Flashcards in Nephrology and Urology Deck (63):
epidemiology of HSP-henoch schonlein purpura?
usually occurs between ages of 3 and 10 years, commonly between 4 and 6
twice as common in boys than girls
peaks in winter mnths-cold exposure may be assoc. environmental factor, and often preceded by URTI-group A streptococci, EBV
aetiology of HSP?
unknown aetiology, presumed immune complex mediated disease
thought that genetic predisposition and antigen exposure increase circulating IgA and disrupt IgG synthesis, the IgA and G interact to produce complexes that activate complement and are deposited in affected organs causing inflammatory response with a systemic vasculitis.
presenting features of HSP?
symmetrical erythematous maculopapular rash that evolves over 24hrs into purpuric lesions that are characteristically palpable, may recur over several wks, and is 1st clinical feature in about 50%. widespread over buttocks and extensor surfaces of arms and legs, and ankles, with trunk sparing unless trauma induces lesions.
arthralgia-part. knees and ankles, usually resolves before rash disappearance, no permanent joint deformity
abdo pain, haematemesis, melena-GI petechiae, intussusception-differential for abdo pain, and occurs in 2-3% of HSP patients
micro and macroscopic haematuria-glomerulonephritis, or mild proteinuria, can be nephrotic syndrome-proteinuria more than 3.5g/24hr along with hypoalbuminaemia and oedema, if renal involvement must be f/u for 1 yr to decide who needs LT f/u, as HTN and deteriorating renal function may develop after interval of several years.
can be orchitis and CNS complications, may be headaches.
differentials for HSP?
purpuric rash-thrombocytopenia e.g. ITP-low PLT count, meningococcal septicaemia-fever
CTD e.g. SLE
other causes of glomerulonephritis e.g. IgA nephropathy-males, haematuria whilst URTI e.g. coughing or sore throat.
acute haemorrhagic oedema of infancy-fever, oedema, and rosette shaped, annular or targetoid purpura affecting face, ears and extremities.
arthralgia-juvenile idiopathic arthritis-systemic form-remitting fever, variable rash
diagnosis is based on clinical picture
FBC: raised WCC with eosinophilia, may be normal or elevated PLT (note reduced PLT in ITP differential)
serum creatinine elevated in renal involvement
raised serum IgA
autoAb screen-CTD e.g. ANA in SLE
urinalysis-haematuria and proteinuria
barium enema-confirm and treat intussuception
renal BIOPSY if persistent nephrotic syndrome
NSAIDs for arthralgia relief, but use with caution if renal impairment-*as inhibit PG prod. which cause dilation of afferent arteriole for adequate renal perfusion
hosp admission for abdo and renal complication monitoring
possibly corticosteroids for arthralgia and GI dysfunction relief
supportive nephropathy tment
what monitoring for renal involvement is advised in f/u of HSP patients?
if no proteinuria, BP and urinalysis at 1 wk, 2 wks and then at 1, 3, 6 and 12 mnths
if proteinuria, monitoring at 1 wk, 2 wks, monthly from 1-6mnths then at 12 mnths.
complications of HSP?
renal impairment, but disease only progressive to ESRD in 1% of patients
CNS complications e.g. seizures, mononeuropathies
what is long term prognosis in HSP directly dependent on?
severity of renal involvement
characteristic blood result findings in patient with nephrotic syndrome?
hypoalbuminaemia: serum albumin less than 25g/L
hypercholesterolaemia: serum cholesterol more than 5.17mmol/L
hypocalcaemia-loss of Vit D binding protein in urine, LT risk of bone demineralisation
hypercoagulability-decreased partial thromboplastin time
clinical presentation of minimal change disease/idiopathic nephrotic syndrome?
usually younger children (2-5yrs), boys (until puberty, then equal sex incidence)
nephrotic syndrome-oedema-peri-orbital swelling, ascites-everted umbilicus, pitting ankle oedema
proteinuria-low molecular weight anionic proteins e.g. albumin, but some higher molecular weight e.g. IgG also lost.
HTN and haematuria in 10%, but transitory
most respond to corticosteroids
usual diagnosis in child with corticosteroid resistant idiopathic nephrotic syndrome?
typical features of nephrotic syndrome caused by FSGS, membranous glomerulonephritis, SLE or mesangial proliferative glomerulonephritis?
older children (6-15 yrs)
variable sex ratio
greater protein leakage through glomerular filtration barrier, higher molecular weight proteins e.g. Igs may be lost.
haematuria often present
HTN may occur
often not responsive to steroids
how can children with minimal change disease be classified?
those in remission: urinary protein excretion less than 4mg/m^2/hr, or no protein trace on dipstick, or protein/creatinine ratio 0.02g/mmol for 3 consecutive days
relapse: proteinuria recurrence as defined in minimal change definition, or 2+ or more on dipstick for 3 consecutive days
frequent relapses: 2 or more within 1st 6 mnths or initial response, or more than 4 in 12 mnths
corticosteroid dependence: 2 consecutive relapses while on prednisolone or within 2 wks of stopping it
corticosteroid resistance: failed response after 8wks of 2mg/kg/day
ciclosporin dependent: relapses when ciclosporin stopped or tapered, steroid dependent children who achieve remission with ciclosporin.
why are children with nephrotic syndrome more susceptible to infection, and which types of infection in particular are they more at risk of?
proteinuria-urinary loss of IgG
loss of factors B and D of alternate complement activation path
altered T cell function
impaired Ab producing ability
loss of opsonising factors*-specifically increases risk of encapsulated organism infection
steroid and immunosuppressive drug tment
mechanical-oedema and ascites
encapsulated bacteria: strep pneumoniae (less so now with vaccination), H.influenzae, E coli, causing cellulitis, UTIs, peritonitis, meningitis, septicaemia.
*peritonitis risk further increased by reduced mesenteric b.flow and increased coagulability, with reduced flow and sludging causing microinfarction.
what worrying complication of nephrotic syndrome is more likely in a child suffering acute fluid loss e.g. viral gastroenteritis with diarrhoea and vomiting?
risk in NS assoc with raised plasma fibrinogen and clotting factors due to increased hepatic synthesis, decreased plasma ATIII and protein S as lost in urine, PLT abnormalities, increased blood viscosity, decreased b.flow and hyperlipidaemia.
what raises our concerns for CVD risk in patients with nephrotic syndrome?
why is nephrotic syndrome thought to cause growth disturbance, especially if congenital?
loss of IGF binding protein in the urine
why is hypothyroidism a complication of nephrotic syndrome?
loss of thyroid binding protein in urine
current symptoms we want to know in patient presenting with nephrotic syndrome?
general health-appetite loss, weight gain, lethargy, poor height gain
oedema-periorbital, ankle swelling-pitting oedema, ascites, scrotal swelling
may be abdo pain and diarrhoea
urinary-haematuria, oliguria, concentrated urine
other-infections*incresed susceptibility with loss of Igs-IgG and complement activation pathway factors and opsonising factors in urine, and immunosuppressive tment, abdo pain, HTN
investigations needed in nephrotic syndrome?
proteinuria-3+ or 4+ on dipstick
cellular casts e.g. hyaline or waxy casts in minimal change
microscopic haematuria-may persist in steroid resistant NS
Us and Es
albumin and total protein levels
serum complements C3 and C4-normal in minimal change, low in SLE
Hep B and C serology-B assoc. with membranous, C with mesangial proliferative.
indications for renal biopsy in nephrotic syndrome?
steroid resistance-no response within 1 mnth
age under 1 yr
nephritic features-HTN, haematuria, raised creatinine/renal impairment
persistent abnormal serum complement (low C3)
older children, part. african americans where FSGS more common-most common progressive glomerular disease in children
best prognostic indicator in nephrotic syndrome?
what is acute glomerulonephritis?
sudden development of immunological damage to the glomerulus
commonest form in childhood result of immune complex formation following infection by nephritogenic form of streptococcus-pt has hx of sore throat or skin infection, and 1-2 wks after presents with haematuria= acute post streptococcal glomerulonephritis
clinical features of acute glomerulonephritis?
haematuria-appearance of smoky or cola-coloured urine (gross haematuria) and microscopic
may be otherwise asymptomatic, although may also be malaise, headache-may occur secondary to HTN, loin discomfort-stretching of renal capsule.
can be oedema around eyes, and dorsum of hands and feet
may be proteinuria
may be HTN
results of investigations in acute glomerulonephritis?
urine microscopy-gross haematuria, with granular and red cell casts
may be complicated course with renal failure, HTN, seizures, and heart failure and pulm oedema-*SOB.
management of acute glomerulonephritis?
diagnosis of post-streptococcal glomerulonephritis made via throat swab and ASO titre-antistreptolysin O titre-blood test to measure Abs produced against streptolysin O-produced by Group A strep. also low C3.
monitor creatinine clearance and fluid balance, restrict Na+ and H2O if oliguria develops.
diuretics and anti-hypertensives if HTN develops, rarely peritoneal dialysis.
penicillin-eradicate strep infection, but no evidence it affects course of disease. also culture family members and treat if organism found.
components to glomerular filtration barrier?
glomerular BM-anionic proteins with -ve charge
visceral epithelium-podocyte foot processes-filtration slit diaphragm
*increase in glomerular capillary wall permeability-nephrotic syndrome
overall nephrotic syndrome management?
discourage excessive fluid intake
limit Na+ intake to no added salt
advise parents when 1st discharged from hosp to monitor daily fluid input and output and record, and weigh child daily
prednisolone to induce remission, must do daily weighing and monitor proteinuria-remission when no protein for 3 days, low dose continued for 4-6wks
prophylactic penicillin during steroid tment
most common organism responsible for UTI in childhood?
clinical features in neonates of a UTI?
indications of UTI on urine MCS?
growth of more than 10^5 colony forming units
plus greater than 50 WCC
(normal WCC urine culture=0-40)
how are children under 6 mnths of age with UTI investigated?
if single confirmed UTI and repsond rapidly to tment, require urinary tract USS.
abnormal opening of urethra along the inferior aspect of the penis, usually near the glans, along the shaft, or near the base.
rarely may extend along the scrotal raphe
how does hypospadias occur?
incomplete fusion of urethral folds:
in normal development, androgen secretion by fetal testes (Leydig cells) stimulates rapid elongation of genital tubercle-now phallus, and during this process, phallus pulls urethral folds forward so they form lateral walls of urethral groove which extends along caudal aspect of elongated phallus but does not reach the glans. epithelial lining of groove forms the urethral plate, and at end of 3rd mnth, urethral folds close over urethral plate to form penile urethra.
?relation to rise in environmental oestrogens
other conditions hypospadias may occur in association with?
cryptorchidism (in about 10% of cases)
9-15% also have an open processus vaginalis or inguinal hernia.
sometimes FH of hypospadias
problems associated with hypospadias?
problems more common the further posteriorly the urethral opening arises on the inferior aspect of the penis:
urine spraying backwards
chordee (tissue tightening on inferior aspect) pulling penis down, can make erection difficult
premature ejaculation in adulthood, and in those who had surgery in childhood
treatment of hypospadias?*
if mild, so urethral opening close to normal location, no treatment required
in most cases, surgery perfomed when child 4-18mnths, may need 2 ops if complicated
position of urethral opening altered and if chordee present then this is corrected
foreskin usually used to make new urethra.
most common cause of haematuria in childhood?
acute nephritis vs. nephritic syndrome, and causes?*
post strep glomerulonephritis
vasculitis-wegener's, HSP, SLE
anti-glomerular BM disease (Goodpasture syndrome)
why is early diagnosis of UTIs in children, especially infants, essential?
as most vulnerable age for renal scarring that can lead to later HTN and renal failure
how are infant urine specimens collected for dipstick in suspected UTI?
routine clean catch with help of carer
bag urine-U bag, if above fails, this must be checked regularly by opening up nappy.
when should urine be sent for culture in children?
as routine in children 3 years and younger, and if child systemically unwell
Abx treatment for acute pyelonephritis in children?
cefuroxime for at least 7 days, and single dose of gentamicin
lower UTI Abx treatment in children?
if aged over 6months and not sick then cefalexin or trimethoprim for 3-5 days
if aged under 6mnths or sick then cefuroxime for at least 7 days and single dose of gentamicin.
indications for US imaging within 6 wks of UTI?
child under 6 months
recurrent UTIs-3 or more lower UTIs, 2 or more with acute pyelonephritis or 1 acute pyelonephritis and 1 or more lower UTIs.
atypical UTI features?
poor urinary flow
abdo or bladder mass
non E-coli organism
raised serum creatinine
failure to respond to suitable Abx within 48hrs
predisposing factors to a 1st UTI in a child?
incomplete bladder emptying
what specific examinations should be performed in the child who presents with enuresis?*
neurological (CNS), including lower limb reflexes
how should the problem of nocturnal enuresis in a 6yr old be explained to parents?
that at an age around 6 years this is normal
child is normal and healthy
child will grow out of it naturally
the problem in beyond the child's conscious control so patience from parents is required, this is a developmental issue
what advice can be given regarding simple management of nocturnal enuresis?
drink plenty of fluid during the day
pass urine regularly during the day
don't drink too large amount of fluid close to going to bed
pass urine before going to bed
praise child when wakes with dry bed e.g. use of star charts
may consider enuresis alarm if no response to star chart
minimise stresses at home
how can short term relief of nocturnal enuresis be provided e.g. for a child going on holiday?
with PO desmopressin-synthetic analogue of ADH, only taken temporarily as achieves a suppressant effect rather than lasting cure.
name of the fatal syndrome that results from bilateral renal agenesis?
Potter syndrome-result of severe oligohydramnios due to absence of fetal urine
oliohydramniosis causes intrauterine compression of the fetus, causing characteristic facies-low set ears, beaked nose, downward slanting eyes, lung hypolasia and limb deformities including severe talipes.
what causes a horseshoe kidney?
failure of kidneys to ascend from the pelvis due to blockage by inferior mesenteric artery, lower poles of the kidneys then fuse in the midline.
risks associated with a pelvic or horseshoe kidney?
due to abnormal position, increased risk of infection or urinary obstruction.
what causes a duplex kidney?
premature division of the ureteric bud
may be a bifid renal pelvis or complete division with 2 ureters
problems with duplex kidney?
if 2 ureters, usually have abnormal drainage so ureter from lower pole moiety often refluxes, and upper pole ureter may drain ectopically into urethra or vagina, or may prolapse into the bladder (ureterocele) and urine flow may be obstructed.
causes of bilateral hydronephrosis?
bladder neck obstruction due to neuropathic bladder
posterior urethral valves-mucosal folds or a membrane in boys
why might mild outflow tract obstruction not be visible in neonates in 1st few days of life?
as newborn kidney has low GFR, so there is low urine flow anyway
management protocol for antenatally diagnosed urinary tract anomalies?
propylactic Abx started at birth
if bilateral hydronepohrosis and/or dilated lower urinary tract in a male-US within 48hr to exclude posterior urethral valves-if abnormal do MCUG, and then surgery if required, if normal stop Abx and rpt US after 2-3mnths.
if unilateral hydronephrosis in male, or any anomal in female, US at 4-6wks, if abnormal further investigate, if normal stop Abx and rpt US at 2-3mnths.
what is vesicoureteric reflex (VUR)?
developmental anomaly where ureters are displaced laterally and enter directly into the bladder rather than at an angle, with a shortened or absent intramural course.
may also occur with bladder pathology e.g. neuropathic bladder or urethral obstruction, or temporarily after a UTI.
problems with VUR?
may only cause mild reflux into ureters on micturition, or may reflux during bladder filling and voiding with a distended ureter, renal pelvis and clubbed calyces so spectrum of disease.
reflux means not all urine expelled on micturition causing stasis, and risk of UTIs-there is part. high risk of renal scarring after UTIs if intrarenal reflux with urine backflow into papillary CDs.
infection can be LUTIs and pyelonephritis
high bladder voiding pressures transmitted to renal papillae may cause renal damage.
renal scarring can cause a shrunken, poorly functioning segment of kidney=reflux nephropathy.
if bilateral and severe scarring, can cause CKD.