Renal Disease Flashcards
Define AKI
Common investigations for renal disease
Urine dip -> blood, protein, leucocytes, nitrates, glucose
Renal USS (only if pyelonephritis or if no identifiable cause)
Outline nephrotic syndrome
Nephrotic syndrome = low albumin, peripheral oedema, proteinuria
· Most commonly caused by Minimal Change Disease: Renal histology is usually NORMAL on light microscopy but fusion of podocytes is seen on electron microscopy
- note that Orthostatic proteinuria = common transient cause of proteinuria -> measure urine protein: creatinine ratio (PCR) in a series of early morning urine specimens
Signs and symptoms of nephrotic syndrome
1st: Periorbital oedema- particularly on waking (often the EARLIEST sign)
2nd: other oedema: Scrotal or vulval, leg and ankle oedema, Ascites
* Breathlessness- due to pleural effusions and abdominal distension
* Infection e.g. peritonitis, septic arthritis or sepsis due to loss of protective immunoglobulins in the urine
* May have haematuria
Steroid-sensitive nephrotic syndrome (80-95% nephrotic syndrome): responds to ≤6 weeks of steroids
Steroid-resistant nephrotic syndrome: does not respond -> further analysis and specialist care
Investigations for nephrotic syndrome
- Urine dipstick testing, urea, U&Es, urine MC&S, urinary sodium
- FBC, ESR, creatinine, albumin, cholesterol
- Complement levels (C3, C4)
- Anti-streptolysin O or anti-DNase B titres (recent streptococcal throat infection)
- ANA - positive in vasculitis such as SLE
- HBV, HCV, malaria screen
Management
Admit if it is a relapse, otherwise admit depending on how ill they are
Twice daily weights and urine input output checked
1st -> oral prednisolone for 4-6 weeks (after 4 weeks, reduce dose or alternate days for 4 wks and slowly weaned off)
* Renal histology of steroid-sensitive nephrotic syndrome = normal on light microscopy
* However, on electron microscopy, fusion of podocytes is seen (minimal change disease)
Patients should be on a fluid restricted and low-salt diet
May need albumin and furosemide if very advanced
If UNRESPONSIVE after 4-6 weeks of corticosteroid therapy OR have atypical features, may have a more complex diagnosis and need a renal biopsy
- Give ciclosporin or tacrolimus and methylprednisolone
- Prophylactic penicillin may be given
- Ensure up to date with immunisations
- On discharge safety net with increased abdo pain, reduced urine e output, puffiness markedly increased
Complications of nephrotic syndrome
Hypovolaemia
* As the oedema forms, the intravascular compartment may become depleted
* The child may complain of abdominal pain and feel faint
* The body will respond with peripheral vasoconstriction and urinary sodium retention
* Low urine sodium (< 10mmol/L) and high haematocrit are suggestive of hypovolaemia
TREATMENT: IV 0.9% saline or 4.5% albumin solution:
* If SEVERE- IV 20% albumin infusion with furosemide may be needed
* NOTE: this can precipitate pulmonary oedema and hypertension from fluid overload, and the diuretics could worsen the hypovolaemia
Thrombosis
- Hypercoagulable state results from:
- Urinary losses of antithrombin III (main anticoag mech hence huge risk of DVT)ys
- Thrombocytosis (may be worsened by steroid therapy)
- Increased synthesis of clotting factors
- Increased blood viscosity from raised haematocrit
- This may affect the lungs, brain, limbs and splanchnic circulation with potentially catastrophic results
Infection
* High risk of infection by capsulated bacteria (especially Pneumococcus)
* Pneumococcal and seasonal influenza vaccination is recommended
* Chickenpox and shingles should be treated with acyclovir
Hypercholesterolaemia
Correlates inversely with serum albumin
Cause is unknown
Prognosis of nephrotic syndrome
Prognosis:
Can resolve directly, have infrequent relapses and have frequent relapses and will be steroid-dependent
Steroid-sparing agents may be considered if relapses are frequent e.g.:
- Immunomodulators e.g. levamisole
- Alkylating agents e.g. cyclophosphamide
- Calcineurin inhibitors e.g. tacrolimus, ciclosporin A
- Immunosuppressants e.g. Mycophenolate mofetil
Steroid-resistant nephrotic syndrome
Congenital Nephrotic Syndrome
- Presents in the first 3 months of life
- RARE
- More common in consanguineous families (recessively inherited)
- Associated with high mortality due to complications with low albumin.
- Albuminuria is so severe that unilateral nephrectomy may be necessary for its control, followed by dialysis for stage 5 CKD which is continued until the children is no longer nephrotic and old enough for renal transplantation.
