10.30: Renal IV Flashcards Preview

MHD V: Renal > 10.30: Renal IV > Flashcards

Flashcards in 10.30: Renal IV Deck (41):

What are the 3 types of AKI?

"Acute Kidney injury"
***AKA: "ATI" "ATN"
1. Ischemic
2. Toxic
3. Combined
***Often stated as: Usually referred to AKI due to ATI


Presentation of ATI?

"Acute tubular injury "
- Rapid reduction in renal function
- Uremia
- Fluid overload
- Electrolyte abnormalities
- Acidosis
- Oliguria
- Increased creatinine
****50% may not show oliguria


Pathogenesis of ATI?

- Tubular injury with disturbance in blood flow
- Reduced GFR, vasoconstriction, low nutrient delivery
- Toxic from waste products and lack of O2
- Necrosis, exfoliation, and regeneration of cells


Difference between ischemic and toxic ATI?

Ischemic: Patchy areas of damage along tubule
Toxic: Diffuse damage along tubule
***Both begin in proximal tubules with necrotic cells detaching and damaging / obstructing later parts of tubules


Classic presentation of ATI?

- Younger person in accident w/ loss of blood
- Drop in BP and urine output
- Increase creatinine


What is common during recovery from ATI?

- Ptn. accumulated excessive fluid and waste
- Will need to undergo weeks of dialysis
- Marked polyuria as renal function returns to normal


Common causes for ischemic ATI?

1. Trauma
2. Sepsis
3. Pancreatitis


Common causes of toxic ATI?

1. Antibiotics
2. Contrast dyes
3. Poisons
4. Organic solvents: Mercury, antifreeze


Common presentation of combined ATI?

- Trauma causing large release of myoglobin in blood and urine: toxic to tubules
- Oliguria with dark brown urine
- Dipstick positive for RBC: is actually myoglobin
- Microscopic negative for RBC
- Increase in BUN


Why is polyuria seen in recovery phase of ATI?

- GFR increase more rapidly than tubule epithelium recovers
- Thus tubules cannot fully resorb leading to polyuria
- Once cells recover, urine output is normal


3 categories of tubulointerstitial nephritis?

1. Infectious: acute or chronic pyelonephritis
2. Drug related
3. Other: Metabolic or neoplastic


Difference between primary and secondary tubulointerstitial nephritis?

Primary: only renal tubules and epithelium
Secondary: Often associated with autoimmune or glomerulonephritis as well


2 types of infectious tubulointerstitial nephritis?

1. BACTEREMIC: circulating bacteria settles in kidney causing nephritis
2. ASCENDING: infection in lower tract (bladder / urethra) with obstruction or other reason for retention allowing urine to flow backwards to kidney = nephritis


Main cause of urinary reflex leading to ascending movement?

- Ureter does not fully close during voiding allowing for backwards flow of urine
- Common cause of htn. in children


Signs of acute pyelonephritis?

1. Sudden onset
2. Costovertebral pain
3. Fever / malaise
4. Increase frequency and urgency
***Chronic is more insidious


What is acute inflammation with PMNs in tubules and interstitium characteristic of?

Acute pyelonephritis


Dispersion of blood between medulla and cortex?

Cortex: 90%
Medulla: 10%
***When there is ischemia the papillary tip of medulla is first to go


Predisposing factors of papillary necrosis?

1. Analgesics
2. Sickle Cell
3. Diabetes
4. Obstruction
5. TB


Who is interstitial nephritis common in?

- Immunosuppressed patients: transplantees
- Mimics rejection of kidneys


Characteristics of chronic pyelonephritis?

- Slow, scarring onset
- Gradual insufficiency with nocturia / polyuria
- Dilated tubules
- Obliterated glomeruli


What is xanthogranulomatous pyelonephritis?

- Mimicks tumor, caused by proteus
- Large stones lead to obstruction and scarring


Presentation of drug induced interstitial nephritis?

- 25% rash
- Renal failure: more prevalent in elderly
- Blood and eosinophils in urine


Cause of drug induced interstitial nephritis?

- IgE T cell mediated response to:
2. Diuretics
3. Antibiotics


How to treat drug induced interstitial nephritis?

- Withdrawal of drug


Typical presentation of drug induced interstitial nephritis?

- Fever
- Rash
- Eosinophils in urine
- Recent diuretic, NSAID, antibiotic administered
***Not dosage dependent


What are fever rash and eosinophils in urine characteristic of in a ptn. who recently began to take new drug?

Drug induced interstitial nephritis


What is pathology of NSAID induced interstitial nephritis?

- NSAIDs inhibit prostaglandin formation
- Demonstrates podocyte effacement seen in MCD
- Renal failure with increased serum creatinine


Difference and similarity between MCD and NSAID interstitial nephritis?

BOTH: show podocyte effacement
NSAIDs: show increased serum creatinine


What is chinese herb nephropathy?

- Caused by aristolochic acid
- Rapidly progressing interstitial fibrosis and failure
- Seen in chinese women using herbs for slimming
- Increased urothelial carcinoma


When is acute uric acid nephropathy seen?

- Ptn. with leukemia or lymphoma on chemotherapy
- Massive degradation of tumor nuclei leads to release of toxic uric acid
- Mainly tubular in acute, chronic is interstitial


When is chronic oxalate nephropathy seen?

- Bariatric surgery
- Crohn's disease
- Leads to interstitial nephritis


What is multiple myeloma?

- Plasma cell malignancy
- Light chain IG from plasma cell precipitate in distal tubules
- Can lead to renal failure
- Uric acid and hypercalcemia seen as well


When are subepithelial deposits seen?

Post infectious state


When is increased creatinine seen?



What does benign htn cause?

- Hyaline arteriolosclerosis
- Narrows lumen


Difference between benign and malignant htn.?

Benign: leads to hyaline arteriolosclerosis
Malignant: Fibrinoid necrosis and hyperplasia of smooth muscle leading to "onion skin" appearance


Common cause of renal artery stenosis?

- Post vascular surgery dislodging clot


What is thrombotic microangiopathy?

- Endothelial injury from many microthrombi in arterioles
- Microangiopathic hemolytic anemia
- Thrombocytopenia from platelet consumption


What can cause thrombotic microangiopathy?

1. HUS
2. TTP
3. Drugs
4. Malignant htn.


Presentation of thrombotic microangiopathy?

- Microangiopathic hemolytic anemia
- Thrombocytopenia
- Renal failure
- Diarrhea in kids
- Often caused by E Coli shiga toxin


What is HUS often associated with?

- Child eating hamburger and getting E Coli
- Leads to HUS and diarrhea