Paeds nephrology and urology Flashcards
(136 cards)
1
Q
Renal agenesis
A
Detected on antenatal ultrasound screening
Amniotic fluid is mainly derived from foetal urine, so the absence of both kidneys leads to oligohydramnios resulting in Potter sequence
This is fatal
2
Q
Multicystic dysplastic kidney aetiology
A
Results from the failure of the union of the ureteric bud and the nephrogenic mesenchyme (NB: ureteric bud gives rise to the ureter, pelvis, calyces and collecting ducts)
The kidney becomes a non-functioning structure with large fluid-filled cysts and no renal tissue and no connection to the bladder
The dysplastic kidney does not produce any urine (so if this was bilateral, it would cause Potter sequence)
Detected on antenatal ultrasound screening
3
Q
Other causes of large cystic kidneys
A
Autosomal dominant and recessive polycystic kidney disease
- Main symptom is hypertension
- Can cause renal failure in late adulthood
- Extra-renal features include liver and pancreatic cysts, cerebral aneurysms and mitral valve prolapse
4
Q
Potter sequence facies
A
Low-set ears
Beaked nose
Prominent epicanthic folds and downward slant to eyes
May also get pulmonary hypoplasia causing respiratory failure
Limb deformities
5
Q
Cause of horseshoe kidney
A
Results from abnormal caudal migration
The lower pole of the two kidneys will fuse in the midline
This may predispose to infection or obstruction of urinary drainage
6
Q
Duplex system
A
Can be detected on the antenatal ultrasound screening
Results from premature division of the ureteric bud
This can vary from simply a bifid real pelvis to complete division with two ureters
There are usually some functional issues with these ureters
The ureter from the lower pole often refluxes
The ureter from the upper pole may drain ectopically into the urethra or vagina or may prolapse into the bladder (ureterocoele)
Urine flow may be obstructed
7
Q
Bladder exstrophy
A
Can be detected antenatally on ultrasound
Results from failure of fusion of the infraumbilical midline structures
Leads to an exposed bladder mucosa
Absence or severe deficiency of the anterior abdominal wall muscles is frequently associated with a large bladder and dilated ureters (megacystitis-megaureter)
It is also associated with cryptorchidism (absence of one or both testes in the scrotum)
8
Q
Places where there may be obstruction to urinary flow
A
Pelvi-ureteric junction
Vesicoureteric junction
Bladder neck
Posterior urethra (due to mucosal folds or a membrane known as posterior urethral valves)
9
Q
Antenatal treatment of congenital abnormalities
A
Male foetuses with posterior urethral valves may develop severe urinary outflow obstruction resulting in progressive bilateral hydronephrosis, poor renal growth and declining liquor volume with the potential to lead to pulmonary hypoplasia
Intrauterine bladder drainage may be performed
10
Q
Postnatal treatment of congenital abnormalities
A
Prophylactic antibiotics may be started at birth to try and prevent UTIs
As GFR is low in newborns, urine outflow is low and so mild outflow obstruction may not be obvious in the first few days of life. Therefore, the ultrasound scan should be delayed for a few weeks
If there is bilateral hydronephrosis in a male infant, investigations are required:
Ultrasound
Micturating cystourethrogram (MCUG)
This is to exclude posterior urethral valves (if this is diagnosed, intervention is required such as cystoscopic ablation)
11
Q
Why is UTI an important presentation in childhood?
A
UP to 50% of patients have a structural abnormality of the urinary tract
Pyelonephritis may damage the growing kidney by forming a scar, predisposing to hypertension and progressive CKD if the scarring is bilateral
12
Q
Clinical features of UTIs in infants
A
Fever Vomiting Lethargy or irritability Poor feeding/faltering growth Jaundice Septicaemia Offensive urine Febrile seizure (>6 months)
13
Q
Clinical features of UTIs in children
A
Dysuria, frequency and urgency Abdominal pain or loin tenderness Fever with or without rigors Lethargy and anorexia Vomiting, diarrhoea Haematuria Offensive/cloudy urine Febrile seizure Recurrence of enuresis (bed wetting)
14
Q
How to collect urine samples in children for investigations?
A
For children in nappies, urine can be collected by:
- A ‘clean-catch’ sample into a waiting clean pot when the nappy is removed (BEST METHOD)
- Adhesive plastic bag applied to the perineum after careful washing -Urethral catheter if there is urgency in obtaining a sample and no urine has been passed
- Suprapubic aspiration (may be used in severely ill infants)
In older children, urine can be collected using a midstream sample
Contamination with white cells and bacteria can occur from under the foreskin in boys and from reflux of urine into the vagina during voiding in girls
Microscopy is used to identify the organisms
A culture should also be performed
Urine dipsticks can be used as a screening tool - culture should still be performed unless BOTH leucocyte esterase and nitrite are negative or if the clinical symptoms and dipstick tests don’t correlate
The presence of a mixed growth of organisms suggests contamination
15
Q
Diagnosis of UTI
A
A bacterial culture of >10^5 colony-forming unites (CFU) of a single organism per millilitre in a properly collected specimen gives a 90% probability of infection
16
Q
Most common causative organisms for a UTI
A
E.coli
Klebsiella
Proteus (more common in boys than girls. Predisposes to formation of phosphate stones)
Pseudomonas (may indicate presence of structural abnormality)
Streptococcus faecalis
UTI usually results from bowel flora entering the urinary tract via the urethra
17
Q
Factors that contribute to incomplete bladder emptying in children
A
Infrequent voiding –> bladder enlargement
Vulvitis
Incomplete micturition with residual postmicturition bladder volumes
Obstruction by a loaded rectum from constipation
Neuropathic bladder
Vesicoureteric reflux
18
Q
Vesicoureteric reflux
A
This is a developmental abnormality of the vesicoureteric junctions
The ureters are displaced laterally and enter directly into the bladder (rather than at an angle)
There is a shortened or absent intramural course
Severe cases may be associated with renal dysplasia
It is familial (30-50% chance of occurrence in first-degree relatives)
It can occur with bladder pathology (e.g. neuropathic bladder, urethral obstruction, after a UTI)
Severity can vary from mild reflux into the lower end of an undilated ureter during micturition to the severest form with reflux during bladder filling and voiding, with a distended ureter, renal pelvis and clubbed calyces.
The more severe forms of vesicoureteric reflux are associated with intrarenal reflux, which is the backflow of urine from the renal pelvis into the papillary collecting ducts
This is associated with a risk of renal scarring if UTIs occur
NOTE: it is unknown whether renal scarring is present from birth in children with VUR or whether it occurs as a result of damage to normal kidneys by UTIs in children with VUR
VUR tends to resolve with age
Infection can destroy renal tissue resulting in a shrunken, poorly functioning kidney
19
Q
Why is vesicoureteric reflux-associated ureteric dilatation important?
A
Urine returning to the bladder from the ureters after voiding result in incomplete bladder emptying which encourages infection
Kidneys may become infected (pyelonephritis)
Bladder voiding pressure is transmitted to the renal papillae which may contribute to renal damage
20
Q
Atypical UTI includes:
A
Seriously ill or septicaemia
Poor urine flow
Abdominal or bladder mass
Raised creatinine
Failure to respond to suitable antibiotics within 48 hours
Infection with atypical (non-E.coli) organisms
21
Q
Investigations for VUR/UTI
A
The extent of investigation is controversial because the investigations are often invasive and may not benefit the patient
Mild VUR usually resolves spontaneously
There has been a move away from extensive investigation of ALL children with UTIs to those who have had atypical or recurrent UTIs
An initial ultrasound will identify:
Serious structural abnormalities and urinary obstruction
Renal defects
If urethral obstruction is suspected, MCUG should be performed promptly
NB: functional scans should be deferred for 3 months after a UTI, unless the ultrasound is suggestive of obstruction, to avoid missing a new scare and because false-positive results may be produced due to transient inflammation
22
Q
Test urine sample in any infant or child presenting with:
A
Unexplained fever >38 degrees
An alternative site of infection in those who remain unwell despite treatment
Symptoms and signs suggestive of UTI
NB: if it is not possible or practical to collect urine by non-invasive methods, catheter insertion or suprapubic aspiration may be considered
23
Q
Urine should be sent fo rculture in:
A
Infants with suspected upper urinary tract infection
Infants and children with a high to intermediate risk of serious illness
Infants < 3 months
Infants and children with a positive result for either leucocyte esterase or nitrites
- Nitrites + leucocyte esterase –> start antibiotics
- Nitrites without leucocyte esterase –> do not start antibiotics without good clinical evidence of UTI
Infants and children with recurrent UTIs
Infants and children with an infection that does not respond to treatment within 24-48 hours
When clinical symptoms and urine dipstick do not correlate
24
Q
Management of UTI
A
ALL infants <3 months of age with suspicion or a UTI or if seriously ill should be referred immediately to hospital
- IV antibiotics (e.g. co-amoxiclav) for at least 5-7 days
- This should be followed by oral prophylaxis
Infants aged > 3 months and children with acute pyelonephritis/upper UTI
- If the urine dipstick is positive for either leucocyte esterase or nitrites, send a urine sample for culture and start antibiotic therapy
- Features of pyelonephritis:
- Bacteriuria + fever > 38 degrees
- Bacteriuria + loin pain/tenderness
- Oral antibiotics (e.g. trimethoprim for 7 days): choice of antibiotic should be based on resistance patterns
- If oral cannot be used, five IV antibiotics (e.g. co-amoxiclav for 2-4 days, followed by oral antibiotics for 7-10 days): choice depends on sensitivities
Children with cystitis/lower UTI:
Features of cystitis/lower UTI: dysuria but no systemic symptoms
Oral antibiotics (e.g. trimethoprim or nitrofurantoin) for 3 days
ADVISE to seek medical attention if the child is still unwell after 24-48 hours of antibiotic treatment, and encourage adequate fluid intake
Infants and children with atypical UTI should have an ultrasound of the urinary tract to identify structural abnormalities
DMSA and MCUG may also be performed in children < 6 months presenting with atypical or recurrent UTI
25
Medical measures for the prevention of UTI
```
AIM: ensure washout of organisms that ascend into the bladder form the perineum and reduce the presence of aggressive oragnisms in the stool, perineum and under the foreskin
High fluid intake to produce high urine output
Regular voiding
Ensure complete bladder emptying
Treatment and/or prevention of constipation
Good perineal hygiene
Lactobacillus acidophilus - probiotic to encourage the colonisation of the gut by this organism and reduce the number of pathogenic organisms
Antibiotic prophylaxis (controversial)
```
26
Follow-up of children with recurrent UTIs, renal scarring or reflux
Urine should be dipsticked with any non-specific illness in case it is caused by a UTI and urine should be sent for MC+S
Long-term low-dose antibiotic prophylaxis can be used
Circumcision in boys may be considered
Anti-VUR surgery may be considered if there is progression of scarring
Regular blood pressure checks if renal defects are present
Urinalysis to check for proteinuria (suggestive of progressive CKD)
Regular assessment of renal growth and function
27
Define daytime enuresis
Lack of bladder control during the day in a child that is old enough to be continent (over 3-5 years)
28
Causes of daytime enuresis
Lack of attention to bladder sensation (manifestation of developmental or psychogenic problem)
Detrusor instability (sudden, urgent urge to void induced by sudden bladder contractions)
Bladder neck weakness
Neuropathic bladder (bladder is enlarged and fails to empty properly, irregularly thick wall, associated with spina bifida and other neurological conditions)
UTI
Constipation
Ectopic ureter
29
Investigations for daytime enuresis
Urine should be sent for MC+S
Ultrasound may reveal abnormalities
Urodynamic studies may be required
MRI may be used to exclude a spinal defect
30
Management tips for daytime enuresis
Children in whom a neurological cause has been excluded, may benefit from:
- Star charts
- Bladder training
- Pelvic floor exercises
Anticholinergic drugs (e.g. oxybutynin), which reduces bladder contractions, may be useful
31
Causes of secondary onset enuresis
The loss of previously achieved urinary continence may be due to:
Emotional upset (most common)
UTI
Polyuria from an osmotic diuresis (e.g. diabetes mellitus, diabetes insipidus, CKD)
32
Investigations for secondary enuresis
Urine dipstick to check for infection, glycosuria and proteinuria
Assessment of urine concentrating ability by measuring osmolality of an early morning urine sample
Ultrasound of the renal tract
33
Management of enuresis
Children < 5 years
REassure the parents tha tmany children aged < 5 years wet the bed and this is usually resolved without intervention
Ensure easy access to the toilet at night (e.g. potty near the bed)
Encourage bladder emptying before bed
Consider a positive reward system
Children > 5 years
If bedwetting is infrequent (<2 per week) reassure the parents and offer watch-and-see approach
If long-term treatemnt is required offer:
1) enuresis alarm with positive reward system
2) desmopressin (NB: fluid should be restricted 1 hour before desmopressin until 8 hours after)
If rapid or short-term control is required (e.g. school trips), offer desmopressin
If bedwetting recurs following treatment, restart previously successful treatments and offer combination treatment with desmopressin and an enuresis alarm
TCAs and antimuscarinics may be considered in special cases
34
When should children with enuresis be referred to secondary care?
If bedwetting has not responded to two courses of treatment, refer to secondary care, enuresis clinic or community paediatrician
All children with primary bedwetting (with daytime symptoms) should be referred to secondary care or an enuresis clinic
If secondary enuresis is caused by UTI or constipation, it can be managed in primary care. However, the following underlying causes are likely to need specialist referral:
Diabetes
Recurrent UTI
Psychological problems
Family problems
Developmental, attention or learning difficulties
Known or suspected physical or neurological problems
35
Advice for enuresis
Explain that bedwetting is NOT the child or the parents' fault
Occurs because the volume of urine produced at night exceeds the capacity of the bladder to hold it, and the sensation of a full bladder does NOT wake the child
Reassure that pretty much all children become dry with time as their bladder capacity increases and they learn to wake at the sensation of a full bladder
The child should go to the toilet to pass urine regularly throughout the day, especially before bed
Caffeine-based drinks should be AVOIDED before bed
A healthy diet should be encouraged
There should be easy access to the toilet
Waterproof mattress or bed pads could be used
Parents and carers should take a neutral attitude towards bedwetting so that they don't embarrass the children
Older children may prefer to change their wet bedding themselves
Lifting or waking during the night does not promote long-term dryness
Positive reward systems can be used (e.g. rewards for going to the toilet before bed, drinking the recommended amount of fluid during the day)
SUPPORT: ERIC (Education and Resources for Improving Childhood Continence)
36
When does proteinuria not need investigating?
Transient proteinuria may occur during febrile illness, or after exercise - this does not require investigation
37
How should persistent proteinuria be investigated?
Measuring the urine protein-to-creatinine ratio in an early morning sample (normal < 20mg/mmol)
38
Causes of proteinuria
```
Orthostatic proteinuria: this is when proteinuria is only found when the child is upright during the day. The prognosis is excellent and further investigation is not necessary
Glomerular abnormalities:
- Minimal change disease
- Glomerulonephritis
- Abnormal glomerula basement membrane (familial nephritides)
Increased GFR
Reduced renal mass in CKD
Hypertension
Tubular proteinuria
Nephrotic syndrome
```
39
What are the three features which characterise nephrotic syndrome?
Proteinuria
Hypoalbuminaemia
Oedema
40
Causes of nephrotic syndrome
Cause is unknown
There are a few secondary causes (e.g. HSP, SLE, infections (e.g. malaria) or allergens)
41
Clinical features of nephrotic syndrome
Periorbital oedema (particularly on waking) - usually the earliest sign
Scrotal or vulva, leg and ankle oedema
Ascites
Breathlessness due to pleural effusion and abdominal distension
Infection such as peritonitis, septic arthritis or sepsis due to loss of protective immunoglobulins in the urine
42
Investigations performed at the presentation of nephrotic syndrome
```
Urine protein
FBC and ESR
U+Es, electrolytes, creatinine, albumin
C3+4
Antistreptolysin O or anti-DNAse B titres and throat swab
Urine microscopy and culture
Urinary sodium concentration
Hepatitis B and C screen
Malaria screen if travel abroad
```
43
Steroid-sensitive nephrotic syndrome
In 85-90% of cases, proteinuria will resolve with corticosteroid therapy
These children will not preogress to CKD
It is associated with atopy
The nephrotic syndrome is often precipitated by respiratory infections
```
Features of steroid-sensitive nephrotic syndrome:
Age 1-10 years
No macroscopic haematuria
Normal BP
Normal comple,ment levels
Normal renal function
```
44
Management of steroid-sensitive nephrotic syndrome
Initially give oral steroids (60mg/m^2 per day of prednisolone)
After 4 weeks, the dose should be reduced or alternate days for 4 weeks
Then it should be weaned or stopped
Children who do not respond after 4-6 weeks of corticosteroid therapy or have atypical features may have a more complex diagnosis and need a renal biopsy
NB: renal histology of steroid-sensitive nephrotic syndrome is usually normal on light microscopy, but fusion of podocytes is seen on electron microscopy (minimal change disease)
45
Complications of steroid-sensitive nephrotic syndrome
Hypovolaemia:
As the oedema forms, the intravascular compartment may become depleted
The child may complain of abdominal pain and feel faint
The body will respond with peripheral vasoconstriction and urinary sodium retention
Low urine sodium (<10 mmol/L) and high haematocrit are suggestive of hypovolaemia
Treated with IV 0.9% saline
If severe, IV 20% albumin infusion with furosemide may be needed (NB: this can precipitate pulmonary oedema and hypertension from fluid overload, and the diuretics could worsen the hypovolaemia)
Thrombosis:
Hypercoagulable state, resulting from:
- Urinary losses of antithrombin III
- Thrombocytosis (may be worsened by steroid therapy)
- Increased synthesis of clotting factors
- Increased blood viscosity from raised haematocrit
Infection:
High risk of infection by capsulated bacteria (Especially Pneumococcus)
Pneumococcal and seasonal influenza vaccination is recommended
Chickenpox and shingles should be treated with aciclovir
Hypercholesterolaemia:
Correlates inversely with serum albumin, though the cause is unknown
46
Prognosis for steroid-sensitive nephrotic syndrome
Relapses can be identified by parents using urine testing
Steroid-sparing agents may be considered if relapses are frequent (e.g. cyclophosphamide, tacrolimus, ciclosporin A, mycophenolate mofetil)
47
Causes of steroid-resistant nephrotic syndrome
Focal segmental glomerulosclerosis
Mesangiocapillary glomerulonephritis (membranoproliferative glomerulonephritis)
Membranous nephropathy
48
Management of steroid-resistant nephrotic syndrome
Oedema is managed with diuretics, salt restriction and ACE inhibitors
49
Congenital nephrotic syndrome
Presents in the first 3 months of life
RARE
More common in consanguineous families
Associated with high mortality
50
How is haematuria confirmed?
Red urine or tests positive for haemoglobin should be examined under the microscope to confirm haematuria (>10 RBCs per high-power field)
51
Glomerular haematuria is suggested by:
Brown urine
Presence of deformed RBCs (occurs as it passes through the glomerular basement membrane)
Casts
Often accompanied by proteinuria
52
Lower urinary tract haematuria is suggested by:
Red
Occurs at the beginning or end of the urinary stream
NOT accompanied by proteinuria
Unusual in children
53
Causes of haematuria
Glomerular:
Acute glomerulnophreitis (Usually + proteinuria)
Chronic glomerulonephritis (usually + proteinuria)
IgA nephropathy
Familial nephritis (e.g. Alport syndrome)
Thin basement membrane disease
```
Non-glomerular:
Infection (bacterial, viral, TB, schistosomiasis)
Trauma to genitalia
Stones
Tumours
Sickle cell disease
Bleeding disorders
Renal vein thrombosis
Hypercalciuria
```
54
Investigations for haematuria
ALL patients:
Urine MC+S
Protein and calcium excretion
Kidney and urinary tract ultrasound
Plasma urea, electrolytes, creatinine, calcium, phosphate and albumin
FBC, platelets, coagulation screen, sickle cell screen
If suggestive of glomerular haematuria:
ESR, complement levels and anti-dsDNA antibodies
Throat swab and antistreptolysin O/anti-DNAse B titres
Hepatitis B and C screen
Renal biopsy
Test mother's urine for blood (if Alport syndrome is suspected)
Hearing test (if Alport syndrome is suspected)
55
Indications for renal biopsy
Significant persistent proteinuria
Recurrent macroscopic haematuria
Renal function is abnormal
Complement levels are persistently abnormal
56
Causes of acute nephritis
Post-infectious (including streptococcus)
Vasculitis (e.g. HSP, SLE, Wegener's granulomatosis, MPA, PAN)
IgA nephropathy and mesangiocapillary glomerulonephritis
Goodpasture syndrome
57
Clinical features of acute nephritis
IN acute nephritis, increased glomerular cellularity restricts glomerular blood flow, and therefore GFR is decreased
This leads to:
Decreased urine output and volume overload
Hypertension (may cause seizures)
Oedema (initially periorbital)
Haematuria + proteinuria
NB: rarely tou may get rapid deterioration of renal function (rapid progressive glomerulonephritis) - this could occur with any cause of acute nephritis, and could lead to CKD if left untreated
58
Post-streptococcal and post-infectious nephritis
Usually follows streptococcal sore throat or skin infection
Diagnosed by evidence of recent streptococcal infection:
- Anti-streptolysin O titre (detects most strains of group A streptococcus)
- Anti-DNAse B titres (also detects group A b-haemolytic streptococci)
- Low complement (C3) levels - returns to normal after 3-4 weeks
59
What usually precedes Henoch Schonlein Purpura?
URTI
Cause is unknown
IgA and IgG interact to produce complexes that activate complement and are deposited in affected organs --> vasculitis
60
Clinical features of Henoch Schonlein Purpura
Fever
Rash (symmetrically distributed over the buttocks and extensor surfaces of the arms and legs (trunk is usually spared); usually palpable; first clinical feature in about 50% of cases)
Arthralgia (particularly knees and ankles; accompanied by periorbital oedema)
Colicky abdo pain (can be treated with corticosteroids; can cause haematemesis and melaena)
Renal involvement (over 80% have haematuria or mild proteinuria; usually, a complete recovery is achieved; persistent haematuria or proteinuria is a risk factor for progressive CKD, so all children with HSP should be followed for a year)
61
Management of Henoch Schonlein Purpura
Most cases resolve spontaneously within 4 weeks
Joint pain can be managed using paracetamol or ibuprofen
If there is scrotal involvement or severe oedema or severe abdominal pain, oral prednisolone may be given
IV corticosteroids are recommended in patients with nephrotic-range proteinuria and those with declining renal function
Renal transplant may be considered in end-stage renal disease
62
IgA Nephropathy
May present with episodes of macroscopic haematuria
Commonly associated with URTIs
Histology and management are same as HSP
63
What is the most common familial nephritis?
Alport syndrome
- X-linked recessive
- Leads to progressive end-stage chronic kidney disease in early adult life
- Associated with sensorineural deafness and ocular defects
- Thin basement membrane disease is a differential
64
What is diagnostic of vasculitides with renal involvement?
ANCA
| Renal arteriography to demonstrate presence of aneurysms will diagnose polyarteritis nodosa
65
Treatment for vasculitides causing nephritis
Corticosteroids, plasma exchange, IV cyclophosphamide
66
SLE
Presents mainly in adolescent girls and young women
Many autoantibodies are present including anti-dsDNA
C3 and C4 may be low, particularly in active disease
Haematuria and proteinuria are indications for renal biopsy (NB: intensity of immunosuppresion is dependent on the severity of renal involvement)
67
When does high blood pressure begin to be considered hypertension?
Above the 95th centile for height, age and sex
68
Causes of hypertension
```
Renal:
Renal parenchymal disease
Renovascular (e.g. renal artery stenosis)
Polycystic kidney disease
Renal tumours
```
Coarctation of the aorta
Catecholamine excess:
Phaeochromocytoma
Neuroblastoma
Endocrine:
Congenital adrenal hyperplasia
Cushing's syndrome or corticosteroids therapy
Hyperthyroidism
Essential hypertension is a diagnosis of exclusion
69
Possible presentations of symptomatic hypertension
```
Vomiting
Headaches
Facialpalsy
Hypertensive retinopathy
Convulsions
Proteinuria
Infants: faltering growth, cardiac failure
NB: phaeochromocytoma will cause paroxysmal palpitations and sweating
```
Any child with a renal tract abnormality should have their blood pressure checked annually throughout life
70
How should any abdominal mass that is identified through palpation be investigated?
Ultrasound
71
Causes of palpable kidneys
```
Unilateral:
Multicystic kidneys
Compensatory hypertrophy
Obstructed hydronephrosis
Renal tumour (Wilms tumour)
Renal vein thrombosis
```
BIlateral:
Polycystic kidneys (autosomal dominant + autosomal recessive)
Tuberous sclerosis
Renal vein thrombosis
Bilaterally enlarged kidneys early in life is most commonly due to autosomal recessive polycystic kidney disease
- This is associated with hypertension, hepatic fibrosis and progression to CKD
Autosomal dominant PKD has a more benign prognosis
72
Predisposing factors for renal calculi
UTI
Structural anomalies of the urinary tract
Metabolic abnormalities
Renal calculi are rare in childhood, so if they occur, predisposing factors should be sought
73
What is the most common type of renal calculus?
Phosphate stones, which are associated with infection (Proteus)
Calcium-containing stones may occur with idiopathic hypercalciuria, increased urinary urate and oxalate excretion
Nephrocalcinosis (deposition of calcium in the parenchyma) may occur in hypercalciuria, hyperoxaluria and distal renal tubular acidosis (it may be a complication of furosemide therapy in neonates)
74
Presentation of renal calculi
Haematuria
Loin or abdominal pain
UTI
Passage of a stone
75
Management of kidney stones
Conservative management with IV fluids, analgesia (morphine) and anti-emetics (ondansetron)
Bacterial infection - antibiotic treatment with co-trimoxazole or nitrofurantoin, or surgical decompression
Small stones - medical expulsive therapy (Tamsulosin OR alfuzosin OR silodosin)
Larger stones that do no pass spontaneously - surgical removal (1st line: ESWL or ureteroscopy)
High fluid intake is recommended in all affected children
76
Fanconi syndrome (Generalised proximal tubular dysfunction)
Proximal tubule cells are very metabolically active
The main features of Fanconi syndrome are excessive urinary loss of amino acids, glucose, phosphate, bicarbonate, sodium, calcium, potassium and magnesium
77
Presentation of Fanconi syndrome
```
Polydipsia and polyuria
Salt depletion and dehydraiton
Hyperchloraemic metabolic acidosis
Rickets
Faltering or poor growth
```
78
Causes of Fanconi syndrome
Idiopathic
Secondary to inborn errors of metabolism
- Cystinosis
- Glycogen storage disorders
- Lowe syndrome (oculocerebroneural dystrophy)
- Galactosaemia
- Fructose intolerance
- Tyrosinaemia
- Wilson's disease
Acquired
- Heavy metals
- Drugs and toxins
- Vitamin D deficiency
79
Causes or acute kidney injury
Pre-renal (most common in children)
- Hypovolaemia (gastroenteritis, burns, sepsis, haemorrhage, nephrotic syndrome)
- Circulatory failure
```
Renal:
Vascular
- HUS
- Vasculitis
- Embolus
- Renal vein thrombosis
```
Tubular
- Acute tubular necrosis
- Ischaemic
- Toxic
- Obstructive
Glomerular
- Glomerulonephritis
Interstitial
- Pyelonephritis
- Interstitial nephritis
POST-renal:
Obstruction
- Congenital (e.g. posterior urethral valves)
- Acquired (e.g. blocked urinary catheter)
80
General management of AKI
Ultrasound may be useful to identify obstruction, small kidneys in CKD or large, bright kidneys with loss of cortical medullary differentiation (typical of an acute process)
Use diuretics when necessary (i.e. to treat fluid overload or oedema whilst the patient is awaiting renal transplant)
Fluid restriction will also be helpful
Consider referral for renal replacement therapy if any of the following are not responding to therapy:
- Hyperkalaemia
- Pulmonary oedema and fluid overload
- Acidosis
- Uraemia (e.g. pericarditis, encephalopathy)
Discuss the triggers of AKI such as dehydration and nephrotoxic drugs
81
Management of pre-renal failure (AKI)
Due to hypovolaemia
Little sodium is excreted because the body is trying to retain it
Hypovolaemia should be urgently addressed with fluid replacement and circulatory support
82
Management of renal failure (AKI)
Monitoring water and electrolyte balance
A high-calorie, normal protein feed will decrease catabolism, uraemia and hyperkalaemia
Metabolic acidosis= sodium bicarbonate
Hyperophataemia= calcium carbonate, dietary restriction
Hyperkalaemia = calcium gluconate if ECG changes. Salbutamol (nebulised or intravenous). Calcium exchange resin. Glucose and insulin. Dietary restriction. Dialysis.
83
Most common causes of acute renal failure in children in the UK
Haemolytic uraemic syndrome
Acute tubular necrosis (this usually happens in the context of multisystem failure, in the ITU or following cardiac surgery)
84
Management of post-renal failure (AKI)
Refer immediately to urology if any of the following are present:
Pyonephrosis
Obstructed solitary kidney
Bilateral upper urinary tract obstruction
Complications of AKI caused by urological obstruction
Requires assessment of the site of obstruction
Relief can be achieved by nephrostomy or bladder catheterisation
85
When is dialysis indicated in AKI?
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Failure of conservative management
Hyperkalaemia
Severe hyponatraemia or hypernatraemia
Pulmonary oedema or severe hypertesion due to volume overload
Severe metabolic acidosis
Multisystem failure
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AKI in childhood generally has a good prognosis unless it is complicating a more serious condition (e.g. severe infection, following cardiac surgery)
86
What triad characterising HUS?
Acute renal failure
MAHA
Thrombocytopenia
87
What is typical HUS secondary to?
Gastrointestinal infection with verocytotoxin-producing E.coli O157:H7
This may be acquired through contact with farm animals or eating undercooked beef
It can also occur with Shigella
88
Pathophysiology of HUS
It follows a prodrome of bloody diarrhoea
The toxin from these organisms can enter the gastrointestinal mucosa and localise to the endothelial cells of the kidney, causing intravascular thrombogenesis
The coagulation cascade is activated (NB: clotting is normal in HUS, unlike in DIC)
Platelets are consumed due to activation of the coagulation cascade, and MAHA results from damage to RBCs as they circulate through an occluded microvascular system
Typical diarrhoea-associated HUS has a good prognosis with early supporting therapy
89
Management of haemolytic uraemic syndrome
Consult nephrology and haematology specialists
Children with typical presentation should be hospitalised
Supportive:
Monitor urine output and fluid balance
Maintain adequate hydration status (avoid cardiopulmonary overload)
Monitor BP (treat if elevated):
- Treatment should be with CCBs (ACE inhibitors can reduce renal perfusion)
Avoid antibiotics, anti-diarrhoeals, narcotic opioids and NSAIDs
50% of patients will require dialysis in the acute phase
Long-term follow-up is necessary because there may be persistent proteinuria and the development of hypertension and progressive CKD
90
Atypical HUS
Has no diarrhoeal prodrome, may be familial and frequently relapses
- This has a high risk of hypertension and progressive CKD with a high mortality
91
HOw many stages of chronic kidney disease are there?
5
Stage 5 renal failure is much less common in children than adults
Congenital and familial causes are more common in childhood
92
Clinical features of stage 4/5 CKD
Anorexia and lethargy
Polydipsia and polyuria
Faltering growth/growth failure
Bony deformities form renal osteodystrophy
Hypertension
Acute-on-chronic renal failure (precipitated by infection or dehydration)
Incidental finding of proteinuria
Unexplained normochromic, normocytic anaemia
93
Management of chronic kidney disease
Aim to prevent symptoms and metabolic abnormalities, allow normal growth and development and preserve residual renal function
Diet
- Anorexia and vomiting are common
- Calorie supplements or NG/gastrostomy feeding is often necessary to optimise growth
- Protein intake should be sufficient to maintain growht and normal albumin (but preventing the accumulation of toxic metabolic by-products)
Prevention of renal osteodystrophy:
- Decreased activation of vitamin D leads to phosphate retention and hypocalcaemia, which, in turn, leads to secondary hyperparathyroidism and eventually osteitis fibrosa cystica and osteomalacia
- Phosphate restriction (by reducing milk), using calcium carbonate as a phosphate binder and activated vitamin D supplements can help
Control of salt and water balance, and acidosis
- Many children will also have obligatory loss of salt and water
- They need salt supplements and a lot of water
- Treatment with bicarbonate supplements is needed to prevent acidosis
Acidosis
- Reduced EPO production and circulation of marrow-toxic metabolites leads to anaemia
- Responds well to the administration of SC recombinant human EPO
Hormonal abnormalities
- Growth hormone resistance, characterised by a high GH level but poor growth, is a feature of CKD
- Recombinant human GH is effective in improving growht for up to 5 years of age
- Many children with stage 4/5 CKD will have delayed puberty or subnormal pubertal growth spurt
94
How is immunosuppression following renal transplant currently achieved?
Combination of tacrolimu,s mycophenolate mofetil and prednisolone
95
Embryology of inguinoscrotal conditions
The development of a testis is determined by genes associated with the Y chromosome
For a testis to descend, it must produce testosterone.
The testis, guided by the mesenchymal gubernaculum, migrates down into the inguinal canal
The structures found within the scrotim in boys (testis, vas, blood vessels) and labium in a girl (attachment of the round ligament of the uterus) pass through the abdominal wall and pick up layers
In a boy, these make up the coverings of the spermatic cord
In boys and girls, there is a remnant of the peritoneal invagination, which can remain patent meaning that fluid or abdominal contents can pass into it turning it into a hydrocoele or a hernia
96
What is the usual cause for an inguinal hernia?
Persistently patent processus vaginalis
| Emerges from the deep inguinal ring through the inguinal canal
97
Why are premature babies more likely to get inguinal hernias?
Because the tissues are weaker and more friable (especially direct hernias)
98
Presentation of ingunial hernia
Typically presents as a lump in the groin that may extend into the scrotum or labium
Usually asymptomatic
Contents of the hernia may become irreducible (incarcerated), causing pain and sometimes, intestinal obstruction or damage to the testes (strangulation): in this case, the lump will be tender and the infant may be irritable or vomiting
The risk of incarceration is higher in infants
99
Management of inguinal hernias
Most hernias can be reduced by taxis (gentle compression in the line of the inguinal canal) with good analgesia
Surgery can be planned once the oedema has setlled and the child is well
If reduction is impossible, emergency surgery is required
Surgery involves ligation and division of the processus vaginalis
100
What is the risk of inguinal hernias in girls?
Sometimes the ovary can get incarcerated within a hernia
101
What is the cause of a hydrocoele?
Similar underlying anatomy to a hernia, but the patent processus vaginalis is not wide enough to form an inguinal hernia
102
How to distinguish between an inguinal hernia and a hydrocoele
You can get above a hydrocoele but not a hernia
| Hydrocoeles also transilluminate
103
Clinical features of hydrocoele
Usually asymptomatic
104
Management of hydrocoeles
Although the processus vaginalis is often patent at birth, it usually closes within months, so hydrocoeles usually resolve spontaneously
Surgery may be considered if symptoms persist beyong the first 2 years of life
<2 years = most resolve spontaneously before the age of 2 so observation is appropriate provided there is no evidence of underlying pathology
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2-11 years:
Open repair
Laparoscopic exploration
Bilateral repair
Abdominoscrotal hydrocoeles - require srgery through an abdominal incisino
```
11-18 years:
Idiopathic hydrocoele= observation is appropriate, however, surgery may be considered if it is large or uncomfortable
Hydrocoele after varicocelectomy= conservative management is the initial approach, surgery is considered in cases that don't resolve
Filarial-related hydrocoele= complete excision of the tunica vaginalis
105
Varicocoele
Scrotal swelling comprising dilated testicular veins
| Occurs in up to 15% of boys, usually at puberty
106
Aetiology of varicocoele
Multifactorial causes, but valvular incompetence plays a role
More common on the left side, because of the drainage of the gonadal vein into the left renal vein, which also received blood containing catecholamines from the left adrenal vein
107
Presentation of varicocoele
May cause a dull ache, but it is usually asymptomatic
| O/E it may feel like a bag of worms
108
Management of varicocoele
Conservative if asymptomatic
| Occlusion of gonadal veins can be achieved by surgical ligation
109
What is important to note when examining newborn testes?
Should be made in a warm environment with warm hands
Testes may be felt in the scrotum or may need to be delivered by gentle pressure along the line of the inguinal canal to the scrotum
110
Presentation of undescended testes
Diagnosis should be made at the routine examination of the newborn
More common in premature infants
May be palpable or impalpable: a palpable undescended testis is usually seen or felt in the groin but cannot be manipulated into the scrotum
NB: occasionally, a palpable undescended testis can be palpated below the external inguinal ring but outside the scrotum = ectopic testis
An impalpable undescended testis may be intra-abdominal or absent
111
Investigations for undescended testes
If there is bilateral impalpable testes, the karyotype must be established to exclude disorders of sex development (NB: this is a medical emergency)
112
What is a retractile testis?
The difference between a retractile testis and an undescended testis is that a retractile tesits can be manipulated into the scrotum with ease and without tension
113
Management of undescended testes
<3 months:
If possibility of disorder of sexual development, urgently refer to a senior paediatrician within 24 hours as genetic or endocrine testing may be necessary
If undescended testes are bilateral at birth, urgently refer to a senior paediatrician within 24 hours as genetic or endocrine testing may be necessary
If unilateral undescended testis:
At birth - arrange review at 6-8 weeks
At 6-8 weeks:
- if both testes are descended, no further action is necessary
- If unilateral undescended testis, re-examine at 3 months
At 3 months:
- If both testes are descended, no further action is needed
- If both testes are in the scrotum, but one or both are rectractile, advise the parents that annual follow up is needed throughout childhood as there is a risk of ascending testes
- If the testis is still undescended, refer the child to a paediatric surgeon before 6 months of age
In 10% of impalpable testis, they have regressed in development and are absent
114
For what reasons may orchidopexy (placement of testis in the scrotum) be performed?
Cosmetic
Reduced risk of trauma and torsion
Fertility (particularly important if bilateral)
Malignancy (increased risk in an undescended testis)
Ideally should be performed <1 year
115
IN what population is testicular torsion most common?
Pre-pubertal boys
116
Presentation of testicular torsion
Very painful, with redness and oedem of the scrotal skin
Pain may localise to the groin or lower abdomen (this is why you must examine the testes of a boy presenting with sudden-onset/abdominal pain)
Must be distinguished from an incarcerated inguinal hernia
117
Risk factors for testicular torsion
Undescended testes
| Bell clapper testis (a testis that is lying transversely on its attachment to the spermatic cord)
118
Management of testicular torsion
Must be treated within hours of onset of symptoms to avoid testicular loss
Surgical exploration in any acute scrotal presentation is essential because of the increased risk of contralateral torsion
Patients presenting within 4-6 hours of symptom-onset have a greater likelihood of testicular viability
Non-neonates:
Immediate urological consultation for operative repair
Decision about orchidectomy vs orchidopexy is based on extent of damage to testicular tissue
During surgery, the contralateral testicle is fixed to the posterior wall
Neonates:
Born with torsion - debate about whether surgical intervention is necessary (risk of anaesthesia)
Born with normal testes but develop torsion - surgical surgical exploration is necessary
Manual detortion may be attempted if surger is not available within 6 hours
Pain relief and sedation
Anti-emetics
119
What is Hydatid of Morgagni?
A testicular appendage: a Mullerian remnant usually located on the upper pole of the testis
Torsion of the testicular appendage is more common than testicular torsion
120
Presentation of torsion of appendix testis
Pain will develop over days and is not as dramatic as testicular torsion
Scrotal exploration and excision of the appendage is often necessary because it cannot be reliably differentiated from testicular torsion
121
Investigations for epididymo-orchitis
It may be indistinguishable from torsion, so scrotal exploration may be necessary
Doppler ultrasound to look at the flow pattern in the testicular blood vessels may be helpful
A urine sample should be obtained to identify an associated UTI
Pus should be sent at operation for microbiology to characterise the nature of the infection
122
Management of epididymo-orchitis
```
Symptomatic relief:
Bed rest
Scrotal elevaiton
Simple elevation
If systemically unwell with a high-grade fever, IV antibiotics and fluids are required
```
Eradication of infection:
Empirical antibiotics
Gonococcal or chlamydia - ceftriaxone + doxycycline
Enteric organisms - quinolone (e.g. ofloxacin, levofloxacin)
Mumps - supportive
Prevention of complications:
Prompt treatment and supportive measures
Possible complications: abscess formation, infertility, chronic pain
123
Idiopathic scrotal oedema
Redness and swelling extending beyond the scrotum into the thigh, perineum and suprapubic area
Testis is normal and non-tender
Requires analgesia and review
124
Non-retractile foreskin
The foreskin becomes adherent to the underlying glans, and acts as protection to the non-keratinised glandular and meatal squamous epithelium
Urine can cause inflammation or even ulceration which can manifest as ammoniacal dermatitis (nappy rash)
- This may appear as mild redness and soreness of the preputial opening
- This can be managed with reassurance and attention to routine hygiene
Needs to be differentiated from infection, or balanoposthitis (inflammation of the glans and foreskin), where the redness is more extensive and there is a purulent discharge
The infection is usually bacterial and usually needs either topical or systemic antibiotics
125
Ballooning of the foreskin on urination
Caused by lysis of the preputial adhesions before those at the preputial opening
Ballooning will stop when preputial adhesions have lysed completely
126
Sub-preputial smegma
Mainly desquamated skin and secretions
| No need to intervene because it will discharge in due course when the preputial adhesions break down
127
What is the most common condition that leads to a true phimosis?
Balanitis xerotica obliterans:
Gives rise of progressive scarring that can extend onto the glans, into the meatus, and, ultimately, into the urethra
Usually affects older boys and adults
BXO is an indication for circumcision
128
What is paraphimosis?
When a retracted foreskin cannot be reduced easily
129
Management of paraphimosis
There is a ring of narrower skin that makes the glans swell and may result in compromise of the blood supply to the glans if it s not reduced
Treatment by reduction is an emergency, which may require local or general anaesthesia
Manipulation with topical analgesia (ice packs, compression, osmotic agents)
Puncture technique - perforating the foreskin at multiple locations to allow exudation of oedematous fluid (if manipulation was unsuccessful)
Surgical reduction followed by circumcision
130
Medical reasons for circumcision
BXO causing true phimosis
Recurrent balanoposthitis causing refractory symptoms
Prophylaxis of recurrent urinary infection (especially if there is congenital uropathy)
If access to the urethra is required reliably for intermittent catheterisation (e.g. spina bifida)
131
Aetiology of hypospadias
Arise from failure of development of ventral tissues of the penis (in particular, failure of the ventral urethral closure)
132
Clinical features of hypospadias
Ventral urethral meatus (urethral meatus is in a variable position (usually on the distal shaft or glans)
Ventral curvature of the shaft of the penis
Hooded appearance of the foreskin
133
Management of hypospadias
Surgery is not mandatory
May be performed on functional or cosmetic grounds (after 3 months)
Ultimate functional aim of surgery is to allow boys to pass urine in a straight line while standing and to have a straight erection
Prepuce may be preserved and reconstructed, although for more proximal hypospadias, it is sometimes required for the repair itself
IMPORTANT: boys with hypospadias should not be circumcised before repair, because the skin is important for the repair
134
Vulvovaginitis
Most common problem is redness of the vulva
Often due to nappy rash due to ammoniacal dermatitis
May be infective, occasionally with Candida infection
Vaginal discharge is common and not usually a problem, but blood vaginal discharge is a red flag symptoms and needs referral to a specialist, because vaginal rhabdomyosarcoma is a rare but important cause in preschool children
135
Management of labial adhesions
Fusion of the labia minora can be a cause of local irritation, but no specific treatment is needed unless this causes significant symptoms
Topical steroids or oestrogens may be hepful to lyse the adhesions
136
O/E, there is a bulging introitus that appears blue - what is the diagnosis?
Imperforate hymen
| Treated with a hymenotomy under anaesthesia
