Nephrology Flashcards
What are the main functions of the kidney?
Filtering water soluble salts and ions from the blood
Reabsorption of necessary small molecules
Dilution or concentration of urine to optimise fluid balance
Regulation of BP
Metabolism of vitamin D
Regulation of acid-base balance
What is plasma creatinine a product of?
Muscle breakdown
What is a MAG3 renogram and what does it test for?
Dynamic scan of isotope-labelled substance excreted from blood into urine
Can identify VUR during micturition in children >age 4.
What are the negatives for performing an MCUG?
Invasive
Unpleasant
High radiation dose
Can introduce infection
How is a micturating cystourthrogram
(MCUG) performed and what does it test for mainly?
Contrast in introduced to the bladder via a catheter and visualised bladder and urethral anatomy
Looks for VUR and urethral obstruction
How is eGFR calculated?
31xheight(cm)/creatinine
How is a DMSA scan performed and what does it look for?
TC99m dimercaptosuccinic acid static scan of renal cortex
Detects functional defects e.g. scars or non-functioning renal tissue
How does renal agenesis usually present?
If bilateral with severe oligohydramnios and causes Potter syndrome which is fatal
How does Potter syndrome present?
Low set ears
Beaked nose
Prominent epicanthic folds
Downward slant to eyes
Limb deformities
Failure of fetal lung development
Which part of the nephron does ADH primarily work on?
Collecting duct
What are the symptoms of post-streptococcal GN?
Haematuria
Oliguria
Oedema
Hypertension
Pulmonary oedema
What is the CH50 test?
Measures total activity of all major complement proteins
Wat would you expect to happen to CH50 levels in post-streptococcal GN?
Decrease
Which hormones play a factor in the inguinoscrotal stage of testicular descent?
Testosterone
Calcitonin gene-related peptide
What is nephronophthisis?
AR ciliopathy causing medullary cystic kidney disease
What are the symptoms of nephronophthisis?
Polyuria
Polydipsia
Progressive renal failure
What extra-renal features can be associated with nephronophthisis?
Hepatic fibrosis
Cardiac anomalies
Situs inversus
What do struvite stones consist of?
Mg
Ammonia
PO4
Calcium apatite
What typically causes struvite stones?
Proteus bacteria UTI
What would typically be seen on electron microscopy in post-streptococcal GN?
Subepithelial humps - caused by immune deposits
What is the defect associated with type I renal tubular acidosis?
Reduced H+ excretion in distal tubule
What is the defect associated with type II renal tubular acidosis?
Impaired HCO3- reabsorption in the proximal tubule
What is the defect associated with type IV renal tubular acidosis?
Impaired aldosterone action causing reduced H+ and NH3+ excretion
What is the usual plasma HCO3- in type I renal tubular acidosis?
<10mmol/l
What is the usual plasma HCO3- in type IV renal tubular acidosis?
Usually >15mmol/l
What is the usual plasma K+ in type IV renal tubular acidosis?
High
What is the usual plasma HCO3- in type II renal tubular acidosis?
Usually 10-20mmol/l
What is the usual plasma K+ in type I renal tubular acidosis?
Low-normal
What is the usual plasma K+ in type I renal tubular acidosis?
Low-normal
What type of renal tubular acidosis is associated with nephrocalcinosis?
Type I
What type of renal tubular acidosis is associated with high urine calcium:creatinine ratio?
Type I
What are factors predictive of a poorer prognosis in HUS?
Non-Shiga toxin HUS
Prolonged oliguria or anuria
Severe hypertension
Involvement of medium-sized arteries
Severity of CNS symptoms
Extensive glomerular involvement (>80%)
Age >5years
What are the indicators for renal biopsy in HSP?
Proteinuria (>200mg/mmol) with increasing trend >4weeks after diagnosis
Nephrotic syndrome
Nephritic syndrome
Hypertension
Macroscopic haematuria
What are the features of nephrotic syndrome?
Low albumin
Oedema
Heavy proteinuria
What are the features of nephritic syndrome?
Hypertension
Haematuria
Rapidly deteriorating renal function
What are the typical features of Bartter syndrome?
Faltering growth
Hypokalaemia
Metabolic alkalosis with low chloride
What is the treatment of Bartter syndrome?
Electrolyte replacement
Potassium-sparing diuretics
NSAIDs
What is grade V VUR?
Grossly dilated ureter, pelvis and calyces along with loss of papillary impressions
What is grade I VUR?
Urine which refluxes into a non-dilated ureter
What is grade II VUR?
Reflux up into the pelvis and calyces with no dilatation
What is grade III VUR?
Mild ureteric dilatation, renal pelvis dilatation and minimal calyceal blunting
What is an absolute indication for renal biopsy in nephrotic syndrome?
Steroid resistant disease
What are the inheritable renal cystic diseases?
Cysts associated with multiple malformations
Infantile (AR) PCKD
Adult (AD) PCKD
What is grade IV VUR?
Reflux into dilater ureter, renal pelvis and calyces and moderate ureteral torturosity
What is the best management for idiopathic hypercalciuria?
Thiazide diuretics
How does Gitelman syndrome typically present?
Hypokalaemia
Hypomagnesaemia
Hypocalciuria
Normotension
Hypokalaemic metabolic alkalosis
What causes Gitelman syndrome?
AR condition with a defect in the NaCl transporter in distal collecting tubules
How is Gitelman syndrome treated?
Electrolyte replacement
Potassium sparing diuretics
What is seen in nephrotic syndrome on electron microscopy?
Foot process fusion of the glomerular epithelial cells
How does IgA nephropathy typically present?
Recurrent episodes of macroscopic haematuria with infections
In what conditions are oxalate stones due to secondary hyperoxaluria more common?
Short gut syndrome
Crohns
Pancreatitis
CF
What does CXR show in Goodpasture syndrome?
Bilateral diffuse infiltrates in lower zones
What is the dose of levamisole when used in nephrotic syndrome?
2.5mg/kg taken on alternate days
What pathological process occurs in nephrogenic diabetes insipidus?
Kidneys are resistant to effects of ADH therefore there is an inability to concentrate urine despite normal/high ADH
What effect does desmopressin have on urine concentration in nephrogenic DI?
No effect
What effect does AR PCKD have on the kidneys?
Cysts which occupy the collecting system and leads to dilatation of the ducts
Which chromosomal defect is most common in ADPKD?
PKD1 on Ch16
What structure does the mesonephric duct give rise to?
Seminal vesicles
Epididymides
Vas deferens
Bladder trigone
Renal pelvis
Ureters
What is the cause of cystinosis?
AR disorder caused by accumulation of cystine in lysosomes
What are the features of cystinosis?
Faltering growth
Low K
Low PO4
Metabolic acidosis
High urinary pH
Multisystem disorder
What is Fanconi syndrome?
Impairment of reabsorption in the proximal tubule
What are the typical blood results in Fanconi syndrome?
Low PO4
Low K
Low HCO3-
What is the typical urinary results in Fanconi syndrome?
Polyuria
Glycosuria
Proteinuria
How does a hydrocoele present?
Painless and fluctuant - most commonly following birth or post-trauma
Which hormonal factor is primarily responsible for the transabdominal phase of testicular descent?
Insulin-like 3 protein
