Flashcards in Nephrology and genito-urinary || Deck (100):
What is the incidence of UTIs in girls and boys before the age of 6?
What % have recurrence within a year?
3-7% of girls and 1-2% of boys have at least 1 symptomatic UTI before the age of 6 years
12-30% have a recurrence within a year
What is the most common infective organism causing UTIs in children?
What other organisms can cause it (4)?
What are the presenting features of UTI in infants?
Less common (4)
5. Poor feeding
6. Failure to thrive
1. Abdominal pain
4. Offensive urine
What are the presenting features of a UTI in preverbal children?
Less common (5)
2. Abdominal pain
3. Loin tenderness,
5. Poor feeding
9. Offensive urine
10. Failure to thrive
What are the presenting features of a UTI in verbal children?
Less common (6)
3. Dysfunctional voiding
4. Changes to continence
5. Abdominal pain
6. Loin tenderness
11. Offensive urine
12. Cloudy urine
What are the ways a urine sample can be collected in children in nappies (4)?
When would they be done?
1. 'Clean-catch' sample into a waiting clean pot when nappy removed
2. Adhesive plastic bag applied to the perineum after careful washing
3. A urethral catheter
4. Suprapubic aspiration, when a fine needle attached to a syringe is inserted directly into the bladder just above the pubic symphysis under US guidance
Which is the recommended method of urine collection in children?
'Clean-catch' sample into a waiting clean pot when nappy removed
What is a disadvantage of the adhesive plastic bag method of collecting urine?
Can have contamination from skin
When would a urethral catheter be used to collect urine from a child?
If there is urgency in obtaining sample or no urine has passed
When would a suprapubic aspiration be used to collect urine from a child?
For severely ill children needing urgent diagnosis and treatment
How can a urine sample be obtained from an older child?
What precautions need to be taken?
Careful cleaning and collection are necessary
-contamination with both white cells and bacteria can occur from under the foreskin in boys and from reflux of urine into the vagina during voiding in girls
What measurement are not a reliable feature for the diagnosis of a UTI?
Urinary white cells - present in febrile children without UTI and those with balanitis and vulvovaginitis
What can be done as a screening test for a UTI?
What findings would you find on a urine dipstick test and interpret results (4)?
1. Leucocyte esterase and nitrite positive - regard as UTI
2. Leuococye esterase negative and nitrite positive - Start Abx treatment if clinical evidence of UTI
-Diagnosis depends on urine culture
3. Leucocyte esterase positive and nitrite negative - Only start Abx treatment if clinical evidence of UTI
-Diagnosis depends on urine culture
4. Leucocyte esterase and nitrite negative - UTI unlikely
What would be done after a urine dipstick test to diagnose a UTI? When would you do it?
Urine culture would always be done after dipsticks unless both leucocyte esterase and nitrite are negative, or if the clinical symptoms and dipstick tests do not correlate
What is the criteria for diagnosing a UTI in urine culture?
1. In a properly caught sample
2. Catheter/suprapubic aspirate
1. A bacterial culture of more than 10^5 colony-forming units (CFU) of a single organism per millilitre gives 90% probability of infection
-If the same result is found in a second sample, probability is 95%
2. Any bacterial growth of a single organism per millilitre in a catheter sample or suprapubic aspirate is diagnostic of infection
Definition of an atypical UTI in NICE guidelines (7)?
1. seriously ill
2. poor urine flow
3. abdominal or bladder mass
4. raised creatinine
6. failure to respond to treatment with suitable antibiotics within 48 hours
7. infection with non-E. coli organisms
Definition of a recurrent UTI in NICE guidelines (3)?
1. 2 or more episodes of UTI with acute pyelonephritis/upper urinary tract infection, or
2. 1 episode of UTI with acute pyelonephritis/upper urinary tract infection plus one or more episode of UTI with cystitis/lower urinary tract infection, or
3. 3 or more episodes of UTI with cystitis/lower urinary tract infection
What is the recommended imaging schedule for infants younger than 6 months with atypical/recurrent UTIs (3)?
1. Ultrasound during acute infection - to identify structural abnormalities of urinary tract
2. DMSA scan 4-6 months following acute infection
3. MCUG scan
What is the recommended imaging schedule for children 6 months-3 years of age with atypical/recurrent UTIs (3)?
1. US during acute infection for atypical infection
-Not for recurrent UTI
2. Ultrasound in 6 weeks for recurrent UTI
3. DMSA 4-6 months following infection for both atypical and recurrent infection
What is the recommended imaging schedule for children 3 years of age or older with atypical/recurrent UTIs (3)?
1. US during acute infection for atypical UTI
-Not recurrent UTI
2. US at 6 weeks for recurrent UTI
3. DMSA 4-6 months after infection for recurrent UTI
What must always be tested in infants with an unexplained fever >38 degrees
What is vesicoureteric reflux (VUR)?
Developmental anomaly of the vesicoureteric junctions. The ureters are displaced laterally and enter directly into the bladder rather than at an angle, with a shortened or absent intramural course.
What is the incidence of VUR?
1. In the general population?
2. In children with UTIs?
2. In children under the age of 1 year with a urinary tract infection, 70% will have VUR
What is the range of severity of VUR?
Mild reflux - into the lower end of an undilated ureter during micturition
Severe reflux - reflux during bladder filling and voiding, with a distended ureter, renal pelvis and clubbed calyces
What can severe VUR be associated with?
The backflow of urine from the renal pelvis into the papillary collecting ducts and is associated with a high risk of renal scarring if UTIs occur
What is the danger of VUR (3)?
1. Renal defects
-Increased incidence of renal defect with increasing severity of reflux
-Can lead to infection which may destroy renal tissue leaving a scar, resulting in a shrunken, poorly functioning segment of kidney
3. Progressive chronic kidney disease
-if scarring is bilateral, increasing the risk of hypertension in childhood/early adult life
Why is VUR-associated ureteric dilation important (3)?
1. Incomplete bladder emptying
-Urine returning to bladder from ureters after voiding leads to incomplete bladder emptying which encourages infection
-If there is intrarenal reflux
3. Renal damage
-Bladder voiding pressure is transmitted to renal papillae which can contribute to renal damage if voiding pressures are high
What is the investigation for VUR?
Children with atypical or recurrent UTIs are investigated
-Initial US will identify serious structural abnormalities and urinary obstruction, renal defects
These can also be used:
Fluoroscopic voiding cystourethrogram (VCUG)
Technetium-99m Dimercaptosuccunic Acid (DMSA) Scintigraphy
NICE definition of pyelonephritis (2)?
1. Infants and children who have bacteriuria and fever of 38°C or higher
2. Infants and children presenting with fever lower than 38°C with loin pain/tenderness and bacteriuria
NICE definition of cystitis?
Infants and children who have bacteriuria but no systemic symptoms or signs
What is the treatment of pyelonephritis (2)?
Oral Abx e.g. trimethoprim for 7 days
iv Abx e.g. co-amoxiclav given for 2-4 days followed by oral Abx for 7-10 days
What is vulvo-vaginitis?
How common is it in young girls?
Symptomatic inflammation of the vagina and/or vulva causing redness, usually due to nappy rash due to ammoniacal dermatitis or caused by Candida infection
What is nephrotic syndrome?
Kidneys leak protein, leading to heavy proteinuria, resulting in a low plasma albumin and oedema
What is the incidence of nephrotic syndrome in children?
Around 1 in every 50,000 children are diagnosed with the condition each year
What are the causes of nephrotic syndrome in children (4)?
Unknown but secondary to:
3. Infections e.g. malaria
4. Allergens e.g. bee sting
What are the clinical features of nephrotic syndrome (5)?
1. Periorbital oedema (particularly on waking) - often the earliest sign
2. Scrotal or vulval, leg and ankle oedema
4. Breathlessness due to pleural effusions and abdominal distension
5. Infection such as peritonitis, septic arthritis or sepsis due to loss of protective immunoglobulins in urine
What is the most common type of nephrotic syndrome in children?
Minimal change disease.
-There is fusion of specialised epithelial cells that invest the glomerular capillaries (podocytes) is seen on electron microscopy
-The cause of minimal change disease is unknown.
What is the management of nephrotic syndrome (3)?
1. Oral corticosteroids (prednisolone) daily for 4 weeks
2. After 4 weeks, reduce dose of steroids and given on alternate days for 4 weeks, then weaned and stopped
3. Those who do not respond to 4-6 weeks of corticosteroid therapy or have atypical features may need a renal biopsy
What are the atypical features of nephrotic syndrome in a child that would prompt consideration of 2nd line treatment and/or a renal biopsy (6)?
1. Age less than 12 months or greater than 12 years
2. Persistent hypertension
3. Impaired renal function
4. Gross haematuria
5. Low plasma C3
6. Hepatitis B or C positive
What is acute nephritis?
Inflammation of the kidneys
What are the causes of acute nephritis in childhood (4)?
-SLE, Wegnergranulomatosis, microscopic polyarteritis, polyarteritis nodosa
3. IgA nephropathy and mesangiocapillary glomerulonephritis
4. Antiglomerular basement membrane disease (Goodpasture syndrome) - very rare
What is the pathophysiology in acute nephritis?
Nephritis can produce glomerular injury, by disturbing the glomerular structure with inflammatory cell proliferation.
This can lead to reduced glomerular blood flow, leading to reduced urine output (oliguria) and retention of waste products (uremia).
As a result, red blood cells may leak out of damaged glomeruli, causing blood to appear in the urine (hematuria).
What are the clinical features of acute nephritis (4)?
1. Decreased urine output and volume overload
2. Hypertension, which may cause seizures
3. Oedema, characteristically initially periorbital
4. Haematuria and proteinuria
What is the management of acute nephritis (2)?
1. Attention to both water and electrolyte balance
2. Diuretics when necessary
What is Henoch-Schonlein purpura (HSP)?
Rare condition where there is a vasculitis
What are the main features of HSP (5)?
1. Characteristic skin rash on extensor surfaces
3. Periarticular oedema
4. Colicky abdominal pain
What age does HSP most common occur at?
What are risk factors for HSP (3)?
1. Twice as common in boys
2. Peaks during the winter months
3. Often preceded by an upper respiratory infection
What is the cause of HSP?
Unknown, could be:
-Antigen exposure increases circulating IgA levels and disrupt IgG synthesis, IgA and G form complexes together that are deposited in affected organs, precipitating an inflammatory response with vasculitis
What are features of the rash that comes with HSP (4)?
1. Symmetrically distributed over the buttocks, extensor surfaces of the arms and legs, and the ankles. Trunk is usually spared
2. Rash may initially be urticarial, rapidly becoming maculopapular and purpuric
3. Rash is characteristically palpable
4. It can recur over several weeks
How is a diagnosis of HSP made?
-Rash is the first clinical feature in about 50% and is the cornerstone of the diagnosis
What are features of the joint pain that occurs with HSP (3)?
1. Occurs in 2/3 of patients
2. Affects particularly knees and ankles
3. Long-term damage to the joints does not occur and symptoms usually resolve before the rash goes
What are the long-term complications of HSP?
Who they occur in (2)?
Progressive kidney disease
1. Children who have persistent renal involvement
2. Those who require treatment for HSP nephritis
What are the symptoms of renal involvement of HSP (2)?
What is the prognosis of renal involvement?
1. Over 80% have microscopic or macroscopic haematuria or mild proteinuria
-These children usually make a complete recovery
2. If proteinuria is more severe, nephrotic syndrome may result
What are risk factors for progressive chronic kidney disease from HSP (4)?
1. Heavy proteinuria
4. Deteriorating renal function
What investigation would be done to see if children with renal involvement as part of HSP need treatment?
What is the follow up for HSP (2)?
1. All children followed up for 1 year to detect those with persisting haematuria or proteinuria (5-10%)
2. Children with persistent renal involvement or required treatment for HSP nephritis require long-term follow-up to look for hypertension and progressive chronic kidney disease
What treatment would be given for HSP nephritis?
What would you advise a parent about looking after a child with HSP (2)?
1. Reassure them that it usually passes in a few weeks, although some can develop kidney problems
2. They can go back to school as soon as they feel well enough as it is not contagious
What is glomerulonephritis?
When the glomeruli become inflamed
What is the most common cause of acute Glomerulonephritis in children?
What investigations would be needed when someone presents with acute glomerulonephritis?
All patients (5)
Specific to glomerular (6)
1. Urine microscpy and culture
2. Protein and calcium excretion
3. Kidney and urinary tract US
4. Plasma urea, elecrolytes, creatinine, calcium, phosphate, albumin
5. FBC, platelets, coagulation screen, sickle cell screen
Specific to glomerular:
1. ESR, completment levels and anti-DNA antibodies
2. Throat swab and antistreptolysin O/anti-DNAse B titres
3. Hep B and C screen
4. Renal biopsy if indicated
5. Test mother's urine for blood (if Alport syndrome syspected)
6. Hearing test (If Alport syndrome suspected)
What is IgA nephropathy?
How does it compare to HSP?
An autoimmune disease that affects the kidneys which may present with episodes of macroscopic haematuria, commonly in association with URTI
Histological findings and management are as for HSP
What presenting feature is usually present for acute kidney injury in children?
What are clinical features of acute-on-chronic renal failure (3)?
Oliguria (<0.5ml/kg per hour)
Acute-on-chronic renal failure:
1. Growth failure
3. Disordered bone mineralisation (renal osteodystrophy)
What are the 3 categories of causes of acute kidney injury (3)?
What are the prerenal causes of acute kidney injury (2)?
2. Circulatory failure
What are the renal causes of acute kidney injury (4)?
-Haemolytic uraemic syndrome
-renal vein thrombosis
-acute tubular necrosis
What is the management of prerenal failure?
The hypovolaemia needs to be urgently corrected with fluid replacement and circulatory support
-to avoid acute tubular injury and necrosis
What is the management of renal failure (5)?
1. If there is circulatory overload
-Restriction of fluid intake
-Challenge with a diuretic to increase urine output sufficiently to allow gradual correction of sodium and water balance
2. A high-calorie, normal protein feed to decrease catabolism, uraemia and hyperkalaemia
3. Emergency treatment of metabolic acidosis, hyperkalaemia and hyperphosphataemia
-with sodium bicarbonate, dietary restriction etc
4. If cause of renal failure is not obvious - renal biopsy. May show rapidly progressive glomerulonephritis which needs rapid treatment with immunosuppression
5. If caused by acute tubular necrosis, it is usually in the setting of multisystem failure which needs ITU or following cardiac surgery
What is the management of postrenal failure (2)?
1. Assessment of the site of obstruction and relief by nephrostomy or bladder catheterisation
2. Surgery can be done once fluid volume and electrolyte abnormalities have been corrected.
When is dialysis in acute kidney injury indicated (6)?
1. Failure of conservative management
3. Severe hyponatraemia or hypernatraemia
4. Pulmonary oedema or severe hypertension due to colume overload
5. Severe metabolic acidosis
6. Multisystem failure?
Why is an MDT important in the management of AKI (6)?
1. May have multisystem failure
2. Can be an emergency and need ITU
3. Can follow cardiac surgery
4. Staff for dialysis
6. Histology for biopsy etc
What is the most common causative organism of childhood diarrhoea associated haemolytic uraemic syndrome (HUS)?
Verocytotoxic-producing E. coli O157:H7
What is the triad of abnormalities which define HUS (3)?
1. Acute kidney injury
2. Haemolytic anaemia
What is the prognosis for typical diarrhoea-associated HUS?
Why is follow up necessary?
Long-term FU needed as there may be persistent proteinuria and the development of hypertension and progressive CKD in subsequent years
How does atypical non-diarrhoea-associated HUS differ from the typical kind (4)?
1. No diarrhoea prodrome
2. May be familial
3. Frequently relapses
4. High risk of hypertension and progressive CKD with high mortality
What is chronic kidney disease (CKD)?
Progressive loss of renal function
What are the 5 stages of CKD?
Stage 1: GFR>90ml/min per 1.73m^2
Stage 2: GFR 60-89ml/min per 1.73m^2
Stage 3: GFR 30-59ml/min per 1.73m^2
Stage 4: GFR 15-29ml/min per 1.73m^2
Stage 5: GFR <15ml/min per 1.73m^2
What are the clinical features of children with stage 4/5 CKD (8)?
1. Anorexia and lethargy
2. Polydipsia and polyuria
3. Faltering growth/growth failure
4. Bony deformities from renal osteodystrophy
6. Acute-on-chronic renal failure
7. Incidental finding of proteinuria
8. Unexplained normochromic, normocytic anaemia
What are the aims of management of CKD (3)?
1. To prevent symptoms and metabolic abnormalities of CKD
2. Allow growth and development
3. Preserve residual renal function
Why is a MDT and multi-professional team important in the management of children with CKD (3)?
1. Different systems of the body are affected e.g. bones, hormones, etc
2. Managing diet is important
3. May need dialysis
What is the management of CKD? What complications do you need to look out for (6)?
-Improve nutrition using calorie supplements and NG or gastrostomy feeding needed to optimize growth
2. Prevention of renal osteodystrophy
-Phosphate restriction by decreasing dietary intake of milk products, calcium carbonate as a phosphate binder and activated vitamin D supplements
3. Control of salt and water balance and acidosis - many with CKD due to congenital structural malformations and renal dysplasia have loss of salt and water
-Treat with salt supplements and free access to water.
-Give bicarbonate supplements to prevent acidosis
4. Anaemia - reduced production of erythropoitin and circulation of metabolites that are toxic to the BM result in anaemia
-Treat with subcutaneous recombinant human erythropoietin
5. Hormonal abnormalities
-Recombinant human growth hormone to combat the growth hormone resistance (despite high growth hormone levels)
6. The optimum management is is renal transplantation
-Children have to be of a minimum weight e.g. 10kg to qualify to avoid renal vein thrombosis
-Immunosuppression with combinations of tacrolimus and mycophenolate mofetil and prednisolone
-Children go on peritoneal dialysis or haemodialysis
How does phosphate retention and hypocalcaemia lead to renal osteodystrophy in CKD?
Phosphate retention and hypocalcaemia due to decreased activation of Vit D lead to secondary hyperparathyroidism, which results in osteitis fibrosa and osteomalacia of the bones
What is the definition of hypertension in a child?
BP above 95th percentile for height, age and sex
Be aware of some causes of hypertension in children (5)
1. Renal disease
-Renovascular e.g. renal artery stenosis
2. Coarctation of the aorta
3. Catecholamine excess
-Congenital adrenal hyperplasia
-Cushing syndrome/Corticosteroid therapy
5. Essential hypertension
-Diagnosis of exclusion
Why is it important to investigate for an underlying cause of hypertension in children (2)?
1. Some causes are correctable and due to underlying pathology:
-e.g. nephrectomy for unilateral scarring
-angioplasty for renal artery stenosis
-surgical repair of coarctation of aorta
-resection of a pheochromocytoma etc
2. Because medical treatment is necessary with anti-hypertensives
What are some presenting features of urinary tract abnormalities on antenatal US screening (6)?
1. Renal agenesis - Severe oligohydramnios resulting in Potter syndrome (fatal)
2. Multicystic dysplastic kidney - Potter syndrome
3. Pelvic kidney (horseshoe kidney)
4. Premature division of the ureteric bud giving rise to a duplex system - varies from simply a bifid renal pelvis to complete division with 2 ureters
5. Failure of fusion of the infraumbilical midline structures results in exposed bladder mucosa
6. Obstruction to urine flow can occur at the pelviureteric or vesicoureteric junction at the bladder neck. In most severe and bilateral cases, it can lead to Potter syndrome
How does Potter syndrome occur?
Amniotic fluid is caused by kidneys producing urine, so in pathologies where kidneys are affected, there is a major reduction in fetal urine excretion, leading to oligohydramnios, causing fetal compression
How can urinary tract abnormalities be suspected after birth, if missed on antenatal scan?
Increases risk of infection (UTI) prompting investigation
What are the investigations used in the diagnosis of antenatal urinary tract abnormalities (5)?
2. DMSA scan
4. MAG3 renogram
5. Plain abdo X-ray
What pathologies are US good for detecting in kidneys (3)?
1. urinary tract dilatation
Describe features of the use of DMSA scans for congenital urinary tract abnormalities
detects functional defects such as scars or areas of non-functioning renal tissue but very sensitive, so need to wait >2months after UTI to avoid diagnosing false scars
Describe features of the use of US scans for congenital urinary tract abnormalities
standard imaging procedure of kidneys and urinary tract to provide anatomical assessment, but not function.
Describe features of the use of MCUG scans for congenital urinary tract abnormalities
Contract introduced into bladder through urethral catheter. Can visualise bladder and urethral anatomy. Detects VUR and urethral obstruction.
Describe features of the use of MAG3 renogram scans for congenital urinary tract abnormalities
dynamic scan, isotope-labelled substance MAG3 excreted from blood into urine. Measures drainage, best performed with a high flow urine so furosemide often given
Describe features of the use of plain abdo x-ray scans for congenital urinary tract abnormalities
identifies unsuspected spinal abnormalities, may identify renal stones, but poor at showing nephrocalcinosis
How does hypospadias occur (3)?
Arises from failure of development of ventral tissues of the penis - in particular failure of ventral urethral closure. Typically leads to 3 features:
1. Ventral urethral meatus (in 80% the urethral meatus is on the distal shaft or glans penis)
2. Ventral curvature of shaft of the penis
3. Hooded appearance of freskin
Be aware of treatment options for hypospadias
Surgery - but not mandatory
-Done to allow a boy to pass urine in a straight line whilst standing, and to have a straight erection