Nephrology and genito-urinary || Flashcards
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)?
E.coli
Klebsiella
Proteus
Pseudomonas
Streptococcus faecalis
What are the presenting features of UTI in infants?
Common (6)
Less common (4)
- Fever
- Vomiting
- Lethargy
- Irritability
- Poor feeding
- Failure to thrive
Less common:
- Abdominal pain
- Jaundice
- Haematuria
- Offensive urine
What are the presenting features of a UTI in preverbal children?
Common (5)
Less common (5)
- Fever
- Abdominal pain
- Loin tenderness,
- Vomiting
- Poor feeding
Less common
- Lethargy
- Irritability
- Haematuria
- Offensive urine
- Failure to thrive
What are the presenting features of a UTI in verbal children?
Common (6)
Less common (6)
- Frequency
- Dysuria
- Dysfunctional voiding
- Changes to continence
- Abdominal pain
- Loin tenderness
Less common:
- Fever
- Malaise
- Vomiting
- Haematuria
- Offensive urine
- Cloudy urine
What are the ways a urine sample can be collected in children in nappies (4)?
When would they be done?
- ‘Clean-catch’ sample into a waiting clean pot when nappy removed
- Adhesive plastic bag applied to the perineum after careful washing
- A urethral catheter
- 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?
Midstream sample
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?
Dipstick
What findings would you find on a urine dipstick test and interpret results (4)?
- Leucocyte esterase and nitrite positive - regard as UTI
- Leuococye esterase negative and nitrite positive - Start Abx treatment if clinical evidence of UTI
- Diagnosis depends on urine culture - Leucocyte esterase positive and nitrite negative - Only start Abx treatment if clinical evidence of UTI
- Diagnosis depends on urine culture - 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?
- In a properly caught sample
- Catheter/suprapubic aspirate
- 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% - 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)?
- seriously ill
- poor urine flow
- abdominal or bladder mass
- raised creatinine
- septicaemia
- failure to respond to treatment with suitable antibiotics within 48 hours
- infection with non-E. coli organisms
Definition of a recurrent UTI in NICE guidelines (3)?
- 2 or more episodes of UTI with acute pyelonephritis/upper urinary tract infection, or
- 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 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)?
- Ultrasound during acute infection - to identify structural abnormalities of urinary tract
- DMSA scan 4-6 months following acute infection
- MCUG scan
What is the recommended imaging schedule for children 6 months-3 years of age with atypical/recurrent UTIs (3)?
- US during acute infection for atypical infection
- Not for recurrent UTI - Ultrasound in 6 weeks for recurrent UTI
- 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)?
- US during acute infection for atypical UTI
- Not recurrent UTI - US at 6 weeks for recurrent UTI
- DMSA 4-6 months after infection for recurrent UTI
What must always be tested in infants with an unexplained fever >38 degrees
Urine sample
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?
- In the general population?
- In children with UTIs?
- 10%
- In children under the age of 1 year with a urinary tract infection, 70% will have VUR
(wikipedia)
What is the range of severity of VUR?
Mild reflux - into the lower end of an undilated ureter during micturition
to
Severe reflux - reflux during bladder filling and voiding, with a distended ureter, renal pelvis and clubbed calyces
What can severe VUR be associated with?
Intrarenal reflux
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)?
- Renal defects
- Increased incidence of renal defect with increasing severity of reflux - Infection
- Can lead to infection which may destroy renal tissue leaving a scar, resulting in a shrunken, poorly functioning segment of kidney - 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)?
- Incomplete bladder emptying
- Urine returning to bladder from ureters after voiding leads to incomplete bladder emptying which encourages infection - Pyelonephritis
- If there is intrarenal reflux - 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:
Cystography
Fluoroscopic voiding cystourethrogram (VCUG)
Technetium-99m Dimercaptosuccunic Acid (DMSA) Scintigraphy
NICE definition of pyelonephritis (2)?
- Infants and children who have bacteriuria and fever of 38°C or higher
- 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
or
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:
- HSP
- SLE
- Infections e.g. malaria
- Allergens e.g. bee sting
What are the clinical features of nephrotic syndrome (5)?
- Periorbital oedema (particularly on waking) - often the earliest sign
- Scrotal or vulval, leg and ankle oedema
- Ascites
- Breathlessness due to pleural effusions and abdominal distension
- 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)?
- Oral corticosteroids (prednisolone) daily for 4 weeks
- After 4 weeks, reduce dose of steroids and given on alternate days for 4 weeks, then weaned and stopped
- 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)?
- Age less than 12 months or greater than 12 years
- Persistent hypertension
- Impaired renal function
- Gross haematuria
- Low plasma C3
- Hepatitis B or C positive