Nephrology Flashcards
You want to obtain urine for a urine culture. How will you get it?
Clean catch urine. This is the same as midstream urine with the additional step of cleaning the genital area before urination and then starting the urinate before filling the cup.
What would you expect to see on a urine dipstick of a UTI patient?
White cells (leukocytes) and Nitrites (maybe blood). Note that urine dipstick in babies isnt the most reliable
A 4 month baby is present at clinic with their mom with irritability and poor feeding. What would you ask their mother to make sure this is a UTI? (predisposing factors)
Predisposing factors:
Reduced fluid intake
previous UTI infection
Dysfunctional pattern of voiding
constipation
Poor perineal hygiene
Vulvitis (if girl) inflammation of labia minora
Anatomical abnormalities (Vesicoureteric reflux, duplex kidneys…)
30% of children with a UTI have what?
How would you diagnose this?
Vesicoureteric reflux
MCUG Micturating cystourethrogram
A 1 month baby is present at clinic with their mom with irritability and poor feeding. On examination you notice vulvitis. What is your full management plan including investigations
0-6 month old with UTI
Admitted to hospital, urine dipstick, urine culture/microscopy/sensitivity
Given IV antibiotics: (<2 months) Triple therapy of amoxicillin + Gentamicin + Cefotaxime
Renal USS during and after admission at the OPD
ONLY IF POSITIVE FINDINGS ON Renal USS
MCUG after 6 weeks
DMSA scan after 4-6 months
A 1 year old baby is present at clinic with their mother with reduced appetite, irritability and fever. Their mother notices that they are in pain when urinating and will only urinate small amounts. What is your full management plan with investigations in a well vs unwell child
6 months - 2 years
Well: No admission and Oral antibiotics (Cephalexin or nitro or co-amoxiclav or trimethoprim) + Renal USS OPD
Unwell: Admission, urine dipstick, urine culture/microscopy/sensitivity, and empiric IV antibiotics (Co-amoxiclav +Gentamicin) + USS during and after admission
A 6 year old presents to the emergency department with their mother. They look well but tell you it hurts when they urinate and they feel like they have to go urgently during the consultation. When asked if this happened before, his mom says that it occurred 3 times in the past 2 years. What is your full workup?
> 2 years
They are well => no admission + oral antibiotics (Cephalexin or nitro or co-amoxiclav or trimethoprim)
Since it is a recurrent infection, Renal USS needs to be used
A 6 year old presents to the emergency department with their mother. They look unwell with fever and nausea and tell you it hurts when they urinate and they feel like they have to go urgently during the consultation. When asked if this happened before, his mom says that it occurred 3 times in the past 2 years. What is your full workup?
> 2 years
They are unwell => admission + urine dipstick + urine culture/microscopy/sensitivity + IV antibiotics (Co-amoxiclav and Gentamicin) + Renal USS
What is MCUG, what does it detect, and how is it performed?
Micturating cystourethrogram detects vesicoureteric reflux. This involves sedating the patient and putting in a urinary catheter which is used to inject a contrast in. That is then scanned to show vesicoureteric reflux
What does a DMSA scan detect? How does it work?
Detects renal scarring. It is an isotope based scan. This involves sedating the patient and putting in a urinary catheter which is used to inject a contrast in. The contrast is absorbed by renal cells that arent scarred. That is then scanned to show renal scarring
What does a Mag 3 renogram detect? How does it work?
Detects obstruction. It is an isotope based scan. This involves sedating the patient and putting in a urinary catheter which is used to inject a contrast in. This is taken up by renal cells. That is then scanned to show dynamic images which can reflect both GFR and renal emptying => can show obstruction
How is Vesicoureteric reflux graded?
It is graded based on the MCUG scan which can grade the reflux based on the extent of reflux and dilatation of the ureters and kidney itself
When should you conduct invasive procedures such as MCUG?
1) Present unwell in <6 months
2) Structural abnormality on Renal USS
3) Recurrent UTIs
What is Phimosis?
Phimosis is when the foreskin cannot be retracted in boys
What organism is most common in boys with phimosis? What is a significant complication of that organism?
Proteus which is an ammonia splitting organism => kidney stones => obstruction and infection
A patient is admitted with a UTI and shows no signs of improvement after 48 hours. Whatre you suspecting?
Abscess or anatomical abnormality causing obstruction or kidney stones
What is the most common organism to cause a UTI? State a few others
E.Coli
klebsiella
Coag-ve staph: Staph saprophyticus
Pseudomonas
Proteus
You have a patient with dribbling urinary incontinence. What are your ddx?
RED FLAG
Posterior urethral valves
Spina Bifida
Spinal abnormality/injury
When taking a history from a patient with suspected UTI, they tell you they are always very thirsty and drink >2 liters per day. What do you suspect
RED FLAG
T1 DM
Diabetes insipidus
Briefly tell me what Diabetes Type 1 is vs Diabetes insipidus
Type 1 DM is due to autoimmune destruction of the beta cells of langerhan => reduced insulin production => hyperglycemia
Diabetes insipidus on the other hand is due to ADH deficiency which controls the ability of the kidney to absorb water => kidneys cannot concentrate their urine => polydipsia and polyuria but NORMAL GLUCOSE LEVELS
Differentiate between polyuria and urinary frequency
Polyuria is going to the bathroom a lot with a full bladder and large volume
Urinary frequency is going to the bathroom a lot with small volumes
Hematuria in children is quite rare. If you do see gross hematuria, whatre you suspecting?
RED FLAG
Kidney stones or other urinary obstruction
What are the red flags to look out for when dealing with UTI or enuresis
Recurrent infections
Positive family history of renal abnormalities, recurrent infections
Not getting better after 48 hours of antibiotics (abscess or obstruction)
Polydispsia/polyuria (T1DM, Diabetes insipidus)
Gross hematuria (kidney stones or obstruction)
Dribbling: Ectopic ureter, spinal pathology, urinary obstruction (Mag 3 renogram)
A mother is asking for advice on how to prevent her child from getting as UTI. What do you suggest?
Perineal hygiene (wiping instructions, more frequent change of nappies)
Encourage increased fluid intake
Encourage regular voiding and full emptying of bladder (10 second rule)
Note: these are also good for enuresis
In kids, urinary retention may lead to vulvitis and hence UTIs/cystitis. What are the effects of an overfilled bladder in terms of infection?
Overfilled bladder will lead to urgency and incomplete emptying which can end up with stale urine remaining that can be prone to infection and even enuresis.
Quick history questions for daytime enuresis!!
Only during the day or at night as well?
During enuresis is it full emptying (from holding) or spotting (incomplete emptying)
Lack of awareness when they have to go
urinary urgency
poor fluid intake (imp)
voiding frequency when dry (are they just holding it in)
Incomplete bladder emptying (going to the bathroom 10 minutes after going)
Early toilet training (when were they toilet trained)
Strong pelvic floor muscles (dancer, gymnast) (hold in more)
Constipation?
Daytime enuresis: What investigations would you like to perform?
Treatment?
Plot centile charts!!
Full abdominal exam for masses (examine perineum) and Lower limb neuro exam (spinal injury causing it e.g. spina bifida)
Urine dipstick for glucose (rule out ddx of T1DM or Diabetes insipidus)
Tx: Encourage increased fluid intake
Voiding frequency (encourage double voiding via 10 second method/10 minute)
Avoid fizzy drinks/ black currant drinks/ caffeine drinks
Treat constipation
Why do we not encourage pelvic floor exercises in children?
In adults/elderly, enuresis occurs due to a leak => weak pelvic floor muscles
In children, it is that they are unaware and holding it for too long => pelvic muscles too strong => incomplete emptying
Red flags specific to enuresis
Polydispsia/polyurea (drinking >2L) => T1DM or Diabetes insipidus
Dribbling => Ectopic ureter, spinal pathology, urinary obstruction
What is diabetes insipidus?
Deficiency of ADH which controls water reabsorption in collecting duct => kidney cannot concentrate urine leading to more water loss. Glucose has nothing to do with it so glucose serum levels are normal but they still have the polydipsia and polyurea
What is the root cause of daytime enuresis vs night time?
Daytime: Due to poor awareness and habit => holding urine in, toilet training, poor fluid intake
Nighttime: Isolated developmental delay, strong familial association, no relation to habit
10% of 5 year olds and 5% of 10 year olds suffer from nocturnal enuresis. At what age would further investigation be needed?
> 11 requires further investigation
Quick history for nocturnal enuresis!!
Deep sleeper
Dry nights (reassuring even if once as that means the nerves required for dryness is present)
Bedwetting in unfamiliar places? (sleep overs, traveling)
Polydipsia
Daytime symptoms
What investigations would you perform for nighttime enuresis?
Treatment?
Plot centile charts!!
Full abdominal exam for masses (examine perineum) and Lower limb neuro exam (spinal injury causing it e.g. spina bifida)
Urine dipstick for glucose (rule out ddx of T1DM or Diabetes insipidus)
Tx: Reassure family and child and advise no drinking after 6pm, wake child for urination before you go to bed, or enuresis alarm.
What is the normal fluid intake for
<8
9-13
>14
<8: 1-1.5 L
9-13: 1.5-2L
>14: Girls: 1.5-2.5L
Boys: 2-3L
