Nephrology & genito-urinary

Question 1

Acute nephritis causes

Answer 1

Post-infectious: incl. streptococcus
Vasculitis: Henoch–Schönlein purpura, SLE (young females with autoantibodies), Wegener granulomatosis (resp tract involement), microscopic polyarteritis, polyarteritis nodosa –> ANCA (anti-neutrophil cytoplasm antibodies) =diagnostic
IgA nephropathy
Mesangiocapillary glomerulonephritis
Familial: Alport syndrome (X-linked recessive)
Anti-glomerular basement membrane disease: Goodpasture syndrome

Question 2

Acute nephritis clinical features

Answer 2

Decreased urine output and volume overload: oliguria
Hypertension: which may cause seizures
Oedema: characteristically peri-orbital oedema
Haematuria & proteinuria

Question 3

Henoch-Schönlein purpura clinical features

Answer 3

3-10y, most boys, winter months, following URTI
Fever
Characteristic palpable rash: buttocks, extensor surfaces of legs & arms and ankles (urticarial –> maculopapular & purpuric)
Arthralgia: knees and ankles
Periarticular oedema: knees and ankles
Abdominal pain: haematemesis, melaena, intussuception
Glomerulonephritis: microscopic/macroscopic haematuria (80%) and nephrotic syndrome (rare)

Question 4

Possible long-term complications of HSP

Answer 4

Ileus
Protein-losing enteropathy
Orchitis
CNS involvement

Severe proteinuria –> nephrotic syndrome may result
Risk factors for progressive renal disease: heavy proteinuria, oedema, hypertension, deteriorating renal function (renal biopsy determines treatment)

Hypertension and declining renal function may develop after an interval of several years

Question 5

HSP management

Answer 5

Joint pain: resolves spontaneously
Abdo pain: corticosteroids. Be wary of intussuseption
Renal involvement: attention to both water and electrolyte balance and the use of diuretics when necessary
Long term follow up for severe renal involvement

Question 6

Glomerulonephritis investigations

Answer 6

Electrolytes and creatinine: to assess renal function
FBC: infection, anaemia
Urinalysis: infection, protein, blood
Urine culture: infection
Complement levels: strep, SLE
ASO titre: group A strep
Anti-DNAase B
Serum IgA measurement

Hx: consistent with acute post-streptococcal glomerulonephritis, low C3 and +ve ASO
and Anti-DNAase B is enough to provide a provisional diagnosis
If this seems unlikely: renal biopsy
Renal ultrasonography: exclude other causes of hypertension and haematuria

Question 7

What condition shares the same histopathological features of HSP nephritis?

Answer 7

IgA nephropathy
May present with episodes of macroscopic haematuria commonly in association with upper respiratory tract infections
Management for both conditions is the same

Question 8

Nephrotic syndrome definition

Answer 8

Proteinuira >200mg protein/mmol creatinine
Serum albumin >25
Oedema
Hypercholesterolaemia

Question 9

Nephrotic syndrome clinical signs

Answer 9

Periorbital oedema: particularly on waking (earliest sign)
Scrotal or vulval, leg & ankle oedema
Ascites
Breathlessness: pleural effusions + abdominal distension
Cloudy/frothy urine

Question 10

Features suggesting steroid sensitive nephrotic syndrome

Answer 10

1-10yo
No macroscopic haematuria
Normal blood pressure
Normal complement levels
Normal renal function

Question 11

Complications of nephrotic syndrome

Answer 11

Hypovolaemia: indicators = faintness, abdo pain, urinary Na <20mmol/L + high PCV. Treatmeant = i.v. albumin

Thrombosis: hypercoagulable state due to urinary losses of antithrombin, exacerbated by steroid therapy, increased synthesis of clotting factors and increased blood viscosity from the raised haematocrit

Infection: relapse = risk of infection with capsulated bacteria (pneumococcus), spontaneous peritonitis may occur, pneumococcal and seasonal influenza
vaccination is recommended. Chickenpox/shingles: aciclovir

Hypercholesterolaemia: correlates inversely with the serum albumin

Question 12

Nephrotic syndrome management

Answer 12

Oral corticosteroids (60 mg/m2 per day of prednisolone) (unless atypical features)
After 4 weeks, the dose is reduced to 40 mg/m2 on alternate days for 4 weeks
The median time for the urine to become free of protein is 11 days
Frequent relapses: other drugs may be used to avoid steroids

Question 13

Steroid resistant nephrotic syndrome causes

Answer 13

Focal segmental glomerulosclerosis
Mesangiocapillary glomerulonephritis
Membranous nephropathy

Question 14

Steroid resistant nephrotic syndrome management

Answer 14

Management of oedema: diuretics, salt restriction, ACEIs, NSAIDs (may reduce proteinuria)

Question 15

Nephrotic syndrome atypical features

Answer 15

No response to 4-8w corticosteroid therapy = renal biopsy
Renal histology in steroid-sensitive nephrotic syndrome is usually normal on light microscop, but fusion of
podocytes is seen on electron microscopy (minimal change disease)

Question 16

Why is it important to diagnose UTIs in children

Answer 16

1/2 of patients have a structural abnormality of their urinary tract
Pyelonephritis may damage the growing kidney by forming a scar –> predisposing to hypertension& chronic renal failure if bilateral

Question 17

UTI common organisms

Answer 17

E. Coli
Klebsiella
Proteus: boys (presence under the prepuce). Predisposes to the formation of phosphate stones by splitting urea to ammonia –> alkalinising the urine
Pseudomonas: may indicate the presence of some structural abnormality in the urinary tract affecting drainage
Strep. Faecalis

Question 18

Haematuria differentials

Answer 18

UTI: bacterial, viral (adenovirus), schistosomiasis, TB
Glomerular: post-infectious glomerulonephriti, HSP, IgA
nephropathy, SLE, thin basement membrane, Alport syndrome
Urinary tract stones: due to hypercalciuria
Trauma
Renal tract pathology: tumour, polycystic kidney disease
Vascular: arteries, renal vein thrombosis
Haematological: coagulopathy, sickle cell
Drugs: cyclophosphamide
Exercise-induced

Question 19

UTI presentation in an infant

Answer 19

Fever
Vomiting
Lethargy and irritability
Poor feeding/failure to thrive
Jaundice
Septicaemia
Offensive urine
Febrile convulsion (>6 months)

Question 20

UTI presentation in a child

Answer 20

Dysuria and frequency
Abdominal pain or loin tenderness
Fever with or without rigors
Lethargy and anorexia
Vomiting and diarrhoea
Haematuria
Offensive/cloudy urine
Febrile convulsion
Recurrence of enuresis

Question 21

Urine sample collection methods

Answer 21

‘Clean catch’ with nappy removed
Urethral catheter
Suprapubic aspiration: invasive, not commonly used
Older children: mid-stream sample

Question 22

Dipstick nitrites and leucocytes result interpretation

Answer 22

Leucocyte +ve nitrite +ve: UTI
Leucocyte -ve nitrite +ve: start abx, diagnosis depends on urine culture
Leucocyte +ve nitrite -ve: start abx if clinical evidence of a UTI
Leucocyte -ve nitrite -ve: UTI unlikely

Question 23

Atypical UTI features

Answer 23

Seriously ill
Poor urine flow
Abdominal or bladder mass
Raised creatinine
Septicaemia
Failure to respond to suitable antibiotics within 48 hours
Infected with non-E.coli organisms

Question 24

Recurrent UTI definitions

Answer 24

2 or more UTIs with acute pyelonephritis/upper UTI

1 episode of UTI with acute pyelonephritis/upper UTI + 1 or more episodes of UTI with cystitis/lower urinary tract infection

3 or more episodes of UTI with cystitis/lower urinary tract infection

Question 25

Atypical/recurrent UTI investigations

Answer 25

USS during acute infection DMSA 4-6 months following acute infection <6m: MCUG

Question 26

Vesicoureteric reflux incidence

Answer 26

10x more common in white children than black Red hair = increased risk 5-6x more common in females 30-70% of infants with febrile UTIs

Question 27

Vesicoureteric reflux investigations

Answer 27

Voiding cystourethrogram (VCUG): main diagnostic + grading test. Catheterisation to administer radiocontrast Renal bladder USS DMSA: radionucleotide

Question 28

Pyelonephritis treatment >3m

Answer 28

Oral abx for 7-10d: cephalosporin, co-amoxiclav If cannot use oral abx, IV abx: cefotaxime or ceftriaxone for 2-4 days followed by oral antibiotics for a total duration of 10 days

Question 29

Cystitis treatment >3m

Answer 29

3d p.o. abx: trimethoprim, nitrofurantoin, cephalosporin, amoxicillin Advised to bring the child for reassessment if still unwell after 24-48 hours --> if an alternative diagnosis is not made, a urine MCS should be sent

Question 30

Vulvovaginitis aetiology

Answer 30

``` Infection: bacterial or fungal Specific irritants: e.g. bubble bath Poor hygiene Sexual abuse Threadworm infestation ```

Question 31

Pre-renal causes of AKI

Answer 31

Hypovolaemia: gastroenteritis, burns, sepsis, haemorrhage, nephrotic syndrome Circulatory failure

Question 32

Renal causes of AKI

Answer 32

Vascular: haemolytic uraemic syndrome, vasculitis, embolus, renal vein thrombosis Tubular: acute tubular necrosis, ischaemic, toxic, obstructive Glomerular: glomerulonephritis Interstitial: interstitial nephritis, pyelonephritis

Question 33

Post-renal causes of AKI

Answer 33

Congenital: e.g. posterior urethral valves Acquired: e.g. blocked urinary catheter, urethral stones

Question 34

Stages of CKD

Answer 34

1: normal GFR>90ml/min per 1.73m2 + persistant albuminuria 2: GFR 60-89ml/min per 1.73m2 + persistant albuminuria 3: GFR 30-59ml/min per 1.73m2 4: GFR 15-30ml/min per 1.73m2 5: GFR<15ml/min per 1.73m2 or end stage renal disease

Question 35

CKD clinical features

Answer 35

``` Symptoms rarely develop before renal function falls to <1/3 of normal Anorexia or lethargy Polydipsia and polyuria Failure to thrive/grow Bone deformities Hypertension Acute-on-chronic renal failure Proteinuria Normochromic, normocytic anaemia ```

Question 36

Renal osteodystrophy pathophysiology and management

Answer 36

Decreased activation of vitD/calcitriol production --> phosphate retention + hypocalcaemia --> secondary hyperparathyroidism --> osteitis fibrosis + osteomalacia Management: phosphate restriction... Decreasing dietary intake of milk products Calcium carbonate as a phosphate binder Activated vitamin D supplements

Question 37

CKD management

Answer 37

Diet: adequate protein intake to maintain growth + albumin production, but prevent accumulation of toxic byproducts Renal osteodystrophy: phosphate restriction, calcium carbonate, calcitriol supplements Salt & water balance + acidosis: salt supplements, bicarbonate supplements to prevent acidosis Anaemia: recombinant human EPO Hormonal abnormalities: recombinant human growth hormone

Question 38

Dialysis & kidney transplantation in children

Answer 38

10kg weight must be reached before transplantation to avoid renal vein thrombosis Kidneys from living doners (HLA type matched) have a higher success rate Immunosuppression: prednisolone, tacrolimus, azathioprine, mycophenolate mofetil Ideally transplant occurs before dialysis is required

Question 39

Haemolytic uraemic syndrome triad

Answer 39

Acute renal failure Microangiopathic haemolytic anaemia Thrombocytopenia

Question 40

HUS aetiology and pathophysiology

Answer 40

Secondary to gastrointestinal infection with verocytotoxin-producing E. coli Acquired through contact with farm animals, eating uncooked beef, Shigella Prodrome: bloody diarrhoea --> verocytotoxin enters the gastrointestinal mucosa & preferentially localises to the endothelial cells of the kidney --> intravascular thrombogenesis Coagulation cascade is activated --> platelets are consumed Microangiopathic haemolytic anaemia: damage to red blood cells as they circulate through occluded microcirculation Brain, pancreas and heart may also be involved.

Question 41

Difference between diarrhoea associated and non-diarrhoea associated HUS

Answer 41

Diarrhoea-associated HUS: good prognosis with early supportive therapy + dialysis Follow-up: check for persistent proteinuria, hypertension, declining renal function ``` Atypical HUS (no diarrhoeal prodrome): may be familial and frequently relapses High risk of hypertension, chronic renal failure, high mortality Intracerebral involvement/atypical HUS: may be treated with plasma exchange or plasma infusions ```

Question 42

Causes of hypertension in children

Answer 42

Renal: renal parenchymal disease, renovascular (eg. renal artery stenosis), polycystic kidney disease (ARPKD and ADPKD), renal tumours Coarctation of the aorta Catecholamine excess: phaechromocytoma, neuroblastoma Endocrine: congenital adrenal hyperplasia, cushing syndrome, corticosteroid therapy, hyperthyroidism Essential hypertension: diagnosis of exclusion

Question 43

Hypertension presentation

Answer 43

``` FTT Cardiac failure Vomiting Headahces Facial palsy Hypertensive: over 95th percentile for height, age, sex Retinopathy Convulsions Proteinuria Paroxysmal palpitations and sweating: phaechromocytoma ```

Question 44

Renal anomalies detectable on antenatal USS screening

Answer 44

Absence of both kidneys (renal agenesis): severe oligohydramnios --> Potter syndrome Multicystic dysplastic kidney: a non-functioning structure with large fluid filled cysts and no renal tissue or connection to the bladder Autosomal dominant or recessive polycystic kidney disease: some renal function is maintained but both kidneys are always affected Pelvic/horseshoe shaped kidneys: predisposed to infection or obstructs drainage Duplex system: varies from a bifid pelvis to complete division and two ureters --> reflux and obstruction Posterior urethral valves: obstruction and reflux Hydronephrosis

Question 45

Antenatal urinary tract abnormalities investigations

Answer 45

USS: provides anatomical assessment but not function DMSA scan: detects functional defects MCUG/VCUG: visualise bladder and urethral anatomy, detect reflux + obstruction MAG3 isotope scan: isotopes excreted from the blood into the urine can be measured Plain abdominal X-ray: spinal abnormalities, renal stones

Question 46

Antenatal urinary tract abnormalities management

Answer 46

Postnatally Prophylactic abx USS delayed for several weeks, unless bilateral hydronephrosis in a male infant (to exclude posterior urethral valves)

Question 47

Hypospadias presentation

Answer 47

Ventral urethral meatus: normally on the glans penis but can be on the corona, shaft or perineum. Hood dorsal foreskin: that has failed to fuse ventrally and a chordae-ventral curvature (of the penis head) (severe hypospadias)

Question 48

Neuropathic bladder symptoms

Answer 48

Urinary incontinence: increased frequency + urgency, dribbling urine, loss of sensation of bladder fullness Urinary tract infection: urine retention Kidney injury: high pressure caused by urine back log Kidney stones: difficult to detect if the child cannot feel pain due to spinal injury Pain, haematuria and fever/chills Erectile dysfunction may present in later life