Nephrology Flashcards

1
Q

What is the definition of acute kidney injury?

A
  1. Abrupt loss of kidney function
  2. Retention of urea and other nitrogenous waste products.
  3. Dysregulation of extracellular volume and electrolytes
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2
Q

What is creatinine?

A

Creatinine is a product of creatinine phosphate in muscle.

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3
Q

What is creatinine used for with regard to kidney function?

A

Creatinine is filtered by the kidney’s and used to estimate kidney function and filtration.

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4
Q

If the creatinine is high what does that mean for kidney function?

A

The higher the creatinine the lower the filtration

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5
Q

What is BUN

A
  1. BUN is urea nitrogen formed from protein metabolism by the liver.
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6
Q

Where is BUN filtered?

A

BUN is filtered by the kidneys and is used as an additional measure of kidney function

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7
Q

If the BUN is high what does that mean about kidney filtration?

A

The higher the BUN the lower the filtration

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8
Q

What are some factors that cause BUN to increase independent of kidney function?

A
  1. Steroids
  2. Tetracycline antibiotics
  3. Reabsorption of blood from GI tract
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9
Q

What is Oliguria?

A
  1. Oliguria is urine output <500 ml/24 hours
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10
Q

What is anuria

A

Less than 100 ml of urine output in 24 hours

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11
Q

Stage this AKI:
Increase in Cr >0.3 mg/dl or 1.5-2 times from baseline
urine output <0.5 ml/kg/h for > 6 h

A
  1. Stage 1
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12
Q

Stage this AKI:
Creatine 2-3 times from baseline
<05.ml.kg/h for > 12 h

A
  1. Stage 2 AKi
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13
Q

What stage of AKI is the following:
Creatine 3-4 times from baseline >4 mg/dl with acute increase >0.5 mg/dl
<0.5 ml.kg/hr for 24 hours or anuria for 12 hours

A
  1. Stage 3 AKI
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14
Q

Pre-renal kidney injury results from:

A
  1. Volume depletion

2. Decreased effective arterial blood pressure

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15
Q

Intrinsic renal injury/failure can be a result of?

A
  1. Tubointersitial disease
  2. Acute tubular necrosis
  3. Acute interstitial nephritis
  4. Acute tubular obstruction
  5. Vascular disease
  6. Glomerular disease
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16
Q

Post renal AKI can be the result of?

A
  1. Urinary obstruction
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17
Q

Name the three categories of AKI:

A
  1. Pre-renal
  2. Intrinsic renal
  3. post renal
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18
Q

Which of the following patients would be diagnosed with stage II acute kidney injury?

A

Patient A: Weight: 100 kg (220.5 lb). Creatine level increased from 1.1–2.3 mg/dL. Total urine output over 14 hours: 600 mL.

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19
Q

Which patient most likely has prerenal acute kidney injury?

A

Patient C presents to the emergency department after a motor vehicle collision. Surgery is performed for splenic laceration, with an estimated blood loss of 1,500 mL. On postoperative day 1, the patient has newly elevated creatinine and BUN levels

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20
Q

What is true volume depletion?

A

Loss of Na+ from the extracellular fluid.

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21
Q

The total ECF may be increased but arterial blood volume perceived by baroreceptors in the carotid sinus and glomerular afferent arterioles is low related to edematous states which are:

A
  1. Heart failure
  2. Hepatic cirrhosis
  3. Sepsis
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22
Q

Which of the following would decrease the glomerular filtration rate?

A
  1. Action of a prostaglandin antagonist at the afferent arteriole of the glomerulus
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23
Q

What does the diagnostic work up for pre-renal AKI consist of?

A
  1. BUN Creatinine >20:1 (normal is 10:1)
  2. Urine osmolality >500 mosm/kg
  3. Urine Na+ <10 mcg/l urine CL < 10 mcg/l
  4. Urinalysis high specific gravity, no protein, blood or white cells,
  5. Sediment review bland- no cast, no cells
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24
Q

Why do nephrologist use FENa?

A

FENa measures the percent of filtered Na+ excreted in the urine and is used to differentiate between pre-renal and acute tubular necrosis

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25
A FENa of less than 1% means
1. The patient will most likely respond to volume replacement
26
Patients with pre-renal disease who are volume depleted how are they treated to restore volume?
1. A Isotonic solution 2. Normal Saline 3. Lactated Ringers
27
Patients who are volume depleted and have heart failure how are they treated to restore kidney function
1. Diuretics 2. Vasodilators 3. Inotropes
28
Patients who are volume depleted with liver failure are treated with what to restore volume and kidney function?
1. Albumin 2. Norepinephrine 3. Midodrine
29
Patients who are septic and volume depleted are treated with what to restore their kidney function?
1. Crystalloid antibiotics | 2. Vasopressor support
30
Which of the following best describes prerenal acute kidney injury?
BUN: Cr ratio: 25:1; urine osmolality: 525 mOsm/kg; urine Na+: 9 mEq/L; urine Cl-: 8 mEq/L; UA: sediment without casts or cells
31
What effect can radiocontrast have on kidney function?
Acute tubular necrosis causing intrinsic renal disease
32
What is the most common cause of kidney injury with a 4-5 increase in mortality?
Acute tubular necrosis
33
What are risk factors for Acute tubular necrosis?
1. Volume depletion 2. underlying CKD 3. use of NSAIDs 4. DM
34
What occurs during tubular necrosis?
1. Endothelial and epithelial cell injury 2. Intratubular obstruction 3. changes in microvascular blood flow 4. Immunological factors
35
Patients with tubular injury often become anuric true or false?
True
36
What is the process of activation of tubuloglomerular feedback?
1. Tubular rate flow changes 2. Alteration of GFR 3. Oliguria 4, Decrease in reabsorption of NaCl, TAL of LOH 5. Increase in NaCl sensed by macula densa 6. Release of adenosine 7. less ATP required for fluid reabsorption
37
Causes of acute tubular necrosis?
1. Ischemia -acute drop in mean arterial pressure 2. prolonged volume depletion 3. Sepsis
38
Why do clinicians need to know a patients serum Cr before administering contrast?
1. Contrast can cause Acute tubular necrosis
39
What medications are toxic to the kidney
1. Aminoglycosides 2. Amphotericin B 3. Cisplatin
40
Tubular necrosis can also be caused by injury, what type of injuries can cause acute tubular necrosis?
1. Rhabdomyolysis 2. Crushing injury 3. Burn 4. Skeletal injury
41
Changes in NaCL concentration due to renal tubular injury are detected in which area of the nephron?
Macula densa
42
A patient is found to have an elevated serum creatinine level following a complicated femur fracture repair associated with severe blood loss. What is the most likely cause of the acute kidney injury?
Ischemic renal tubular necrosis
43
A patient presents to the emergency department after a marathon complaining of significant muscle pain and 'bloody' urine. What is the most likely cause of the urine color change?
Heme pigment
44
What does a Acute Tubular Necrosis workup consist of?
1. Prolonged periods of hypotension 2. Exposure to contrast 3. Sepsis 4. Medications 5. Crush injury 6. Rhabdomyolysis
45
What is the Bun/Cr in acute tubular necrosis
1. Bun/Creatinine is 10-15:1
46
Will the urine Na and Cl levels be low or high with acute tubular necrosis?
High because they're not being reabsorbed
47
What will the FEna level be with tubular acid necrosis
>2%
48
During workup of tubular necrosis what will a urinalysis show?
Isosthenuric specific gravity ~1.01 due to loss of concentrating ability • Urine osmolality < 450 mOsm/kg
49
Why will patients have low grade proteinuria in a tubular necrosis work up?
• May have low grade proteinuria • ~ < 500 mg 1g per 24 h • Due to impaired reabsorption of protein at the proximal tubule
50
During work up for acute tubular necrosis what will urine sediment show?
Urine sediment • Pigmented granular casts or free floating tubular epithelial cells
51
What is the clinical course of Acute Tubular Necrosis?
1. Initiation phase 2. Maintenance phase-Cr plateaus around 7-10 days 3. Recovery phase- excess solutes and water are excreted as tubules under goes repair Marks the poly-uric phase (10-14) >3 L of urine output in 24 hours Recovery usually occurs between days 14-21
52
What patients are at risk for Acute tubular necrosis
1. Major surgery | 2. Comorbid conditions, cancer, heart failure, malnourished, CKD
53
What are things that can be done to decrease the risk of ATN
1. optimize volume 2. avoid nephrotoxic medications 3. contrast induced nephrotoxicity- Volume status optimized, volume expand with crystalloids NS Minimize amount of contrast
54
Which of the following would you expect to see on urine microscopy in a patient with acute tubular necrosis?
Pigmented granular cast
55
A man fell and broke his hip during the night and was not able to access his phone to call for help until the morning. He was noted to have dark urine with an FeNa concentration of >2% on admission, and he reported generalized pain in the hip region. Which of the following is most likely present?
Intrinsic renal disease
56
A woman is admitted for sepsis related to a urinary tract infection and is found to have acute tubular necrosis. Fourteen days after discharge, she is complaining of significant urine output of more than 3 L a day. What is the most likely cause of this polyuria?
Recovery of kidney function after the accumulation of solutes during intrinsic kidney disease
57
What is allergic interstitial nephritis?
Acute interstitial nephritis is an inflammatory cell infiltration in the kidney interstitium caused by an immune response
58
Acute/allergic interstitial nephritis would most likely show which of the following on urinalysis?
White blood cell cast
59
Medications that cause acute interstitial nephritis?
1. NSAIDS 2. PCN's 3. Cephalosporins 4. Sulfonamides 5. Rifampin 6. Cipro 7. PPI
60
Acute interstitial nephritis can be related to autoimmune diseases like:
1. Sjogren's syndrome | 2. Sarcoidosis
61
Infections can also cause acute interstitial nephritis such as:
1. Legionella leptospira | 2. CMV
62
Clinical presentation of patients with AIN:
1. Onset 3-5 days after a 2nd exposure Rash Fever Eosinophilia
63
Laboratory workup for patients with acute interstitial nephritis will present as the following:
1. Acute rise in serum Cr, related to drug administration 2. Peripheral eosinophilia 3. Proteinuria typically <1000 mg/day 4. Urine sediment-WBC's, WBC cast 5. Renal biopsy needed for definitive diagnosis
64
How is allergic intersititual nephritis treated?
1. Remove offending drug | 2. Short course of steroids may be indicated
65
A patient presents with fever, eosinophilia, elevated creatinine, and proteinuria after starting penicillin for a Streptococcus infection. Which type of acute kidney injury is most likely?
1.Acute interstitial nephritis
66
Which of the following is most consistent with acute interstitial nephritis?
An increase in serum creatinine after drug administration and white blood cell casts on urinalysis
67
Which of the following is recommended for the treatment of interstitial nephritis if discontinuing the offending drug does not resolve the kidney injury?
Steroids
68
Acute tubular obstruction can be caused by what?
1. uric acid | 2. tumor lysis-tumor liquifies
69
Why are patients oliguric with Acute tubular obstruction?
1. There is acute obstruction
70
Which of the following would be expected in tumor lysis syndrome?
Elevated uric acid levels
71
What causes of acute tubular obstruction?
1. Protein 2. urate 3. calcium phosphate 4. intratubular occurs in the setting of volume depletion and acidic urine
72
Why does multiple myeloma cause tubular obstruction?
1. plasma cell dyscrasia/malignancy | 2. overproduction of immunoglobulin light chains are produced and filtered into the urine.
73
What causes tumor lysis syndrome?
1. occurs after chemo 2. large tumor burden 3. intracellular release of uric acid phosphate, potassium 4. bowel prep with phosphorus 5. IV medications acyclovir 6. methotrexate 7. sulfonamides
74
What does a diagnostic w/u of acute tubular obstruction look like:
1. History 2. Malignancy 3. recent use of enema's oral sodium phosphorus laxatives 4. medications
75
What would lab work look like for tubular obstruction?
1. elevated free immunoglobulin light chains with serum | 2. serum protein electrophoresis with serum immunofixation
76
With tumor lysis syndrome what will the uric acid and phosphorus levels in serum look like?
1. high uric acid 2. phosphorus 3. potassium levels in seum
77
Acute tubular obstruction phosphate nephropathy what will the phosphorus and low calcium levels be?
1. ↑phosphorus | 2. ↓ calcium
78
What would a urinalysis reveal during a acute tubular obstruction work up?
1. Intratubular crystal precipitation from medications | 2. urine sediment will show crystals from precipitated medication
79
Cast nephropathy is treated how?
1. Chemo agents a. dexamethasone b. proteasomal inhibitor based regimen
80
How is tumor lysis syndrome treated?
1. Isotonic fluids and uric acid lowering agents (allopurinol or rasburicase)
81
Which of the following is NOT an expected cause of acute tubular obstruction?
Cellular debris from necrosis
82
Which of the following may cause calcium phosphate crystal deposition in the renal tubules?
Bowel prep for colonoscopy
83
What lab value would suggest cast nephropathy of the renal tubules related to multiple myeloma?
Elevated immunoglobulin light chains
84
Which of the following is the most appropriate treatment for tumor lysis syndrome-induced renal tubular obstruction?
Saline with allopurinol
85
What causes livedo reticularis?
Is a lace like purplish skin discoloration and is caused by a disturbance in the blood flow to the skin
86
What are causes of Renal Atheroembolic Disease?
1. Cholesterol emboli 2. Patients with atherosclerotic disease following manipulation of the aorta or large arteries 3. Coronary angiography and percutaneous coronary intervention 4. Aortic manipulation 5. Renal artery angioplasty/stent placement 6. Cholesterol plaque after manipulation
87
Serum cr after a procedure will rise how?
1. between 2-8 weeks slow rise after procedure or manipulation
88
When a patient has contrast the serum Cr levels will rise within?
72 hours
89
What is vaculitis?
1. Inflammation and necrosis of small arteries and arterioles A. Polyarteritis nodosa B. Granulomatosis with polyangiitis C. Microscopic polyangiitis
90
What are causes of thrombotic microangiopathies?
1. Endothelial injury with formation of platelet occluding small vessels 2. low platelets A. thrombotic thrombocytopenic B. Shiga toxic-mediated hemolytic uremic syndrome C. Complement mediated TMA D. Drug induced TMA E. Malignant HTN
91
Which of the following causes obstruction in atheroembolic renal disease?
Cholesterol emboli
92
Which of the following vasculitides is associated with hepatitis B?
Polyarteritis nodosa
93
A young boy eats an undercooked hamburger at a barbecue and later develops diarrhea and bloody urine. Which of the following is most likely related to these symptoms?
Shiga toxin-mediated hemolytic uremic syndrome
94
What does a work up consist of when diagnosing a patient with vascular disease?
1. Aortic manipulation 2. mental status change 3. uncontrolled HTN
95
What would a clinician see on a lab workup when assessing a patient with vascular disease?
`. 1. Thrombotic microangiopathy 2. schistocytes 3. urine may have rbc's
96
How are Thrombotic microangiopathies treated?
``` • TTP plasma exchange • Shiga-toxin HUS supportive care • Complement mediated TMA eculizumab • Drug-induced TMA remove offending drug ```
97
Which of the following is a sign of thrombotic microangiopathy
Petechiae
98
Which of the following may be seen on urine microscopy with cholesterol emboli-induced thrombotic angiopathy?
Bland sediment
99
A patient presents with elevated creatinine and schistocytes on a peripheral blood smear. Thrombotic thrombocytopenic purpura is suspected. What is the most appropriate treatment option?
Plasma exchange
100
How many types of progressive glomerulonephritis are there?
1. Type 1- antiglomerular basement membrane 2. Type 2- Pauci-immune ANCA associated vasculitis/glomerunephritis 3. Type 3-immune complex disease. A. Lupus, b. IgA nephropathy. C. post infectious glomerulonephritis. D. Membrane proliferative glomuerunephritis
101
A patient presents with glomerulonephritis, hemoptysis, and sinusitis. Which of the following is the most likely diagnosis?
Granulomatosis with polyangiitis
102
Which of the following conditions is most likely to present with acute kidney injury?
Lupus nephritis
103
Glomerular disease will most likely show which of the following on urinalysis?
RBC casts
104
Which medication is likely to exacerbate symptoms of urinary obstruction in a patient with BPH?
1. Phenylephrine
105
What are causes of obstructive uropathy
1. Stones 2. Anatomic abnormality 3. BPH 4. Malignancy 5. Urethral stricture
106
How is obstructive uropathy worked up?
1. BPH-hesitancy, dribbling, double voiding. 2. Stones-flank pain, gross hematuria 3. History of malignancy
107
Physical exam of obstructive uropathy should include?
1. BPH-digital exam 2. Palpation for stones at the costovertebral angle. 3. Malignancy-palpation of abdominal or pelvic mass 4. Renal ultrasound 5. CT of abdomen 6. BUN: Cr ratio >20:1 7. Urine sediment is bland or may contain crystals in the case of calculi/stones
108
How is obstructive uropathy related to BPH treated?
1. Urinary catheter 2. removal of medications that can participate obstruction 3. Medical/Surgical therapy for prostate
109
How is obstructive uropathy treated when the cause is related to stones?
Stones • Stone removal • Ureteral stent placement • Nephrostomy
110
Symptoms of uremia?
``` Nausea • Vomiting • Anorexia • Dysgeusia • Altered cognition • Pericarditis ```
111
What electrolyte abnormalities will be seen with patients with AKI
``` • Hyperkalemia • Aminoglycosides, cisplatin can cause hypokalemia due to polyuria/increased urinary flow • Metabolic acidosis • Extracellular volume excess • Volume overload (edema) ```
112
Unresolved AKI or repeated episodes of AKI can lead
CKD
113
Renal arterial perfusion should be maintained at what?
65-70 mm/hg
114
Which of the following medications may cause acute kidney injury due to crystal precipitation?
Acyclovir
115
Which of the following would help distinguish between prerenal disease and acute tubular necrosis?
Urine Na+ and FENa
116
Which of the following is NOT a common indication to initiate dialysis?
Refractory alkalosis