Nephrology Flashcards Preview

Systems: Paediatrics AB > Nephrology > Flashcards

Flashcards in Nephrology Deck (121)
Loading flashcards...
1
Q

How much blood does the nephron receive?

A

25% of cardiac output per minute

2
Q

How does GFR between neonates and children?

A
  • 20-30ml/minute in neonates

- 90-120ml/minute by age 2 (same as adults)

3
Q

What are the 5 functions of the kidneys?

A
  • Waste handling
  • Water handling
  • Salt balance
  • Acid base control
  • Endocrine (RBC/BP/Bone health)
4
Q

What are the components of the glomerular filtration barrier?

A
  • Endothelial cells
  • GBM
  • Podocytes
  • Mesangial cells
5
Q

What are the features of the endothelial cells of the glomerular filtration barrier?

A
  • Fenestrated

- Vulnerable to immune mediated injury

6
Q

What are the features of the glomerular basement membrane of the glomerular filtration barrier?

A
  • 2 proteins - Type IV collagen (COL4) and laminin
  • Synthesis from podocytes and endothelial cells
  • Mesangial cells playing a role in turnover
7
Q

What are the features of the podocytes in the glomerular filtration barrier?

A

Contain proteins

-Podocin and nephrin

8
Q

What are the features of the mesangial cells in the glomerular filtration barrier?

A
  • Glomerular structural support
  • Embedded in GBM
  • Regulates blood flow of the glomerular capillaries
9
Q

How patients with a glomerulopathy usually present?

A

Blood and/or protein in the urine

10
Q

What does blood/protein in the urine in varying amounts dictate?

A
  • Clinical presentation

- Suggests diagnosisq

11
Q

What does proteinuria signify?

A

Glomerular injury

12
Q

What leans towards nephritic syndrome?

A
  • Increasing haematuria

- Intravascular overload

13
Q

What leans towards nephrotic syndrome

A
  • Increasing proteinuria

- Intravascular depletion

14
Q

What can cause acquired glomerulopathy by affecting the epithelial (podocyte) cells?

A
  • Minimal change disease
  • FSGD
  • Lupus
15
Q

What can cause acquired glomerulopathy by affecting the basement membrane?

A
  • Membranous glomerulopathy
  • Membranoprolifertive glomerulonephritis
  • Post-infection glomerulonephritis
16
Q

What can cause acquired glomerulopathy by affecting the endothelial cells?

A
  • Post-infectious glomerulonephritis
  • Haemolytic uraemic syndrome
  • Membranoproliferative glomerulonephritis
  • Lupus
17
Q

What can cause acquired glomerulopathy by affecting the mesangial cells?

A
  • HSP
  • IgA nephropathy
  • Lupus
18
Q

What can cause congenital glomerulaopathy by affecting the podocyte cytoskeletal integrity?

A

Proteins

  • Podocin (autosomal recessive)
  • Nephrin (autosomal recessive
19
Q

What can cause congenital glomerulopathy by affecting the basement membrane proteins?

A
  • Alport syndrome (X-linked)

- Thin basement membrane disease (autosomal dominant)

20
Q

What can cause congenital glomerulaopthy by affected the endothelial/ microvascular integrity?

A

Complement regulatory proteins (MPGN)

21
Q

What is the definition of nephrotic syndrome?

A

-Nephrotic range proteinuria with hypoalbuminaemia and oedema

22
Q

Why does oedema occur in nephrotic syndrome?

A

Starling’s forces

  • Osmotic vs hydrostatic
  • Protein is a magnet to water
  • Leakage of protein into 3rd space leads to osmotic force
23
Q

How can proteinuria be tested for?

A
  • Dipstix (3 or above= abnormal)
  • Protein creatinine ration (early morning, PR:CR >25mg/mmol= nephrotic range)
  • 24 hour urine collection (>1g/m^2/24 hours= nephrotic range
24
Q

How is nephrotic syndrome diagnosed?

A

Oedema and proteinuria

Urine dipstix

  • Protein 3+
  • Blood 2+ (not frank)

Protein creatinine ration: 1200mg/mmol

Urine Na 10

Bloods

  • Albumin low
  • Normal creatinine
25
Q

What are the atypical features of minimal change disease?

A
  • Suggestions of autoimmune disease
  • Abnormal renal function
  • Steroid resistance
26
Q

What type of nephrotic syndrome is most common in children?

A

Minimal change disease

27
Q

What are the typical features of minimal change disease?

A
  • Age (2-5yrs)
  • Normal blood pressure
  • Resolving microscopic haematuria
  • Normal renal function
28
Q

When should renal biopsy be considered in minimal changed disease?

A

Only if atypical features present

29
Q

What is the treatment for nephrotic syndrome?

A
  • If typical features 8 week course of prednisolone

- Second line immunosupression

30
Q

What are the possible side effects of high dose glucocorticoids?

A
  • Behavioural changes
  • Increased susceptibility to infection so review varicella status and give pneumococcal vaccination
  • Growth disturbance
  • Hypertension
  • GI distress due to increased acid
31
Q

What is the spectrum of idiopathic nephrotic syndrome in childhood?

A
  • Non-relapsing
  • Infrequently relapsing
  • Frequently relapsing
  • Steroid dependent
  • Steroid resistant
32
Q

What is the pathogenesis of minimal change disease?

A
  • Interaction between lymphocytes (T and B cells) and podocytes
  • Affect the integrity of the podocytes leading to loss of size and charge barrier
33
Q

What are the possible outcomes of minimal change disease?

A
  • 95% in remission within 2-4 weeks
  • 80% relapse
  • 80% reach long term remission
34
Q

What are the causes of acquired steroid resistant nephrotic syndrome?

A

Focal segmental glomerulosclerosis

  • Podocyte loss
  • Progressive inflammation and slcerosis
35
Q

What are the congenital causes of steroid resistant nephrotic syndrome?

A
  • NPHS1 – nephrin
  • NPHS 2 – podocin
  • Podocyte loss
36
Q

Give examples of idiopathic nephrotic syndrome.

A
  • Minimal change
  • Focal segmental glomerularsclerosis
  • Membranproliferative glomerulonephritis
37
Q

Give examples of acquired nephrotic syndrome.

A
  • HSP/IgA
  • Lupus
  • Post infectios
38
Q

What is the approach to haematuria?

A

Macroscopic
-Investigated

Microscopic

  • Investigated if trace on more than 2 occasions
  • Haemoglobulinaria is dipstix positive and microscopy negative

Persistent haematuria and proteinuria
-Glomerular disease

39
Q

What can cause haematuria?

A

Glomerulonephritis

  • Post-infectious
  • IgA/HSP
  • UTI (dysuria)
  • Trauma
  • Stones (pain)
40
Q

How does nephritic syndrome present?

A

Haematuria and proteinuria

Reduced GFR

  • Oliguria
  • Fluid overload (raised JVP and oedema)
  • Hypertension
  • Worsening renal failure
41
Q

What type of AKI can nephritic syndrome cause?

A

Intrarenal AKI

42
Q

Give examples of causes of glomerulonephritis.

A
  • Post Infectious GN
  • HSP / IgA nephropathy
  • Membranoproliferative GN
  • Lupus Nephritis
  • ANCA positive vasculitis
43
Q

What age group is usually affected by post-infectious GN?

A

Usually 2-5 years

44
Q

What is usually the cause of post-infectious GN?

A
  • Group a B-haemolytic streptococcus
  • From throat 7-10 days
  • From skin 2-4 weeks
45
Q

What is the pathogenesis of post-infectious GN?

A
  • Nephrogenic antigens on strep
  • Bind to specific sites in the glomerulus or antibodies bin Ag forming circulating complexes and deposits in the kidneys
  • Set up humeral and cellular response and activates alternative complement pathway
  • AKI
46
Q

How is post-infectious GN diagnosed?

A
  • Bacterial culture
  • Positive ASOT
  • Low C3 normalises
47
Q

What is the prognosis of post-infectious GN?

A

Good prognosis with no recurrence

48
Q

How is post-infectious GN treated?

A

Antibiotic for group A strep

  • Support renal functions
  • Overload / hypertension (give diuretics)
49
Q

What is the most common GN worldwide?

A

IgA nephropathy

50
Q

Who does IgA nephropathy usually affect?

A

Older children and adults 1-2 day after an URTI

51
Q

How does IgA nephropathy present clinically?

A
  • Recurrent macroscopic haematuria
  • +/-Chronic microscopic haematuria
  • Varying degree of proteinuria
52
Q

What is the pathogenesis of IgA nephropathy?

A
  • Increased circulating levels of GD-IgA
  • Production of anti IgA1 antibodies (IgA or IgG)
  • Immune complexes form in the circulation and in situ-Immune complexes in the mesangium cause local immune activation and injury
53
Q

How is IgA nephropathy diagnsosed?

A

Clinical picture
-Negative autoimmune workup
Normal compliment

Confirmation biopsy

54
Q

How is IgA nephropathy treated?

A

Mild disease
-Proteinuria with ACEI

Moderate to sever disease
-Immunosuppression (KDIGO)

55
Q

What is the outcome of IgA nephropathy?

A
  • Variable
  • 25% in ESRF by 10 years
  • Outcome better in children
56
Q

What is the age of onset for HNS?

A

5-15 years old

57
Q

How is a clinical diagnosis of HNS made?

A

Mandatory palpable purpura plus 1 of:

  • Abdominal pain
  • Renal involvement
  • Arthritis or arthralgia
  • Biopsy (IgA deposition)
58
Q

What is the most common childhood vasculitis?

A

IgA vasculitis

59
Q

How is IgA vasculitis triggered?

A

Occurs 1-3 days post trigger

  • Viral URTI in 70%
  • Strep, drugs
60
Q

What is the duration of symptoms in IgA vasculitis?

A
  • 4-6 weeks

- 1/3rd then relapse

61
Q

What is the treatment for IgA vasculitis?

A
  • Symptomatic treatment for joints and gut
  • Glucocorticoid therapy (May help GI involvement but not useful in renal disease)
  • Immunosuppression (trial in mod-sever disease)
  • Long term hypertension and proteinuria screening
62
Q

What is AKI?

A

Abrupt loss of kidney function, resulting in the retention of urea and other nitrogenous waste products and in the dysregulation of extracellular volume and electrolytes

63
Q

What are the clinical features of AKI?

A
  • Anuria/oliguria (<0.5ml/kg/hr)
  • Hypertension with fluid overload
  • Rapid rise in plasma creatinine
64
Q

How is AKI defined?

A

Serum creatinine: > 1.5x age specific reference creatinine (or previous baseline if known)

Urine output<0.5 ml/kg for > 8hours

65
Q

What is AKI 1?

A

Measured creatinine >1.5-2x reference creatinine/ULRI

66
Q

What is AKI 2?

A

Measured creatinine 2-3x reference creatinine/ULRI

67
Q

What is AKI 3?

A

Serum creatinine >3x reference creatinine/ULRI

68
Q

How is AKI managed?

A

Monitor
-Urine output, PEWs, BP, weight

Maintain
-Good hydration

Minimise
-Drugs

69
Q

What causes pre-renal AKI?

A

Perfusion problem

70
Q

What are the intrinsic causes of AKI?

A

Glomerular disease

  • HUS
  • Glomerulonephritis

Tubular injury: Acute tubular necrosis (ATN)

  • Consequence of hypoperfusion
  • Drugs

Interstitial nephritis
-NSAID, autoimmune

71
Q

What causes post-renal AKI?

A

Obstruction

72
Q

What causes atypical HUS?

A
  • Autoimmune process

- Can be congenital or acquired

73
Q

What can cause HUS?

A

Typical: post-diarrhoea
-Entero-haemorrhagice E. coli (vertoxin producing E.coli or Shiga toxin

Other causes
-Pneumococcal infection, drugs

74
Q

What serotype of E.coli is responsible for HUS?

A

E.coli O157

75
Q

What is the period of risk of HUS with E coli O157 infection?

A
  • Up to 14 days after the onset of diarrhoea

- 15% develop HUS

76
Q

What is blood diarrhoea in children?

A

Medical emergency

77
Q

What organs are vulnerable in shiga toxin dissemination?

A
  • Kidneys
  • Brain
  • Lungs
  • Pancreas
  • Adrenals
  • Heart
78
Q

What is the triad of HUS?

A
  • Microangiopathic haemolytic anaemia
  • Thrombocytopenia
  • Acute renal failure / AKI
79
Q

How is HUS managed?

A

Monitor (5 kidney functions)

  • Fluid balance, electrolytes, acidosis
  • Hypertension
  • Aware of other organs

Maintain

  • IV normal saline and fluid
  • Renal replacement therapy

Minimise
-No antibiotics

80
Q

What are the potential long term consequences of AKI?

A
  • Blood pressure
  • Proteinuria monitoring
  • Evolution to CKD
81
Q

What can cause paediatric CKD?

A

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) 55%

  • Reflux nephropathy
  • Dysplasia
  • Obstructive Uropathy (example - posterior urethral valves)

Hereditary conditions 17%

  • Cystic kidney disease
  • Cystinosis (most common inherited tubular disease)

Glomerulonephritis 10%

82
Q

What syndromes may be associated with CAKUT?

A
  • Turner
  • Trisomy 21
  • Branchio-oto-renal
  • Prune Belly syndrome
83
Q

What are the stages of CKD?

A
  • Normal: GFR 90-120
  • CKD 2: GFR 60-89
  • CKD 3: GFR 30-59
  • CKD 4: GFR 15-29
  • CKD 5: ESRD
84
Q

What is presentation of CKD dependent on?

A

Which kidney functions are affect

85
Q

How can CKD present?

A

Asymptomatic

Abnormalities in

  • Waste handling
  • Water handling
  • Salt balance
  • Acid base control
  • Endocrine functions

Bladder dysfunction

Itch

86
Q

How does NICE define UTI?

A

Clinical signs PLUS

  • Bacteria culture from midstream urine
  • Any growth on suprapubic aspiration or catheter
87
Q

How do neonates present with UTI?

A
  • Fever
  • Vomiting
  • Lethargy
  • Irritability
  • Poor feeding
  • Failure to thrive
88
Q

How do pre-verbal children present with UTIs?

A
  • Fever
  • Abdominal pain
  • Abdominal/loin tenderness
  • Vomiting
  • Poor feeding
  • Lethargy
  • Irritability
89
Q

How doe verbal children present with UTI?

A
  • Frequency
  • Dysuria
  • Dysfunctional voiding
  • Changes to continence
  • Abdominal/loin pain or tenderness
  • Fever
  • Malaise
  • Vomiting
90
Q

How can urine samples be obtained in children?

A
  • Normal social cleanliness - water
  • Clean catch urine or midstream urine
  • ?? collection pads, urine bags (contamination risks)
  • Sick infants via catheter samples or suprapubic aspiration (USS)
  • Acutely unwell - do not delay treatment to obtain sample
91
Q

How is UTI diagnosed?

A

Suggestive tests

  • Dipstix: Leucocyte esterase activity, nitrites but unreliable < 2 yrs of age
  • Microscopy: Pyuria >10 WBC per cubic mm and bacturia

Culture > 105 Colony forming units
-E.coli

92
Q

Why do we worry about UTIs?

A
  • UTI on top of vulnerable kidney with VUR can lead to scarring
  • Scarring predisposes to future problems
93
Q

How is VUR graded?

A

Unilateral/bilateral

  • Grade1: Ureter only
  • Grade2: Ureter, pelvis and calyces
  • Grade3: Dilatation of ureter
  • Grade4: Moderate dilatation of ureter, pelvis, tortuous ureter and obliteration of fornices
  • Grade5: Gross dilatation/tortuosity, no papillary impression in calyces
94
Q

What are the principles of investigating the renal tract?

A

Screening for children at risk of progressive scaring
-Reflux nephropathy

Capture those with renal dysplasia

Urological abnormalities / unstable bladder
-Voiding dysfunction

95
Q

Who should be investigated with UTI?

A
  • Upper tract symptoms
  • Younger <6 months
  • Recurrent
  • Septic presentation
96
Q

What investigations are used in complex UTI?

A

Ultrasound
-Structure

DMSA (isotope scan)
-Scaring/function

Micturating cystourethrogram MAG 3 scan
-Dynamic

97
Q

How are UTIs treated?

A

Lower tract
-3 days oral antibiotic

Upper tract / pyelonephritis
-Antibiotics for 7-10 days (Oral if systemically well_
-Prophylaxis is falling out of favour unless anatomical abnormality or high grade VUR
Prevention

98
Q

How can UTIs be prevented

A
  • Fluids, hygiene, constipation treatment

- Voiding dysfunction

99
Q

What factors affect progression of CKD?

A
  • Late referral
  • Hypertension
  • Proteinuria
  • High intake of protein, phosphate and salt
  • Bone health
  • Acidosis
  • Recurrent UTIs
100
Q

What is proteinuria a sign of in CKD?

A

Renal injury and causes ongoing renal injury

101
Q

What system is used to classificy CKD and prognosis?

A

KDIGO

102
Q

How is BP measured in children?

A

Doppler
-Children under 5

Sphigmanomter

Oscillomerty

White coat effect use 24 hour Ambulatory Blood Pressure Monitoring
-Need to be about 120cm (5/6 years of age to tolerate)

103
Q

What factors affect blood pressure?

A
  • Sex
  • Age
  • Height
104
Q

How is hypertension defined in a child?

A

95th centile or higher

105
Q

What is considered borderline in terms of hypertension in children?

A

Between the 90th and 95th centiles

106
Q

Why does bone disease occur in kidney disease?

A
  • Kidneys excrete phosphate.
  • Damage leads to high levels of phosphate and therefore high levels of PTH
  • PTH aims to increase serum calcium and so drives calcium out of the bones
  • Kidney unable to activate vitamin D. Activated vitamin D would normally suppress PTH
107
Q

How is metabolic bone disease treated?

A
  • Low phosphate diet
  • Phosphate binders
  • Active Vitamin D

If ongoing poor growth then growth hormone (if normalised bone biochemistry)

108
Q

Why is there increase cardiovascular risk in kidney disease?

A

Accelerated atherosclerosis

  • Traditional risk factors
  • Anaemia and metabolic bone disease (high PTH levels)
109
Q

How can cystic renal disease be defined?

A

Simple

Developmental

  • Dysplasia
  • Multicystic dysplastic

Genetic

  • Autosomal Recessive (ARPKD)
  • Autosomal Dominant (ADPKD)
  • Syndromic (Various forms of Juvenile Familial Nephronophthisis (JFN))

Acquired
-Cancer

110
Q

What is the incidence of developmental multicystic kidney?

A

1 in 2,000-4,000 (usually sporadic)

111
Q

How does developmental multicystic kidney present?

A

Non-functioning kidney
Ureteric atresia
Hypertrophy of the normal contralateral kidney

112
Q

What is Potter sequence?

A
  • Decreased amniotic fluid
  • Pulmonary hypoplasia
  • Fetal compression of faces, contracture
  • Bilateral renal agenesis (absent ureteric bud)
  • AR polycystic kidney disease (truncating mutation)
113
Q

How do babies with autosomal recessive polycystic kidney disease present?

A
  • Antenatally large bright kidneys
  • Oligohydramnios
  • Severe respiratory distress (pulmonary hypoplasia, nephromegaly mass effect)
114
Q

What are the target organs in ARPKD?

A
  • Renal collecting duct

- Hepatic ductal plate

115
Q

What are the target organs in ADPKD?

A
  • All nephron segments
  • Liver
  • Pancreas
  • Brain
116
Q

What are the target organs in nephronophthisis?

A
  • Tubular (medullary)cysts
  • Retina
  • Liver
  • Brain
  • Bones
117
Q

What are the clinical features of ciliopathy syndromes?

A
  • Renal cysts on US
  • Retinal pigment increases
  • Cystic tubular dilatation on renal biopsy
  • Cerebellar vermis aplasia (molar tooth sign)
118
Q

What is RCAD?

A

Renal cysts and diabetes

-Autosomal dominant glomerulocystic kidney disease

119
Q

How does RCAD present?

A
  • US - cortical cysts
  • Early onset diabetes mellitus (MODY)
  • Genetic heterogeneity (HNF1β mutations)
120
Q

What is Alport syndrome?

A
  • Glomerular Basement Membrane disease
  • Collagen 4 abnormalities
  • X linked dominant inheritance (COL4A5 gene on the X chromosome)
  • Less common AR and AD inheritance
121
Q

What is the clinical presentation of Alport syndrome?

A

Renal

  • Haematuria - microscopic and macroscopic
  • Proteinuria
  • Hypertension

Deafness - high tone sensori-neural loss

Renal failure in early adult life
-Age 20-30 years

Eye changes

  • Lenticonus
  • Macular changes in retina