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Flashcards in Nephrology Deck (117):
1

What are the causes of dehydration?

Hypotonic dehydration
- Decreased intake: inadequate sodium intake after vomiting/diarrhea
- Increased loss
   >> Adrenal failure (e.g. CAH)
   >> Adrenalectomy
   >> Thiazide diuretics
   >> Diarrhea/fistula Isotonic dehydration
- GI losses
   >> Vomiting
   >> Diarrhea
   >> Fistulae
   >> GI bleeding
- Skin losses
   >> Fever
   >> Burns

Hypertonic dehydration
- Decreased water intake
   >> Acute illness
   >> Breast feeding
   >> Eating disorders
- Increased water loss
   >> Sweating
   >> Urinary loss
        :: Osmotic diuresis by DKA/hyperglycemia
        :: Diuretics
        :: Diabetes insipidus
        :: Post-ATB recovery diuresis/polyuric phase of ARF
        :: Chronic nephropathy
   >> Respiratory loss
        :: Hyperventilation
        :: Bronchiolitis
        :: Pneumonia

2

How do we grade the severity of dehydration?

>2 years of age
- Mild: 3%
- Moderate: 6%
- Severe: 9%

<2 years of age
- Mild: 5%
- Moderate: 10%
- Severe: 15%

3

What are the clinical parameters used to assess the degree of dehydration?

- Eyes: normal or sunken
- Skin tugor: normal, decreased or tenting
- Oral mucosa: dry or moist
- Capillary refill: instantaneous or >3 seconds
- Anterior fontanelle: normotensive or sunken?
- Pulse
- Blood pressure
- Urine output

C BASE H2O
Capillary refill
Blood pressure
Anterior fontanelle
Skin tugor
Eyes sunken
Heart rate
Oral mucosa
Output of urine

+ Decreased body weight

The first thing to go is URINE OUTPUT

4

What is nephritic syndrome?

Acute or chronic syndrome affecting the kidney,
characterized by glomerular injury and inflammation

HEMATURIA (>5RBCs/>10RBCs per high-powered microscopy field - Canada/UK) with the presence of dysmorphic RBCs and RBC casts on urinalysis

Often accompanied by at least one of the following:
- Proteinuria (<50mg/kg/day)
- A: Azotemia
- R: RBC casts in urine
- O: Oliguria
- H: Hypertension

5

What is the most common cause of acute glomerulonephritis in paediatrics?

Post-infectious/post-streptococcal glomerulonephritis

6

What is the cause of hypertension in nephritic syndrome?

- Fluid retention
- Increased renin secretion by ischemic kidneys

7

What is the most common cause of hematuria in children?

Urinary tract infection (but rarely as the only symptom)

8

When is a renal biopsy indicated in hematuria?

- Significant persistent proteinuria
- Recurrent macroscopic hematuria
- Renal function is abnormal
- Complement levels are persistently abnormal

9

When is a renal biopsy indicated in nephritic syndrome?

- No evidence of streptococcal infection
- Normal C3/C4 levels
- Acute renal failure (abnormal renal function)

10

When is a renal biopsy indicated in nephrotic syndrome?

Age of onset
- Presentation before first year of life (likely to be congenital nephrotic syndrome)
- Presentation after 12 years of life (need to rule out more serious renal pathology than minimal change disease)

Clinical features at presentation
- Hypertension (increased risk for focal segmental glomerular sclerosis)
- Gross hematuria
- Abnormal renal function
- Low serum C3/C4

Management response
- No response to steroids after 4 weeks of therapy
- Frequent relapses: >2 relapses in 6 months

11

What is the classical clinical course of post-streptococcal nephritis?

Following a streptococcal pharyngitis or skin infection with evidence of a recent streptococcal infection by:
- Culture of the organism (throat swab)
- Raised anti-streptolysin O (ASO) titres
- Anti-DNAse B titres

Also characterized by low complement C3 levels that RETURN TO NORMAL after 3-4 weeks

12

What are the characteristic clinical features of Henoch-Schonlein purpura?

- Palpable rash over the buttocks and extensor surfaces of the bilateral lower limbs
- Abdominal pain
- Arthralgia with periarticular edema
- Hematuria/glomerulonephritis

>> Usually preceded by an URTI
>> Usually between ages 3-10 years
>> M:F 2:1
>> Gastrointestinal petechiae can cause hematemesis and melena
>> Associated with intussusception

13

What are the causes of hematuria?

Hematological/Vascular causes
- Sickle cell anemia
- Bleeding disorders: e.g. hemophilia, vWF disease
- Renal vein thrombosis

Lower urinary tract/Nonglomerular
- Urinary tract infections
   >> Bacterial
   >> Viral
   >> TB
   >> Schistosomiasis
- Trauma
- Stones/Hypercalciuria
- Tumours

Upper urinary tract/Glomerular
- Nephritic syndrome
   >> Acute glomerulonephritis (+/- proteinuria)
   >> Chronic glomerulonephritis (+/- proteinuria)
   >> IgA nephropathy
   >> Familial nephritis (Alport syndrome)
   >> Thin basement membrane disease
   >> Can also classify by primary/secondary and normal/decreased C3 levels

14

Name the causes of nephritic syndromes that are associated with decreased C3 levels.

Primary
- Post-streptococal/post-infectious glomerulonephritis
- Membranoproliferative glomerulonephritis

Secondary
- SLE (systemic lupus erythematosus)
- Bacterial endocarditis
- Abscess/shunt nephritis
- Cryoglobulinemia

15

What are the four types of rapidly progressive glomerulonephritis/crescentic glomerulonephritis?

Type I: Anti-GBM Mediated
- With lung hemorrhage: Goodpasture's disease
- Without lung hemorrhage: Anti-GBM disease

Type II: Immune-complex mediated
- C3 normal
   >> IgA nephropathy
   >> Henoch-Schonlein Purpura
- C3 decreased
   >> Membranoproliferative GN
   >> Post-infectious GN
   >> Systemic lupus erythematosus (SLE)
   >> Bacterial endocarditis
   >> Cryoglobulinemia

Type III: Non-immune mediated
- c-ANCA (anti-neutrophil cytoplasmic antibody) +
   >> Granulomatosis with polyarteriitis
- p-ANCA +
   >> Churg-Strauss disease
   >> Microscopic polyangiitis

Type IV: Double antibody positive disease
- Features of type I and III combined
- Double antibody positive

16

What are the causes of nephritic syndrome?

Primary
- Decreased C3 levels
   >> Post-streptococcal GN
   >> Membranoproliferative GN
- Normal C3 levels
   >> IgA nephropathy
   >> Idiopathic rapidly progressive GN (RPGN)
   >> Anti-GBM disease

Secondary
- Decreased C3 levels
   >> SLE
   >> Bacterial endocarditis
   >> Cryoglobulinemia
   >> Shunt nephritis/abscess
- Normal C3 levels
   >> Goodpasture's syndrome
   >> Henoch-Schonlein Purpura
   >> Polyarteritis nodosa
   >> Granulomatosus with polyarteriitis

17

What are the investigations that will be helpful in cases of nephritic syndrome?

Urine
- Dipstick: hematuria and 0-+2 proteinuria
- Microscopy: >5 RBCs/HPF, RBC casts and acanthocytes

Bloods
- CBC: mild anemia from hematuria
- RFT
   >> Increased Cr and BUN
   >> Hyperkalemia
   >> Hyperphosphatemia
   >> Hypocalcemia
- LFT
   >> Hypoalbuminemia from proteinuria
- ABG
   >> pH decreased: impaired H excretion in the kidneys
- Bloods to determine etiology:
   >> C3/C4 levels
   >> ASO titre and anti-DNAse B
   >> ANA, ANCA (c-ANCA and p-ANCA), anti-dsDNA Ab
   >> Anti-GBM Ab
   >> Serum IgA levels
   >> Cryoglobulins

Renal biopsy (indicated when:)
- Acute renal failure
- No evidence of streptococcal infection
- Normal C3/C4 levels Imaging
- Renal USG to R/O oubstruction

Audiology if Alport's syndrome is suspected (less in nephritic syndrome)

18

What are the possible complications of nephrotic syndrome?

- Hypertension
- Heart failure
- Pulmonary edema
- Chronic kidney injury requiring renal transplant

19

What is the typical age of presentation in children for nephritic syndrome?

5-15 years of age

20

What is the typical age of presentation in children for nephrotic syndrome?

2-6 years of age (M>F)

21

What is the most common cause of nephrotic syndrome in children?

Minimal change disease (glomerular infiltration absent on renal biopsy) -- >90%

22

What is the management plan for nephritic syndrome?

- Monitoring >> Serial BP >> Daily urinalysis >> Daily body weight >> Accurate I&O chart - Supportive treatment: consider dialysis if severe - Adequate hydration - Fluid and salt restriction with diuretics if edema is present - Consider ACEI/ARBs in hypertension, but avoid in acute cases as these drugs can further decrease GFR

23

What is nephrotic syndrome?

Clinical syndrome affecting the kidney:

P: Proteinuria (>50mg/kg/day)
A: HypoAlbuminemia (<20g/L)
L: HyperLipidemia
E: Edema

24

What is the earliest sign of nephrotic syndrome in children?

Periorbital edema particular on waking

>> Edema is gravity-dependent: periorbital edema decreases with pretibial edema increases over the day

25

What are the clinical signs of nephrotic syndrome?

- Periorbital edema upon waking
- Scrotal/vulval, leg and ankle edema
- Breathlessness from pleural effusions and abdominal distention (ascites)
- Foamy urine as a possible sign of proteinuria

26

What are the features suggestive of steroid-sensitive nephrotic syndrome?

- Age: 1-10 years
- No macroscopic hematuria
- Normal blood pressure
- Normal renal function
- Normal complement levels

 

>> Often precipitated by respiratory infections (similar to HSP and ITP!!!)

27

What are the physiological causes of proteinuria?

Transient proteinuria
- Febrile illnesses
- After exercise
- Does not require investigations

Orthostatic proteinuria
- Only found when the child is upright/during the day
- Dx: early morning urine protein/creatinine ratio in series
- Prognosis is excellent

28

What are the causes of proteinuria in children?

Physiological
- Orthostatic proteinuria
- Transient proteinuria from febrile illnesses/exercise


Pathological
- Overflow
   >> Multiple myeloma
   >> Amyloidosis
   >> Waldenstrom's macroglobulinemia
- Tubular: Fanconi's syndrome
- Glomerular
   >> Primary
         :: Minimal change disease
         :: Focal segmental glomerular sclerosis
         :: Membranoproliferative glomerulonephritis
         :: IgA nephropathy
   >> Secondary
         :: Infections: HIV, HBV, HCV, post-strep, bacterial endocarditis
         :: Inflammatory/Autoimmune: SLE, JIA, RA, DM, vasculitis (HSP, GPA)
         :: Malignancies: lymphoma, leukemia
         :: Genetic: Alport syndrome, sickle cell disease, polycystic kidney disease
         :: Medications: captopril, NSAIDs, anticonvulsants

29

What are the presenting features of nephrotic syndrome?

Nonspecific signs
- General malaise
- Weakness
- Anorexia
- Nausea and vomiting
- Diarrhea
- Irritability
- Dull lumbar pain

Edema
- Periorbital and pretibial edema
- Scrotal/labial edema
- Breathlessness from pleural effusions and ascites

Glomerular leakage
- Hematuria
- Proteinuria (foamy urine)

Glomerular blockage
- Edema (refer to above)
- Hypertension
   >> Encephalopathy
   >> Congestive heart failure

30

What is the definition of acute glomerulonephritis?

Acute inflammatory process of presumed immunological origin affecting predominantly or exclusively the glomerulus - nephritic syndrome is only one of the clinical manifestations

31

What is the prognosis of post-streptococcal glomerulonephritis?

- 90% complete recovery
- Mortality 0.5-2% in acute stage
   >> Uremia
   >> Heart failure
   >> Encephalopathy
- Morbidity: <10% develop chronic renal failure

32

What are the C3/C4 levels in post-streptoccocal glomerulonephritis?

C3 levels are typically decreased with subsequent recovery in 4-6/6-8 weeks


C4 levels are typically normal.
If depressed, one must rule out the following:
- SLE
- MPGN
- Bacterial endocarditis with renal involvement


>> Failure to recover is a poor prognostic sign indicating chronic glomerulonephritis

33

What is the specific management for post-streptococcal glomerulonephritis?

- Oral penicillin x 10 days
- Salt and fluid restriction with I.V. frusemide
- IM hydralazine for moderate hypertension
- Aggressive treatment for hypertensive encephalopathy
- Dialysis when indicated
- NOT STEROIDS NECESSARY


Follow-up
- 4-6 weeks clinic visits for 6 months
   >> Urinalysis
   >> BP measurement
- Hypertensive control

34

What are the indications for renal biopsy in post-streptococcal glomerulonephritis?

- Rapidly deteriorating renal function
- Atypical presentation
   >> Anuria
   >> Nephrotic syndrome
   >> Severe azotemia
   >> Lack of evidence of streptococal etiology
   >> Family or personal history of renal disease
   >> Systemic evidence for SLE etc.
- Delay in resolution
   >> Oliguria and/or azotemia persisting beyond 2 weeks
   >> Hypertension/gross hematuria persisting beyond 3 weeks
   >> Low C3 beyond 6 weeks
   >> Persistent proteinuria with or without hematuria beyond 6 months
   >> Persistent hematuria beyond 12 months

35

What is the most accurate predictor for eventual renal failure in Henoch-Schonlein Purpura?

Persistence of nephrotic-range proteinuria (>50mg/kg/day; >40mg/m2/hour)

36

How do we quantify response to treatment in nephrotic syndrome?

Reduction in rate of urinary excretion of protein to <4mg/m2/hr (albustix 0-trace) for 3 consecutive days

37

How do we quantify a relapse of nephrotic syndrome?

Reappearance of proteinuria >=3+ on albustix or >=4mg/m2/hr for 3 consecutive days

38

What is the definition of frequent relapse in nephrotic syndrome?

- 2 relapses within 6 months of the initial response
- 4 or more relapses within any 12-month period

39

How do we define steroid dependency in nephrotic syndrome?

- Relapse within 14 days after the end of a course of therapy
- Relapse during the tapering regimen

40

What are the investigations to help diagnose the nephrotic syndrome and its cause?

Urine
- Dipstick: proteinuria and microscopic hematurita
- Microscopy: hyaline casts
- First morning urine protein/creatinine ratio >0.2g/mmol

Blood
- RFT
   >> Hyponatremia
   >> Hyperkalemia
   >> Hypocalcemia
   >> Increased creatinine and BUN
- LFT
   >> Hypoalbuminemia
- Lipid profile
   >> Hypercholesterolemia (TC >5mmol/L)
   >> Hyperlipidemia
- To rule out secondary causes
   >> CBC and smear
   >> C3/C4 levels
   >> ANA and other autoimmune markers
   >> ASOT, HBV/HCV titres, HIV serology etc.

Renal biopsy when indicated

41

What are the diagnostic investigation results for nephrotic syndrome?

- Hypoalbuminemia (5mmol/L TC)

42

What is the treatment regimen for minimal change disease?

Oral prednisone 60mg/m2/day in 3 divided doses for 6 weeks + 40mg/m2 single morning dose in alternate days for 6 weeks

Relapse: oral prednisone 60mg/m2/day until protein free for 5 out of 7 days + 35mg/m2 single morning dose in alternate days for 4 weeks

43

What is the management plan for frequent relapsers of minimal change disease?

Oral prednisone 60mg/m2/day until protein-free urine for 5 out of 7 days + 35mg/m2 single morning dose in alternate days for 4 weeks
(same as for relapse)


Alternative treatment
- Cyclophosphamide x 8-12 weeks (+ prednisone)
- Cyclosporin x 6 months
   >> Need renal monitoring
   >> Indicated in steroid dependence with toxicity after 1 course of cyclophosphamide
   >> Indicated in steroid dependence in pre-pubertal boys
- Levamisole alternate days for 6m-1y
   >> Usually used as an adjunct
   >> S/E: Leucopaemic, rash

44

What is the management plan for nephrotic syndrome?

- Treatment of underlying disease (e.g. oral prednisone)
- Symptomatic treatment
   >> Edema: salt and water restriction; furosemide + albumin if severe
   >> Hyperlipidemia: usually resolves with remission
   >> Hypoalbuminemia: usually resolves with remission
   >> BP changes: control and monitor
   >> Secondary infections (peritonitis)
        :: Parenteral penicillins for gram positives
        :: Parenteral aminoglycosides for gram negatives
   >> Watch out for hypercoagulability (rare in Chinese)
- Diet: supplement with Ca and vit D if on steroids
- Monitoring
   >> Daily weight
   >> Blood pressure

45

What are the complications of nephrotic syndrome?

Increased risk of infections
- Spontaneous peritonitis
- Cellulitis
- Sepsis

Hypercoagulability: decreased intravascular volume and antithrombin III depletion
- Pulmonary embolism
- Renal vein thrombosis

Others
- Intravascular depletion >> shock
- Renal failure
- Drug side effects (Cushing's syndrome)

46

What is the rate of relapse in minimal change disease?

80%

>> Usually sustained remission with normal kidney function by adolescence

47

What is the definition of acute kidney injury (AKI)?

- Reversible increase in Cr and BUN/nitrogenous waste
- Inability to regulate fluid and electrolyte homeostasis

48

How do we classify acute kidney injury?

pRIFLE classification

R: Risk ----------- U/O <0.5mg/kg/hour x 8 hours
I: Injury ----------- U/O <0.5mg/kg/hour x 16 hours
F: Failure -------- U/O <0.5mg/kg/hour x 24 hours; Anuric x 12 hours
L: Loss ----------- Persistent failure x 4 weeks
E: End-stage --- Persistent failure x 3 months

49

What is the definition of oliguria?

Newborn: <0.5mL/kg/hr
Infants: <1.0m/kg/hr
Children: <200mL/m2/day
Adolescents or adults: <400mL/1.73m2/day

50

What is the blood volume of term newborns?

80mL/kg >> Easily over-hydrated

51

What are the risk factors for acute kidney injury in children?

- Sepsis and toxemia
- Hypotension and hypovolemia
- Hypoxia and acidosis
- Anesthesia
- Surgery and/or trauma
- Chronic disease states
- Nephrotoxic agents

52

What is the management plan for AKI?

1. Assess the volume status
2. Optimize:
     >> Circulation
     >> Blood pressure
     >> Hematocrit
     >> Oxygen delivery
3. Restore renal:systemic vascular resistance ratio
     >> Ionotropic agents: dopamine
     >> Furosemide: synergistic with dopamine (do NOT use in volume depletion)
     >> Calcium channel blocker

53

What are the indications for dialysis in AKI?

Due to complications of AKI itself
- Fluid overload unresponsive to conservative management
   >> Congestive heart failure
   >> Pulmonary edema
   >> Severe hypertension +/- encephalopathy
- Life-threatening/uncontrollable metabolic disturbances
   >> Hyperkalemia
   >> Intractable metabolic acidosis
   >> Hyperuricemia
   >> Hyperphosphatemia
- Symptomatic azotemia leading to lethargy or seizures
- Prolonged oliguria with problematic nutritional support


Due to underlying etiology
- Poisoning due to dialyzable compounds
- Tumour-lysis syndrome
- Hyperammonemia
- Organic acidemia

54

Why are antibiotics contraindicated in hemolytic uremic syndrome?

Death of bacteria leads to increased toxin release and worsens clinical outcome

55

What are the presenting features of hemolytic uremic syndrome?

- Non-immune microangiopathic hemolytic anemia
- Thrombocytopenia
- Acute renal failure

56

What are the types of HUS (hemolytic uremic syndrome)?

Diarrhea-positive: 90% (E. coli O157:H7 shiga-like toxin)

Diarrhea-negative
>> No prodrome of diarrhea
>> Other bacteria, viruses, familial causes and drugs

If presents with fever and seizure: thrombocytopenic purpura (TTP)

57

What is the pathophysiology of hemolytic uremic syndrome (HUS)?

Toxin invades and destroys colonic epithelial cells >> bloody diarrhea

Toxin enters systemic circulation >> injures endothelial cells,
especially in the kidney >> renal failure

Toxin causes platelet/fibrin thrombi in multiple organ systems >>
thrombocytopenia and microangiopathic hemolytic anemia

58

What are the investigations useful for diagnosing HUS?

Bloods
- CBC: anemia and thrombocytopenia
- Blood smear: schistocytosis
- RFT: renal failure (Cr/BUN increased)

Urine
- Urinalysis: microscopic hematuria

Stool
- Culture and stain
- Verotoxin/shigella toxin assay

59

What is the management for HUS?

MAINLY SUPPORTIVE

- Nutrition/Hydration
- Ventilation
- Blood transfusion
- Monitoring
- Dialysis if indicated

RMB:
>> Steroids are NOT helpful
>> Antibiotics are CONTRAINDICATED as the death of bacteria leads to increased toxin release and worse clinical course

60

What is the prognosis of HUS?

>95% survive the acute phase

~10-30% have renal damage

61

What are the differential diagnoses for antenatal hydronephrosis?

- Urethrovesicular junction obstruction
- Posterior urethral valve in boys
- Vesicoureteric reflex
- Duplication anomalies
- Ureterocele
- Ectopic ureter
- Multi-cystic dysplastic kidney

62

What is the most common congenital obstructive urethral lesion in males?

Posterior urethral valve

63

What is the presentation of posterior urethral valve?

Age-dependent

1. Antenatal
   - Bilateral hydronephrosis
   - Distended bladder
   - Oligohydramnios
2. Neonatal, recognized at birth
   - Palpable abdominal mass
   - Ascites from transudation of retroperitoneal urine
   - Respiratory distress from pulmonary hypoplasia due to oligohydramnios
   - Weak urinary stream
3. Neonatal, not recognized at birth
   - Urosepsis
   - Dehydration
   - Electrolyte abnormalities
   - Failure to thrive
4. Toddlers
   - Recurrent urinary tract infections
   - Voiding difficulties
5. School-aged boys
   - Voiding difficulties >> urinary incontinence

64

What are the investigations for posterior urethral valve?

- Prenatal USG: keyhole sign from dilated posterior urethra
- Voiding/Micturating cystourethrogram
   >> Dilated and elongated posterior urethra
   >> Trabeculated bladder
   >> Vesicoureteral reflux

65

What is the pathophysiology of posterior urethral valve?

Abnormal mucosal folds at the distal prostatic urethra in males causing varying degrees of obstruction

66

What is the management of posterior urethral valve?

- Immediate catheterization to relieve obstruction
- Cystoscopic resection of PUV when stable
- Cystectomy if PUV resection is not possible

67

What is the most common congenital defect of the ureter?

Ureteropelvic Junction (UPJ) Obstruction

68

What is the common presenting complaints in ureteropelvic junction obstruction?

Infants: abdominal mass, urinary infection
Children: pain, vomiting, failure to thrive
Adolescents: triggered by episodes of increased diuresis, e.g. after alcohol

69

What is vesicoureteral reflux?

Retrograde passage of urine from the bladder through the ureterovesicular junction (UVJ) into the ureter

70

What is the grading for vesicoureteral reflux (VUR)?

Grade 1: only ureters
Grade 2: ureters and pelvis
Grade 3: ureters and pelvis with some dilation
Grade 4: ureters, pelvis and calyces with significant dilation
Grade 5: ureters, pelvic and calyces with major dilation and tortuosity

71

What are the causes of vesicoureteral reflux (VUR?)

Primary: incompetent or inadequate closure of UVJ

Secondary: abnormally high intravesical pressure
- Anatomic bladder obstruction: posterior urethral valve
- Functional bladder obstruction: neurogenic bladder

72

What are the investigations necessary for VUR?

History: symptoms of voiding dysfunction
- Frequency
- Urgency
- Diurnal enuresis
- Constipation
- Encopresis

Infection/Renal failure screening
- UTI, pyelonephritis and urosepsis
- RFT: uremia
- BP: hypertension

Evaluation of other complications due to renal scarring:
- Height and weight
- Blood pressure
- Creatinine
- Urinalysis and urine stain C/ST
- Renal ultrasound
- Dimercaprosuccinic acid scan (DMSA)

73

What are the risk factors for vesicoureteral reflux?

- Caucasians
- Female
- <2 years of age
- Genetic predisposition

74

What is the management for VUR?

TO PREVENT INFECTION OR RENAL DAMAGE


Medical treatment
- Long-term ABx prophylaxis at half of treatment dose for half of treatment time
   >> Trimethroprim-sulfamethoxazole
   >> Trimethroprim
   >> Nitrofurantoin
   >> Cephalexin (1st generation cephalosporin)

Surgical treatment
- Ureteral reimplantation +/- ureteroplasty
- Subureteral injection with debulking agents (e.g. Deflux)

75

What are the indications for surgical therapy in VUR?

- Persistent high-grade VUR
   >> Frequency
   >> Severity
- Failure of medical treatment (Non-compliance)
- Breakthrough urinary tract infections
- Presence and severity of renal scarring

76

What is hypospadias?

When the urethral meatus opens on the ventral side of the penis, proximal to the normal location in the glans penis

77

What is hypospadias associated with?

- Ventral penile curvature
- Disorders of sexual differentiation
- Undescended testicles
- Inguinal hernia

78

What is an absolute contraindication to circumcision?

Hypospadias
- Or epispadias, penile curvature and other genitalial problems
- The foreskin may be utilized in surgical correction for these conditions

79

What is the average age of incidence for Wilm's tumour/nephroblastoma?

3 years

80

What is the chance that Wilm's tumour is bilateral?

5%

81

What is the common clinical presentation of Wilm's tumour?

- Large, firm and unilateral abdominal mass
- Hypertension in 25%
- Flank tenderness
- Microscopic hematuria
- Nausea/vomiting

82

What is the management plan for Wilm's tumour?

- Check for contralateral involvement
- Unilateral: radical nephrectomy +/- RT +/- chemo
- Bilateral: neoadjuvant chemo + nephron-sparing OT

83

What are the complications of cryptorchidism?

- Reduction in fertility
- Increased malignancy risk
- Increased risk of testicular torsion

84

What are the types of disorders of sexual differentiation?

1. 46XY
    - Defect in testicular synthesis of androgens
    - Androgen resistance in target tissues
    - Palpable gonad
2. 46XX
    - Congenital adrenal hyperplasia
3. Ovotesticular DSD
4. Mixed gonadal dysgensis
    - 46XY
    - 45XO

85

When should reconstruction of external genitalia take place in patients with disorders of sexual differentiation?

6-12 months

86

What is circumcision?

Removal of some or all of foreskin from the penis

87

What are the medical indications for circumcision?

- Phimosis and recurrent phimosis
- Recurrent UTIs
- Balantitis xerotica obliterans or other inflammatory conditions

88

What are the contraindications for circumcision?

- Unstable/sick infants
- Congenital genital abnormalities: hypospadias
- Family history of bleeding disorders

89

What are the possible complications of circumcision?

- Bleeding
- Infection
- Penile entrapment
- Glans injury
- Penile sensation defects

90

What are the features suggestive of pyelonephritis?

- High-grade fever
- Flank or high abdominal pain
- Costo-vertebral angle tenderness on palpation

91

What are the possible causative organisms of urinary tract infections in children?

- Gram-negative bacteria
   >> E. COLI
   >> Klebsiella
   >> Proteus
   >> Enterobacter
   >> Pseudomonas
- Gram-positive bacteria
   >> Staph. saprophyticus
   >> Enterococcus
- Viral
   >> Adenovirus
- Fungal
   >> Candida albicans

E. coli causes ~70% of all urinary tract infections

92

How does constipation increase the risk of urinary tract infections?

Compression of the bladder and the bladder neck increases bladder storage pressure and post-voiding residual urine volume.

A distended colon also provides a reservoir for pathogens.

93

What are the risk factors for urinary tract infections?

Non-modifiable
- Female gender
- Caucasian
- Previous UTIs
- Family history

Modifiable
- Urinary tract abnormalities
   >> Posterior urethral valve
   >> Obstructive uropathy
   >> Neurogenic bladder
   >> Vesicoureteral reflux
- Dysfunctional voiding
- Repeated bladder catheterizations
- Uncircumcised males
- Labial adhesions
- Sexually active
- Constipation

94

How can we diagnose UTI?

- Gold standard by culture of urine specimen
   >> Clean-catch midstream urine sample
   >> Suprapubic aspiration
   >> Urinary catheterization
- Urine dipstick
   >> Nitrite
   >> Leukocyte esterase
- Urine microscopy
   >> For WBC
   >> Examine urine specimen within 2 hours of voiding

95

Why is nitrite elevated in UTI?

Gram-negative bacteria in the urine reduces dietary nitrate to nitrite, and thus nitrite will be elevated in UTI dipstick.

>> Sensitivity 37%
>> Specificity 100%
>> PPV 90%, NPV 100%

96

What are other causes of presence of leukocyte/+ve leukocyte esterase in urine dipstick other than UTI?

- Vaginal secretions
- Dehydration
- Glomerulonephritis
- Interstitial nephritis
- Tuberculosis

97

What are the complications of urinary tract infection?

- Renal scarring
- Hypertension
- Proteinuria
- End-stage renal disease

98

What are the criteria for atypical UTI?

- Severely ill
- Septicaemia
- Poor urine flow/output
- Abdominal or bladder mass
- Increased creatinine
- Infection of non E.coli organisms
- Lack of response to antibiotic treatments after 48 hours

99

What are the criteria for recurrent UTI?

Any one of the following within 1 year:
- 2 or more episodes of upper urinary tract infection/acute pyelonephritis
- 1 episode of upper urinary tract infection/acute pyelonephritis and 1 or more episodes of lower urinary tract infection/cystitis
- 3 or more episodes of lower urinary tract infection/cystitis

100

What are the indications for hospital admission of UTI?

- <3 months of age
- Immunocompromised

- Persistent vomiting
- Inability to tolerate oral medication
- Moderate-severe dehydration
- Urosepsis
- Complex urologic pathology

- Inadequate follow-up
- Failure to respond to outpatient therapy

101

What is the management of acute UTI?

Supportive management
- Hydration
- Pain control

Antibiotics treatment
- According to urine dipstick
   >> WBC +, nitrite +: start and send urine for culture
   >> WBC -, nitrite +: start and send urine for culture
   >> WBC +, nitrite -: hold and send urine for culture
   >> WBC -, nitrite -: ABx not necessary
- Neonates: admit for IV ampicillin and gentamicin
- >3 months with upper tract infection
   >> Oral antibiotics (cephalexin/Augmentin) x 7-10 days
   >> IV antibiotics (ceftriaxone) x 2-4 days
        + oral ABx (cephalexin/Augmentin) for the remaining days until 10 days
- >3 months with lower tract infection
   >> Oral antibiotics x 3 days
        (TMP-SMX, nitrofurantoin, cephalosporins, amoxicillin)
   >> Reassess if still unwell after 48 hours


Imaging
- <6 months old
   >> Recurrent UTI
        :: USG kidneys during acute illness
        :: DMSA 4-6 months after acute illness
        :: MCUG
   >> Atypical UTI
        :: USG kidneys during acute illness
        :: DMSA 4-6 months after acute illness
        :: MCUG
   >> UTI resolving within 48hours of ABx initiation
        :: USG kidneys within 6 weeks of acute illness
        :: Consider MCUG if USG is abnormal only
- >6 months of age
   >> Recurrent UTI
        :: USG kidney within 6 weeks of acute illness
        :: DMSA 4-6 months after acute illness
   >> Atypical UTI
        :: USG kidney during acute illness
        :: DMSA 4-6 months after acute illness
   >> UTI resolving within 48 hours of ABx initiation
        :: No imaging necessary
- >3 years of age
   >> Recurrent UTI
        :: USG kidney within 6 weeks of acute illness
        :: DMSA 4-6 months after acute illness
   >> Atypical UTI
         :: USG kidneys during acute illness only
   >> UTI resolving within 48 hours of ABx initiation
         :: No imaging necessary

102

What are we looking for in an USG kidney?

- Congenital renal and urinary tract anomalies
   >> Hydronephrosis
   >> Ectopic kidney
   >> Duplex collecting system
   >> UPJ obstruction
   >> Uretocele
- Renal abscess
- Acute focal bacterial nephritis

103

What is the voiding/micturating cystourethrogram (VCUG/MCUG) for?

Gold standard for diagnosing VUR (vesico-ureteric reflux)

>> Should be performed after completion of antibiotics

104

What is the DMSA (dimercaptosuccinic acid) for?

Diagnosing renal scarring
>> More sensitive than USG or CT scan

Also sensitive in diagnosing acute pyelonephritis, but does not change clinical management

105

Does primary vesicoureteric reflux resolve spontaneously?

YES!

Over 5 years:
Grade I: 82%
Grade II: 80%
Grade III: 40%
Grade IV: 30%
Grade V: 13%

>> Resolution of VUR is particularly true of mid-to-moderate grades of VUR, caused by the lengthening of the submucosal segment of the ureter

106

What are the complications of VUR?

- Recurrent urinary infections
- Hypertension (20%)
- Proteinuria
   >> Microalbuminuria
   >> Persistent proteinuria
   >> Nephrotic range of proteinuria
- End-stage renal disease

107

What are the 4 most common causes of end-stage renal failure in children?

- Obstructive uropathy
- Renal hypolasia/aplasia
- Focal segmental glomerular sclerosis (FSGS)
- Vesicoureteric reflux

108

What is enuresis?

Voluntary or involuntary repeated discharge of urine into clothes or bed after a developmental age when bladder control should have been established

109

How can we classify enuresis?

Primary noctural enuresis
- Lifelong bed-wetting (~90%)
- Persistent bed-wetting since early childhood until >= 7 years of age
- A form of personal-social developmental delay

Secondary nocturnal enuresis
- Acquired enuresis after being dry for a minimum of 6 months

110

When are children usually toilet-trained?

Most children of normal intelligence & health are dry by day before the 5th birthday
>> Dry by NIGHT at a later age

111

What are the risk factors for primary nocturnal enuresis?

- Familial nocturnal enuresis
- Environmental causes
   >> Later initiation of toilet training
   >> Stressful life events
   >> Lower socioeconomic groups
   >> Overcrowded conditions
- Personal health causes
   >> Urinary tract infection
   >> Constipation
- Maternal causes
   >> Maternal smoking
   >> Teenage pregnancy

112

What are the possible causes of secondary nocturnal enuresis?

Inorganic causes
- Stress
- Anxiety

Organic causes
- Urinary tract infections
- Polyuric states
   >> Diabetes mellitus
   >> Diabetes insipidus
- Neurological causes
   >> Neurogenic bladder
   >> Cerebral palsy
   >> Seizures
- Systemic diseases
   >> Sickle cell disease

113

What is the management for primary nocturnal enuresis?

1. Time and reassurance (~20% spontaneous resolution each year)
2. Lifestyle modifications
     >> Avoid fluid intake 2 hours before bedtime
     >> Voiding before sleep
3. Reward system with star chart - involve child
4. Enuresis alarm
     >> Works by conditioning
     >> Requires highly-motivated parents and child
     >> Success rate 60-80% in 4 months
5. Drugs
     >> DDAVP/desmopressin: short-term use; associated with quick relapse
     >> Oxybutynin: anticholinergic effect (detrusor tone)
     >> Imipramine: anticholinergic; not recommended due to narrow therapeutic window and lethal side effects

114

What are the possible complications of imipramine overdose?

- Ventricular tachycardia
- Seizures
- Coma

115

What are the side effects of desmopressin?

- Hyponatremia
- Abdominal discomfort
- Headache

116

What is diurnal enuresis?

Daytime wetting (60-80% also associated with nocturnal enuresis)

117

What are the possible causes of diurnal enuresis?

- Micturition deferral due to psychosocial stress
- Structural abnormalities
   >> Ectopic urethra
   >> Neurogenic bladder
- Urinary tract infection
- Constipation
- CNS disorders
   >> CP
   >> Seizures