acute and chronic renal failure Flashcards
1
Q
How should we approach renal disease
A
- Assess cause and severity (duration, UA, GFR)
- Pre/Post renal or intrinsic?
- Duration: acute (hr to d) or chronic (mo to yr)
2
Q
UA should be examined when
A
w/in 1 hr collection
3
Q
what does the dipstick measure
A
specific gravity pH protein Hbg glu ketones bilirubin nitrites leukocyte esterase
4
Q
What dose the UA microscopic exam measure
A
crystals cells casts organisms *the "C's" and org
5
Q
hematuria, RBC casts and mild proteinuria =
A
glomerulonephritis
6
Q
Heavy proteinuria and lipiduria =
A
nephrotic syndrome
7
Q
on a UA, WBC, WBC casts and slight proteinuria suggests
A
interstitial nephritis
8
Q
UA: WBC casts suggests
A
pyelonephritis (usually fever too)
9
Q
UA: pyuria suggests
A
UTI
10
Q
what are the four reasons for proteinuria in the UA
A
- Functional: benign process ie illness/exercise
- Overproduction of filterable plasma pro
- Abnormality in glomerular basement membrane
- Tubular: damaged reabsorption of PT
11
Q
Functional reason for proteinuria indicates
A
benign process such as illness or exercise
12
Q
Bence Jones proteins (MM) found in UA is due to what cause of proteinuria? What follow up test should be done?
A
Bence jones = OVERPRODUCTION of FILTERABLE plasma proteins
*need to do UPEP
13
Q
What does an abnormality in the glomerular basement membrane cause and what associated finding will you normally see
A
BM abnormality causes proteinuria
*see large ALBUMIN spike
14
Q
Damaged reabsorption of PT is a Tubular condition that causes what finding in UA? What does this suggest?
A
UA: proteinuria
*suggests acute tubular necrosis (think drugs or hereditary metabolic disorders)
15
Q
what is the number one reason for renal failure
A
acute tubular necrosis = #1 cause renal failure?? this was my note
16
Q
what often causes acute tubular necrosis
A
drugs or hereditary metabolic disorders
17
Q
false positives for Hematuria may be due to
A
vitamin C, beets, rhubarb (myoglobin, Hbg too?)
18
Q
what percent of cases of Hematuria are due to renal causes
A
10%
19
Q
What is GFR and how do you measure it
A
GFR = index of renal function
*measure by Creatinine clearance: 24 hr collection and plasma Cr on same day
20
Q
with stable renal function, Cr production and excretion should be..?
A
EQUAL
production = excretion with healthy kidney
21
Q
Causes of elevated serum Cr include
A
Ketoacidosis
Drugs: Ceph, ASA, Cimetidine, Bactrum
22
Q
Conditions that decrease serum creatinine include
A
Advanced age
Cachexia
Liver disease
23
Q
Besides GFR, what is another way to assess renal function
A
Urea
*product of liver protein catabolism that is filtered then 50% reabsorbed in nephron
24
Q
what is a normal BUN:Cr ratio
A
10-15:1
25
increased BUN is seen in
*Dehydrration
GI bleed
steroid use
CHF
26
reduced BUN is seen in..
liver disease (liver dz causes low BUN and low Cr)
27
Ultrasound is used to look for what?
1. Hydronephrosis
2. PCKD
3. Kidney size
4. Postvoid bladder residuals
*hydronephrosis and cysts especially
28
IVP is used to look at what?
IVP --> views entire urinary tract
| *requires contrast injection
29
When would you not want to perform an IVP on a pt
if. ..
1. DM, serum Cr >2
2. Chronic Renal Failure, serum Cr>5
3. MM (bence jones proteins already clogging up liver)
30
If you want to look at neoplasms in kidney or retroperitoneal space, what test should you go for
CT
31
CT is good for looking at
renal carcinoma
32
What does MRI look for in regards to Renal conditions
corticomedullary function in...
1. glomerulonephritis
2. hydronephrosis
3. renal vascular occlusion
*MRI is used when CT is contraindicated due to contrast
33
Arteriography and venography are good for looking at
stenotic lesions, aneurysm, renal v thrombosis
34
Unexplained acute renal failure, proteinuria or lesions warrant what type of study?
Percutaneous needle biopsy! tissue is issue
35
Percutaneous needle biopsy is indicated in what conditions
1. unexplained acute renal failure
2. proteinuria
3. lesions
36
Acute vs Chronic renal failure: TIME
acute: hr to d
chronic: m to yr
37
Acute vs Chronic renal failure: CR and BUN
acute: high Cr, normal BUN
Chronic: high Cr, high BUN
38
Acute vs Chronic renal failure: PROTEINURIA
acute: mild proteinuria
chronic: +proteinuria
39
Acute vs Chronic renal failure: PTH
acute: normal PTH
chronic: high PTH, high Ca, high AlkPhos
40
Acute vs Chronic renal failure: CBC
acute: normal CBC
chronic: anemia
41
Acute vs Chronic renal failure: kidney size
acute: normal size kidney
chronic: small kidney
42
Acute vs Chronic renal failure: FLUID OUTPUT
acute: sudden oliguria
chronic: gradual fluid retention
43
Acute vs Chronic renal failure: N/V
acute: acute N/V
chronic: N/V
44
s/sx of ACUTE renal failure include
N/V, Malaise and altered sensorium
* may get pericardial effusion and hear friction rub
* Rales potentially heard if fluid overload
45
What lab values are consistent with acute renal failure
* SUDDEN increase in BUN or CR (usually just Cr)
* Hyperkalemia with peaked T waves
* potentially anemia due to decreased EPO
46
What is the most common cause of acute renal failure
prerenal azotemia
| *due to renal hypoperfusion
47
If hypoperfusion (prerenal azotemia)persists, what is the result
ischemia --> intrinsic renal failure
48
What are reasons for hypoperfusion (causing prerenal azotemia)
1. Decrease in intravascular volume (GI loss, pancreatitis, burns)
2. Change in vascular resistance (sepsis, ACEI, NSAIDS, epi)
3. Low CO (CHF, PE, arrhythmias)
49
what are some reasons for decrease in intravascular volume (related to decreased renal perfusion)
GI loss, pancreatitis, burns
50
What are some reasons for changes in vascular resistance (related to decreased renal perfusion)
Sepsis,
ACEI,
NSAIDS,
Epinephrine
51
What are causes of low CO (related to decreased renal perfusion)
CHF
PE
arrhythmias
52
what is the key to prerenal azotemia
careful assessment of
1. volume status
2. drug usage
3. cardiac function
53
what are lab findings reflective of Prerenal azotemia
UA: volume depleted, tubular casts
High BUN:Cr
Urine Na low in volume depletion
Urine Na high in Acute tubular necrosis**
54
Postrenal Azotemia is what related to renal failure
LEAST common cause (5%) but MOST important bc REVERSIBLE
| *occurs when urinary flow is obstructed
55
What are causes of Postrenal azotemia (urinary flow obstructed)
1. Urethral obstruction
2. Bladder dysfunction
3. Obstruction in both ureters
MEN: BPH*, also anticholinergic drugs (sudafed, antihistamines), stones
56
What are signs/sx of postrenal azotemia
lower abdominal pain or distended bladder
57
what are lab values indicative of postrenal azotemia
High urine osm
Low urine sodium
High BUN:Cr
58
What type of imaging should you do if you suspect Postrenal azotemia
bladder US or cath.. then if these are normal, consider CT or MRI
59
Is postrenal azotemia reversible
yes
60
What percent of renal failure is due to actual INTRINSIC renal failure
50%
| *need to exclude pre/postrenal causes
61
What causes Intrinsic renal failure
there are multiple causes
| *85% due to acute tubular necrosis
62
Acute TUbular Necrosis is responsible for 85% of intrinsic renal failure cases which comprise 50% of renal failure cases. What are the major causes of acute tubular necrosis?
1. Ischemia
| 2. Toxin
63
What are reasons for the ischemia that causes acute tubular necrosis (most common cause of intrinsic renal failure)
ischemia due to
| hypotension, hypoxemia, dehydration, shock, sepsis
64
What are reasons for toxin exposure
| *cause of acute tubular necrosis
EXOGENOUS toxins: aminoglycosides (gentamicin, vancomycin), cephalosporins, cyclosporine (rejected transplant), radiographic contrast (esp in DM)
ENDOGENOUS toxins: Myoglobinuria (crush injury), HyperK+ and hyperphos (cell lysis), hemoglobinuria (hemolytic anemia or transfusion rxn), Bence Jones proteins (MM)
65
How should you treat the hyperK and hyperphos (endogenous toxins in acute tubular necrosis)
```
hydration
urine alkalinization (perhaps a CA inhibitor? - acetazolamide?)
```
66
What are lab findings in acute tubular necrosis (intrinsic renal failure)
brown urine with pigmented granular casts
| *may see hyperK and hyperpho
67
How should you treat acute tubular necrosis
*avoid volume overload and hyperK
= Loop diuretics (Lasix)
= restrict protein
*dialysis if life threatening electrolyte abn, worsening acidosis and no response to diuretic tx
68
what is the prognosis for a pt with acute tubular necrosis
Medical illness: 20-50% mortality
Surgical setting: 70% mortality
*logically, mortality increases with age and additional co-morbidities
69
What is the most common cause of interstitial nephritis?
DRUGS (responsible for 70% of cases)
*PCN, ceph, sulfa, NSAIDS, allopurinol
infection (strep, CMV, histoplasmosis) are also causes of interstitial nephritis
70
what are s/sx of interstitial nephritis
fever, rash, arthralgias
71
A pt comes in with fever, rash, arthralgias and a history of strep infection and PCN use.. you suspect what and what lab results might confirm your ddx?
suspect this pt has INTERSTITIAL NEPHRITIS
Labs: peripheral blood EOSINOPHILIA
UA may show RBC, WBC and WBC casts
*Proteinuria if NSAID induced
72
How should you treat the pt you diagnosed with interstitial nephritis
1. remove offending agent (ie PCN, ceph, sulfonamide, NSAIDS, allopurinol)
2. short term high dose Prednisone
* good prognosis! :)
73
what is the good news you can tell you pt with interstitial nephritis after telling them to stop their meds and start a short term high dose Prednisone
they have a good prognosis!
74
Post infectious glomerulonephritis is associated with what pathogen and what are indications for this condition?
associated with group A beta hemolytic strep (GBS)
* high ASO titer
* cola colored urin
* supportive tx
75
What is the most common form of glomerulonephropathy in the US
IgA nephropathy (deposition of IgA in glomerulus)
76
What population typically do we see IgA nephropathy? what is the typical CC?
Children, young adults
*cc: gross hematuria
may be associated with URI
(note: adults usually have microscopic hematuria)
77
A 10 yr old pt comes in with hx of URI 2 wks ago and has gross asymptomatic hematuria, cola colored urine, RBC casts... You order a serum IgA because you suspect what?.. how do you confirm this dx?
IgA nephropathy glomerulonephritis
renal biopsy needed for confirmation (serum IgA is increased in 50% of pt)
78
what prognosis can you give a pt dx with IgA nephropathy
33% clinical remission
| 40-50% progressive renal insufficiency :(
79
what are causes of membranous nephropathy
1. immune mediated (ie hep B, endocarditis, SLE, thyroiditis, cancer) *may need prednisone or tranplant
2. amyloidosis (primary in kidney, progressise to end stage renal dz in 2-3 yr)
80
In regards to immune mediated membranous nephropathy, if you see signs of nephrotic syndrome, what should you think?
think occult neoplasms of lung, stomach and colon
81
what tx might immune mediated membranous nephropathy need
prednisone or transplant
82
what is the fiver year survival for a pt with membranous nephropathy
<20% five year survival
83
What 2 conditions are responsible over 50% of chronic renal disease, and which is the most common
DM or HTN
| *DM more common
84
What s/sx are consistent with chronic renal disease (*note: DM, HTN most common causes)
- progressive over mo to yr
- uremic fetor (fishy odor on breath bc ^BUN)
- s/sx multi system
85
in any patient with renal failure you should what?
identify and correct all possibly reversible causes
1. UTI
2. HTN
3. CHF
4. toxins
86
In both acute and chronic renal failure, what lab findings do you see
elevated BUN and Cr
87
What is diagnostic for chronic renal failure
ultrasound showing BILATERAL SMALL KIDNEYS is diagnostic for chronic renal failure
88
what are some complications associated with chronic renal failure
* HyperK+: due to endogenous causes (trauma, hemolysis) or exogenous (diet, ACEI, K sparing diuretics)
* Metabolic Acidosis (bc limiting production of NH4
* HTN: salt/ water retention
* CHF: extracellular fluid overload
89
complications of chronic renal failure
hyperK, metabolic acidosis, HTN, CHF
90
how do you treat chronic renal failure
* Restrict: Pro, Na, H20, K
* Dialysis if:
- uremic sx appear,
- fluid overload unresponsive to diuretics,
- refractory hyperK,
- severe metab acidosis
- neuro sx
91
What is nephrotic syndrome
Urine protein >3.5 g/24 hr
albumin <3 g
peripheral edema (usually due to Na retention)
*proteinura, edema, hyperlipidemia
92
What s/sx might you see in additional to gross proteinuria, edema and <3 g albumin in a pt with nephrotic syndrome
* Dyspnea due to pulm edema, pleural effusions or ascites
| * Hyperlipidemia due to increased hepatic production
93
What are pt with nephrotic syndrome frequently associated with having
33% have systemic renal disease (DM, Amyloidosis, SLE)
94
A pt has DM or amyloidosis, they develop nephrotic syndrome.. do you need to biopsy?
there is NO NEED for renal biopsy if DM or amyloidosis is cause of nephrotic syndrome
95
how do you treat nephrotic syndrome
* Mod protein restriction (avoid neg N balance)
* Na restriction, probably thiazide or loop (higher dose if hypoalbumemia)
* anticoagulation tx if serum albumin <2 g
96
if serum albumin is less than 2 g (such as in nephrotic syndrome), what tx is needed and why?
anticoagulation tx due to losses of ATIII, Pro C and Pro S
97
what is the most common cause of end stage renal disease in the US
Diabetic nephropathy!
| Type I DM carries 30-40% chance of nephropathy after 20 yr
98
what should you always check in DM pt
MICROALBUMINURIA
99
in a pt with diabetic nephropathy, what might help slow progression of nephropathy
strict glycemic control and HTN tx
*ACEI used in DM pt may increase GFR initially but with macroalbuminuria, GFR drops
100
What are the types of tubulointerstitial disease and what causes them
1. Acute tubulointerstitial dz: caused by toxins and/or ischemia
2. Chronic Tubulointerstitial disease: caused by *obstructive uropathy, vesicoureteral reflux, analgesics or heavy metals
101
In acute tubulointerstitial dz, what are the primary causes, what will the UA show, and what imaging should you order
Acute tubulointerstitial disease:
caused by toxin exposure or ischemia
*need US, CT and maybe MRI
102
in Chronic tubulointersitial disease, what are the primary causes, which is the most common, and what is associated with that specific cause
Obstructive Uropathy, Vesicoureteral reflux, analgesics, heavy metals
* most common is obstructive uropathy:
- prostatic dz in men
- bilateral ureteral calculi
- cancer of cervix, colon or bladder
103
what is Vesicoureteral reflux and who is it usually seen in?
kids
* urine passing retrograde from bladder to kidney during void due to incompetent vesicoureteral sphincter
* common cause of chronic tubulointerstitial disease
104
how do pt with vesicoureteral reflux usually present
HTN, chronic UTIs
*need US or IVP
remember: vesicoureteral reflux is a common cause of chronic tubulointerstitial disease
105
How do analgesics such as acetaminophen, ASA or NSAIDS (usually OD) cause chronic tubolointerstitial disease? what lab findings are associated and what study should you order
analgesics decrease medullary blood flow --> chronic tubulointerstitial disease
* may see hematuria, mild proteinuria, polyuria or anemia
* do IVP
106
s/sx of chronic tubulointerstitial dz
```
polyuria (bc damage to tubular area causing inability to concentrate urine)
HyperK (distal tubules become aldo resistant)
Hyperchloremic acidosis (reduced ammonia production)
```
107
how should you treat chronic tubulointerstitial dz?
depends on cause
108
what three US sonographic criteria must simple cysts meet to be benign
echo free, sharply demarcated with smooth walls, an enhanced back wall (good transmission)
109
why must you do US or CT in pt found with cysts
to differentiate simple cysts from malignancy, abscess or PCKD
110
how will renal cell carcinoma show on US
it enhances but is lower density than rest of parenchyma (hypodense?)
111
Frequency, prognosis, CC for PCKD is?
PCKD is somewhat common
50% pt have ned stage renal disease by age 60
CC: abdominal or flank pain with hematuria
112
PCKD pt may have hx of..
hx of UTI or stone
| strong family hx and 50% time associated with HTN
113
PE on PCKD will reveal
usually palpable kidneys
114
how do you confirm PCKD dx
US that shows multiple cysts
115
If PCKD pt presents with flank pain, fever and leukocytosis what should you suspect
infection of renal cysts
116
what is MM
malignancy of plasma cells, presence of Bence jones protein in urine
117
what dose MM cause in kidney
tubular toxicity and obstruction by Bence Jones proteins precipitating in tubules (endogenous acute tubular necrosis)
118
What is interesting about the bence jones proteins in MM
bence jones protein is light chain which is not detected in urine dipstick
119
How is sickle cell anemia damaging to kidneys and what is the primary manifestation
sickling of RBC in medulla causes stasis, hemorrhage and papillary infarct
*primary manifestation = proteinuria
120
how does aging after GFR
after 40, GFR starts to decline
* more adverse drug rxn in older population bc:
1. altered volume of distribution
2. altered drug half life
3. altered elimination
