Renal/Urinary System Flashcards
Which organism causes 85-90% of paediatric UTIs?
E.coli
Which organism causes uncomplicated cystitis in boys in 30% of those with a UTI?
Proteus mirabilis
Which bacteria causes acute UTI is adolescents in both sexes?
Staphylococcus saprophyticus
Which viral infection is a rare cause of UTI in paediatrics?
Adenovirus
What % of boys and girls respectively will have had a UTI by the age of 7?
Girls 8%
Boys 2%
What are the risk factors for young people developing UTIs? (7)
- Age below one year
- Female sex (however in the first three months of life, UTI is more common in boys)
- Caucasian race
- Previous UTI
- Voiding dysfunction
- Vesicoureteral reflux (VUR)
- Immunosuppression
Why do UTIs need to be taken seriously in children?
There is an associated with urinary tract abnormalities
Which conditions can lead to urinary stasis?
- Renal calculi
2. Vesico-ureteric reflux
In infants less than 3 years of age, what are the symptoms/signs of a UTI?
- Fever
- Vomiting
- Lethargy
- Irritability
- Poor feeding
- Jaundice
- Haematuria
- Offensive urine
What are the imaging techniques used to investigate recurrent UTIs?
- USS
- DMSA - a radionuclide scan that uses dimercaptosuccinic acid
- MCUG - micturating cystourethrogram (can result in re-implantation of ureters in the bladder)
What is involved in DMSA testing?
Injection of radionuclide and then X-ray which will show areas of kidney that may be scarred that haven’t taken up the nuclide, and the computer can also tell you how much of each kidney has taken up the radionuclide - obviously you would hope it is 50/50.
What is haemolytic uraemic syndrome (HUS)?
It is a triad of:
- Microangiopathic haemolytic anaemia (Coombs’ test negative)
- Thrombocytopenia
- Acute kidney injury
What is the most common cause of HUS?
E.coli with somatic antigen 157 and flagella antigen 7 (O157:H7) also known as Shiga toxin-producing E.coli (STEC) as it produces a toxin called Shiga
Why is HUS a systemic disease?
Because the damaged arises from the circulating toxin which binds to endothelial receptors, particularly in the renal, GI and CN systems. Thrombin and fibrin are deposited in the microvasculature.
How does haemolysis occur in HUS?
The thrombin and fibrin which are deposited in small vessels leads partial occlusion of the vessels and subsequently haemolysis occurs
In addition to E.coli, which other pathogens can cause HUS? (3)
- Streptococcus pneumoniae and Shigella
- HIV and coxsackie virus
- Ciclosporin, tacrolimus
Which age range is most affected by HUS?
Children under 5
Where was the largest outbreak of HUS in the UK and how many people did it affect?
In Cumbria in 1999, affected 114 people
What are the risk factors for developing HUS? (5)
- Rural populations more affected than urban populations
- Warmer summer months (June-September)
- Young age (6 months to 5 years)
- Older people or those who are immunocompromised
- Contact with farm animals
When is HUS at its most transmissible?
During the diarrhoea phase
How does HUS tend to present? (4)
- Profuse diarrhoea that turns bloody 1 to 3 days later
- Fever
- Abdominal pain
- Vomiting
(most adults infected with E.coli 0157 remain asymptomatic)
What investigations are carried out in suspected HUS? - and when is clinical suspicion of HUS greatest? (7)
When they present with bloody diarrhoea
- FBC and film - evidence of haemolysis, anaemia and thrombocytopenia. A raised WCC and low platelet count are early indicators of development of HUS.
- LFTs
- Lactate dehydrogenase (high levels - HUS)
- CRP
- Clotting screen
- Stool culture
- Urine analysis (haematuria and proteinuria appear early in HUS)
What are the features of microangiopathic haemolysis? (3)
- Falling haemoglobin
- Fragmented red cells
- Falling platelet count
What are the differential diagnoses for HUS? (4)
- GI upset = acute gastroenteritis, appendicitis, IBD, intussusception
- DIC + sepsis
- HELLP syndrome (haemolysis, elevated liver enzymes, low platelet count)
- Thrombotic thrombocytopenic purpura
What is the management for HUS? (5)
- Fluid management
- Electrolyte management
- Antihypertensive treatment (nifedipine)
- Dialysis
- Monoclonal antibodies
What are the possible gastrointestinal complications of HUS? (4)
- Intestinal strictures and perforations
- Intussusception
- Pancreatitis
- Severe colitis
What are the neurological complications of HUS? (3)
- Altered mental state
- Cerebrovascular accident
- Seizures
What are the renal complications of HUS? (5)
- AKI
- CKD
- Haematuria
- Hypertension
- Proteinuria
What is nephrotic syndrome?
It is a condition that causes the kidneys to leak large amounts of protein into the urine, due to damage of the glomerulus. It is a triad of:
- Proteinuria
- Oedema
- Hypoalbuminemia
What is the other name for childhood nephrotic syndrome?
Nephrosis
What is the most common cause of nephrotic syndrome in children?
Minimal change disease
What is minimal change disease?
It is an immune mediated condition affected the kidneys. It is usually of an unknown cause but can be associated with Hodgkin’s disease or the use of NSAIDs
Why does nephrotic syndrome cause oedema?
The reduced protein in the blood means less fluid is transported into the blood and more is retained in the tissues, leading to oedema, particularly around the eyes - periorbital oedema
How is nephrotic syndrome diagnosed?
A urine dipstick showing elevated levels of protein combined with a blood test showing low protein.
If kidney damage has already occurred then blood tests may show signs of early kidney failure with a raised creatinine level
Minimal change disease is the main cause of primary nephrotic syndrome, what are the secondary causes of childhood nephrotic syndrome? (7)
- Diabetes
- Henoch-Schonlein purpura
- Leukaemia
- Lupus
- Malaria
- Streptococcal infection/HIV/hepatitis
- Sickle-cell anaemia
What are the signs/symptoms of childhood nephrotic syndrome? (9)
- Oedema (legs, ankles, hands, face)
- Albuminuria (high levels in urine)
- Hypoalbuminemia (low levels in blood)
- Hyperlipidaemia (blood cholesterol/fat levels higher than normal)
- Haematuria
- Symptoms of infection - irritability, fever
- Anorexia
- Diarrhoea
- Hypertension
What are the complications of childhood nephrotic syndrome?
- Infection
- Blood clots
- High blood cholesterol
(due to liver trying to make more albumin to make up for the albumin lost in the urine, it also produces more cholesterol)
At what age range is nephrotic syndrome first diagnosed?
2 - 5 years
Which gender is more affected by nephrotic syndrome?
Males
In which ethnicity is nephrotic syndrome more common?
Asian
Which form of medication do children respond well to in treatment of nephrotic syndrome?
Steroids - prednisolone (stops protein leaking from the kidneys into the urine)
What are the side effects of children being on steroids?
- Increased appetite
- Weight gain
- Red cheeks
- Mood changes
In addition to steroids, what other medications may be given to children with nephrotic syndrome? (to deal with symptoms)
- Diuretics
- Antibiotics - during relapses to reduce chances of infection
If steroids don’t work:
- Levamisole
- Ciclosporin
- Tacrolimus
- Rituximab
What are the signs/symptoms of infants <3 months with a UTI? (9)
From most common to least common:
- Fever
- Vomiting
- Lethargy
- Irritability
- Poor feeding
- FTT
- Abdominal pain
- Haematuria
- Offensive urine
What are the signs/symptoms of UTI in infants and children >3 months old? (8)
- Fever
- Dysuria
- Abdominal pain/loin tenderness
- Vomiting
- Poor feeding
- Dysfunctional voiding
- Changes to continence
- Haematuria
If a urine sample is collected, but cannot be cultured within 4 hours of collection, what can be done to preserve the sample?
Add boric acid immediately or keep the sample refrigerated
What is the NICE guideline for children under 3 months old with a suspected UTI?
Refer all infants under 3 months with a suspected UTI to paediatric specialist care, and:
- send a urine sample for urgent microscopy and culture
- manage in line with the NICE guidelines on fever in under 5’s
In infants older than 3 months but younger than 3 years, what is the action to take with the results of the urine dipstick?
If leukocyte esterase or nitrites, or both, are positive, start on antibiotic treatment and send a urine sample for culture.
If both are negative, do not start ABX treatment and do not send a sample for microscopy and culture unless at least 1 criteria is met. (e.g. if clinical symptoms do not correlate with test results)
What is the criteria for urine samples being sent for culture? (6)
- If acute pyelonephritis is suspected
- High risk of serious illness
- Infants under 3 months old
- Recurrent UTIs
- No response to treatment within 24-48 hours
- If clinical symptoms and dipstick tests do not correlate
In children over the age of 3, using the urine dipstick testing, what is the guidance?
- If both leukocyte/nitrite are positive = treat with ABX (send urine sample for culture if this is recurrent UTI)
- If leukocyte is negative but nitrite is positive = ABX should be started if the urine was a fresh sample, send for culture too
- If leukocyte positive and nitrite negative = Send sample for microscopy and culture, ABX should not be started unless clinical evidence of UTI (e.g. urinary symptoms)
If the urine dipstick is positive for leukocyte esterase but negative for nitrites, what could this be a sign of?
That there may be an infection outside of the urinary tract which may need to be managed differently
What does microscopy testing for UTI test for?
Bacteriuria and pyuria
According to NICE, what are the risk factors for UTI with serious underlying pathology in children? (9)
- Poor urine flow
- Recurrent fever of uncertain origin
- Antenatally diagnosed renal abnormality
- Vesicoureteric reflux
- Dysfunctional voiding
- Enlarged bladder
- Abdominal mass
- Poor growth
- High blood pressure
When should children with a UTI be considered to have acute pyelonephritis?
In children with bacteriuria and fever of 38 degrees or higher
Although MCUG is not performed routinely, when should it be considered - when which features are present? (4)
- Dilatation on USS
- Poor urine flow
- Non E.coli infection
- FHx VUR
When is an USS recommended during an acute UTI infection in each category - <6 months, >6months <3 years, and >3 years?
<6 months = if the UTI is atypical or recurrent
>6 months - any age = if the UTI is atypical (but not recurrent)
When is an USS done within 6 weeks post-treatment for UTI for each age category?
<6 months = basically any child who has responded will to treatment within 48 hours (as if they hadn’t they would have had other scanning)
What is DMSA?
DMSA scan is a radionuclide scan that uses dimercaptosuccinic acid in assessing renal morphology, structure and function. Radioactive technetium-99m is combined with DMSA and injected into a patient, followed by imaging with a gamma camera after 2-3 hours.
What is MCUG?
Micturating cystourethrograms are the gold standard for evaluating vesicoureteric reflux (VUR).
What is classed as an atypical UTI? (7)
- Seriously ill
- Poor urine flow
- Abdominal or bladder mass
- Raised creatinine
- Sepsis
- Failure to respond to treatment with suitable ABX within 48 hours
- Infection with non-coli organisms
What is classed as a recurrent UTI? (3)
- 2 or more episodes of UTI with acute pyelonephritis/upper urinary tract infection
- 1 episode of UTI with acute pyelonephritis plus 1 or more of UTI with cystitis
- 3 or more episodes of UTI with cystitis/lower urinary tract infection
What is the most common presenting features with WIlms’ tumour?
Abdominal pain
Which syndrome (other than Beckwith-Wiedemann) is WIlms’ tumour associated with?
WAGR
Aniridia
Genitourinary malformations
mental Retardation
