HUS, Chronic Renal Failure, Hypospadias Flashcards
Haemolytic Uraemic Syndrome (HUS) triad?
Consists of a triad:
1) Acute renal failure
2) Microangiopathic haemolytic anaemia
3) Thrombocytopenia
Aetiology + Ex of HUS?
Secondary to GI infection from:
1) E.coli O157
2) Contact from farm animals/eating uncooked beef
3) Less often - Shigella
Ex: Rare, mortality 5-10%
Pathophysiology of HUS?
- Follows prodrome of bloody diarrhoea
- Toxins from organism enter GI mucosa and localises preferentially to the endothelial cells of the kidney where it causes intravascular thrombogenesis.
- Coagulation cascade is activated and clotting is normal (unlike DIC).
- Platelets are consumed in the process and microangiopathic haemolytic anaemia results from damage to red blood cells as they try and circulate through the occluded microcirculation.
- Other organs - brain, heart, pancreas - may be involved
Clinical presentation of HUS? Ddx?
Typical - profuse diarrhoea that turns bloody 1-3 days later
Atypical - those infected with E.coli O157 may be asymptomatic (familial and frequent relapses)
- Fever, abdominal pain and vomiting
Ddx: Thrombotic thrombocytopenia purpura
Diagnosis of HUS?
1) FBC - thrombocytopenia
2) U & E’s - raised creatinine, K+, phosphate + low Ca2+, Na+
Treatment of HUS?
Typical diarrhoeal:
1) Fluid resuscitation
2) Red blood cell transfusion
3) Dialysis
4) May be persistent proteinuria and development of hypertension and declining renal function in subsequent years - follow-up required
Atypical non-diarrhoeal:
1) Plasma exchange
2) High risk of hypertension and chronic renal failure - associated with high mortality
Chronic Renal Failure definition + Ex?
Longstanding, usually progressive, impairment in renal function for more than 3 months. Chronic renal failure defined as a GFR <15ml/min per 1.75^3.
Ex: Much less common in children than in adults
Incidence of only 10 per million of the child population each year.
Aetiology of Chronic Renal failure?
1) Congenital and familial causes (more common than acquired disease)
2) Congenital dysplastic kidneys
3) Glomeruloephritis
4) Pyelonephritis
5) Reflux nephropathy
Clinical presentation of Chronic Renal Failure?
1) Anorexia and lethargy
2) Polydipsia and polyuria
3) Failure to thrive
4) Bone deformities due to renal ricketts/osteodystrophy
5) Hypertension
6) Proteinurea
7) Acute-on-Chronic renal failure - anaemia, growth failure, + renal osteodystrophy
Diagnosis of Chronic Renal Failure?
1) U & E’s
2) Ultrasound
Treatment of Chronic Renal Failure?
Aim of treatment - prevent symptoms and metabolic abnormalities as well as promoting normal growth and development as well as preserving residual renal function.
1) Diet - Calories supplements through NG/PEG to optimise growth, protein intake should be sufficient maintaining growth and albumin.
2) Prevention of renal osteodystrophy: Phosphate retention and hypocalcaemia due to decreased activation of Vitamins D - leads to secondary hyperparathyroidism resulting in osteitis fibrosa and osteomalacia - WEAK BONES.
- Dietary phosphate restriction and calcium carbonate (phosphate binder) + activated Vitamin D supplement (Calcitrol) to help.
3) Salt/water balance and acidosis: Regular fluids and sodium bicarbonate
4) Anaemia - Reduced erythropoietin and circulation of toxic metabolites to bone marrow = anaemia. Use RECOMBINANT HUMA ERYTHROPOIETIN .
5) Dialysis - Peritoneal - less disruptive and done at home by parents. Haemodialysis - done in hospital 3/4 times weekly.
6) Transplant - when end-stage failure has been reached - min weight of 10kg required, to avoid renal vein thrombosis, better outcome if donor is relative. Lifelong immunosuppression required to prevent rejection - combo of prednisolone, tacrolimus and azathioprine.
Hypospadias def, Ex and PPx?
- Congenital abnormality of penis.
- 1 every 200 boys (common)
- In male foetus - urethral tubularisation occurs in a proximal to distal direction under influence of foetal testosterone. Failure to complete this process leaves the urethral opening proximal to the normal meatus on the glans - this is hypospadias.
Presentation and diagnosis of Hypospadias?
1) Ventral urethral meatus - In most cases urethra opens on or adjacent to the glans penis but in severe cases the opening may be on the penile shaft or in the perineum.
2) Hooded dorsal foreskin - Foreskin has failed to fuse ventrally
3) Chordee - Ventral curvature of the shaft of the penis - most apparent on erection.
Dx: Clinical
Treatment of Hypospadias?
1) Surgery: Correction often undertaken before 2 yrs - aims of surgery to produce:
- a terminal urethral meatus so that boy can micturate in standing position
- a straight erection and normal looking penis.
