Renal Flashcards
What make up the triad in nephrotic syndrome?
Proteinuria
Hypoalbuminaemia
Oedema
Why are patients with nephrotic syndrome pre-disposed to thrombosis?
Because they have loss of antithrombin-3, protein C and protein S along with a rise in fibrinogen and clotting factors
What are the most common causes of nephrotic syndrome?
MMF DA Membranous nephropathy Minimal change nephropathy Focal segmental glomerulosclerosis Amyloidosis Diabetic retinopathy
Why are persistently nephrotic patients at increased risk of infection?
Is anything done to take this into account?
Because they lose immunoglobulins in the urine
They may be on immunosuppressive medication.
Why do patients with nephrotic syndrome also suffer from hyperlipidaemia?
Because there is increased production of proteins by the liver to compensate for the hypoalbuminaemia, and as a consequence there is increased production of lipids
What is the underlying pathophysiology behind nephrotic syndrome?
Podocyte or subepithelial injury
What treatment is successful in 90% of patients with minimal change disease?
Steroids
What are the values of proteinurea and hypoalbuminaemia used in the definition of nephrotic syndrome?
Proteinuria (> 3g/24hr)
Hypoalbuminaemia (< 30g/L)
What are clinical signs of nephrotic syndrome?
- Periorbital oedema
- 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 the urine
Describe the peri-orbital oedema that is usually seen with nephrotic syndrome
What can it sometimes be misdiagnosed as?
It is usually worst in the morning and improves during the day
It is often misdiagnosed as an allergy
What vaccinations are children with nephrotic syndrome recommended?
Pneumococcal
Seasonal influenza vaccine
How is recurrence of nephrotic syndrome monitored for?
Parents of children with nephrotic syndrome dip the child’s urine daily with albustix to see if they have a recurrence
What are the 2 types of nephrotic syndrome?
Steroid resistant and Steroid sensitive
What are the 3 ways that steroid sensitive nephrotic syndrome can progress?
1/3 resolves directly
1/3 have infrequent relapses
1/3 have frequent relapses and are steroid dependent
What types of medications may be used for the treatment of frequently relapses nephrotic syndrome?
Steroid sparing agents e.g:
- Levamisole
- Cyclophosphamide
- Tacrolimus/cyclosporin A
- Mycophenalate mofetil
- Tacrolimus (for difficult cases)
What are some of the complications of nephrotic syndrome?
lHyperlipidaemia
Hypercoagulability
Predisposition to infection
If a patient is resistant to steroids or whilst you wait for the steroids to begin working in recurrence of steroid sensitive nephrotic you may give a diuretic. What type of diuretic do you give?
Is prescribing of the diuretic how to you work out how much to give and why?
Loop diuretic (e.g furosemide)
You calculate the amount to give based on the child’s surface area, not weight.
This is because patients with nephrotic syndrome often have an increased weight due to their oedema, which once prescribed fluids will drop quite quickly.
What signs or symptoms and infants <3 months present with for a UTI?
Most common:
Temp >38, Vomiting, Lethargy, Irritability, Poor feeding, failure to thrive
If a child present with an UNEXPLAINED fever >38 or higher within what time period should they have a urine sample tested?
When else should you carry out a urine sample?
Within 24 hours
Children with an alternative site of infection but who remain unwell (consider urine test after 24 hours at the latest)
What signs or symptoms and infants and children >3 months PRE-VERBAL present with for a UTI?
Most common: Fever >38, Abdo pain, loin tenderness, vomiting, poor feeding
What signs or symptoms and infants and children >3 months VERBAL present with for a UTI?
Frequency, dysuria
Dysfunctional voiding, changes to continence, abdominal pain, loin tenderness, haematuria
What is the gold standard for the collection of a urine sample?
‘Clean-catch’ sample - into a waiting clean pot when the nappy is removed
OR
Midstream sample in the older child
What value on a urine bacterial culture is suggestive of infection?
A bacterial culture of >10^5 colony-forming units (CFU) of a single organism
If the gold standard method of urine collection is not possible what other methods can be used?
If clean catch is not possible then urine collection pads should be used
Cotton wool balls, gauze and sanitary towels are not suitable
Invasive methods such as suprapubic aspiration should only be used if non-invasive methods are not possible
How should urine be preserved?
If urine is to be cultured but cannot be cultured within 4 hours of collection, the sample should be refrigerated or preserved with boric acid immediately (this is to prevent overgrowth of contaminating bacteria)
What is the further management of infants <3 months with a UTI?
They should be referred immediately to a paediatrician
What are the most common causative organisms of UTI?
E coli Klebsiella Proteus Pseudomonas Streptococcus faecalis
What is the anatomical problem in vesicoureteric reflux?
The ureter is displaced laterally so enters directly into the bladder rather than at an angle
What is the mildest form or ureteric reflux?
What is the most severe form?
Mildest = reflux into the lower end of the ureter during micturition
Most severe = reflux during bladder filling and voiding, with distended ureter, renal pelvis and calyces
What is intra-renal reflux? When does it occur? What does it result in?
Backflow of urine from the renal pelvis into the papillary collecting ducts
It occurs with more severe VUR
It is associated with a high risk of renal scarring if UTIs occur
Why is vesico ureteric reflux associated with increased risk of bladder infections?
How can this be avoided?
Because the bladder is not fully emptied during voiding
This can be avoided by getting child to go to the toilet and then go to the toilet again 5 minutes later to voided to refluxed urine (double voiding)
When should children be referred for an US following a UTI?
If they are <3 months
If they have atypical UTIs
If they have recurrent UTIs
What encompasses an atypical UTI?
- Seriously ill or septicaemia
- Poor urine flow
- Abdominal or bladder mass
- Raised creatinine
- Failure to respond to Abx within 48 hours
- Atypical causative organism (e.g not E.coli)
What advice can be given in order to try to prevent UTIs in patients with VUR?
- Void regularly
- Double voiding
- Good fluid intake
- Avoid/treat constipation
- Good perineal hygiene
What medication can be given in order to try and prevent UTIs?
- Probiotics
- Antibiotic prophylaxis
When a child has recurrent UTI/scarring/reflux what should be checked annually?
Urinalysis for proteinurea (indicative of progressive chronic kidney disease)
BP (increased risk of HTN)
What is nocturnal enuresis?
How common is it?
Child wetting themselves at night
Bedwetting greater than 2 nights/week is present in about 6% of 5 year olds and 1.5% of 10 year olds
Affects males more than females (2:1)
What are some of the causes of nocturnal eneuresis?
Genetically determined delay in acquiring sphincter competence
Stress
What are some organic causes of enuresis?
- UTI
- Faecal retention severe enough to reduce bladder volume and cause bladder neck dysfunction
- Underlying diabetes/ renal concentrating disorders (e.g chronic kidney disease)
When is investigations of enuresis indicated?
- If the enuresis occurs in the daytime
- If it is of recent onset
- Features of a UTI
- Features of diabetes mellitus or ill health
What is the management of nocturnal eneuresis?
When is treatment of enuresis considered?
- Children should not be punished from the wetness - this is counterproductive
- Excessive or insufficient fluid intake and abnormal toileting patterns should be addressed
- Star chart for helping to change sheets rather than dry nights
- Eneuresis alarm - goes off when becomes wet and the alarm must wake the child, go to pass urine, return and help to remake the wet bed before going back to sleep
Treatment is considered when the child is >5 years
What is desmopressin?
In which cases is desmopressin used to treat enuresis?
It is a synthetic analogue of ADH
It can be used in children >7 if treatment with alarm is unsuccessful or unacceptable
OR
If short term relief is required e.g holidays/sleep overs
What is the definition of daytime enuresis?
What is considered the age that a child is old enough to be continent?
Lack of bladder control during the day in a child who is old enough to be continent (age 3-5)
Nocturnal enuresis is also usually present
What are some causes of daytime enuresis?
- UTI
- Diabetes
- Lack of attention of bladder sensation
- Ectopic ureter
- Constipation
- Neuropathic bladder
What is likely to be the cause in girls who are dry at night but wet on getting up?
Ectopic ureter into the vagina
What can be used to treat children where the underlying cause of daytime enuresis is lack of attention to bladder sensation?
A small portable alarm with a pad in the pants, which is activated by urine
What is secondary (onset) enuresis?
The loss of previously achieved urinary continence
What are some causes of secondary enuresis?
- Emotional upset (most common)
- UTI
- Polyuria - osmotic diuresis in DM, renal concentrating disorder e.g SCD/CKD
What investigations should be carried out for secondary enuresis?
- testing a urine sample for infection, glycosuria, and proteinuria using a dipstick
- assessment of urinary concentrating ability by measuring the osmolality of an early morning urine sample. Rarely, a formal water deprivation test may be needed to exclude a urinary concentrating defect
- ultrasound of the renal tract.
What investigations should be carried out for daytime enuresis?
Urine sample of microscopy, culture and sensitivity. Other investigations may include:
- US (bladder pathology, ?bladder thickness)
- Urodynamic studies
- X-ray of the spine (?vertebral anomaly)
- MRI scan (?spinal defect?)
What is a neuropathic bladder?
Bladder that is enlarged and fails to empty properly. It has an irregular thick wall and is associated with spina bifida and other neurological conditions
Explain further the cause behind lack of attention to bladder sensation
It is a manifestation of a developmental or psychogenic problem, although it may occur in otherwise normal children who are too preoccupied with what they are doing to respond to the sensation of a full bladder
What is the management of daytime enuresis in children where a neurological cause has been excluded?
- Star charts
- Bladder training
- Pelvic floor exercises
- Portable alarm
- Anticholinergic drugs (e.g oxybutynin) - if all other measures fail. Dampens down bladder contractions
What is nephritic syndrome/acute nephritis?
- Haematuria (RBC casts)
- Proteinuria (<3.5g/day)
- Hypertension
- Oliguria
- Progressive renal impairment
Characterised by endothelial damage and inflammation
What is the most common cause of haematuria?
UTI - but it is rarely the only symptom in UTI.
When may a renal biopsy be indicated in patients with haematuria?
- If there is significant persistent proteinuria
- If there is recurrent macroscopic haematuria
- If renal function is abnormal
- If the complement levels are persistently abnormal
What investigations are carried out all patients with haematuria?
- Urine microscopy (with phase contrast) and culture
- Protein and calcium excretion
- Kidney and urinary tract US
- Plasma urea, electrolytes, calcium, phosphate and albumin
- FBC, platelets, coag screen, sickle cell screen
(If you think through your different causes then you can eliminate based on different investigations)
What investigations are carried out on patients if the findings from results is suggestive of glomerular haematuria?
- ESR, complement levels, and anti-DNA antibodies
- Throat swab and antistreptolysin O/anti-DNAse B titres
- Hepatitis B and C screen
- Renal biopsy if indicated
- Test mother’s urine for blood (if Alport syndrome suspected)
- Hearing test (if Alport syndrome suspected)
What is the management of acute nephritis?
Management is by attention to both water and electrolyte balance and the use of diuretics when necessary
Rarely, there may be a rapid deterioration in renal function (rapidly progressive glomerulonephritis). This may occur with any cause of acute nephritis, but is uncommon when the cause is poststreptococcal
If rapidly progressive glomerulonephritis occurs how is this managed?
Renal biopsy and subsequent treatment with immunosuppression and plasma exchange may be necessary
What is Henoch-schonlein purpura? (describe the clinical features)
It is a combination of the following features:
- Characteristic skin rash on the EXENSOR surfaces
- Arthralgia
- Periarticular oedema
- Abdominal pain
- Glomerulonephritis
- Fever
How is post-strep nephritis diagnosed?
It is diagnosed by evidence of a recent streptococcal infection (culture of the organism, raised ASO/anti-DNAse B titres) and low complement C3 levels that return to normal after 3 weeks to 4 weeks
Who does Henoch- Schonlein purpura typically affect?When does it typically present?
Children aged 3-10
Twice as common in boys
Peaks in the winter months
It is often preceded by an upper respiratory infection
What is thought to be the cause behind Henoch-schonlein purpura?
It is thought that genetic predisposition and antigen exposure increase circulating IgA levels and disrupt IgG synthesis. The IgA and IgG interact to produce complexes that activate complement and are deposited in affected organs, precipitating an inflammatory response with vasculitis
Describe the distribution of the rash in Henoch schonlein purpura
RASH IS THE MOST OBVIOUS FEATURE
Symmetrically affects the buttocks
Affects the extensor surfaces of the arms and legs, and the ankles
Trunk is usually spared
The rash may be originally urticarial, rapidly becoming maculopapular and purpuric, is characteristically palpable and may recur over several weeks
If proteus is the causative organism of a UTI what is this suggestive of?
It often indicates underlying renal tract abnormalities and predisposes to renal calculi
What further investigations may you want to carry out following a UTI and US?
What are the investigations looking for?
When do you carry out each of the investigations?
<1 year - MCUG and DMSA
>1-<3 years - DMSA
DMSA: assesses renal function, structure (e.g scarring)
MCUG: how the bladder functions
MCUG is performed after control of the current infection
DMSA is performed 3-4 months after the acute episode
A child is found to have VUR which caused pyelonephritis. Following discharge what information may the parents be given?
If atypical UTI - give prophylactic antibiotics
Dip the childs urine whenever they are ill.
