Ch 18 - Kidney & Urinary tract disorders Flashcards
Renal Agenesis (absence of both kidneys): features (1 syndrome - 5 features)
So lack of kidneys > no urine > oligohydramnios (because most of amniotic fluid is made up of fetal urine)
F - Oligohydramnios results in Potter Syndrome (fatal) - fetal compression, low set ears, beaked nose, prominent epicanthic folds, pulmonary hypoplasia causing resp failure, limb deformities > infants may be still born/ die soon after due to resp failure
Multicystic dysplastic kidney: cause, features (1), management (1)
Cause - failure of union of ureteric bud (forms ureter, pelvis, calyces, collecting duct) with nephrogenic mesenchyme - so get a non-functioning structure with large fluid-filled cysts and no renal tissue or connection with bladder.
M - half involute by 2 yr so no treatment required, nephrectomy is done only if still very large/ or causing HTN
Polycystic kidney disease: autosomal dominant features (5), autosomal recessive PKD feature (1)
ADPKD - discrete cysts of varying size within normal renal parenchyma, HTN, haematuria, enlarged kidneys, extra renal - e.g. hepatic cysts
ARPKD - diffuse bilateral enlargement of both kidneys
What is horseshoe kidney?
Fusion of both kidneys at lower poles; predisposes to infection/ obstruction
Duplex anomalies: cause (1) 2 examples
Premature ureteric bud division
Duplex ureters - abnormal drainage: ureter from lower pole refluxes, upper pole drains ectopically into urethra/vagina/ may prolapse into bladder, may obstruct urine flow
Duplex pelvis
What is bladder extrophy?
When there is failure of fusion of infraumbilical structures - basically the bladder mucosa is exposed (kinda like gastroschisis)
Absence musculature syndrome: what is it?
Absence/ def in anterior abdo wall muscles > megacystic megaureters + crytorchidism (undescended testicle)
Urine flow obstruction: can be unilateral (2) or bilateral (2) Give 2 places for each where the obstruction would be
Consequences (2)
Obstruction to urine flow leads to dilatation of urinary tract proximal to obstruction.
Unilateral can be at: pelvicoureteric junction (PUJ) or Vesicoureteric junction (VUJ)
Bilateral can be at: Bladder neck or urethra (this will cause hydroureters & hydro nephrosis)
Consequences - Dysplastic kidneys (small + poor function) & if v. severe Potter syndrome
Dysuria alone: differentials 2 Male & 2 Female
M - cystitis/balanitis (uncircumsized)
F - Cystitiis/ vulvitis
UTI predisposition: infecting organisms (4)
UTIs are usually result of bowel flora entering UT via urethra - except in newborn where its most likely haematogenous.
E. Coli - commonest organism, Klebsiella, Pseudomonas, Proteus, E. Faecalis
UTI predisposition: Antenatally diagnosed renal or urinary tract abnormality
increases risk of infection
UTI predisposition: incomplete bladder emptying (4)
Contributing factors in some children are: infrequent voiding > bladder enlargement Vulvitis Incomplete micturition Obstruction from loaded rectum Neuropathic bladder vesicoureteric reflux
UTI predisposition: VUR - definition, complications (4)
VUJ developmental abnormality (the ureters are displaced laterally and enter directly into bladder rahter than at an angle) > tends to resolve with age
C - Mild reflux into ureters, reflux during bladder filling, intrarenal reflux (into collecting ducts - high risk of scarring), predisposition to UTI/ hydronephrosis
UTI suscpicioun: investigations (2)
USS
MCUG - micturating cystourethrogram
DMSA - to check for renal scarring 3 months post UTI
UTI suscpicion/ confirmed management:
1) infant 3 months and children with acute pyelonephritis/ upper UTI - features (3), management (1)
3) Cystitis/lower UTI - feature (1), management (1)
1) Refer to hospital! IV Cefotaxime until temp settles > oral AB
2) F - bacteriuria + fever/ loin pain, M - PO co-amoxiclav 7-10 days or IV Cefotaxime for 3 days then oral AB for a week
3) Dysuria only, M - 3 day course of Nitrofurantoin/ tripethoprim/ ceftriaxone/ amoxicillin
Prevention of UTIs (4)
Aim is to washout organisms that ascend into bladder from the perineum
High fluid intake
Regular voiding
Ensure complete voiding - double micturition (encourage child to try a second time to empty bladder)
Lactobacillus acidophillus; probiotic colonizes the gut & reduces the number of pathogenic organisms (that may invade)
Primary nocturnal enuresis: definition, causes (3)
D - involuntary voiding of urine at least 3/7 in child
Secondary (onset) nocturnal enuresis: definition (1), causes (3), Ix (3)
D - child had previously achieved night time dryness
C - Emotional upset (most common), > , constipation, Diabetes
Ix - Urine dipstick, early morning urine osm/ water deprivation test, USS
Management of nocturnal enuresis (3)
1st line: Reward systems - star charts: give for agreed behaviour rather than dry nights e.g. if they go to toilet before bed
2nd line: enuresis alarm 7 yrs old
Daytime enuresis: causes (4), Ix (3), management (4)
Causes:
detrusor instability (sudden urgent urge to void induced by sudden bladder contractions)
Bladder neck weakness
Neuropathic bladder - enlarged and fails to empty properly, associated with spinda bifida
UTI
Constipation
Ectopic ureter - causes constant dribbling and always damp child
Ix - urine sample microscopy, culture, USS, urodynamic studies
M - Bladder training, pelvic floor exercises, Oxybutynin (anti-cholinergic)
Proteinuria: causes (4)
Orthostatic - common postural proteinuria
Minimal change disease
GN
HTN
Nephrotic syndrome: triad, causes (3)
Proteinuria (hypoalbuminaemia)+ hyperlipidaemia + oedema
Causes - unknown, but some cases secondary to HSP, SLE, minimal change disease
Nephrotic syndrome features (3), Ix (3)
F - periorbital oedema, ascites, dyspnoea
Ix - dipstick, U & C, albumin, complement levels
Steroid sensitive nephrotic syndrome: Features (3), management (1), Complications (2)
F - proteinuria resolves with steroids, does not progress to renal failure, precipitated by resp infection
M - oral steroids
C - hypovolaemia, infection, hypercholesterolaemia
Management of steroid resistent Nephrotic syndrome: (3)
Refer to nephrologist Diuretics, Salt restriction, ACEI
Congenital nephrotic syndrome: feature (1), Complication (1), Managment (1)
F - presents in 1st 3 months of life
C - hypoalbuminaemia
M - unilateral nephrectomy + dialysis
Haematuria: characteristics if glomerular (3), if lower UT (3)
Glomerular - Brown, deformed RBCs, casts, proteinuria
UT - red, no proteinuria, unusual in kids
Haematuria causes: non glomerular (3), glomerular (3)
Non glomerular: infection (by far most common), trauma, stones, bleeding disorders
Glomerular: GN, IgA nephropathy, familial nephritis e.g. Alport syndrome
4 causes of acute nephritis
Post infectious/strep GN
HSP or other vasculitides
IgA nephropathy
Anti-GBM (v. rare)
Post-infectious/strep GN: definition, Ix (2)
D - causes a diffuse proliferative GN following a strep sore throat/ skin infection
Ix - Raised ASO + low C3 levels
HSP features (3)
Preceded by URTI (peak in winter months) palpable rash on buttocks, arthralgia, joint swelling, abdo pain
Alport syndrome features (2)
Most common familial nephritis (X-linked)
Nerve deafness + ocular defects
Vasculitides that affect the kidney: (3)
HSP most common, but aslo polyarteritis nodosa, Wegner granulomatosis
HTN causes (6)
Renal disease: renal parenchymal disease, PKD, RAS
Hyperthyroidism, Phaeo, Cushing, CAH
HTN features in kids (4)
headache vomiting convulsions facial palsy FTT HF
Renal masses causes: unilateral (3) bilateral (3)
Wilm's tumour Multicystic kidney obstructed hydronephrosis Bilat: ARPKD ADPKD tuberous sclerosis
Predisposing causes of Renal calculi in children (3)
Uncommon in childhood so when they occur need to figure out the predisposing factor:
UTI
structural anomalies of UT
Metabolic abnormalities
Renal calculi are either phosphate or Calcium containing, give examples of what would cause these types of stones (1, 2)
Phosphate - most common; occur with infection - commonly Proteus
Calcium containing - idiopathic hypercalciuria, distal renal tubular acidosis,
Features of renal calculi (3), management (4)
F - haematuria, loin pain, UTI, structural anomaly
M - spontaneous passing, high fluid intake, surgery, correction of anomaly, lithotripsy
Renal tubular disorders: Fanconi syndrome - general description, features (4)
Abnormalities of renal tubular function may occur at any point along nephron. Fanconi is generalized proximal tubular dysfunction - excessive loss of AAs, glucose, phosphate, Bicarb, sodium, calcium, urate.
F - polydispia + polyuria; salt depletion & dehydration; hyperchloraemic metabolic acidosis; rickets; FTT
Refer to Lissaeurs pg 342 for image of specific transport defects, but basically there can be a defect at any point & depending on that the substance that should have been reabsorbed/secreted will not. Give some examples (4)
Glycosuria
Cystinuria - renal calculi
Pseudohypoparathyroidism - due to increased phosphate reabsorption; obesity, depressed nasal bridge & short fing
RTA II - due to reduced bicarb reabsorption; metabolic acidosis + alkaline urine + growth failure
Bartter syndrome: due to reduced chloride reabsorption; hypokalaemia + hyponatremia + hypochloraemia + metabolic alkalosis
AKI causes: pre-renal (2) causes
Hypovolaemia - gastroenteritis, burns sepsis, haemorrhage
Circulatory failure
(pre renal causes most common)
Renal causes of AKI: vascular (2), tubular (2), glomerular (1), interstitial (2)
Vascular: vasculitides, HUS, renal vein thrombosis
Tubular: ATN, ischaemic, obstructive
glomerular: GN
Interstitial: pyelonephritis, interstitial nephritis
Post renal causes of AKI (2)
Obstruction:
Congenital - post urethral valves
acquired - blocked urinary catheter
Management of pre-renal failure(1) renal failure: if metabolic acidosis (1), hyperphosphataemia (2), hyperkalaemia (3)
Pre-renal - fluid replacement
Renal failure - 2 most common causes are HUS & ATN
metabolic acidosis - Sodium bicarb
Hyperphosphataemia - CaCO3 + dietary restriction
Hyperkalaemia - calcium gluconate if see ECG changes, glucose + insulin
Management of post-renal failure (2)
Nephrostomy after correction of electrolyte abnormalities
Indications for dialysis in renal failure: (4)
If conservative management fails severe hypo/hypernatremia HTN pulmonary oedem severe acidosis
HUS: cause (1), features (3), Management (1)
C - secondary to E. Coli O157 due to uncooked beef
F - Triad of renal failure + MAHA + TTP
M - dialysis
CKD causes (3)
Very uncommon in children
Most commonly caused by structural malformations
GN
Systemic disease
CKD features (5)
anorexia FTT polyuria/polydipsia incidential finding of proteinuria HTN unexplained normocytic normochromic anaemia
Management of CKD: diet (2), prevention of renal osteodystrophy (2), control acidosis and fluid balance (2), hormonal abnormalities (1)
Diet - cal supplements, NGT
Prevention of renal osteodystrophy - 2dary HPT develops > osteitis fibrosa cystica + osteomalacia > phosphate restriction via diet, CaCO3,
Acidosis - salt supplements + HCO3 + fluid
Hormonal abnormalities - get GH resistance - give recombinant HGH
