Renal Clinical Medicine Part 3: Approach to Proteinuria, Oliguria, and Polyuria (Selby) Flashcards
A urine output of less than 50-100 ml/day is defined as?
UOP less than 400-500 ml/day?
UOP more than 3,000 ml/day?
1) Anuria
2) Oliguria
3) Polyuria
Elevated blood urea nitrogen (BUN) without symptoms is known as?
Elevated BUN with symptoms?
1) Azotemia
2) Uremia
What is the criteria for chronic kidney disease (CKD)?
1) Markers of kidney damage
2) Decreased GFR (less than 60 ml/min)
When can a diagnosis of acute kidney injury be changed to chronic?
After 3 months of symptoms
In absence of evidence of kidney damage, what GFR categories do NOT fulfill the criteria for CKD?
Stage 1 or Stage 2
What are the main risk factors for CKD?
1) Diabetes mellitus
2) Hypertension
3) Cardiovascular disease
4) Acute Kidney Injury
What are some signs and symptoms of CKD? (8)
1) Edema
2) Hypertension
3) Decreased urine output
4) Foamy urine (proteinuria)
5) Uremia
6) Pericardial friction rub
7) Asterixis
8) Uremic frost
What are the 3 simple tests to identify most CKD patients?
1) eGFR
2) Urine albumin-to-creatinine ratio or urine protein-to-creatinine ratio
3) Urinalysis
What are the renal ultrasound findings for CKD?
1) Atrophic or small kidneys
2) Cortical thinning
3) Increased echogenicity
4) Elevated resistive indices
What is used if you are worried about renal artery stenosis or renal vein thrombosis?
Doppler ultrasound
What complications of CKD are treated with renal failure diet that consists of low salt, potassium and phosphorus?
1) Hyperkalemia
2) CKD-BMD (Bone mineral disease)
What are the indications for dialysis when treating CKD?
AEIOU:
A: Severe Acidosis
E: Electrolyte disturbance (usually hyperkalemia)
I: Ingestion (ex: ethylene glycols, methanol, etc…)
O: Volume overload
U: Uremia
Acute kidney injury (AKI) can be defined by changes in either?
1) Serum creatinine
2) Urine output
What are the different categories when determining the etiology of AKI?
1) Prerenal
2) Intrinsic
3) Postrenal
What are causes of prerenal AKI?
1) Hypotension
2) Hypovolemia
3) Reduced cardiac output
4) Systemic vasodilation
What is the most common intrinsic AKI?
What are other causes?
1) Acute Tubular Necrosis
2) Interstitial Nephritis and Glomerulonephritis
What are causes of postrenal AKI?
1) Bladder outlet obstruction
2) Ureteral obstruction
3) Renal pelvis (Papillary necrosis from NSAIDS)
What are labs to obtain on all patients with AKI?
1) Urinalysis with urine microscopy
2) Urine Albumin/creatinine ratio or urine protein/creatinine ratio
What other diagnostic test may be done in patients with AKI in order to rule out hydronephrosis?
Renal ultrasound
Urinary pattern consisting of renal tubular epithelial cells, transitional epithelial cells, granular casts, or waxy casts are characteristic of what kidney disease?
Acute tubular necrosis
Urinary pattern consisting of WBC, WBC cast, or urine eosinophils are characteristic of what kidney disease?
Acute interstitial nephritis or pyelonephritis
Urinary pattern consisting of dysmorphic RBCs, RBC casts are characteristic of what kidney disease?
Vasculitis or glomerulonephritis
Urinary pattern consisting of proteinuria (<3.5 g/day), hematuria, dysmorphic RBC and RBC casts are characteristic of what kidney disease?
Nephritic syndrome
Urinary pattern consisting of heavy proteinuria (>3.5g/day), lipiduria, minimal hematuria are characteristic of what kidney disease?
Nephrotic syndrome
Urinary pattern consisting of hyaline casts are characteristic of what kidney disease?
Non-specific, prerenal azotemia
Urinary pattern consisting of WBCs, RBCs, and bacteria are characteristic of what kidney disease?
Urinary tract infection
What is Nephrotic Syndrome defined as?
1) Proteinuria (> 3-3.5 grams/day)
2) Hypoalbuminemia
3) Peripheral edema
4) Hyperlipidemia
5) Lipiduria
Why is infection a common complication of Nephrotic Syndrome?
Why is Vitamin D deficiency a common complication of Nephrotic Syndrome?
Why is Anemia a common complication of Nephrotic Syndrome?
1) Urinary loss of IgG
2) Urinary loss of Vitamin D Binding Protein
3) Urinary loss of Transferrin and Erythropoietin
What is the most common cause of Nephrotic Syndrome?
What is the most common cause in children?
1) Diabetic Nephropathy
2) Minimal Change Disease
What should be done to diagnosis Nephrotic Syndrome and Nephritic Syndrome?
Renal biopsy
Between Nephritic and Nephrotic syndrome, which usually has active urinary sediment?
Nephritic
What is Nephritic Syndrome defined as?
1) Hematuria
2) HTN
3) Proteinuria (< 3.5 grams/day)
4) AKI
What can be very helpful in determining the DDx of Nephritic Syndrome?
Low complement levels (C3 or C4)
What is Diabetes Insipidus characterized by?
Polyuria (Urine output more than 3 L/day)
The differential diagnosis of polyuria includes?
1) Solute diuresis
2) Water diuresis
What falls under the solute diuresis category?
1) Glucosuria
2) Urea
3) Sodium
4) Mannitol
What are the basic requirements for forming concentrated urine?
1) Hypertonic Medullary Interstitium
2) High levels of ADH
Serum osmolality is normally around?
It is regulated by?
1) 282 mOsm/kg
2) Osmoreceptor-ADH system and Thirst mechanism
ADH has a short half-life of about?
It is metabolized by?
1) 15-20 minutes
2) Liver and kidney
The glomerulus filters how much fluid per day from the plasma?
Where is 90% of it reabsorbed in?
The remaining 18 L is reabsorbed under the regulation of?
1) 180 L
2) Proximal tubule and descending limb of the loop of Henle
3) ADH
ADH (aka Arginine Vasopressin) is a preprohormone synthesized by specialized nuclei in the?
Hypothalamus (Magnocellular nuclei)
Once the ADH is produced in the magnocellular nuclei, it is transported down the axons of these nuclei to?
Once it reaches this area, it is released in response to?
1) Posterior pituitary
2) Osmotic or non-osmotic stimuli
Osmotic stimuli is characterized by increases in serum osmolality which is detected by?
Osmoreceptors
Non-osmotic stimuli is characterized by decrease in BP or increase in blood volume which are detected by?
1) Arterial baroreceptors
2) Atrial stretch receptors
When ADH binds to V2 receptors it increases what levels?
This leads to insertion of what transporters in the apical and basolateral membrane?
1) cAMP
2) AQP-2 and Urea transporters
What are the 2 main types of Diabetes Insipidus?
1) Central Diabetes insipidus
2) Nephrogenic diabetes insipidus
Central Diabetes insipidus is caused by?
Nephrogenic diabetes insipidus?
1) Decreased release of ADH
2) Decreased response to ADH
What can lead to Nephrogenic diabetes insipidus?
1) Lithium toxicity
2) Hypercalcemia
When activated by elevated calcium levels, what induces degradation of AQP-2 channels by autophagosomes?
What does this lead to?
1) Apical membrane calcium sensor
2) Nephrogenic diabetes insipidus
How is Diabetes insipidus diagnosed?
1) 24 hour urine volume collection
2) Urine osmolality < 300 mOsm/kg
3) Water deprivation test
When performing the water deprivation test, if there is increase in urinary osmolality with exogenous vasopressin or desmopressin then what is the diagnosis?
If there is little or no increase?
1) Central diabetes insipidus
2) Nephrogenic diabetes insipidus
What is the treatment of central diabetes insipidus?
Vasopressin
What is the treatment of nephrogenic diabetes insipidus?
1) Decrease solute intake
2) Thiazide diuretics
3) NSAIDs
