Diseases of urinary tract 1 Flashcards
What are the functions of kidney>
Eliminating metabolic waste products
Regulate fluid and electrolyte balance
Influence acid based balance
Hormone production - renin (fluid balance) and EPO (haemopoiesis)
What are the clinical presentations of acute renal failure?
- Generally unwell
- Raised creatinine and urea
What are the clinical presentations of chronic renal failure?
Progressive decline in renal function
Raised creatinine and urea
What are the clinical features of nephrotic syndrome?
Oedema
Proteinuria (>3g per day)
Hypoalbuminaemia
What are the clinical features of nephritic syndrome?
Oedema
- Proteinuria (not as much as nephrotic syndrome)
- Haematuria
- Acute renal failure
How are patients diagnosed?
Radiology - abnormalities, kidney sie, structural abnormalities
Blood - urea/creatinine; urine - protein/electrolytes
Biopsy
Cystoscopy - obstruction/haematuria
Renal physician - clinical exam/history
What components of the glomerulus can be damaged?
Vessel
Basement membrane
Podocytes
How are the mechanisms of glomerular disease divided?
Immune and non immune mediated
How doe the immunological mechanisms of glomerular damage occur?
Circulating immune complexes/antibodies/antigens - deposit into glomerulus (BM) - activating of coagulation cascade, neutrophil activation, ROS species, clotting factors -> inflammatory/immune response -> damage to glomerulus
What are the non-immunological mechanisms by which glomerular damage occurs?
Direct damage e.g. hypotension, toxins, gout
Altered basement membrane - hyperglycaemia
Inherited disorders - alters basement membrane/podocytes
Deposited abnormal proteins e.g. amyloid
“Any damage to glomerulus will likely cause damage tubule.” Why?
Reduced blood supply to tubule - ischaemia
What re the two main means by which the kidney tubule can be damaged?
Ischaemia
Toxic
Give some examples of cause of ischaemia to the kidney tubule?
Hypotension e.g. toxic shock
Damage to the vessel
Glomerular damage
Give some examples of toxic causes of damage to kidney tubule?
Direct toxins e.g. lead, mercury, X-ray contrasts - damage tubules DIRECTLY
Hypersensitivity reactions e.g. drugs
Deposition of crystals/abnormal protein in tubules e.g. gout
Renal function correlates well with…
Damage to renal tubule! (not glomeruli)
What are main means by which the kidney vasculature is damaged?
- Diabetes
- Hypertension
- Atheroma e.g. renal stenosis
- Vasculitis
- Thrombotic micro-angiopathy
What damage is always seen with nephrotic syndrome?
Glomerular damage
What are the criteria for nephrotic syndrome? What are the complications?
Proteinuria (>3g in 24 hrs)
Oedema
Hypoalbuminaemia
Complications - infections and thrombosis
What are the main causes of nephrotic syndrome?
Membranous nephropathy (most common) - idiopathic (damage to Basement membrane)
Focal segmental glomerulosclerosis (FSGS) - usually idiopathic but can be due to genetic (podocyte abnormalities), HIV, heroine use, hypertension etc
Minimal change disease - MOST common in children - no change in light microscopy
Diabetes
Lupus nephritis
Amyloid
What are the clinical presentations of nephritic syndrome?
- Haematuria
- Oedema
- Proteinuria (not as much as nephrotic syndrome)
- Hypertension
- Acute renal failure
What are the main causes of Acute nephritis?
Post-infective glomerulonephritis - post strep throat infection
IgA nephropathy - common, IgA deposits, haematuria in teenager/young adults
Vasculitis - fever, unwell, rash myalgia, arthralgia
Lupus
What are the main causes of acute nephritis in children?
Post infective glomerulonephritis (most common0)
IgA Nephropathy
Henoch-Schonlein purpura - type of IgA nephropathy - typically young boys with haematuria, rash, abode pain, arthralgia
Haemolytic uraemic syndrome - E coli 0157 - acute nephritis + haemolysis + thrombocytopenia
What are the 3 cardinal signs of haemolytic uraemic syndrome?
Acute nephritis
+
Thrombocytopenia
+
Haemolysis
What are the diagnostic features of acute renal failure?
Oliguria (reduced urination) and anuria (no urination)
Raised creatinine and urea levels
What are the three main causes of acute renal failure?
Pre-renal failure - reduced blood flow e.g. dehydration, hypotension (septic shock, blood loss)
Renal: kidney damage
Post-renal failure - obstruction tumour (pelvic/ureter), bladder stone, enlarged prostate
What types of acute renal failure is biopsies useful?
Renal: damage to kidney (not pre/post renal!)
What will all acute renal failures show on biopsies?
ATN - Acute tubular necrosis
What are the main causes of acute renal failure in adults and children?
Adult
- vasculitis
- acute interstitial nephritis (tubular damage inflammation - drugs)
Children
- Henloch-Scholein purpura
- Haemolytic uraemic syndrome (E coli 0157)
- Acute interstitial nephritis - drugs?
What are the complications of acute renal failure?
-Cardiac failure
(fluid overload)
- Arrythmias (electrolyte imbalance)
- Jaundice
- GI bleeding
- Infection - lung, urinary tract
What is the treatment for acute renal failure?
- Course of dialysis might be required
- Treat underlying course!
What is chronic renal failure defined as?
Progressive, permanent reduction in GFR - related to reduced number of nephrons
What are the 5 stages of chronic renal failure?
Stage 1 Kidney damage with normal GFR (>90 mL/min)
Stage 2 - mild reduction in GFR (60-89 mL/min)
Stage 3 - Moderate reduction - 30-59 mL/min)
Stage 4 Severe reduction - 15 - 29 mL/min)
Stage 5 - Kidney failure (GFR
What are the main causes of chronic renal failure in adults and children?
Adults
- DIABETES
- Glomerulonephritis
- reflux nephropathy - chronic reflux up ureter - repeated infection)
Children
- Developmental abnormalities
- Glomerulonephritis
- Reflux nephropathy
If chronic failure is established, are renal biopsies helpful?
No - severe scarring (loss of glomeruli/tubules - doesn’t show cause!)
What are the effects of chronic renal failure?
Reduced H2O and electrolytes excretion - hypotension and oedema
Reduced toxic metabolite excretion
Reduced EPO production - anaemia
Renal bone disease
What is the likely cause of an elderly patient with acute renal failure?
Acute interstitial nephritis (new drug reaction?)
Myeloma - Ig’s deposit in kidney
What is the likely cause of a young male with haematuria and rash?
Henloch Schonlein purpura
What is the likely cause of a young male with haematuria?
Post infective glomerulonephritis
IgA Nephropathy
Whats the main cause of an adult with acute renal failure, fever and myalgia?
Vasculitis
Whats the main cause of an female adult with haematuria and facial rash?
Lupus
Whats the main cause of an adult with nephrotic syndrome?
Membranous nephropathy
Whats the main cause of an child with nephrotic syndrome?
Minimum change syndrome
