Renal / Gu Flashcards
How do urinary tract anomalies present
Uti - usually recurrent Recurrent abdo pain Palpable mass Haematuria Failure to thrive
3 types of urinary tract anomalies
Renal abnormalities
Obstructive lesions of urinary tract
Vesicouretic reflux
Egs of renal anomalies
Renal agenesis Ectopic kidney Duplex kidney Horseshoe kidney Cystic disease of kidney
What is renal agenesis and what does it result in
Absence of both kidneys
Potters syndrome - oligohydraminos (caused by lack of fetal urine)
What is associated with renal agenesis
Lung hyperplasia
Postural deformities
What is an ectopic kidney ?
Why about it makes pain misleading
Failure of kidney to ascend from pelvis / ascend too far to thorax
Pain depends on site
What is a duplex kidney
Premature division of ureteric bud -> duplex system
Kind of get extra bit of kidney on one / both sides which may have an extra ureter as well
What other abnormalities are associated with duplex kidney
Renal dysplasia
Vesicouretic reflux
Complications with extra ureter in duplex kidney
Often have abnormal drainage eg into urethra -> continuous urinary leakage / into wrong part of bladder -> reflux
What is horseshoe kidney ? Why?
Kidneys joined at lower poles
Abnormal migration and separation
4 types of kidney cystic disease
Muticystic dysplastic kidney
Autosomal recessive polycystic kidney disease
ADPKD
Tuberous sclerosis
Which cystic disease has no functional renal tissue
MCKD - large fluid filled cysts like grapes
ARPKD causes
Diffuse bilateral enlargement of kidneys
ARPKD causes
Separate cysts of varying sizes between normal renal parenchyma
Kidneys are enlarged
Ages of kidney failure in PKD
Recessive by around 15-20
Dominant by around 60
Locations of obstructive lesions in urinary tract
Pelviureteric junction, vesicouretic junction, the bladder, urethra
What causes obstruction in Pelviureteric obstruction (congenital hydronephrosis)?
Prognosis ?
Narrow lumen, compression by fibrous band / blood vessel.
Mild - often reduce spontaneously
Severe- surgery with conservation of renal tissue where possible
Prognosis of antenatal hydronephrosis? When to investigate ?
Often reduces after birth.
Investigate if bilateral ?urethral obstruction
Causes of vesicouretic obstruction? Where is the swelling ?
Stenosis, kinking / dilation of lower part of ureter (ureterocele)
Combination of hydroureter and hydronephrosis
Where do abnormal folds of urethral mucosa occur in males ? What do they cause?
Region of verumontanum.
Impede flow of urine with back pressure on bladder, ureters and kidneys
Prognosis of abnormal folds in posteriors urethral vales
Death in Utero from renal failure / after birth from potters syndrome
Uti, poor urinary stream, renal insufficiency
What causes primary vesicouretic reflux
Developmental anomaly of vesicouretic junction
Ureters enter directly into bladder rather than at an angle & the segment of ureter within bladder is abnormally short
What are the consequences of vesicouretic reflux
Reflux when voiding -> infection & exposing kidneys to bacteria & high pressure
Grading of vesicouretic reflux
I-V
Mild I- reflux into ureter only
Moderate III - dilation of ureter and renal pelvis
Severe V - gross dilation of ureter, renal pelvis and calyces
Features of VUR
Along with other GU anomalies & may be due to bladder pathology (eg. Neuropathic bladder)
Consequences of VUR
Predisposed to uti & pyelonephritis
Reflux nephropathy -tissue damage & scaring due to infection and back pressure -> hypertension and chronic renal failure
How is VUR diagnosed
Micturating cystourethrography (MCUG)
How does MCUG work ? What else can you look for
Bladder filled with contract medium via catheter -> bladder outlined and reflux detected
Obstruction can be demonstrated with views during voiding without catheter
Issues with MCUG
Radiation dose is high and there is risk of infection
Management of VUR
Mild VUR resolves spontaneously (10%/year) but, Prophylactic Abx (eg trimethoprim)
Surgery if the prophylaxis fails / VUR in stages IV / V
How long is prophylactic Abx given to kids with VUR
Until free of infection, regained bladder control and is older than 5
Types of radiological investigation of kidney and urinary tract
Ultrasound
Functional scanning - static nuclear medicine scanning / dynamic nuclear medicine scanning
How does static nuclear medicine scanning work? What is is particularly good at identifying ?
An isotope labeled substance (eg DMSA) that is incorporated into renal tissue is used.
Identifying renal scaring
How does dynamic nuclear medicine scanning work? What does it give information on? When can it be used to detect VUR ?
An isotope labeled substance usually MAG3 that is excreted at PCT is used
Info on Blood flow, renal functioning & drainage
In an older child who can cooperate by stopping & starting micturition on command
What are the key Inguinal scrotal disorders
Undescended testis
Inguinal hernia and hydrocele
Acute scrotum
Where do testis develop? When do the go into scrotum? Who has undescended testis more commonly?
Intraabdominally via Inguinal canal in third trimester therefore preterm more frequently
2 types of undescended testis
Incompletely descended - lying along normal pathway (20%)
Maldescended/ectopic - deviated from normal path agree emerging from superficial Inguinal ring
When are testis checked ? When referee to a surgeon?
Birth, 6/12, 18/12
If impalpable or ectopic testis found at 6/52
Further investigations for undescended testis
Uss, MRI, laparoscopy to determine existence and location
Management of undescended testis
Orchidopexy - best between 1-2 years
What are the benefits of orchidopexy
Decreased risk of torsion & malignancy, increased fertility.
Psychological and cosmetic benefits
When the testis descend into scrotum what do they take and what can this cause ?
Connecting fold of peritoneum (process vaginalis) - failure to close -> Inguinal hernia / hydrocele
Who gets more Inguinal hernias
Boys, preterm, FHx
How does Inguinal hernia present
Parents note intermittent swelling in groin or scrotum
What are the danger signs of irreducible hernia? What are you worried about?
Hard , tender, vomiting
.Strangulation
Treatment of hernia
Surgery
When does a hydrocele form rather than hernia?
If process vaginalis is small
How to differentiate hydrocele from hernia
Possible to get above and trans illuminates
Treatment of hydrocele
Reassurance - usually spontaneously reduces by 1 year
Acute swelling and pain in scrotum is what until proven otherwise
Torsion
What causes torsion
Inadequate fixation of tunica vaginalis allows testis to rotate and occlude its blood supply
Treatment of torsion
Surgical exploration without delay
Often affects both testis as Defect commonly bilateral
DD of torsion
Torsion of testicular appendix (hydratid of morgani) - vestigigial remnant of Müllerian duct
Epididymo-orchitis
Idiopathic scrotal odema
What is hypospadias? Severe forms associated with?
Congenital abnormalities of the position of the urethral meatus .
Chordee (ventral curvature of penis)
What is phimosis ? How can mild be managed ?
Adhesion of foreskin to glans penis after 3 years .
Mild - periodic gentle retraction
Is a none retracting foreskin and ballooning / preputial adhesions indications for circumcision
No they are normal and common in small boys
Indications for circumcision
Balanitis xerotrica obliterans
Recurrent balanitis
Sometimes- recurrent uti
What is balanitis xerotica obliterans
Thickens scarred white prepuce adherent to glans (caused by recurrent infection )
Why is uti in childhood important
Up to half have structural abnormalities.
Pyelonephritis may scar growing kidney predisposing to hypertension and chronic renal failure if scarring is bilateral
Causes of urinary stasis
VUR
Obstructive uropathy - ureterocele, urethral valves
Neuropathic bladder - eg. Spina bifida
Behavioural infrequent voiding & constipation
Commonest organism(s) causing uti
E. coli
Proteus, pseudomonas
Who is more likely to get proteus infection? Predisposes to?
Boys
Phosphate stone formation
What does pseudomonas infection possibly indicate
Structural abnormality in the urinary tract affecting drainage
Uti features infancy
Fever, lethargy, vomiting & diarrhoea, poor feeding / failure to thrive, prolonged neonatal jaundice, septicaemia, febrile convulsions
Uti features childhood
Dysuria & frequency, fevers (+/- rigors), lethargy & anorexia, V&D, febrile convulsion, recurrence / secondary enuresis
Investigations for uti
Urine sample - dipstick (nitriles, leukocyte), M,C&S (microscopy, culture and sensitivity)
Diagnosis of uti
Culture of pure growth of a single pathogen at at least 105 colony forming units per L of urine
Methods for collecting urine and when used
Suprapubic aspirate - all babies
Why do you treat UTIs quickly
Reduce risk of scarring
How do you treat most UTIs ? Eg?
Oral Abx
eg. Coamoxiclav for 5/7, 10/7 if systemically unwell (adjusting according to sensitivity on urine M,C&S
Uti treatment for infants / severely unwell ? Eg?
IV Abx
Ampicillin / cefotaxime plus gentamicin
In severe why is augmentin given for 48hrs ? Switched to?
Reduce fever and risk of meningitis - then switch to trimethoprim
Further investigation post uti
Imaging to assess for anatomical / functional abnormalities eg VUR and for renal scarring.
Initial uss to identify a) presence of 2 kidneys, b) obstructions with urinary tract dilutions
Management of infants post uti ? When is it done ? What else is done?
Initial uss and MCUG (looking for VUR) + static radioisotope scan (DMSA) to identify renal scars
Defer until 3/12 after acute infection to avoid detecting transient abnormalities
Abx prophylaxis in interim
Management of 1-5 year olds post uti
Uss & static radioisotope scan (MCUG reserved for abnormality on DMSA scan, recurrent infections, FHx of reflux)
When is risk of renal scarring with uti less
With increasing age (uncommon after 5 years old )
Advise to prevent uti recurrence
High fluid intake, regular unhurried voiding, lactobacillus, cranberry juice, good perineal hygiene
When might transient proteinuria occur and not warrant investigation
During febrile illness / after exercise
How can you measure persistent proteinuria ? What should it not exceed ?
24 HR urine or a timed collection.
Not exceed 4mg/h per m2
What is a more useful urine sample than 24 HR collection in young children ? Why? What should it be?
Early morning protein:creatine ratio - early morning to exclude orthostatic changes
Protein should be
What characterises nephrotic syndrome ? Levels?
Gross proteinuria 300-400 mg/mmol
Hypoalbuinaemia (
Usual cause of nephrotic syndrome (others)?
Idiopathic
Can secondary to systemic disease eg. HSP & other vasculitis (SLE…), infections (eg. Malaria), allergens (eg. Bee stings)
Features of nephrotic syndrome ? Earliest?
Peri orbital oedema (particularly on walking) - earliest sign
Scrotal / vulval, leg & ankle oedema
Ascities
Breathlessness due to plwural effusions &abdominal distension
Investigations for nephrotic syndrome
Urine dipstick (+++protein) FBC & ESR (inflam / infection) U&E, creatine, albumin Compliment levels (c3/c4) Urinary sodium concentration Antistreptolysin titre (ASOT) & throat swab Urine microscopy &a culture Hepatitis serology Anti DNAse B (?group A strep)
What’s more common steroid sensitive or steroid resistant nephrosis
90% steroid sensitive
Usual demographic for steroid sensitive nephrosis
Histology of steroid sensitive
Minimal change
Management of steroid sensitive
Oral corticosteroids (60mg/m2/day prednisolone) for 4 weeks then 49mg/m2 every other day for 4 weeks then stop. Manage hypovolaemia
When is nephrosis defined as steroid resistant
No remission on 4 weeks of steroid therapy
Usual demographic for steroid resistant nephrosis
Age 12, elevated BP, heamaturia, decreased renal function, features of nephritis
Histology of steroid resistant nephrosis
Various, underlying glomerulonephropathy (eg. Focal segmental glomeruloscerosis, membrano-proliferative glomerulonephritis)
Management of steroid resistant
Refer t paediatric nephrologist
Complications of nephrosis
Hypovolaemia
Thrombosis
Secondary infection
Hypercholesterolaemia
Features of hypovolaemia
Increased packed cell volume (PCV), hypotension, peripheral vasoconstriction, urinary sodium
Why does nephrosis -> thrombosis ?
What can add to this?
Hypercoagulable state due to urinary losses of antithrombin.
thrombocytosis may be exaggerated by steroid therapy
Why do you get secondary infections with nephrosis ? What is usual cause? What can happen? And what is the prophylaxis
High risk of infection with capsulated bacteria (especially pneumococcus). Peritonitis may occur. Penicillin prophylaxis in acute phase
Why do you get hypercholesterolaemia in nephrosis
Inversely correlated with albumin
How many people with nephrosis relapse
2/3
What can be done for frequent relapses of nephrosis
Further immunosuppression eg cyclophosphamide, levamisole or cyclosporin A
Characteristics of nephritis
Salt & retention - (hypertension, oedema), decreased urine output (+seizures)
Heamaturia - often macroscopic “smokey” coloured
Proteinuria - varying degree
Impaired GFR - rising creatinine (variable)
Causes of nephritis
Post infectious
Vasculitis
IgA nephropathy & mesangiocapillary glomerulonephritis
Anti GBM disease
Usual infection for secondary nephritis
Skin/ throat with group A b-haemolytic strep
Egs of vasculitis -> nephritis
Henoch-schlonlein purpura, SLE, Wegners granulomatosis
Other name for anti GBM disease? Other feature
Goodpastures syndrome
Heamoptysis
General investigations for nephritis
Urine - blood, protein, red cell casts (microscopy)
AXR - exclude other causes
Diagnosis of post strep glomerulonephritis
Evidence / Hx of recent (~10/7) infection (culture of organism, increased ASOT)
Low complement c3 levels
What is ASOT
Anti streptolysin O
Demographic of who gets henoch - schonlein purpura
Aged 3-10, males 2x, peaks during winter months & often preceded by LRTI
Features of nephritis (4 things)
Rash - over buttocks, extensor surfaces of legs and arms ; purpuric
Joint and pain swelling - knees and ankles (large joints)
Abdo pain - haematemesis / malaena, intussusception
Renal - nephritis
Management of nephritis
Fluid balance - measure urine output, low/moderate fluid intake, diuretics, decrease salt
Treat hypertension
Correct other imbalances (potassium / acidosis)
Penicillin (to treat underlying strep infection)
What is the most common cause of paediatric acute renal failure
Haemolytic ureamic syndrome
What is HUS associated with
Diarrhoea caused by E. coli 0157:H7 which produces a verocytotoxin
How does a verocytotoxin cause damage
Released from GI tract & causes fragmentation of RBCs, microangiopathic haemolytic anaemia & thrombocytopenia
-> kidney vasculature becomes thrombosed and infarcted
Management of HUS
Supportive and 90% regain full renal function
What is contraindicated in HUS
Abx
