Nephrology Flashcards
(117 cards)
1
Q
What are the causes of dehydration?
A
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
Q
How do we grade the severity of dehydration?
A
- *>2 years of age**
- Mild: 3%
- Moderate: 6%
- Severe: 9%
- *<2 years of age**
- Mild: 5%
- Moderate: 10%
- Severe: 15%
3
Q
What are the clinical parameters used to assess the degree of dehydration?
A
- 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**
- *C**apillary refill
- *B**lood pressure
- *A**nterior fontanelle
- *S**kin tugor
- *E**yes sunken
- *H**eart rate
- *O**ral mucosa
- *O**utput of urine
+ Decreased body weight
The first thing to go is URINE OUTPUT
4
Q
What is nephritic syndrome?
A
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
Q
What is the most common cause of acute glomerulonephritis in paediatrics?
A
Post-infectious/post-streptococcal glomerulonephritis
6
Q
What is the cause of hypertension in nephritic syndrome?
A
- Fluid retention
- Increased renin secretion by ischemic kidneys
7
Q
What is the most common cause of hematuria in children?
A
Urinary tract infection (but rarely as the only symptom)
8
Q
When is a renal biopsy indicated in hematuria?
A
- Significant persistent proteinuria
- Recurrent macroscopic hematuria
- Renal function is abnormal
- Complement levels are persistently abnormal
9
Q
When is a renal biopsy indicated in nephritic syndrome?
A
- No evidence of streptococcal infection
- Normal C3/C4 levels
- Acute renal failure (abnormal renal function)
10
Q
When is a renal biopsy indicated in nephrotic syndrome?
A
- *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
Q
What is the classical clinical course of post-streptococcal nephritis?
A
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
Q
What are the characteristic clinical features of Henoch-Schonlein purpura?
A
- 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
Q
What are the causes of hematuria?
A
- *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
Q
Name the causes of nephritic syndromes that are associated with decreased C3 levels.
A
Primary
- Post-streptococal/post-infectious glomerulonephritis
- Membranoproliferative glomerulonephritis
Secondary
- SLE (systemic lupus erythematosus)
- Bacterial endocarditis
- Abscess/shunt nephritis
- Cryoglobulinemia
15
Q
What are the four types of rapidly progressive glomerulonephritis/crescentic glomerulonephritis?
A
- *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
Q
What are the causes of nephritic syndrome?
A
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
Q
What are the investigations that will be helpful in cases of nephritic syndrome?
A
- *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
Q
What are the possible complications of nephrotic syndrome?
A
- Hypertension
- Heart failure
- Pulmonary edema
- Chronic kidney injury requiring renal transplant
19
Q
What is the typical age of presentation in children for nephritic syndrome?
A
5-15 years of age
20
Q
What is the typical age of presentation in children for nephrotic syndrome?
A
2-6 years of age (M>F)
21
Q
What is the most common cause of nephrotic syndrome in children?
A
Minimal change disease (glomerular infiltration absent on renal biopsy) – >90%
22
Q
What is the management plan for nephritic syndrome?
A
- 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
Q
What is nephrotic syndrome?
A
Clinical syndrome affecting the kidney:
P: Proteinuria (>50mg/kg/day)
A: HypoAlbuminemia (<20g/L)
L: HyperLipidemia
E: Edema
24
Q
What is the earliest sign of nephrotic syndrome in children?
A
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 day**s + **35mg/m2 single morning** dose in **alternate days** for **4 weeks**
| (same as for relapse)
## Footnote
**_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
## Footnote
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_**
## Footnote
- 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_**
## Footnote
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_**
## Footnote
**_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
## Footnote
***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.
## Footnote
\>\> 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
