16 - Nephrology Flashcards
What are some risk factors for a UTI in children?
- <1
- Female (if neonate then male)
- Caucasian
- Voiding dysfunction
- Vesicoureteral reflex (VUR) (33%)
- Sexual abuse
- Spinal abnormalities
- Constipation
- Immunosuppression
How may a UTI present in babies and younger children?
- Fever
- Vomiting
- Lethargy
- Irritability
- Vomiting
- Poor feeding
- Urinary frequency
- Offensive smelling urine
Once children are old enough to verbalise, what are some symptoms they may have if they have a UTI?
- Increased frequency
- Painful urination
- Changes in continence
- Abdominal pain (suprapubic)
- Loin tenderness
- Fever
- Haematuria
- Cloudy urine
- Offensive smelling urine
When should you consider pyelonephritis over cystitis in children?
- Temp of 38oC or higher and bacteriuria
- Temp lower than 38oC with loin pain/tenderness and bacteriuria
If no systemic symptoms but bacteriuria present then cystitis should be considered
If a child has urinary symptoms, what examinations should you do on them?
What are some differentials for a UTI in children?
- Vulvovaginitis
- Kawasaki disease
- Voiding dysfunction
- Threadworms
- Consider abuse if recurrent but no underlying cause
What investigations should be done if you suspect a child to have a UTI?
- Clean Catch Urine Sample for Urine Dipstick
- MC+S MSU: if temp over 38 or leucocytes and nitrates positive on dipstick
- Arrange imaging
How do you describe to a parent how to get a clean-catch sample?
- Clean genitals with water
- Tap suprapubic area with two fingers 1 hour after feed
- Avoid first stream of urine
What are the different types of imaging used in investigating UTIs in children and what all they show us?
- Abdominal US: look for reflux but low sensitivity
- DMSA (Dimercaptosuccinic Acid) Scan: Assess for damage after recurrent UTIs 4-6 months after infection. Inject radioactive material and a gamma camera to see how much is taken up by kidney. Patches indicate areas of scarring
- Micturating Cystourethrogram (MCUG): Used to diagnose VUR. Catheterise the child and inject contrast into bladder and take a series of X-Rays to see if contrast is refluxing back into ureters. Given prophylactic abx for 3 days before
What is the definition of the following:
- Recurrent UTI in children
- Atypical UTI in children
Atypical UTI features:
- Poor urine flow
- Abdominal or bladder mass
- Raised creatinine
- Sepsis
- Failure to respond to treatment within 48 hours
- Non-E.Coli organism
Definition of recurrent UTI:
- 2 or more episodes of upper UTI (pyelonephritis)
- 1 episode of upper UTI and 1 episode of lower UTI
- 3 episodes of lower UTI
When should children be offered an US for a UTI and at what time frame?
<6 months: within 6 weeks
Recurrent UTI: within 6 weeks
Atypical UTI: during illness
If just normal UTI and over 6 months no US needed
When should children be offered a DMSA for a UTI and at what time frame?
Needs to be minimum 4 months since infection as pyelonephritis changes can look like scarring
Do for any atypical or recurrent UTIs in children up to 3.
If over 3 only do if atypical UTI
When should children be offered an MCUG for a UTI and at what time frame?
Only in under 6 months if recurrent/atypical UTI
Should also be considered in those with FHx of VUR, poor urinary flow or abnormal dilatation of ureter on US
What is the gold standard for diagnosing VUR and how is this managed if diagnosed?
MCUG
Causes scarring due to reflux and predisposes to further UTIs
Usually give prophylactic antibiotics or ureteric reimplantation surgery if grade 4/5 VUR
Investigate siblings as genetic component
How are lower UTIs (cystitis) treated in children?
Under 3 months: immediate referral to paediatrics for IV antibiotics (Ceftriaxone) and investigations for sepsis
Over 3 months: PO Nitrofurantoin for 3 days, if not improved within 48 hours reassess so safety net to parent. Use Cephalexin if cannot swallow
How are upper UTIs (pyelonephritis) treated in children?
Under 3 months: Immediate referral to paediatrics for IV antibiotics (Ceftriaxone) and septic screen
Over 3 months: PO Cefalexin or Co-Amoxiclav for 10 days. Consider referral to paediatrics if poor fluid intake, cannot take oral antibiotics or is deteriorating
What advice can be given to parents to prevent UTIs in their children in the future?
- Treat and prevent constipation
- Clean the perineum from front to back
- Avoid nylon underwear and bubble baths
- Encourage fluid intake and double micturition
- Consider prophylaxis if recurrent UTIs
What are the complications of UTIs in children?
- Renal scarring
- Hydronephrosis
- Chronic renal failure
- Hypertension
Vulvovaginitis is common in girls aged 3-10 before puberty. What are some causes of this?
- Wet nappies
- Use of chemicals or soaps in cleaning the area
- Tight clothing that traps moisture or sweat in the area
- Poor toilet hygiene
- Constipation
- Threadworms
- Pressure on the area, for example horse riding
- Heavily chlorinated pools
How may vulvovaginitis present in young girls?
Often have positive leucocytes on dipstick and negative nitrites so misdiagnosed as UTI
- Soreness
- Itching
- Erythema around the labia
- Vaginal discharge
- Dysuria
How can vulvovaginitis be managed in young girls?
Do not treat as UTI or Thrush!!!
- Avoid washing with soap and chemicals
- Good toilet hygiene, wipe from front to back
- Keep the area dry
- Emollients, such as sudacrem
- Loose cotton clothing
- Treating constipation and worms where applicable
- Avoiding activities that exacerbate the problem
In severe cases may recommend oestrogen cream to improve symptoms
What is an AKI and the causes of this in children?
Acute rapid decline in renal function leading to a rise in creatinine and/or oliguria/anuria. Pre-renal, Renal and Post-renal causes
- Nephroxicity (NSAIDs, aminoglycosides, vancomycin, aciclovir, and contrast nephropathy)
- Sepsis
- Gastroenteritis causing diarrhoea/dehydration
- Glomerulonephritis
- Haemolytic uraemic syndrome (HUS)
What are the different stages of AKI in children and how may it present?
Uses pRIFLE or AKIN criteria
Always consider if child has haematuria, oedema or oliguria
What investigations should be done for a suspected AKI?
- Detailed history and examination (e.g drugs)
- Urine dipstick testing and MSU and consider nephritic screen
- U+Es
- Creatinine
- Calcium, phosphate, bicarbonate, chloride
- LFTs (inc. albumin)
- Glucose
- FBC
- ECG
- Abdominal US: look for obstruction of above show no cause
- Renal biopsy
What are the serious complications of an AKI in a child?
- Hyperkalaemia
- Metabolic acidosis
- Pulmonary Oedema
Need dialysis for these!!!!!
What might you see on MSU for AKI caused by GN?
- Red cell casts
- Proteinuria
How is an AKI in children managed?
- Remove any cause e.g NSAIDs
- Refer to paediatric nephrology team to treat underlying cause
- Initial fluid management depending on cause of AKI. Start fluid chart
- Monitor BP
- Monitor weight daily (aim for 0.5% loss/day)
- Monitor ECG (give no K+ in fluids)
- If fluid overload consider haemodialysis
What is haemolytic uraemia syndrome and what is it caused by?
Thrombosis within small blood vessels throughout the body
Triggered by a bacterial toxin called shiga toxin produced by e.coli 0157 or Shigella
Use of antibiotics and anti-motility medications such as loperamide to treat gastroenteritis caused by these pathogens increases the risk of developing HUS
What is the classic triad in HUS?
- Haemolytic anaemia: caused by red blood cells being destroyed
- AKI
- Thrombocytopenia: low platelet count
How may HUS present?
Preceded by blood diarrhoea around 5 days before
- Reduced urine output
- Haematuria or dark brown urine
- Abdominal pain
- Lethargy and irritability
- Confusion
- Oedema
- Hypertension
- Bruising
How is HUS managed in children?
Medical emergency and has a 10% mortality so refer to paediatric nephrologist.
Self limiting and supportive management:
- Urgent referral to the paediatric renal unit for renal dialysis if required
- Antihypertensives if required
- Careful maintenance of fluid balance
- Blood transfusions if required
What is nephrotic syndrome characterised by and what is the pathophysiology of this?
Glomerular basement membrane is damaged allowing proteins through. In children usually due to podocyte foot processes being fused together
- Hypoalbuminaemia (<25g/L)
- Proteinuria (>3+ protein on urine dipstick or >200mg/mmol)
- Oedema
- Hypercholesterolaemia/Hyperlipidaemia
What are some of the causes of nephrotic syndrome?
- Minimal change disease: MOST COMMON!!! 90% of cases in children. Usually affects 2 to 5 year olds
- Secondary to intrinsic kidney disease
- Secondary to systemic disease
How may nephrotic syndrome present and what are some differentials for this presentation?
- Frothy urine
- Oedema (starts periorbital then generalised)
- Pallor
- Ascites
- Anorexia
Differentials: heart failure, anaphylaxis, malnutrition (Kwashiorkor)
What are some atypical features of nephrotic syndrome that would warrant a renal biopsy?
- Poor renal function
- Haematuria
- Hypertension
What investigations should you do to confirm a diagnosis of nephrotic syndrome (minimal change disease cause)?
Baseline
- Urine dip and MSU: small molecular weight proteins and hyaline casts
- Urinary protein:creatinine ratio
- U+Es: usually normal
- FBC
- Bone profile and Serum albumin
- VZIG: check for immunity as will be starting steroids
Additional
Complement levels, Anti-streptolysin O Titre (ASOT) and autoimmune ANA, ANCA, anti-dsDNA.
What are the different types of minimal change disease based off of how they respond to treatment?
Steroid Sensitive Nephrotic Syndrome: 80% of children are this type and 80% of those children will have a relapse but remit
Steroid Dependent: difficult to wean off steroids
Steroid Resistant: Do not respond to steroids, need ACEi and immunosuppressants like cyclophosphamide, tacrolimus
What are the complications of nephrotic syndrome?
- Intravascular hypotension: only give diuretics if symptomatic oedema to prevent this complication
- Spontaneous pneumococcal peritonitis: give vaccine and penicillin
- Infection: loss of Ig’s and steroids
- Relapse of minimal change disease
- VTE: proteins that normally prevent blood clotting are lost in the kidneys, and because the liver responds to low albumin by producing pro-thrombotic proteins
What is nephritic syndrome characterised by and the pathophysiology of this?
Inflammation within the nephrons of the kidney
- Haematuria
- Oliguria
- Hypertension
What are the main causes of nephritic syndrome in children and some other causes?
- Post Streptococcal Glomeruonephritis
- IgA Nephropathy (Berger’s)
Others: autoimmune like SLE and ANCA
How does post-streptococcal GN present and what is the pathophysiology of this?
Occurs 7-21 days after GROUP A B-HAEMOLYTIC strep infection e.g tonsillitis or impetigo by Strep Pyogenes
Immune complexes made up of streptococcal antigens, antibodies and complement proteins get stuck in the glomeruli of the kidney and cause inflammation and AKI
What is the management for PSGN?
- Antihypertensives
- Diuretics e.g Furosemide
How does IgA nephropathy present and what is the pathophysiology of this?
- Related to Henoch-Schonlein Purpura
- Days after URTI, UTI or gastroenteritis
- IgA deposits in the nephrons of the kidney causes inflammation
- Normal complement
- Renal biopsy will show IgA deposits and glomerular mesangial proliferation
It usually presents in teenagers or young adults
How is IgA nephropathy treated?
- Supportive treatment of the renal failure such as ACE inhibitor treatment
- Immunosuppressant such as corticosteroids and cyclophosphamide to slow progression of the disease
How do you work out eGFR in children?
What are the causes of CKD in children?
-Congenital – Renal dysplasia, obstructive uropathies like PUV, VUR
-Hereditary – ARPKD, ADPKD, hereditary nephritis like Alport syndrome
-Glomerulonephritis – FSGS, MPGN, lupus nephritis, congenital nephrotic syndrome, ANCA vasculitis
-Tumours/Vascular – Wilms tumour, renal venous thrombosis, renal artery stenosis
-Infection – Hemoltic uraemic syndrome
-AKI leading to CKD
What are the stages of CKD?
How may a child present with CKD?
- Weakness
- Tiredness
- Headache
- Hypertension
- Hypertensive retinopathy
- Anaemia
- Failure to thrive
What are the complications of chronic renal disease in children? (important)
- Failure to grow/thrive
- Intellectual disability
- Tendency to bleed
- Hyperuricaemia
- Renal osteodystrophy
- Anaemia
- Metabolic acidosis with low sodium and increased potassium
- CVD due to HTN and hyperlipidaemia
What is renal osteodystrophy and how is it managed?
- Poor mineralization due to renal failure, causing poor growth, muscle weakness, slipped epiphyses, bone pain, and bone deformity
- If glomerular filtration falls to <25% of normal, compensatory mechanisms to enhance phosphate excretion fail causing hyperphosphataemia and hypocalcaemia, so PTH rises, which enhances bone resorption to release Ca2+ in an attempt to correct hypocalcaemia. Also, the failing kidneys cannot convert enough 25-hydroxycholecalciferol to active 1,25-dihydroxycholecalciferol, so GI calcium absorption falls, so worsening hypocalcaemia
- Use phosphate binders, eg calcium carbonate taken just before food
- If Ca2+ is low despite correcting serum phosphate, give calcitriol
What are some important things to monitor when a child has CKD?
- Always look at growth and nutrition
- Educate family about the function of the kidneys
What type of polycystic kidney disease presents in children rather than adults and how does it present?
Autosomal recessive polycystic kidney disease (ARPKD) usually picked up on antenatal ultrasound scans
Features
- Cystic enlargement of the renal collecting ducts
- Oligohydramnios on antenatal scans leading to pulmonary hypoplasia and Potter syndrome
- Congenital liver fibrosis
Pulmonary hypoplasia present with difficult breathing after birth and Potter syndrome has dysmorphic features
What is the management of ARPKD?
Renal dialysis within the first few days of life Most patients develop end stage renal failure before reaching adulthood.
The prognosis is poor, around 1/3 will die in the neonatal period. Around 1/3 will survive to adulthood.
What is Multicystic Dysplastic Kidney and how does it differ to ARPKD?
Only one of the kidneys is made up of many cysts while the other kidney is normal
Normally diagnosed on antenatal ultrasound scans.
Cystic kidney will atrophy and disappear before 5 years of age.
What is a posterior urethral valve and how is it diagnosed?
- Affects male fetuses
- Folds of bladder mucosa block proximal urethra, causing outflow obstruction and hydronephrosis
- Usually diagnosed antenatally with oligohydramnios and renal tract dilatation or postnatally with absent or feeble voiding
- Do MCUG and US then catheterise and do an ablation
What is hypospadias and the complications of this?
- Urethral meatus displaced to the ventral side of the penis. 90% at bottom of glans
- Epispadias is where the meatus is displaced to the dorsal side
Complications: Cordee, Difficulty directing urination, Sexual dysfunction, Cosmetic concerns
If a child has haematuria what differentials are you considering?
- Glomerulonephritis (e.g PSGN)
- Nephritic syndrome
- Alport syndrome
- UTI
- Trauma
- Wilm’s tumour
- Obstructing stone
B, D, E
Need bone profile because albumin comes under this
A, C and D
Need antibiotics in form of Penicillin V for all oedematous patents to prevent infection with Pneumococcal
B and D
How can you tell the difference between glomerular and non-glomerular haematuria in children?
Glomerular
Raised BP: due to decreased filtration
Rusty colour
Red cell casts
What are some clues for the cause of a childs GN?
Henoch-Schonlein purpura is painful. It is an IgA autoimmune vasculitis precipitated by infections and vaccinations
Bleeding tendency: Increase in urea results in abnormal platelet adhesion and aggregation
Hyperuricaemia: decreased urinary excretion
Intellectual impairment: Neurological findings can range from seizures and severe intellectual disability to subtle deficits resulting in poor school performance.
How does PUV present?
- Poor wee stream
- Eneuresis
- UTI
