Renal and Urinary System Flashcards
1
Q
By what age are most children dry by night?
A
5 yrs
2
Q
What are the two types of enuresis (involuntary urination)? More common in M or F?
A
Nocturnal - M2:1F
Diurnal (much rarer) - F>M
3
Q
What is primary enuresis?
A
Continence never established
4
Q
What is secondary enuresis?
A
Loss of continence after a continuous period of at least 6 months dryness (most likely to have organic cause)
5
Q
What are some biological causes of nocturnal enuresis?
A
1) UTI = 5% secondary enuresis
2) Urinary tract abnormalities
- Low bladder capacity
- Incomplete bladder voiding
- Detrusor instability 2ndary to constipation
3) Lack of ADH during sleep
4) Genetic predisposition
- 70% have FH
5) DM
6
Q
What are some psychosocial causes of nocturnal enuresis?
A
1) Inability to wake to full bladder sensation
2) Psychosocial trauma eg distress, bullying, abuse
3) Accidental behavioural conditioning eg child comes to parents bed when wet
4) Developmental delay
7
Q
What is a major cause of diurnal enuresis?
A
Bacteriuria
Cycle - bacteriuria causes detrusor instability causes urge incontinence causes damp pants and perineal irritation causes bacteriuria
8
Q
What features are important to include in an enuresis hx?
A
Age when first dry night Age when started wetting Any stressors at school Safeguarding Does child have own room/bed Fluid intake - fluids before bed / fizzy drinks
9
Q
What investigations can be done for enuresis? (4)
A
1) DM testing - random and fasting blood glucose
2) Urinalysis if symptomatic
- Bacteriuria is common in diurnal enuretic girls
3) GU tract abnormality
4) Consider psychological screening
10
Q
What is the management of enuresis?
A
Intervention not usually required until age 7
Behavioural management eg reward chart for good behaviours
Enuresis alarm
Bladder training
Avoid caffeine and fruit juice
Treat any constipation
Medication
11
Q
What medications can be given for enuresis?
A
Desmopressin = antidiuretic can be taken as tablets, sublingual or nasal spray at bed time. Reduces UO. Avoid excessive fluid intake for 8hrs after dose
Anticholinergics = if daytime symptoms / unresponsive
Imipramine = tricyclic antidepressants if still no response (rarely used bc of side effects)
12
Q
Why is a UTI significant in young children?
A
It may be a marker for urinary tract abnormalities =
Half of child UTI pt have renal tract abnormality
13
Q
How common is are UTIs in children?
A
Most common bacterial infections in children <2yrs
14
Q
How may a UTI present in neonates? What may it be associated with?
A
Atypically
May be associated with neonatal sepsis
15
Q
What is a lower UTI?
A
UTI involving bladder and urethra
16
Q
What is an upper UTI?
A
Involving renal pelvis and/or kidney (pyelonephritis)
17
Q
When clinically should an upper UTI be assumed?
A
Fever of 38 or higher + bacteriuria
Fever lower than 38 but with loin pain/tenderness + bacteriuria
18
Q
When are UTIs considered recurrent?
A
1) 2 x upper UTI
2) 3 x lower UTI
3) 1 x upper + 2 x lower UTI
19
Q
What features make a UTI atypical?
A
1) Seriously ill / septicaemia
2) Poor urine flow
3) Presence of abdo / bladder mass
4) Lack of response within 48hrs to treatment with suitable abxs
5) Unusual causative oranges (not E coli)
6) Inc serum creatinine
20
Q
Are UTIs more common in boys or girls?
A
More common in boys up to 6 months
More common in girls after
21
Q
What are some risk factors for UTI?
A
1) Anything that leads to urinary stasis - renal calculi, obstructive uropathy, vesicle-ureteric reflux (VUR)
2) Poor urine flow eg phimosis (unretractable foreskin)
3) Dysfunctional elimination syndrome
4) Sexual abuse
5) Constipation
6) Spinal abnormalities
No RF in most cases
22
Q
How may a UTI present in infants <3 months?
A
Presents differently than in older children
Fever Vomiting Lethargy Irritability \+/- poor feeding \+/- FTT
Less commonly: Abdo pain Jaundice Haematuria Offensive urine
More likely to develop urosepsis
Less likely to be due to E coli
23
Q
How may a UTI present in infants and preverbal children >3 months?
A
Fever = common Abdo pain Loin tenderness Vomiting Poor feeding
Less commonly: Lethargy Irritability Haematuria Offensive urine FTT
24
Q
What is the most common presentation of a UTI in a preverbal child?
A
Fever with no apparent cause
25
How may a UTI present in a child >3yrs?
Urinary symptoms eg freq, dysuria, suprapubic / abdo / lumbar pain
Dysfunctional voiding
Fever, malaise, vomitn, haematuria, offensive / cloudy urine
26
Ddx for UTI (6)
```
Vulvovaginitis
Urethritis
Irritation eg soaps
Threadworm infestation
Balanitis
Sexual abuse
```
27
What should be included on examination of a child with a UTI?
Temp
Throat and cervical LN
Abdo - constipation, tender / palpable kidney
Back - spina bifida / sacral agenesis signs
Genitalia - phimosis, labial adhesions, vulvitis or epididymo-orchitis
28
How may urine be collected in a child with a UTI?
Clean catch
Collection bag attached to clean genitalia
Urine collection pads (easily contaminated)
29
What may urinalysis show in a UTI?
Nitrites +
Leucocytes +
Haematuria +
Albumin +
30
Why are nitrites not very sensitive dipstick test in infants?
Not all urinary pathogens reduce nitrate to nitrite
Urine not often held in bladder long enough for conversion to occur
31
What imaging can be performed for a child with a UTI?
USS
Micturating cystography
DMSA scintigraphy
32
When are renal USS used?
Recurrent UTI
| <6 months of age
33
What are USS effective and ineffective at visualising when investigating a UTI?
Accurately assess renal size and outline and identify most congenital abnormalities, renal calculi and hydronephrosis or hydroureter (indicating the presence of obstruction or severe reflux)
Less effective in detecting mild or moderate VUR
34
When are micturating cystography used?
Children <6 months of age with recurrent/atypical UTI in which dilation shown on renal USS
35
What is the gold standard investigation for VUR?
Micturating cystography
Only imaging technique that provides information about the urethra
36
What is a disadvantage of micturating cystography?
Invasive - requires catheterisation
37
What DMSA scintigraphy effective at imaging? How does it work?
Gold standard for renal parenchymal defects
Study renal function using a radio-pharmaceutical such as technetium
Isotope is concentrated in proximal renal tubules - its distribution correlates with functioning renal tissue
38
When are DMSA used?
4-6 months post infection - show scarring
39
Which children presenting with a UTI should be immediately referred to specialist care?
Serious illness
3 months or younger
Do not delay treatment if sample cannot be obtained and the child is at serious risk of illness
40
What factors make a UTI recurrence in a child more likely? (4)
1) Younger ie <6 months
2) Female
3) VUR grade 3-5 vs 1-2 or no reflux
4) Dysfunctional voiding syndrome
75% risk <1yr
Over 1yr:
40% for girls
30% boys
VUR usually resolves
41
What is the pharmacological management of a child with a UTI? Lower and upper
7-10 days oral antibiotics
IV if cannot tolerate or under 3 months of age but switch to oral as soon as possible
Lower UTI:
1st - trimethoprim or nitrufurantoin
2nd - cefalexin
Upper:
1st - co-amoxiiclav
2nd - cefixime
42
What is dysfunctional voiding syndrome?
Abnormality of emptying, due to either a small-capacity, unstable bladder or a large-capacity, poorly emptying bladder
43
What are potential complications of a UTI in children? (3)
1) Renal scarring - more likely in children with VUR
2) HTN - associated with renal scarring
3) Possible link with inc risk of bacteriuria, pre-eclampsia and HTN in pregnancy later in life
44
What is the diagnosis of infants or children that have:
1) Bacteriuria and a fever of 38 or more
2) Fever <38 associated with loin pain/tenderness and bacteriuria
3) Bacteriuria but no systemic symptoms or signs?
1) Pyelonephritis/upper UTI
2) Pyelonephritis/upper UTI
3) Cystitis/lower UTI
45
What measures can be adopted to prevent UTI?
Good hygiene
| Encourage micturition
46
What is a complication of UTI?
Vesicoureteric reflux (can be bilateral)
47
What is primary vesicoureteric reflux?
Incomplete closure of the VU valve
48
What is secondary vesicoureteric reflux?
Obstruction of the posterior urethral valve (boys)
49
List some causes of haematuria (9)
1) UTI
2) Trauma
3) Acute glomerulonephritis
4) Stones and hypercalciuria
5) Congenital abnormalities
6) Tumour
7) Bleeding disorder
8) Exercise
9) Drugs
50
What is important to include in a hx of haematuria?
Colour of urine
- Originating from kidney = brown / cola-coloured
- Originating from bladder / urethra = red / pink colour and may contain clots
NB not all red urine is blood eg could be from beetroots or blackberries
Urinary symptoms
Pain
- Abdo pain or renal colic suggest clot, calculus or obstructive malformation
Precipitating factor
- Trauma
- Preceding URTI or skin infections often precede acute glomerulonephritis
- Intense exercise
FH
- Bleeding disorders, HTN or kidney disease
51
What is important to include on examination of someone presenting with haematuria?
BP:
- HTN suggests renal malfunction and child should be admitted to hospital
Oedema:
- Periorbitally and ankles
- Can be a feature of glomerulonephritis
Renal mass:
- Palpate abdo for tenderness and renal masses
52
What are the most likely diagnoses if a renal mass is found upon abdo examination of a child presenting with haematuria?
Hydronephrosis
Polycystic kidneys
Tumour
53
What investigations are performed for haematuria?
1) Urinalysis
2) Urine culture
3) FBC
4) ASO titre and throat culture
5) Serum creatinine, U&Es
6) 24hr urine for creatinine, protein and calcium
7) Serum C3 level
8) ANF / autoantibodies
9) Abdo / pelvic US and intravenous pyelogram
10) Renal biopsy
54
When performing urinalysis for haematuria, what may the results show?
Red cell casts and proteinuria = glomerular lesion
Pyuria and bacteriuria = UTI
55
What the relevance of an ASO titre and throat culture when investigating haematuria?
Recent strep infection often precedes acute glomerulonephritis
56
What the relevance of serum C3 level when investigating haematuria?
Low C3 is specific for certain types of glomerulonephritis
57
What the relevance of ANF / autoantibodies when investigating haematuria?
Positive in SLE
58
When is a renal biopsy required when investigating haematuria?
If haematuria is persistent with proteinuria, HTN or impaired renal function
59
What does haematuria with dysuria, freq and urgency suggest?
UTI
60
What does smoky, coca-cola coloured, granular and red cell casts haematuria with malaise, oliguria, HTN and oedema suggest?
Glomerulonephritis
61
What does haematuria with renal colic suggest?
Renal stone
62
What dues haematuria with a renal mass and abdo pain suggest?
Tumour
63
What does haematuria with a painless renal mass suggest?
Congenital abnormality
64
What is haemolytic uraemia syndrome (HUS)?
Triad of:
1) Microangiopathic haemolytic anaemia - Coombs' test negative
2) Thrombocytopenia
3) AKI
65
How common is HUS?
Most common cause of AKI in children
Some children may develop partial / incomplete HUS with thrombocytopenia, +/- anaemia, but serum creatinine concentrations remain normal
66
What is HUS associated with?
90% follow infection
Infection with E coli 0157 (15% of cases will develop HUS)
Produces Shiga toxin or verotoxin
HUS can occur up to 2 weeks after infection
67
What is the pathophysiology of HUS?
Systemic disease caused by damage arising from circulating toxin which binds to endothelial receptors, esp renal, GI and CNS
Thrombin and fibrin are deposited in the microvasculature
This occurs early in the disease, prior to development of HUS and thus abx are of no benefit
Erythrocytes are damaged as they pass through partially occluded small vessels and subsequently haemolysis occurs
Platelets are sequestered but without cascade of clotting factors (similar to in DIC)
68
Other than E coli 0157, what pathogens may induce HUS?
Bacteria - strep pneumoniae and shigella dysenteriae type 1
Viruses - HIV and Coxsackievirus
69
What can cause atypical HUS?
10%
Exposure to certain medications eg ciclosporin / tacrolimus
Genetic mutations in complement pathway
Systemic conditions eg lupus, cancer and pregnancy
70
What is the incubation period of E coli 0157?
1-6 days
HUS usually arises within 14 days, even when appear to be recovering form initial illness
71
List some RF for HUS (5)
```
Rural populations
Warmer summer months
Age 6 months - 5 yrs
Altered immune response
Contact with farm animals
```
72
When are children with E coli 0157 gastroenteritis able to go back to school?
After two negative stools
Post-symptomatic shedding can occur but highest transmissibility thought to occur during acute diarrhoea phase
73
How may HUS present?
Classical = profuse diarrhoea that turns bloody 1-3 days later
- Rare for diarrhoea to be bloody from the outset
Fever (often afebrile by time reach hospital)
Abdo pain ++
Vomiting
Painful defecation
74
What investigations are performed for HUS?
FBC and film
- Evidence of haemolysis, anaemia and thrombocytopenia
- Raised WCC and low platelets = early indicator
- Features of microangiopathic haemolysis
Renal function and electrolytes
- Rise in urea and creatinine can be due to dehydration, but if associated with haemaolysis and thrombocytopenia indicates HUS
LFTs
LDH
- High is early indicator of HUS
CRP
Clotting screen
Stool culture
Urinalysis
75
List some ddx for HUS (6)
Other causes of abdo pain and diarrhoea:
- Acute gastroenteritis, appendicitis, IBD, intussusception
DIC eg with sepsis
HELLP syndrome
Autosomal dominant form of HUS occurs with specific genes
Inherited abnormalities of complement regulation
Thrombotic thrombocytopenic purpura
- Can cause thrombotic microangiopathy
76
What is HELLP syndrome?
Haemolysis
Elevated Liver enzymes
Low Platelet count
= complication in pregnancy usually presents in women who have pre-eclampsia or eclampsia
77
What gene is affected in autosomal dominant form of HUS?
Abnormality of the ADAMTS13 gene which encodes vWF
Tends to present in childhood
78
What is thrombotic thrombocytopenia purpura?
Rare form of thrombotic microangiopathy
Characterised by:
1) Microangiopathic haemolysis
2) Thrombocytopenia
3) Neurological abnormalities
4) Renal dysfunction
5) Fever
TTP = medical emergency, without treatment mortality = 90%
79
What is the management of HUS?
Infectious diarrhoea, HUS or VTEC (verocytotoxin-producing E coli) = report to public health
Supportive treatment
New treatments include:
- Early plasma exchange to remove mutant complement proteins
- Specific targeted treatments eg factor H comcentrate
- Liver or liver and kidney transplants
80
What are some complications of HUS?
GI:
- Intestinal strictures and perforations
- Intussusception and rectal prolapse
- Pancreatitis
- Severe colitis
Neuro:
- Altered mental state
- CVA
- Seizures
Renal:
- AKI
- CKD
- Haematuria
- HTN
- Proteinuria
81
What is nephrotic syndrome?
aka nephrosis
1) Proteinuria
2) Low albumin
3) Oedema
4) High triglycerides
82
What is the pathophysiology of nephrotic syndrome?
Increased permeability of serum protein through damaged basement membrane in renal glomerulus
Oedema results due to hypoalbuminaemia
83
What values define nephrotic syndrome?
Protienuria = to / more than 3.5g/day
Hypoalbuminaemia = serum albumin = to / less than <30g/L
84
What is the most common cause of nephrotic syndrome in children?
Minimal change = 85%
Changes on renal biopsy are very mild
85
How does minimal change nephrotic syndrome initially present?
PC usually oedema
- Most noticeable in mornings around eyelids and pitting oedema in legs
May be hx of recent viral URTI
86
What is the second most common cause of nephrotic syndrome in children?
Focal segmental glomerulosclerosis
87
Following initial presentation of oedema, what symptoms / sign follow?
Weight gain
Ascites
Pleural effusion
- Due to hypoalbuminaemia
```
Rarely HTN
Anorexia
Abdo pain
Diarrhoea
Oliguria
```
88
Why is there an increased risk of infections in nephrotic syndrome?
Leakage of immunoglobulins
89
What investigations are carried out for nephrotic syndrome?
Urinalysis
- 3+ or 4+ protein or microscopic haematuria
Serum albumin
- Low
Serum cholesterol and triglyceride
- High
C3 levels
- High
Renal biopsy only if clinical picture does not appear typical of minimal change nephrotic syndrome or if child does not respond to treatment within a month
90
What is the management of nephrotic syndrome?
Hospital admission
Fluid restriction
Low salt diet
Corticosteroids = prednisolone
Prophylactic penicillin until proteinuria cleared
91
How long should prednisolone be continued when treating nephrotic syndrome?
Until remission of proteinuria (usually 2 weeks), then continued at a weaning dose over 2-3 months
Advise parents to avoid live vaccines and chickenpox during this time
92
What % of children with nephrotic syndrome relapse?
75%
93
What should be performed in children who are steroid resistant and how may they be treated?
Renal biopsy to confirm pathology
| May need cyclophosphamide
94
What is the prognosis of nephrotic syndrome?
Caused by minimal change = good prognosis
Other causes worse eg HSP
95
What is acute glomerulonephritis?
Results from immunological damage to the glomerulus
Commonest form in childhood results from immune complexes following infection by nephritogenic form of streptococcus
Other forms of glomerulonephritis are rare and only considered if atypical course
96
When does haematuria occur in acute glomerulonephritis?
1-2 weeks after throat or skin infection
97
How does acute glomerulonephritis present?
Smokey / cola-coloured urine
Otherwise asymptomatic, can have:
- Malaise
- Headache
- Vague loin discomfort
- Oedema around eyes, necks of hands and geed
Usually mild oliguria, but can have:
- Renal failure
- HTN
- Seizures
- HF
98
What may be found when investigating acute glomerulonephritis?
Urine microscopy shows gross haematuria with granular and red cell casts
Proteinuria
99
How is acute glomerulonephritis confirmed to be post-strep form?
Throat swab
ASO titre
Low complement (C3) levels
100
What is the management of acute glomerulonephritis?
No specific therapy, managed similarly acute renal failure
Monitor creatinine clearance and fluid balance
Restrict fluid intake if oliguria develops
Diuretics and hypotensive drugs if HTN
Rarely peritoneal dialysis required
Treat strep infection with penicillin but no evidence this affects course of disease
101
What is the prognosis of acute glomerulonephritis?
Post-strep has excellent prognosis
Usually resolves in 10-14 days
Other causes have poorer prognosis
102
What is hypospadias?
External urinary meatus is abnormally sited
Can be anywhere from ventral aspect of glans penis (most common) to penoscrotal junction or even perineum
103
What is the treatment of hypospadias?
May be mild = needing no treatment
Severe = surgical repair (before 2 yrs)
- Allows boys to void standing
- Allow future sexual function
- Psychological impacts
Parents advised not to have the child circumcised so that the foreskin tissue can be used in reconstructive surgery
104
How common is hypospadias?
1 in 500 boys
105
How common is vulvovaginitis?
Most common gynae problem in prepubertal girls
106
List some RF for vulvovaginitis
```
Close anatomical proximity of rectum
Lack of labial fat pads and pubic hair
Small labia minora
Thin and delicate vulvar skin
Thin, atrophic vaginal mucosa
Poor hygiene
```
107
How may vulvovaginitis present?
Itching
Redness
Soreness
Green/yellow discharge
108
What age is vulvovaginitis most common?
3-10years
109
What are some causes of vulvovaginitis?
Infection eg candida, bv
- Prepubertal can be caused by GABS
Dermatological eg allergic dermatitis
110
How is vulvovaginitis managed?
Lifestyle advice eg avoid irritants / tight underwear
Treat cause
