Kids and the Kidney Flashcards
What is normal HTN in kids, and how is it measured?
Changes based on age and height.
- normal <90th centile
- pre-HTN 90th-95th or >120/80
- HTN
- stage 1 = 55mmHg above 95th-<99th
- stage 2 = 5mmHg above 99th
Symptomatic HTN - regardless on the measurement take seriously (e.g. headache and vomiting).
measure using the largest cuff you can get between the shoulder and elbow. Often high because cuff is too small.
don’t measure in everyone only kids who are unwell or have systemic disease (e.g. CVD/kidney disease)
What are some common presentations of children with HTN?
- asymptomatic
- raised ICP symptoms:
- headaches
- blurred vision
- malignant HTN (medical emergency)
- CCF
- APO
- encephalopathy
- treat by admitting to reduce BP
Examination:
- end organ:
- LVH
- pulmonary oedema
- retinopathy
- neuro
- Cause:
- 4 limb BP (coarctation)
- abdominal masses (phae)
- dysmorphic features (cardiac abnormalities)
- urinanalysis (secondary and end organ effects)
What is the definition and classifications of Haematuria in Children?
- microscopy = >10RBC/µL
- very common with 10% of the population at any time
- macroscopic = >1,000,000 RBC/µL
What is the Presentation of a kid with haematuria related to kidney disease and what does it make you think of?
Generally:
- Pain - think structural/urological
- BP/HTN - think renal
- Proteinuria - think renal
Some specifics:
- febrile illness - UTI
- rash/brusing - HSP, ITP, bleeding disorder
- oedema/HTN - nephritic
- loin pain - calculus, hydronephrosis, PCKD, wilms
- bloody diarrhoea - haemolytic uraemic syndrome
- isolated microhaematuria (GP with 3 confirmations get f/u)
List some Causes of Haematuria in Children
- artefact (microhaematuria common)
- transient
- UTI
- medical renal disease = usually painless
- hypercalciuria (calculi)
- thin BM disease (BM collagen deficiency due to missing collagen 4 gene) - affects 1 parent
- alport syndrome - defect in X linked collagen 4 gene
- males
- sensorineural hearing loss
- renal failure
- GN (IgA, HSP)
- coagulopathy
- urological disease = painful
- calculi
- tumour (wilms tumour - nephroblastoma)
- stricture
- trauma
Definition of Proteinuria
- 24 hour collection >160mg/day
- spot collection = less feasible
- done early in the morning
- measures protein:creatinine ratio
- N <20mg/mmol
- N ACR <3.5mg/mmol
degree of proteinuria proportionate to severity of renal failure due to hyperfiltration injury and RAAS.
- loss of glomeruli, glom HTN, podocyte loss, more bare GBM, progressive scarring (and repeat)
- ACE and ARB stop HTN
What are some causes of proteinuria?
- Transient
- illness
- UTI
- Benign - orthostatic
- especially tall adolescents
- no long term consequences
- renal disease
- acute/chronic kidney disease
- GN
- DM
- tubular proteinuria
- acute/chronic kidney disease
Differentiate between Nephrotic syndrome and Nephritic Syndrome, give some examples of each.
Nephrotic Syndrome
- nonproliferative
- Oedema
- PrOteinuria 24hr or spot Pr:Cr
- hypOalbuminemia <25g/L
- High triglycerides/lipids (hypercholestrolemia)
- Minimal change disease the main childhood cause
- 2-10
- triggered by infection
- 90% respond to steroids
- membranoproliferative GN
- 2 strips - tramtracking (proliferation around the membrane)
- FSGS (adult minimal change, less responsive)
- SLE
Nephritic Syndrome
- proliferative (dark urine, oliguria, HTN)
- Reduced GFR (oliguria)
- Hematuria (cast and dysmorphic)
- Increased BP
- Proteinuria
- Post infectious (post strep throat) - classic
- 3 weeks later after an URTI or GBS skin
- streptolysin O titre
- antibodies caught in the kidney
- treat with frusemide
- main risk HTN and K+
- IgA nephropathy
- 3 days later
- inflammatory
- IgA in mesangium
- Crescenteric
- wegners c-ANCA
- Goodpastures anti-GBM antibodies
- HSP - purpura on the bum
What are the Special Hs in Kidney disease? Describe them.
HUS (haemolytic uraemic syndrome)
- bloody diarrhoea
- often afebrile
- toxin mediated (shiga-toxin produceing usually E. coli)
- thrombotic microangiopathy (mechanical destruction)
- anaemia
- thrombocytopenia
- DCT (coombs) negative
- AKI, INR and other organs (CNS, pancreatitis, myocarditis)
HSP (Henoch-Scholein Purpura)
- small vessel vasculitis affecting the GIT, skin, and joints
- looks like IgA GN
- exclude bleeding disorders and sepsis (rule out meningococcal)
- consider steroids
What are the Major Causes of CKD in kids? What are the complications?
- GN major cause
- Hypoplasia
- Posterior Urethral Valve
Complications:
- anaemia
- bone disease (hyperparathyroidism)
- growth impairment
- others:
- electrolytes (hydration, K, Na)
- acid-base
- continence and body image
What is an approach to AKI in children?
Pre-renal:
- vascular insufficiency (common)
Renal:
- ATN
- GN
- TIN (tubulointerstitial nephritis)
- HUS
Post-Renal:
- obstruction (BOO in boys, posterior urethral junction)
Features:
- oedema
- HTN
- arrythmias
- hyperventilation
- uremia
- phosphate (tetany, seizures)
Non-renal causes of high BP in children?
- Conn’s
- Cushings
- Phaechromocytoma
- Raised ICP
- coarctation of the aorta
- renal artery stenosis
Initial Management for a child with high BP?
- admit and Ix
- renal function, urine, adrenal, TFT, Renal U/S, Echo.
What is your management for someone with Post-Strep Glomerulonephritis? What tests would you order?
Investigations:
- Streptolysin O antibodies ASOT (2 weeks post)
- ANA (Acute Phase Reactant) - always have discussion, no alarm.
- ANCA (wegners and goodpastures)
- MSU phase contrast (microscopy) urinalysis:
- casts (RBC cast)
- haematuria
- streptococcal throat swab and treat it with penicillin (low grade colonization?)
- complements (C3/C4) - lower C3, normal C4
- U&Es
- FBC
Treatment:
- treat HTN/possible HF - diuretics
- frusemide to unload fluid.
- also gets rid of K+
- fluid and salt restrict
- no immunosuppression
- rarely need to use dialysis - mostly self-limiting.
A 4 year old boy been a bit puffy for 3 weeks soon after recovering from an URTI. Thought allergies and treated with antihitamines. Puffiness is now obvious, especially in the morning. On examination he has generalised oedema with pitting lower limb oedema. His feet are a bit cool. What is the dianosis? What is the examination thing you would do?
DDx:
- nephrotic syndrome (main one) - look for proteinuria
- heart failure or liver disease (hypoalbuminuria)
Treatment:
- give steroids in high doses (gastritis so start ranitidine) - prednisolone - 4 weeks 90% respond
- prevent complications:
- aspirin (hypercoagulation)
- penicillin
- frusemide (rarely on its own, in kids with less circulatory collapse) and IV albumin (concentration - slight increase in oncotic pressure to use frusemide to get water out) for symptoms
