Renal Other Flashcards
What is renal tubular acidosis?
Metabolic acidosis due to pathology in the tubules of the kidney (responsible for balancing hydrogen + bicarbonate ions)
What causes type 1 renal tubular acidosis?
Distal tubule unable to excrete hydrogen ions
Causes:
- genetic
- SLE
- Sjogrens
- primary biliary cirrhosis
- hyperthyroidism
- sickle cell
- Marfan’s
How does type 1 renal tubular acidosis present?
Failure to thrive in children
Hyperventilation (compensation)
CKD
Osteomalacia
What are the biochemical findings in type 1 renal tubular acidosis?
Hypokalaemia
Metabolic acidosis
High urinary pH (above 6)
How is type 1 renal tubular acidosis treated?
Oral bicarbonate
What causes type 4 renal tubular acidosis?
Reduced aldosterone:
- adrenal insufficiency
- ACE inhibitors
- spironolactone
- SLE
- diabetes
- HIV
What are the biochemical findings in type 4 renal tubular acidosis?
Hyperkalaemia
High chloride
Metabolic acidosis
Low urinary pH
How is type 4 renal tubular acidosis treated?
Fludrocortisone
Sodium bicarbonate + treatment of hyperkalaemia may also be required
What causes acute interstitial nephritis?
Hypersensitivity reaction to:
- drugs (NSAIDs or antibiotics)
- infection
What are the features of acute interstitial nephritis?
AKI + hypertension May be features of hypersensitivity: - rash - fever - eosinophilia
How is acute interstitial nephritis managed?
Treat underlying cause
Steroids to reduce inflammation
What causes haemolytic uraemic syndrome (HUS)?
Shiga toxin, usually produced by E.coli 0157
Can also be produced by shigella
What increases the risk of developing HUS following infection?
Use of antibiotics and anti-motility drugs e.g. loperamide
What is the classic triad of HUS?
Haemolytic anaemia
AKI
Low platelets (thrombocytopenia)
What are the clinical features of HUS?
Brief gastroenteritis with bloody diarrhoea About 5 days later: - reduced urine output - haematuria or dark brown urine - abdominal pain - lethargy + irritability - confusion - hypertension - bruising
How is HUS managed?
Medical emergency –> supportive management
- antihypertensives
- blood transfusions
- dialysis
What is rhabdomyolysis?
Breakdown of skeletal muscle cells releasing contents into the blood:
- myoglobin (–> myoglobinuria)
- potassium
- phosphate
- creatinine kinase
What are the consequences of breakdown product release in rhabdomyolysis?
Potassium –> hyperkalaemia –> arrhythmias
Myoglobin is toxic to kidneys –> AKI
What are the signs and symptoms of rhabdomyolysis?
Muscle aches and pains Oedema Fatigue Confusion (esp in elderly) Red-brown urine
Which investigations help diagnose rhabdomyolysis?
CK will be in thousands
Red-brown urine –> positive for blood
U&Es for kidney injury + potassium
ECG essential
What causes rhabdomyolysis?
Prolonged immobility
Extremely rigorous exercise
Crush injuries
Seizures
How is rhabdomyolysis managed?
IV fluids mainstay of treatment Treat hyperkalaemia Consider: - IV sodium bicarb to protect kidneys - IV mannitol to increase GFR
