Renal Disease Flashcards
What is AKI and how is it’s severity assessed in children?
Rapid rise in creatinine or development of oliguria/anuria. Severity is based on the paediatric RIFLE criteria that looks at magnitude of changes in GFR, urine output and outcome measures.
What are the common causes of AKI in children in the developed world?
Developed countries:
• Secondary to cardiac surgery
• Bone marrow transplantation
• Toxicity (NSAIDs), aminoglycosides, vancomycin, Aciclovir and contrast)
What are the common causes of AKI in the developing world?
Developing world: • Vomiting and Diarrhoea • Glomerulonephritis • Drug induced haemolysis in G6PD • Snake bite • Haemolytic uraemic syndrome • Myoglobinuria
What are the common causes of acute tubular necrosis in children?
Acute tubular necrosis causes: crush injury, burns, dehydration, shock, sepsis and malaria.
How does AKI present in children?
Anuria, not eating or drinking, systemically unwell
Red cell casts on MSU = GN
Labstix on MSU = haemo/myoglobinuria
Chemistry
Raised potassium, creatinine, urea and phosphate
Decreased calcium, sodium and chloride
How should suspected AKI in children be investigated?
MSU Urine output ECG for signs of hyperkalaemia Us and Es and Blood gas Platelets and clotting studies Urine plasma osmolality BP
Abdominal US and AXR
How should AKI be managed in children?
Treat cause promptly
Treat shock and dehydration if good urine/plasma osmalitiy as it will respond well to rehydration. If the ratio is low, try furosemide
If very high blood pressure, then give nitroprusside
Fluid requirement should be worked out by their daily requirement plus rehydration
Monitor for hyperkalaemia
What is haemolytic uraemic syndrome and what causes it?
This is very rare and occurs due to microangiopathic haemolytic anaemia triggered by shiga toxin producing E. coli. It is characterised by a triad to haemolytic anaemia, AKI and thrombocytopenia.
Acquired from food or water contaminated with E. Coli, shigella or campylobacter.
These bacteria release toxins which bind to the glomerular epithelium stimulating apoptosis and clotting. The clots form all over the body resulting in haemolytic anaemia.
How does haemolytic uraemic syndrome present and how should it be investigated?
Schistocytes, burr cells, thrombocytopenia, AKI
95% of cases associated with diarrhoea
Children usually < 3 years and present in summer
Abdominal pain Raised LDH Decreased haptoglobin Colitis Oliguria and haemoglobinuria Nausea and vomiting Fatigue and oedema CNS signs encephalopathy and coma
Investigations
Full blood count: anaemia, thrombocytopaenia, fragmented blood film
U&E: acute kidney injury
Stool culture looking for evidence of STEC infection
PCR of stool culture for Shiga toxins
How is haemolytic uraemic syndrome managed?
Treatment is supportive e.g. Fluids, blood transfusion and dialysis if required,
there is no role for antibiotics, despite the preceding diarrhoeal illness in many patients
The indications for plasma exchange in HUS are complicated. As a general rule plasma exchange is reserved for severe cases of HUS not associated with diarrhoea
Eculizumab (a C5 inhibitor monoclonal antibody) has evidence of greater efficiency than plasma exchange alone in the treatment of adult atypical HUS
What causes chronic renal disease in children?
Congenital Dysplastic kidneys Pyelonephritis Glomerulonephritis Recurrent UTI Reflux nephropathy - damage from posterior urethral valves AKI that causes cortical necrosis
What features do you get from chronic renal disease in children?
Weakness Tiredness and anaemia Vomiting Headaches Restlessness Twitches Raised BP and retinopathy due to that Failure to thrive Seizures and coma
How should suspected chronic kidney disease be investigated?
Must monitor growth
BP, Us and Es, Ca (often decreased) and Phos (often increased)
How is chronic renal disease managed?
Refer to specialists and get dieticians helps
Make sure high protein diet
Vitamins and maybe GH
Acidosis doesn’t need treating if bicarb is > 20mmol/L
What bone manifestations can occur in chronic renal disease in children?
Be wary of renal osteodystrophy – bone malformations due to low Vit D, Ca and high PO.
Treat raised phosphate with calcium binder, should also treat the low Ca with Vitamin D.
