Urinary System Flashcards
1
Q
Common pathogens in UTI
A
- bacterial: E.coli, Kebsiella, Enterobacter, Staphylococcus aureus…
- viral and fungi less common
- Viral Utis are limited to the lower urinary tract
2
Q
Classification of UTI according to site
A
CYSTITIS (lower urinary tract)
- urinary bladder mucosa with symtpoms like dysuria, stranguria, frequency, urgency, malodorous urine, incontincence, hematuria and suprapubic pain
PYELONEPHRITIS (upper urinary tract)
- diffuse pyogenic infection of the renal pelvis with symtpoms like fever (>38)
- infants and children may have non-specific signs like poor appetite, failure to thrive, lethargy, irritability, vomiting, diarrhea
3
Q
Classification of UTI according to episode
A
- First infection
- Recurrent infection can be
- unresolevd
- persistent
- reinfection
4
Q
Classification of UTI according to symtpoms
A
ASYMPTOMATIC BACTERIRUIA (ABU)
- pathogens that are incapable of activating symtpomatic response
- in significant ABU, luekocyturia can be present without any symptoms
SYMPTOMATIC UTI
- irritative voiding symtpoms, suprapubic pain, fever, malaise
5
Q
Classification of UTI according to complicating factors
A
UNCOMPLICATED UTI
- infection with morhpological and functional upper and lower urinary tract, normal renal function and competent immune system
COMPLICATED UTI
- in newborns, most patients with clinical evidence of pyelonephritis, children with mechanical or functional obstructions or problems of the upper urinary tract
6
Q
For acute treatment of UTI, what factors are most important
A
Site and severity
7
Q
Atypical UTI criteria
A
- seriously ill
- poor urine flow
- abdominal or bladder mass
- raised creatinine
- septicemia
- failure to response to treatment within 48 h
- ifection with non e. coli organisms
8
Q
Recurrent UTI
A
- 2 or more episodes of acute pyelonephritis/ upper urianry tract ifection
or
- 1 episode of acute pyelonephritis + > 1 episode of cystitis
or
- > 3 episodes pf cystitis / lower urinary tract infections
9
Q
Pathogenesis of UTI
A
- result of ascending infection
- colonization of the reiurethral area by uropathogenic enteric pathogens
- in E. coli: pili on the cell surface aid in attaching
- in kidney, bacterial pathogen generated intense inflammatory resposne that can lead to renal scarring
10
Q
Risk factors for UTI
A
- weak anti-bacterial features of the mucous membrane and urine
- girls
- incomplete bladder emptying
- neurogenic bladder
- white children
- family history
- urinary obstruction
- VUR
- infrequent voiding
- vulvitis, balantitis
- hurried micturition
- constipation
- sexual activity
- bladder catheterization
11
Q
Bacterial factors that predispose to UTI infection
A
- infecting organisms are more likely to be associated with structural obnormalities in renal tract
- in newborn, UTI is more often hematogenous
- most common infection: e. cloli
- Proteus infection more common in boys because of its presence under foreskin and predisposes to stone formation
12
Q
Vesicoureteral reflux
A
- is the retrograde passage of ruine from the bladder into the upper urinary tract
- the most common urologic anomaly in children
13
Q
Pathogenesis of VUR
A
PRIMARY VUR
- most common form
- due to incompetent or inadequate closure of the ureterovesical junction
SECONDARY VUR
- result of abnormally high pressure in the bladder that results in the failure of closure of the UVJ during bladder contraction
- often associated with anatomic or functional bladder destruction
14
Q
Grading of VUR
A
- Grade I: reflux only fills the ureter without dilation
- Grade II: refluc fills the ureter and the collecting system without dilation
- Grade III: reflux fills and mildly dilates the ureter and the collecting system with mild blunting of the calyces
- Grade IV: reflux fills and grossly dilates the ureter and the collecting system with blunting of the calyces
- Graade V: massive reflux grossly dilated the cpllecting system; all the calyces are blunted with a loss of papillary impression and intrarenal reflux may be presnet; ureteral dilation and tortuosity
15
Q
Risk factors for renal scarring
A
- recurrent febrile UTI
- delay in treatment of acute infection
- dysfunctional elimination, constipation
- obstructive malformations
- VUR
16
Q
When to suspect UTI according to NICE guidelines
A
- present symtpoms and signs of UTI
- unexplained fever over 24 hours
- an alternate site of infection, but who remains unwell
17
Q
Symptoms of UTI in neonates
A
- jaundice
- hypothermia or fever
- failure to thrive
- poor feeding
- vomiting
18
Q
Symptoms of UTI in infants
A
- poor feeding
- fever
- vomiting, diarrhea
- strong-smelling urine
19
Q
Symptoms of UTI in preschoolers
A
- vomiting, diarrhea, abdominal pain
- fever
- strong-smelling urine, enuresis, dysuria, urgency, frequency
20
Q
Symptoms of UTI in school children
A
- fever
- vomitign, abdominal pain
- strong-smellign urine, frequency, urgencya, flank pain or new enuresis
21
Q
Symptoms of UTI in adolescents
A
- more likely to have classic adult symptoms
- girls are more likely to have vagintis than UTI
22
Q
Urine sampling for newborns, non-toilet trained children
A
- plastic bag attached to the cleaned geitalia –> often contaminated
- clean catch urine collectioin: sterile bowl catches urine mid-stream
- Suprapubic bladder aspiration: most sensitive
- bladder catherization: rates of contamination are higher
23
Q
Blood test in UTI
A
- blood white cell counts
- C-reactive protein
- serum pro-calcitonin
24
Q
Imaging procedures in UTI
A
- ultrasound
- MCUG (Micturating cysturetherogram)–> for VUR, bladder volumes, …
- DMSA scintigraphy: for pyelonephritis and renal scarring
- Radionuclide cystogram: for VUR
25
When to do an ultrasound in UTI
- girls younger than 3 with first UTI
- boys of any age with first UTI
- children with recurrent UTI
- First UTI in child with family history of renal disease, abnormal voiding pattern, poor grwoth, hypertension
26
How to distuingish between upper UTI and lower UTI
Acute pyelonephritis: bacteriuria and fever of 38 or higher
| Bacteriruia but no systemic featuers: cystitis
27
Criteria for UTI in children (in urine specimen)
Suprapubic baldder puncture: any number of CFU per ml (at least 10 identical colonies)
Bladder catherization: >1000 - 50.000 CFU/ml
Midstream void: >10 4 CFU/ ml with symtpoms
>10 5 CFU/ml without symptoms
28
MCUG indications
- boys < 6 months
| - if there was atypical UTI
29
Acute pyelonephritis dignostic criteria in children
- fever of 38 or higher
- leukocyturia
- significant bacteriuria
- Changes in blood showing a bacterial infection (leukocytosis and CRP > 20 mg/l)
- general signs of infalmmation (intoxication, abdominal and flank pain)
- changes in echoscopy
to confirm diagnosis there must be urine abnormality and at least two other criteria
30
Acute cystitis diagnostic criteria in children
- micturition disturbances
- luekocyturia
- significant bacteriruia
to confirn diagnosis there must be urinary disturbances and at least one other diagnosis
31
General treatment stretegy in UTI
- dont treat dysuria without urine test
- start treatment immediatly if UTI is suspected without urine culture result
- in patients with uncomplicated cystitis, oral treatment should be given for at least 3-4 days
32
Duration of therapy in febrile urinary tract infection
- parenteral treatment should be continued until the child is afebrile, after which oral antibiotics ahould be given or 7-14 days
- in complicated UTI with pathogens other than E. coli --> parenteral treatment with broad-spectrumm antibitoics is preferred
- newborn: 14 days (as for sepsis)
- pyelonephritis: 10-14 days
- cystitis: 3-7 days
33
Initial pyelonephritis treatment
- Aminoglycosides iv until the child has no fever and an additional 1-2 days, but no longer than 7 days, then other antibacterial drug by antibiogram until 10-14 days
or
- group 2 cephalosproins iv until the child has no fever and an additional 1-2 days, then PO until 10-14 days
amoxicillin and clavulanic acid?
34
Acute cystitis treatment
- nitrofurantoinum, furanginum
- trimethoprimum
or
- trimethoprimum/ sulfamethoxazolum
treatment duration 3-5 days or until recepit of microbiologuc findings, then treatment can be adjusted according to patient's condition and antibiogram
35
Long-term sequelae of UTI
- 40% have VUR
- renal scars in 8%
- large majority will have no long term sequelae
36
Classification of GN by course
- acute
- chronic
- rapidly progressing
37
Classification of Gn by clinical picture
- nephritic syndrome
| - nephrotic syndrome
38
Classification of GN by histology
- memnraboproliferative
- membranous nephropathy
- extracapillary
- minimal change
- focal segmental glomerulonecrosis
39
Classification of GN by etiology
- primary
| - secondary
40
Classification of GN by IHC
- pauci immune
- Anti-GBM
- immunocomplex
41
Key features of nephritic syndrome
- hematuria
- proteinuria (non-nephrotic range)
- Hypertension (BP>95th percentile)
- Oliguria (<0.5ml/kg/hr)
- Renal failure (decrease in GFR < 90ml/min/1.73m2)
- Edema (less severe, periorbital)
42
Causes of nephritic syndrome (primary and secondary renal diseases)
PRIMARY RENAL DISEASE
- IgA nephropathy
- membranoproliferative GN
- Anti-GBM
- idiopathic crescentic GN
SECONDARY RENAL DISEASE
- post-infectious GN
- Henoch-Schönlein purpura nephritis
- SLE
- Wegener's granulomatosus
- Microscopic polyangiitis
43
Post-infectious glomerulonephritis clinical features
- most commonly post-streptococcal
- 1-2 weeks after strep throat infection and up to 6 weeks after strep skin infection
- acute nephritic syndrome
- decreased C3, increased ASO
- decreased GFR
- resolves in 2-3weeks
- C3 normalization in 6-8 weeks
- isolated microscopic hematuria up to 2 years
44
Therapy in post-infectious GN
supportive
- bed rest
- fluid and salt intake restriction
- diuretics (loop diuretics, furoseminde --> potassium wasting)
- anti-hypertensives
- correction of hyprekalemia/ acidosis
45
When to do a biopsy in post-infectious GN
usually not needed
INDICATIONS
- low C3 over 3 months
- abnormal serum creatinine at 6 weeks
- proteinuria > 6 months
- rapidly progressing course
--> shows diffuse endocapillary porliferative GN with subepithelial humps
46
IgA nehpropathy clinical features
- macroscopic hematuria 1-2 days after URTI
- asymptomatic microhematuria +- proteinuria
- acute nephritic syndrome
- nephrotic syndrome
- nephritic-nephrotic syndrome
- decreased GFR
47
Histological features of IgA nephropathy and MEST
- IgA deposition in mesangium
- C3 and IgG and IgM may be present in up to 50%
M: Mesangial hypercellularity
E: endocapillary hypercellularity
S: Segmental gloermulosclerosis
T: Tubular atrophy/ interstitial fibrosis
48
Therapy of IgA nephropathy
- microscopic hematuria --> no therpay required
- proteinuria over 1g/l --> long-term renoprotection with ACEi/ ARBs
- blood pressure control (stricter case in proteinuria > 1g/l)
- if supportive therapy fails: steroids or immunosuppressants (MFF, cyclophosphamide)
- omega 3 fatty acid supplementation in case of proteinuria > 1g/l
49
Key features of nephrotic syndrome
- heavy proteinuria (> 3 g/l in dipstick or >40 mg/m2/hr or urine protein to creatinine ratio >200mg/mmol, >2.0 mg/mg)
- hypoalbuminemia (<25g/l)
- edema (moderate/severe, generalized)
- hypercholesterolemia
50
Pathophsyiology of nephrotic syndrome
- glomerular filtration barrier consists of fenestrated endothelial cells, GBM and Podocytes
- loss of negative charge og GBM
- foot process effacement --> increased protein permeability, loss of protein to urine, hypoalbuminemai
51
General causes of nephrotic syndrome
- 0-3 months: congenital (genetic)
- 3-12 months: infantile (genetic and idiopathic)
- first decade: idiopathic
- < 10 years: idiopathic/ secondary
52
Congenital nephrotic syndrome
mutations in genes encoding podocyte and GBM portiens, lead to impairment of glomerular filtration barrier
53
Finnish type congenital syndrome
- most common cause of congenital NS
- autosomal recessive
- heavy proteinuria and severe hypoalbuminemia
- albumin infision dependence --> nephrectomy frequently needed
54
Nephrotic syndrome beyond infancy
- most commonly idiopathic
- -> minimal change (80%)
- -> FSGS
- -> other (mesangial proliferative GN, membranoproliferative GN, membranous nephropathy)
- genetic
- secondary (rare, in second decade of life)
- -> infections (HBV, HCV, malaria, schistosomiasis, HIV)
- -> systemic disease (HSP, SLE, DM)
- -> metabolic diseases (Fabry disease, glycogen-storage diseases)
- -> oncohematological disorders, drugs...
55
Minimal change nephrotic syndrome
- most common form of chilhood NS
- no changes on light microscopy
- EM: podocyte feet effacement
- typically suspected in a non-infant with NS
- typically non familial
- frequent triggers: viral, allergies
- initial therapy with steroids
56
Definitions of NS
- complete remission
- partial remission
- Steroid dependent nephrotic syndrome
- frequently relapsing nephrotic syndrome
- steroid resistant nephrotic syndrome
- complete remission: uPCR 200mg or 1+ protein on urine dipstick for 3 consecutive days
- partial remission: proteinuria reduction of 50% or greater from the presenting value and absolute uPCR between 200 and 2000 mg/g
- Steroid dependent nephrotic syndrome: two consecutive relapses during corticosteroid therapy, or within 14 days of ceasing therapy
- frequently relapsing nephrotic syndrome: two or more relapsing within 6 months of initial response, or four or more relapses in any 12 month period
- steroid resistant nephrotic syndrome: failure to achieve complete remission after 8 weeks of ccs therapy
57
Focal segmental glomerulosclerosis
- suspected in cases of steroid resistant nephrotic syndrome
- can only be proven by biopsy
- MCNS can transform to FSGS
- some forms are genetic
58
Nephrotic syndrome: supportive measures
- edema correction
- -> diuretics (furoseminde)
- -> Albumin + furoseminde infusion in case of diuretic resistance and severe hypoalbuminemia)
- -> moderate slat and fluid restriction
- blood pressure control
- complication prevention
- -> hypercoagubility states (anticoagulation)
- -> severe hyperlipidemia (statins)
- -> risk of infections (vaccinations)
59
When to do genetic testing in nephrotic syndrome
- congenital or infantile nephrotic syndrome
- patients with familiar history of NS of chronic kidney disease
- multiple associated extrarenal manifestations
- persistent non-responsiveness to heavy immunosuppression
60
Other therapies for nephrotic syndrome
used in cases of SRNS, some cases of DSNS; FRNS, steroid intolerance
- cyclophosphamide
- levamisole
- calcineurin inhibitors
- myophenolate mofetil
- azathioprine
- rituximab
61
Membranoproliferative Glomerulonephritis two mechanisms
- Alternative complement pathway dysregulation
| - Immunocomplex mediated injury via classical complement pathway
62
MPGN therapy
- blood pressure control (ACEi/ ARBs)
- Moderate disease (proteinuria > 0.5g/24h, risk of CKD) --> predinsone or MMF
- severe disease (proteinuria > 2g/24 h and despite CKD despite immunosuppression)
- -> Methylpredisolone pulstherapy, other immunisuppressants
63
Membranous nephropathy
- up to 43% of cases secondary to infections (HBV, malaria), systemic disease (SLE, DM, IBD), drug (NSAIDS), malignancies
- nephrotic syndrome, asymtpomatic proteinuria, macroscopic or microscopic hematuria, hypertension, CKD
64
Histologica features of membranous nephropathy
- uniform thickening of the capillary wall within the glomerulus secondary to deposition of subepithelial immune aggregates
- no inflammation
