Paediatric nephrology Flashcards
1
Q
Functions of the kidneys
A
- Waste handling
- Water handling
- Salt balance
- Acid base control
- Endocrine → red cells, blood pressure, bone health
2
Q
Glomerular filtration barrier
A
- Endothelial cells → fenestrated
- Glomerular basement membrane → 2 proteins
- Podocyte → podocin, nephron
- Mesangial cells → support
3
Q
Nephritic vs nephrotic syndrome
A
- Nephritic
- Increasing haematuria
- Intravascular overload
- Nephrotic overload
- Increased proteinuria
- Intravascular depletion
4
Q
Acquired glomerulonephropathy
A
- Minimal change syndrome → podocyte
- Post-infectious glomerulonephritis → Basement membrane and endothelial cell
- Haemolytic-uraemic syndrome → endothelial cell
- IgA nephropathy/ HSP → mesangial cel
- Systemic lupus erythematosis
5
Q
Congenital glomerulonephropathy
A
- Congenital nephrotic syndrome → podocyte cytoskeletal integrity
- Alport syndrome → basement membrane
- Thin basement membrane disease → basement membrane
- Membrano-proliferative glomerulonephritis → complement regulatory proteins
6
Q
Proteinuria: how much is too much
A
- Dipstix → > 3+ abnormal
- Protein creatinine ratio → >250mg/mol
- 24 urine collection (gold standard) → 1g/m2/24 hours
7
Q
Pathophysiology of nephrotic syndrome
A
- Proteinuria
- Hypoalbuminaemia
- Peripheral oedema
8
Q
Clinical features of nephrotic syndrome
A
- Typical
- Age 1-10
- Normal blood pressure
- No frank haematuria
- Normal renal function
- Atypical
- Suggested autoimmune disease
- Abnormal renal function
- Steroid resistance
- Only then consider renal biopsy
9
Q
Management of nephrotic syndrome
A
- PREDNOS → prednisolone in nephrotic syndrome
- 8 weeks
10
Q
Side effects of high dose glucocorticoids
A
- Cushings syndrome
- Personality changes
- Hypertension
- Increased susceptibility to infection
- GI distress/ increased gastric acid
- Growth retardation
- Emotional lability
- Behavioural changes
- Sleep disturbances
11
Q
Steroid resistant nephrotic syndrome
A
- Acquired → focal segmental glomerulosclerosis (FSGS)
- Congenital
- NPHS1 → nephron
- NPHS2 → podocin
12
Q
Haematuria
A
- Macroscopic/ frank
- Micoscopic
- Investigate
- Haemoglobinuria
- associated proteinuria = glomerular disease
13
Q
Causes of haematuria
A
- Lower urinary tract
- Urethritis
- Trauma
- UTI
- Malignancies →
- Upper urinary tract
- Cysts
- Tumours → Wilm’s nephroblastoma
- Glomerulonephritis
- Systemic → clotting disorder
14
Q
Nephritic syndrome
A
- Clinical diagnosis
- Haematuria and proteinuria
- Reduced GFR
- Oliguria
- Fluid overload → oedema and raised JVP
- Hypertension
- Worsening renal failure → rapidly progressive glomerulonephritis
- Intrarenal cause of Acute Kidney Injury (AKI)
15
Q
Acute post-infectious glomerulonephropathy
A
- Between aged 3-5
- Usually group A strept
- Causes beta haemolytic
- Site
- Throat → 7-10 days
- Skin → 2-4 weeks
- Self-limiting
16
Q
Pathogenesis of PIGN
A
- Nephrotgenic antigens on strep
- Binds to specific sites in glomerulus/ formation of antibody-antigen complex deposit in kidneys
- Activation of immune response/ alternative complement pathway
- Acute kidney injury
17
Q
Diagnosis of PIGN
A
- Diagnosis
- Bacterial culture
- Positive ASOT (anti streptolysin O titer)
- Low C3
18
Q
Treatment of PIGN
A
- Antibiotics
- Support renal function → electrolyte/ acid-base balance
- Overload/ hypertension → diuretics
- Outcome → not often recurrent
19
Q
IgA nephropathy
A
- Most common glomerulonephritis
- 1-2 days after URTI
- Older children and adults
20
Q
Differential of Acute post-infectious glomerulonephritis
A
- IgA nephropathy (Berger’s disease)
21
Q
Clinical features of IgA nephropathy
A
- Recurrent macroscopic haematuria
- +/- chronic microscopic haematuria
- Varied proteinuria
22
Q
Pathogenesis of IgA nephropathy
A
- Increased circulating levels of Gd-IgA1
- Production of antibodies in response (IgA or IgG)
- Immune complexes form in kidneys and circulation
- Invasion of immune complexes to mesangium
- Local inflammation and injury
- Glomerunephritis
23
Q
Diagnosis of IgA nephropathy
A
- Negative autoimmune workup
- Normal compliment
- Definitive diagnosis → renal biopsy
*
24
Q
Treatment of IgA nephropathy
A
- Mild → ACEI for proteinuria
- Moderate/ severe → immunosuppression (KDIGO guidelines)
- Outcomes → better in children
25
Henoch Scholein Purpura related to IgA vasculitis
* Age 5-15
* Palpable purpura
* 1 of following
* Abdo pain
* Renal involvement
* Arthritis/ arthralgia
* Biopsy → IgA deposits
26
IgA vasculitis
* Most common vasculitis of children
* Affects small vessels
* Associated with IgA nephropathy
* 1-2 days post-trigger
* Viral URTI
* Streptococcus
* Drugs
* 4-6 week duration
* Mesangial cell injury → nephritis
27
Treatment of IgA vasculitis
* Symptomatic → joints and gut
* Glucocorticoid therapy → only severe and GI related disease
* Immunosuppression → moderate and severe
* Long-term → hypertension and proteinuria screening
28
Definition of Acute Kidney Injury (AKI)
* Acute loss of kidney function leading to:
* Retention of urea and other waste products
* Dysregulated extracellular volume
* Electrolyte imbalance
* Anuria/oliguria **(\<0.5ml/kg/hr for 8 hours)**
* Hypertension of fluid overload
* Raised creatinine \>1.5 age specific reference
29
AKI warning stages
* AKI 1 → 1.5-2x reference creatinine
* AKI 2 → 2-3x reference creatinine
* AKI 3 → \>3x reference creatinine
30
Clinical features of AKI
* Raised urea and creatinine
* Fluid overload
* Hyperkalaemia
* Hyperphosphataemia
* Hyponatraemia
* Hypocalcaema
* Metabolic acidosis / bicarb loss
* Hypertension
31
Management of AKI
* Prevention
* 3 Ms
* Monitor → Paediatric early warning scores, urine output, weight
* Maintain → hydration, electrolytes, acid-base balance
* Minimise → drugs
32
Causes of AKI
* Pre-renal
* Perfusion problems
* Renal
* Glomerular disease
* Tubular injury
* Interstital nephritis
* Post-renal
* Obstructive uropathy
33
Haemolytic-uraemic syndrome (HUS)
* Packed cell volume \>30%
* Haemoglobin level \<10g/dl + fragmented erythrocytes on blood film
* Thrombocytopenia
* AKI
* High serum creatinine
* GFR \< 80ml/min/1.73m2
* Proteinuria
34
Cause of HUS
* Post-diarrhoea
* Entero-haemorrhagic E.coli (EHEC)
* Verotoxin producing
* Shiga toxin producing (STEC)
* Pneumococcal infection
* Drugs
* Atypical HUS
35
Presentation of HUS
* Infection by E.coli 0157:H7
* Up to 14 days post diarrhoea
* Abdominal pain
* Fever
* Vomiting
* Bloody diarrhoea
* Resolution/ HUS (15%)
36
HUS triad
* Microangiopathic haemolytic anaemia
* Thrombocytopenia
* AKI
37
Management of haemolytic uraemia syndrome
* 3 Ms
* Monitor → fluid balance, electrolytes, acidosis, waste, hormones, other organ function
* Maintain → IV saline + fluids, renal replacement therapy
* Minimise → no antibiotics/ NSAIDs
38
Complications of AKI
* Evolution to CKD
* Monitor blood pressure and proteinuria
39
Causes of chronic kidney disease in paediatrics
* Congenital anomalies of the kidneys and urinary tract (CAKUT)
* 55% of paediatric CKD
* Reflux nephropathy
* Dysplasia
* Obstructive uropathy → e.g. posterior urethral valves
* Hereditary conditions
* 17%
* Cystic kidney disease
* Cystinosis
* Glomerulonephritis → 10%
40
Presentation of CKD
* Symptoms variable depending on which function affected
* Waste handling
* Water handling
* Salt balance
* Acid-base control
* Endocrine → red cells/ blood pressure/ bone health
*
41
Obtaining urine specimen in children
* Requires normal social cleanliness
* Clean catch urine or midstream urine
* Collection pads, urine bags → not accurate
* Sick infants → catheter or suprapubic aspiration
* Acutely unwell → **don't delay treatment**
42
Diagnosis of UTI
* Urine dipstix
* Leucocyte esterase activity
* Nitrites
* Unreliable \<2 years old
* Microscopy
* pyuria
* Bacturia
* Culture → \> (10)5 colony → gram negative bacteria e.coli
43
Why are UTI's relevant in paediatrics
* Vesico-ureteric reflux disease → kidney injury
* Graded 1-5
* Higher grade associated with renal dysplasia
* Combination of UTI, vesico-ureteric reflux and vulnerable kidney → permanent scarring
44
What to look out for
* Screening for children at risk of progressive scarring → reflux nephropathy
* Capture those with renal dysplasia
* Urological abnormalities
* Unstable bladder → voiding dysfunction
*
45
Investigations VUR
* Ultrasound → structural
* DMSA (isotope scan) → scarring and function
* Micturating cysto-urethrogram (MAG 3 scan) → dynamic
46
Treatment of UTI
* Lower tract → 3 days oral antibiotics
* Upper tract/ pyelonephritis
* Antibiotics for 7-10 days
* Oral if systemically well
* Prevention → fluids, hygiene, constipatio
* Manage voiding dysfunction
47
Risk factors of developing CKD
* Late referrale
* **Hypertension**
* **Proteinuria**
* Diet high in protein, phosphate and salt
* Poor bone heaoth
* PTH
* Phosphate
* Vitamin D
* Acidosis
* Recurrent UTIs
48
Role fo blood pressure control
* Gold standard to monitor hypertension → risk factor to CKD
* Sphygmomanometer
* Oscillometry
* Prevent white coat effect → 24 hours ambulatory BP
49
Factors affecting BP
* Sex, age, height
50
Criteria for hypertension
* 3 separate ocassiona
* Hypertension → \>95 percentile
* Borderline → \>90 but \<95th percentile
51
Management of CKD
* Depends of kidney function affected
* Waste handling → reduce protein intake
* Water handling → fluid restriction
* Salt balance → reduce salt
* Acid-base control
* Endocrine
* Bladder dysfunction
51
Management of CKD
* Depends of kidney function affected
* Waste handling → reduce protein intake
* Water handling → fluid restriction
* Salt balance → reduce salt
* Acid-base control
* Endocrine
* Bladder dysfunction
52
Metabolic bone disease in CKD
* Kidneys function to excrete phosphate (high phosphate → increase in PTH)
* Kidneys activate vitamin D3
* Treatment
* Low phosphate diet
* Phosphate binders
* Active vitamin D
* Growth hormone → if poor growth
53
Cardiovascular risk in CKD
* Accelerated atherosclerosis
* Traditional risk factors + anaemia/ metabolic bone disease (PTH)
