Q1

What are the manifestations of nephrotic syndrome?

  • Massive proteinuria
  • Hypoalbuminaemia
  • Oedema (generalised)
  • Hyperlipidaemia
  • Lipiduria

Pass criteria:

  • Bold to pass

What are the underlying processes responsible for these features?

  • Derangement of glomerular capillary walls resulting in increased permeability to plasma proteins. Either structural damage or physicochemical alterations > massive proteinuria
  • Hypoalbuminaemia
    • 1) secondary to above and
    • 2) inability of liver to synthesise enough replacement albumin.
    • 3) Additionally increased renal catabolism of filtered albumin
  • Generalised oedema secondary to
    • 1) loss of colloid osmotic pressure of blood.
    • 2) Compounded by sodium and water retention due to activation of renin-angiotensin system, enhanced ADH secretion, stimulation of sympathetic system and reduction in natriuretic factors
  • Hyperlipidaemia (complex causation). Causes include increased liver synthesis, abnormal lipid transport and decreased catabolism
  • Lipiduria a combination of increased production (see point 4) and increased glomerular permeability (see point 1)

Pass Criteria:

  • Bold to pass

What are the causes of the nephrotic syndrome?

  • Primary glomerular disease (95% kids and 60% adults)
  • Kids:
    • 60% minimal change, 10% each focal segmental, membranoproliferative and other, 5% membranous
  • Adults:
    • 35% focal segmental, 30% membranous, 10% minimal change 10% membranoproliferative, 15% other
  • Systemic disease (mostly adults)
    • diabetes, amyloidosis, SLE, drugs (NSAID’s, penicillamine), infections (malaria, hepatitis B&C, HIV), malignancies, other (bee-sting allergy, hereditary nephritis)

Pass criteria:

  • PGN required to pass
  • Should know difference in causation between kids and adults

 


Q2

What are the manifestations of the nephrotic syndrome?

  • Massive proteinuria, with the daily loss of 3.5 gm or more of protein (less in children)
  • Hypoalbuminemia, with plasma albumin levels less than 30 gm/L
  • Generalized oedema
  • Hyperlipidemia and lipiduria

Pass criteria:

  • 3 out of 4

 

What are the mechanisms of the oedema?

  • Loss of colloid osmotic pressure
  • Loss of serum albumin
  • Accumulation of water and sodium in tissues
  • Due to compensatory secretion of aldosterone
  • Mediated by
    • Hypovolaemia
    • Increased ADH
    • Increased Sympathetic system

Pass criteria:

  • 3 out of 4

 

 


Q3

What is the pathogenesis of post streptococcal glomerulonephritis?

  • Initiated by Group A Beta-haemolytic streptococcal infection (commonly pharyngitis or impetigo), 90% due to types 1, 4 or 12 (cell wall M protein)
  • Antibody and immune complex production over 1-4 weeks
  • Immune complex deposition in glomeruli. (IGG and C3)
  • Acute proliferative glomerulonephritis

Pass criteria:

  • All 4

What is the clinical course of the disease in children?

  • Recent streptococcal infection as above
  • Abrupt onset of fever, malaise, nausea, oliguria and haematuria
  • Oedema
  • Mild to moderate hypertension
  • Red cell casts in urine and mild proteinuria
  • 95% fully recover (with complete resolution of glomerular lesions), 4% chronic GN, 1% rapidly progressive GN. Prolonged and persistent proteiniuria or abnormal GFR = poorer prognosis

How does the clinical course differ in adults?

  • Less benign
  • Sporadic cases @ 60% fully recover. (Better recovery rates in epidemic outbreaks)
  • In the remainder glomerular lesions resolve less quickly or not at all. Prolonged proteinuria, haematuria and hypertension. Outcomes slow resolution, chronic GN or rapidly progressive GN

Pass criteria:

  • Bold required

 

 


Q4

Describe the aetiology and pathogenesis of post streptococcal glomerulonephritis.

  • Group A Beta-hemolytic streptococci (eg: 90% types 12, 4, and 1)
  • Typically post pharyngeal/skin infections (impetigo) – sometimes epidemic, partic in overcrowded insanitary conditions
  • An immunologically mediated disease  Type 2/ or 3 type e.g. Circulating or antigen deposit disease.
  • Granular immune deposits in the glomeruli (IgG & C3) – partic GBM- leading to leaking glomeruli.
  • Streptococcal antigen found in the glomeruli.
  • Complement activation – low serum complement
  • Elevated titres of anti streptococcal Ab
  • Nephritis associated streptococcal plasmin receptor NAPlr, Strep pyogenic exotoxin B (SpeB), zSPeb

Pass criteria:

  • 2 x bold and 1 other

Describe the clinical features of post Streptococcal GN.

  • 1 to 4 weeks after a streptococcal infection of the pharynx or skin (impetigo).
  • Malaise, fever, nausea, oliguria, and haematuria
  • Red cell casts, mild proteinuria (usually < 1 gm/day), periorbital and otheroedema, mild to moderate hypertension
  • 95% will recover quickly in 1-3 weeks, 4 % chronic, 1% severe acute renal failure. Adult onset has worst prognosis
  • Depleted C3 and almost always Strep Ags

Pass criteria:

  • 2 x bold and 2 others

 


Q5

What are the types of urinary calculus?

 

1. Ca oxalate 70%

Idiopathic hypercalcuria 50%
Hypercalciuria & hypercalcaemia 5%

–              (hyperparathyroid, bone diseases, Sarcoid)
Hypercalcaemia only 5%

–              (increased absorption, renal, idiopathic, fasting)
Hyperoxaluria    5%

–              4.5% enteric

–              0.5% Primary.
Hypocitaturia     1%

Unknown            15-20%

 

Pass: Bold plus 3 of 6 with examples

 

2. Magnesium ammonium phosphate (Struvite) (triple phosphate) 15%

–              (staghom talc)

Urea splitting organisms….

–              (proteus, some staph),

Pass: Bold plus 1 example

 

3. Uric acid

Raised uric acid

Over 50% normal uric acid and excretion (pH <5.5)

Pass: Bold plus 1 example

 

4. Cysteine 1-2%

What is the pathogenesis of renal stones?

Increased concentration of stone constituents

Change in urinary pH
Decreased urine volume
Infection — bacteria

Deficiency in inhibitors-pyrophosphates, Diphosphonates, Citrate, Glycosaminoglycans, Osteopontin, nephrocalcin-

Pass: 3 of 6

 


Q6

Infections by what types of streptococci can lead to glomerulonephritis?
Prompt: What groups of streptococci are there?

Strains of Group A beta haemolytic strep with M protein in wall

Rarely others

What is the cause of the glomerular damage?
Prompt: Do streptococci produce any harmful antigens?

1 Latent period of 1+ weeks

2 Immune complex disease

3 Several possible antigens involved

4 Antigens have affinity for glomeruli

5 Also activates alternative complement cascade

Pass: Immune complex plus 2 others

What abnormalities are seen in the urine in a patient with glomerulonephritis?
Prompt: What happens when glomerular membranes are damaged?

  1. Haematuria
  2. Proteinuria
  3. Cellular casts
  4. Other debris

 


Q7

What different substances can renal calculi be composed of?
Prompt: What can become concentrated in the urine and crystallize?

  1. calcium (oxalate and/or phosphate) 80%
  2. struvate (magnesium/ammoninmlphosphate) 15%
  3. uric acid 5%
  4. cystine 1%
  5. Others (metabolic byproducts, drugs)

Pass: Calcium and one other

What factors may lead to formation of struvate calculi?
Prompt: Are there any general factors that could lead to formation of crystals?

  1. Anatomical: polycystic, horseshoe, sponge, diverticulae, reflux
  2. Concentration of urine
  3. Substrate formed by urea-splitting bacteria (proteus, klebsiella, pseudomonas).
  4. Metabolic causes

What are the potential complications of renal calculi?
Prompt: What can happen if urine flow is obstructed?

  1. 1 Infection
  2. 2 Renal parenchymal damage
  3. 3 Obstruction
  4. 4 Bleeding
  5. 5 Pain
  6. 6 Renal failure

 


Q8

What are the causes of acute tubular necrosis?
Prompt: What substances can damage the renal tubules?

  1. Ischaemic: hypotension, vasoconstriction, intracapsular pressure
  2. Direct toxic injury: aminoglycosides, amphotericin, sulfas Other substances: contrast, myoglobin, crystals, proteins
  3. 3.       Acute tubulo-interstitial nephritis
  4. Urinary obstruction (post-renal)
  5. DIC, sepsis

Pass: Bold

Describe the phases of acute tubular necrosis?
Prompt: What is the first thing that happens in ATN?

  1. Initiation phase: decreased urine output, elevated urea, 36 hrs
  2. Maintenance phase: sustained decreased output, salt and water overload, uraemia, hyperkalaemia
  3. Recovery phase: increased output and possibly polyuria, hypokalaemia, vulnerable to infection

Pass: 1 and 3

 


Q9

What are the main types of renal calculi?

  • Calcium oxalate and phosphate (70%)
  • Struvite or triple (magnesium ammonium phosphate) (15-20%)
  • Uric acid (5-10%)
  • Cystine (1-2%)

Pass Criteria:

  • Calcium + 1 other to pass

What conditions in urine favour stone formation?

  • Increased concentration of stone constituents
  • Changes in urinary pH
  • Decreased urine volume
  • Bacteria

Pass Criteria:

  • 2 to pass

What are the complications of ureteric calculi?

  • Pain
  • Haematuria
  • Infection
  • Obstructive renal impairment

Pass Criteria:

  • 1 bold and 1 other

 


Q10

Define Acute Kidney Injury

  • Clinico-pathological entity
  • Acute reduction of renal function with morphologic tubular injury (usually)

Pass Criteria:

  • Bold to pass

What are the causes of AKI? (Please give examples)

  1. Ischaemia/abnormal blood flow
    • Systemic – thrombosis (HUS, TTP, DIC) or hypovolaemia
    • Intra-renal – angiopathies, malignant hypertension
  2. Toxic injury to tubules – drugs, radio-dye, myoglobin
  3. Acute tubulointerstitial nephritis – reaction to drugs
  4. Obstruction (“post-renal”) – tumour, clot

Pass Criteria:

  • Bold and 1 other category
  • 1 example for each

Describe the typical clinical course of AKI.

  • Variable
  • (1) – Initiation 36 hours: decreased urine output, increased urea
  • (2) – Maintenance: oliguria, salt/water overload, incr urea/K/H
  • (3) – Recovery: incrased urine volume (up to 3L/day), H2O/Na/K loss. Ur/Cr r/t normal.

Pass Criteria:

  • Oliguric phase
  • Polyuric recovery

A 70 year old lady with a history of bipolar disorder is found on the floor many hours after a fall. On arrival in ED, she is tachycardic and complaining of severe thirst and thigh pain. On secondary survey, you suspect a fractured femur. What are the most likely causes in this 70 year old lady?

  • Ischaemic injury from hypovolaemia/hypotension from femur fracture +/- inability to get to water
  • Myoglobin deposition from rhabdo

Q11

urinalysisUrine Analysis Results                                                         Leukocytes: 3+                                                                                  Nitrite: 1+                                                                                             Protein: 2+                                                                                               Blood: 2+                                                                                             Ketones: Negative                                                                                       Bilirubin: Negative                                                                                       Glucose: Negative

 

 

 

 

Please describe the abnormalities

  • High poly and RBC counts with positive protein and blood (in the absence of epi-clean catch) indicates infection

Pass Criteria:

  • Bold to pass

What is the most likely diagnosis?

  • In the clinical context c/w pyelonephritis +/- stone

Pass Criteria:

  • Bold to pass

Q12

What organisms cause acute pyelonephritis?
Prompt: What are the most common?

  • G -ve bacilli (>85%)
  • Endogenous organisms
  • E. coli
  • Proteus
  • Klebsiella
  • Enterobacter
  • Strep faecalis (enterococcus)
  • Other: staph, fungi, viruses in immunocompromised and renal transplant patients

Pass Criteria:

  • G-ve & 3 organisms to pass

What steps are involved in ascending infection of the urinary tract?

5 Steps:

  1. Colonisation distal urethra
  2. Entry into bladder
  3. Urinary tract obstruction/stasis of urine
  4. Vesicoureteric reflux
  5. Intrarenal reflux

Pass Criteria:

  • Need to explain the concept clearly

What conditions predispose to acute pyelonephritis?

  • Urinary tract obstruction
  • Instrumentation
  • Vesico-ureteric reflux
  • Pregnancy
  • Female up to 50 yrs
  • Males > 50 yrs
  • Abnormalities – congenital/acquired
  • DM/Immunosuppression

Pass Criteria:

  • 4/9 to pass

Q13

Photo – myoglobinuria

Biochemistry:

Interpret the biochemistry results?

  • Renal failure likely acute kidney injury in clinical context
  • Elevated urea + Cr
  • Markedly elevated CK – rhabdomyolysis
  • Normal K+

Pass Criteria:

  • Bold

Why is the urine dark?

  • Rhabdomyolysis
  • Breakdown of skeletal muscle –> myoglobinuria

Pass Criteria:

  • Bold