Nephrology Flashcards
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
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%
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**
- *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
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
What is the most common cause of acute glomerulonephritis in paediatrics?
Post-infectious/post-streptococcal glomerulonephritis
What is the cause of hypertension in nephritic syndrome?
- Fluid retention
- Increased renin secretion by ischemic kidneys
What is the most common cause of hematuria in children?
Urinary tract infection (but rarely as the only symptom)
When is a renal biopsy indicated in hematuria?
- Significant persistent proteinuria
- Recurrent macroscopic hematuria
- Renal function is abnormal
- Complement levels are persistently abnormal
When is a renal biopsy indicated in nephritic syndrome?
- No evidence of streptococcal infection
- Normal C3/C4 levels
- Acute renal failure (abnormal renal function)
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
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
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
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
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
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
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
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)
What are the possible complications of nephrotic syndrome?
- Hypertension
- Heart failure
- Pulmonary edema
- Chronic kidney injury requiring renal transplant
What is the typical age of presentation in children for nephritic syndrome?
5-15 years of age
What is the typical age of presentation in children for nephrotic syndrome?
2-6 years of age (M>F)
What is the most common cause of nephrotic syndrome in children?
Minimal change disease (glomerular infiltration absent on renal biopsy) – >90%
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
What is nephrotic syndrome?
Clinical syndrome affecting the kidney:
P: Proteinuria (>50mg/kg/day)
A: HypoAlbuminemia (<20g/L)
L: HyperLipidemia
E: Edema
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
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
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!!!)
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
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
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
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
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
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
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
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
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)
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
How do we quantify a relapse of nephrotic syndrome?
Reappearance of proteinuria >=3+ on albustix or >=4mg/m2/hr for 3 consecutive days
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
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
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
What are the diagnostic investigation results for nephrotic syndrome?
- Hypoalbuminemia (5mmol/L TC)
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
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
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
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)
What is the rate of relapse in minimal change disease?
80%
>> Usually sustained remission with normal kidney function by adolescence
What is the definition of acute kidney injury (AKI)?
- Reversible increase in Cr and BUN/nitrogenous waste
- Inability to regulate fluid and electrolyte homeostasis
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
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
What is the blood volume of term newborns?
80mL/kg >> Easily over-hydrated
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
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
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
Why are antibiotics contraindicated in hemolytic uremic syndrome?
Death of bacteria leads to increased toxin release and worsens clinical outcome
What are the presenting features of hemolytic uremic syndrome?
- Non-immune microangiopathic hemolytic anemia
- Thrombocytopenia
- Acute renal failure
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)
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
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
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
What is the prognosis of HUS?
>95% survive the acute phase
~10-30% have renal damage
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
What is the most common congenital obstructive urethral lesion in males?
Posterior urethral valve
What is the presentation of posterior urethral valve?
Age-dependent
- Antenatal
- Bilateral hydronephrosis
- Distended bladder
- Oligohydramnios
- Neonatal, recognized at birth
- Palpable abdominal mass
- Ascites from transudation of retroperitoneal urine
- Respiratory distress from pulmonary hypoplasia due to oligohydramnios
- Weak urinary stream
- Neonatal, not recognized at birth
- Urosepsis
- Dehydration
- Electrolyte abnormalities
- Failure to thrive
- Toddlers
- Recurrent urinary tract infections
- Voiding difficulties
- School-aged boys
- Voiding difficulties >> urinary incontinence
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
What is the pathophysiology of posterior urethral valve?
Abnormal mucosal folds at the distal prostatic urethra in males causing varying degrees of obstruction
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
What is the most common congenital defect of the ureter?
Ureteropelvic Junction (UPJ) Obstruction
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
What is vesicoureteral reflux?
Retrograde passage of urine from the bladder through the ureterovesicular junction (UVJ) into the ureter
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
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
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)
What are the risk factors for vesicoureteral reflux?
- Caucasians
- Female
- <2 years of age
- Genetic predisposition
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)
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**
What is hypospadias?
When the urethral meatus opens on the ventral side of the penis, proximal to the normal location in the glans penis
What is hypospadias associated with?
- Ventral penile curvature
- Disorders of sexual differentiation
- Undescended testicles
- Inguinal hernia
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
What is the average age of incidence for Wilm’s tumour/nephroblastoma?
3 years
What is the chance that Wilm’s tumour is bilateral?
5%
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
What is the management plan for Wilm’s tumour?
- Check for contralateral involvement
- Unilateral: radical nephrectomy +/- RT +/- chemo
- Bilateral: neoadjuvant chemo + nephron-sparing OT
What are the complications of cryptorchidism?
- Reduction in fertility
- Increased malignancy risk
- Increased risk of testicular torsion
What are the types of disorders of sexual differentiation?
- 46XY
- Defect in testicular synthesis of androgens
- Androgen resistance in target tissues
- Palpable gonad
- 46XX
- Congenital adrenal hyperplasia
- Ovotesticular DSD
- Mixed gonadal dysgensis
- 46XY
- 45XO
When should reconstruction of external genitalia take place in patients with disorders of sexual differentiation?
6-12 months
What is circumcision?
Removal of some or all of foreskin from the penis
What are the medical indications for circumcision?
- Phimosis and recurrent phimosis
- Recurrent UTIs
- Balantitis xerotica obliterans or other inflammatory conditions
What are the contraindications for circumcision?
- Unstable/sick infants
- Congenital genital abnormalities: hypospadias
- Family history of bleeding disorders
What are the possible complications of circumcision?
- Bleeding
- Infection
- Penile entrapment
- Glans injury
- Penile sensation defects
What are the features suggestive of pyelonephritis?
- High-grade fever
- Flank or high abdominal pain
- Costo-vertebral angle tenderness on palpation
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
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.
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
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
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%
What are other causes of presence of leukocyte/+ve leukocyte esterase in urine dipstick other than UTI?
- Vaginal secretions
- Dehydration
- Glomerulonephritis
- Interstitial nephritis
- Tuberculosis
What are the complications of urinary tract infection?
- Renal scarring
- Hypertension
- Proteinuria
- End-stage renal disease
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
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
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
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
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
What is the voiding/micturating cystourethrogram (VCUG/MCUG) for?
Gold standard for diagnosing VUR (vesico-ureteric reflux)
>> Should be performed after completion of antibiotics
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
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
What are the complications of VUR?
- Recurrent urinary infections
- Hypertension (20%)
- Proteinuria
>> Microalbuminuria
>> Persistent proteinuria
>> Nephrotic range of proteinuria - End-stage renal disease
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
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
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
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
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
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
What is the management for primary nocturnal enuresis?
- Time and reassurance (~20% spontaneous resolution each year)
- Lifestyle modifications
>> Avoid fluid intake 2 hours before bedtime
>> Voiding before sleep - Reward system with star chart - involve child
-
Enuresis alarm
>> Works by conditioning
>> Requires highly-motivated parents and child
>> Success rate 60-80% in 4 months - 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
What are the possible complications of imipramine overdose?
- Ventricular tachycardia
- Seizures
- Coma
What are the side effects of desmopressin?
- Hyponatremia
- Abdominal discomfort
- Headache
What is diurnal enuresis?
Daytime wetting (60-80% also associated with nocturnal enuresis)
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
