depression
66
Hyperkalemia
Rare
Generally not from increase intake, but an inability to excrete in the urine
67
Hyperkalemia a few causes
Catabolism of tissue (rhabdo)
Beta blockers
Hypoaldosteronism
68
Drugs that cause hyperkalemia
K sparing diuretics
ACEI/ARBs
Trimethoprim
Digitalis toxicity
69
Hyperkalemia EKG changes
Peaked T waves
Wide QRS
Vfib, cardiac arrest
70
Acute kidney injury definition
Abrupt loss of kidney function causing retention of urea and nitrogenous waste
Dysrregulation of extracellular volume and electrolytes
71
How is AKI determined?
By serum Cr, GFR and urine output
72
KDIGO criteria of AKI
Serum Cr increase of >.3 in 48 hours
Serum Cr increase of >1.5x baseline within prior 7 days
Urine volume 6 hours
73
AKI signs and symptoms
Uremia causes symptoms, like NV, malaise, abdominal pain
Signs- HTN, hypo or hypervolemia, electrolyte imbalances
74
If prerenal AKI, BUN:Cr is...
If ATN AKI, BUN:Cr is...
>20:1
Normal
75
If ATN AKI, micro UA shows...
Muddy brown granular and epithelial cell casts
76
If prerenal AKI, fractional excretion of sodium is...
Low, <1%
77
If ATN causes AKI, fractional excretion of sodium is...
High, >2-3%
78
Urine osmolality in AKI with prerenal versus ATN
Prerenal is >500
ATN is <450
79
AKI lab findings (random)
```
Hyperkalemia
Hyperphosphatemia
Hyperuricemia
Hypocalcemia
Anemia
Metabolic acidosis (lost the ability to buffer)
```
80
AKI imaging
Should all (with unknown etiology) undergo imaging
Renal US, helical CT for stones
81
Most common cause of AKI?
Prerenal!
Hypovolemic, decreased CO, CHF, liver failure, impaired renal autoregulation
82
Prerenal AKI is caused by...
Renal hypoperfusion
Volume depletion, changes in vascular resistance, low cardiac output
Can result in ischemia and intrinsic injury
83
NSAID effect on afferent arteriole
Blocks the dilation of the afferent arteriole in response to decrease of renal blood flow
84
ACEI/ARB effect on efferent arteriole
Blocks the constriction in response to decreased renal blood flow
85
Prerenal AKI labs
BUN:Cr >20:1
Low fractional excretion of sodium
86
Prerenal AKI traetment options
Maintain euvolemic
Monitor potassium
Treat underlying cause
87
Post renal AKI is most commonly...
Obstructive
BPH in men
Urinary flow blocked causing increase in intraluminal pressure, parenchyma damage
Least common
88
Anticholinergic drugs and neurogenic bladder cause...
Postrenal AKI
89
Postrenal AKI signs/symptoms
Abdominal pain
Anuria/polyuria
Azotemia
Enlarged prostate
Distended bladder
Mass on pelvic exam
90
Later labs of postrenal AKI
Increase fractional urine excretion
| Isosthenuria
91
Isosthenuria
Same osmolality in the urine and the plasma because the kidneys are not concentrating/diluting the urine properly
Seen in postrenal AKI
92
Eval of postrenal AKI
Bladder cath/US
CT or MRI
Avoid volume depletion !
93
Two major causes of acute tubular necrosis
Ischemia (prolonged HOTN or hypoxemia)
Neophrotoxin exposure (endogenous or exogenous)
94
Can't use contrast die if the Cr >....
1.4
95
Endogenous nephrotoxins
Heme products, uric acid, paraproteins
Myoglobinuria, Hb, hyperuricemia, bence jones in multiple myeloma
96
Rhabdo general
Necrotic muscle releases large amounts of myoglobin which is freely filtered across the golmerulus
97
Rhabdo causes injury to...
Renal tubules- direct damage from reabsorption of myoglobin
Distal tubular obstruction from casts and intrarenal vasoconstriction
98
Rhabdo signs/symptoms
Muscular pain
Serum CK >20,000-50,000
Dark brown urine
99
Rhabdo treatment
Volume repletion
Mannitol
100
Acute tubular necrosis labs
BUN:Cr <20:1
Hyperkalemia
Hyperphosphatemia
Hypermagnesemia
101
Urine in acute tubular necrosis
Urine sodium concentration >20
| Muddy brown, granular renal tubular casts
102
Avoid volume overload and hyperkalemia in acute tubular necrosis treatment
Loop diuretics
| Thiazide diuretics
103
Interstitial nephritis general
Interstitial inflammatory response with edema and tubular cell damage
Cell mediated immune reactions with T lymphocytes
104
Interstitial nephritis etiologies
Usually drugs (even NSAIDs and PPIs)
Could be infectious or immunologic
105
Clinical findings of interstitial nephritis
Fever
Rash
Arthralgias
Eosinophilia
106
Urine in interstitial nephritis
RBCs in urine almost always, WBC and white cells casts
Proteinuria
Eosinophiluria
107
Renal artery stenosis causes
Atherosclerosis almost always (especially if older than 45)
Fibromuscular dysplasia (women <40 with unexplained HTN)
108
RAS clinical findings
```
HTN at <30 years old
Severe or stage 2 HTN after 55 years old
Resistant HTN
Acute rise in BP
Bruits
```
109
What happens in a patient with RAS that is given an ACEI or ARB?
Acute increase of serum Cr at least 30%
Prevents constriction of efferent arteriole, the blood flow to the kidney is already decreased so GFR decreases
110
RAS imaging
Renal angiography is the gold standard
Beads on a string for fibromuscular dysplasia
CT angiography highly accurate for atherosclerosis but not as much for fibromuscular dysplasia
111
RAS treatment
Angioplasty (with or without stenting)
Surgical bypass
112
Renal tubular acidosis general
Syndrome due to defect in proximal tubule bicarb reabsorption, or defect in distal tubule hydrogen ion secretion (or both)
Results in: hyperchloremic metabolic acidosis with normal to moderately decreased GFR
113
Anion gap in RTA is...
Normal
Bicarb decreases, but chloride increases
114
Type 1 RTA
Distal RTA
Defective H secretion
Can't acidify urine, renal sodium wasting
Hypokalemia
115
Type 2 RTA
Proximal
Defective bicarb reabsorption
Inappropriately high urine pH, bicarb replaced in circulation by chloride so hyperchloremic
Hypokalemia
116
CKD definition
Presence of kidney damage OR decreased kidney function (GFR <60) for 3 or more months regardless of cause
117
CKD signs/symptoms
Develop slowly, nonspecific
| Uremic syndrome in ESRD
118
Labs in CKD
```
Anemia
Hyperkalemia
Hyperphosphatemia
Hypocalcemia
Metabolic acidosis
```
119
Urine in CKD
Broad, waxy casts
Isosthenuria
Proteinuria
120
CKD imaging
Ultrasound
If small, CKD because they are scarred down
If normal or large, could have nephropathy, adult PCKD, etc
121
Hemodialysis
Constant flow of patient's blood along side of semipermeable membrane with a cleansing solution along the other
Diffusion and removal of unwanted substances in blood while adding back necessary o nes
122
HD types
Arteriovenous fistula (preferred)- takes 6 to 8 weeks to mature, lasts longer than graft
Prosthetic graft
**time consuming
123
Peritoneal dialysis
Peritoneal membrane is the dialyzer
Could be continuous ambulatory (4-6 x a day manually) or automated peritoneal dialysis (automatically performs exchange, usually at night)
124
BP traetment goal in CKD patient
<130/80 with protein in urine
<140/90 with no protein in urine
125
Treatment goal for urinary protein excretion in CKD
<1000 mg/d proteinuria
126
Life expectancy of those undergoing dialysis
3-5 years
127
CVD complications of CKD
80-90% of patients die of CVD before reaching dialysis
Electrolytes, oxidative stress, etc cause death
HTN is the main issue
128
HTN of CKD
Most common complication
Salt and water retention with a high renin state
ACEI and ARBS
129
CHF in CKD
CKD increases cardiac workload from HTN, volume overload, anemia and atherosclerosis
Can cause cardiorenal syndrome
130
Pericarditis in CKD
Rare in uremic patients
Fever, chest pain, friction rub
131
Mineral metabolism in CKD
Disturbances of PTH, Ca and Ph metabolism, active vitamin D
132
Minerals in CKD issues
Bone disease
Increased fracture risk
Vascular calcification
133
Renal osteodystrophy
Advanced CKD
Osteitis fibrosa cystica- most common
Bony pain, muscle weakness, fracture risk
134
Anemia in CKD
Decreased EPO production
Fe deficiency
135
Coagulopathy in CKD
Platelet dysfunction
Mildly decreased platelet count and prolonged bleeding time f
136
Hyperkalemia in CKD
Stage 5,but earlier in type 4 RTA, acidemic state, cellular dystruction
*EKG monitoring
137
Acid base in CKD
Metabolic acidosis due to retention of H ions
138
Uremic encephalopathy in CKD
Develops with GFR <5-10
Nystagmus, weakness, asterixis, hyperreflexia, coma, lethargy
139
Neuropathy in CKD
Stocking glove
Isolated or multiple isolated
Autonomic dysfunction
140
Endocrine in CKD
Diabetics at increased risk of hypoglycemia
Lactic acidosis risk with metformin and GR <60
Women: anovulation, pregnancy can exacerbate CKD, fetal mortality with ESRD
141
Nephritic syndrome general
Inflammatory injury or cell proliferation
Acute kidney injury
142
Nephritic syndrome presentation
Hematuria
Proteinuria 1-3 g/d
HTN
Edema
143
Gold standard for glomerular disorders ?
Kidney biopsy!
144
More common in nephritic versus nephrotic?
Increased sediment
RBC
RBC casts
145
Rapidly progressive glomerulonephritis general
Severe inflammatory, weeks to months
**crescents within bowman's capsule that develop
146
Post infectious glomerulonephritis commonly caused by...
Strep, staph skin infections
GABHS
Some viral, fungal and parasitic
147
Presentation of postinfectious GN
1-3 weeks post infection
Common in young kids 2-10
Edema, Coca Cola colored urine
HTN
148
Post infectious GN labs
ASO antibodies
RBC and RBC casts
<3 G protein
149
Post infectious GN biopsy
Large and dense humps
| Lumpy bumpy or starry sky pattern
150
IgA nephropathy general
IgA immune complexes deposit in the mesangium
Most common glomerulonephritis in the US
151
IgA nephropathy presentation
Children and young adults
Associated with other infection, like URI, viral illness
*gross hematuria and dark Coca Cola colored urine 1-2 days after onset of infection
152
Indicator of poor prognosis in IgA nephropathy?
Proteinuria >1g/d
153
Essential diagnostic to IgA nephropathy
Immunofluorescene microscopy, has both IgA and C3
154
Henoch schonlein purpura general
Small vessel vasculitis, IgA deposition in vessel walls
Young males
155
Henoch presentation
Inciting infection
Palpable purpura
Arthralgia
Abdominal symptoms
HTN
156
Pauci-immune glomerulonephritis genearl
ANCA associated small vessel vasculitides, has inciting infections:
Granulomatosis with polyangiitis
Churg- Strauss
Microscopic polyagiitis
157
Pauci-immune glomerulonephritis presentation
Fever, malaise and weight loss prodrome
Hematuria, proteinuria
Purpura
Mononeuritus
158
Granulomatosis with polyangiitis
Sinusitis, lower respiratory tract
Can result in hemoptysis
159
Pauci-immune GN diagnostics
ANCA subtyping
Necrosis and crescents
160
Pauci-immune GN prognosis
Very poor without treatment
161
Anti GBM GN general
Renal disease or combined with pulmonary hemorrhage to be Goodpasture syndrome
Autoimmune response against GBM, cross reacts with pulmonary alveolar capillary basement membranes
162
Anti GBM GN presentation
Hemoptysis, dyspnea, respiratory failure maybe
Often after URI
Hematuria, HTN, edema
163
Anti GBM GN biopsy
Crescents
Ribbon like on immunofluorescence
164
Cryoglobulin associated GN general
Vasculitis associated with cold precipitable immunoglobulins
HCV common underlying infection
GN develops from precipitation of cryoglobulins in glomerular capillaries
165
Cryoglobulin associated GN presentation
Purpuric and necrotizing skin lesions
Fever
Arthralgias
HSM
166
Membranoproliferative GN
Nephritic along the entire spectrum, can also be nephrotic
Two types, type 1 more common
Immune complex deposition
167
Membranoproliferative GN biopsy
Treat track appearance from double contours of GBM
Mesangial hypercellularity
168
Difference in type 1 and type 2 membranoproliferative GN on electron microscopy
Type 1- subendothelial and eubepithelial deposits
Type 2- dense deposit disease, dense ribbons of C3 deposits
169
Most common cause of nephrotic spectrum glomerular disease
Diabetes!
170
Nephrotic spectrum general
Heavy proteinuria, >3 g/d
Edema, peripheral and generalized
Dyspnea
Hyperlipidemia
Hypoalbuminemia
171
Minimal change disease general
Most common cause of proteinuric kidney disease in kids
Follows URI, tumor, etc.
172
Minimal change disease presentation and diagnosis (biopsy)
Nephrotic syndrome
Diffuse obliteration of epithelial cell foot processes, but not specific for minimal change disease
173
Membranous nephropathy (glomerulopathy) genearl
Most common cause of primary nephrotic syndrome in adults
50% progress to ESRD in 3-10 years
Immune mediated, accumulation of immune complexes in subepithelial zone
174
Membranous nephropathy presentation
DVT is a common initial sign or renal vein thrombosis
175
Renal biopsy for membranous nephropathy
Spike and dome pattern
176
Focal segmental glomerulosclerosis general
Damage to podocytes
Chronic inciting issue
177
FSGS biopsy
Sclerosis of some glomeruli
Fusions of epithelial foot processes
178
Diabetic nephropathy general
Most common cause of ESRD in US
Initially increased GFR, then decreased when macro-albuminuria
179
Renal amyloidosis general
Extracellular deposits of amyloid within the glomeruli (abnormally folded protein)
Secondary- from chronic inflammation
180
Renal amyloidosis biopsy
Amyloid stains apple green with Congo red stain
Destruction of foot process
181
HIV associated nephropathy
Collapsing pattern of focal sclerosis
Advanced HIV/AIDs patients
May have low CD4
182
Simple renal cysts
Incidental finding on US or CT
Don't lead to renal impairment
Periodic imaging, refer to urology
183
Autosomal dominant polycystic kidney disease general facts
Often silent, half not diagnosed
50% develop ESRD by age 60
Genetic- systemic disease
184
AD PKD pathology
Abnormal variants in proteins, affect structure of tissue
Leads to leakage and cyst formation
185
AD PKD presentation
```
Flank pain
Hematuria
Proteinuria
Nephrolithiasis
HTN
```
Palpable kidneys on exam
186
Complications of PKD
```
Pain
Hematuria (recurrent bleeding in men >50 consider RCC)
Renal infection
Hypertension
Cerebral aneurysm in circle of Willis
Heart disease
```
187
Medullary sponge kidney general
Common and benign, autosomal dominant
Swiss cheese appearance from medullary cysts
188
Medullary sponge kidney presentation
Hematuria
Neprhocalcinosis
Decreased urinary concentration
189
Wilms tumor general
Most common malignant renal tumor of childhood
Painless abdominal mass id'd by parents
190
What is the first line imaging for the kidney?
Ultrasound
191
Renal cell carcinoma general
6th decade of life
Smoking contributes
192
RCC presents with..
Hematuria
Flank pain
Abdominal mass
193
Labs and imaging for RCC
increased EPO or anemia, hypercalcemia
Solid renal lesion is RCC until proven otherwise
CXR, may see cannonball mets
194
What determines the stages for RCC?
Tumor size and degree of extension
195
Main difference in I and II versus III and IV
3 and 4 have thickened walls, smooth or irregular with enhanced septa
