Tubulointerstitial Disease Flashcards
Renal tubular acidosis causes what acid-base balance? (be specific)
Hyperchloraemic metabolic acidosis
What is the anion gap in the metabolic acidosis of renal tubular acidosis?
Normal
What is type 3 renal tubular acidosis?
A rare combination of types 1 and 2
What is the commonest cause of type 1 renal tubular acidosis in adults?
Autoimmune disease (e.g. SLE, Sjogren’s)
What are some examples of drugs which may cause type 1 renal tubular acidosis?
Lithium, amphotericin B
Fanconi syndrome is a cause of which type of renal tubular acidosis?
Type 2
What are some examples of drugs which may cause type 2 renal tubular acidosis?
Heavy metals, acetazolamide, tetracyclines
Diabetic nephropathy is a recognised cause of which type of renal tubular acidosis?
Type 4
What are some examples of drugs which may cause type 4 renal tubular acidosis?
Potassium-sparing diuretics, beta blockers, NSAIDs
Addison’s disease is a recognised cause of which type of renal tubular acidosis?
Type 4
What are the initial symptoms of renal tubular acidosis?
GI symptoms, such as decreased appetite, vomiting and abdominal pain
How may renal tubular acidosis eventually lead to shock?
Metabolic acidosis causes vasodilation of the peripheral arterioles
What is the most recognised complication of type 1 renal tubular acidosis?
Nephrocalcinosis with calcium phosphate stones
What is the most recognised complication of type 2 renal tubular acidosis?
Rickets or osteomalacia
Describe what is meant by type 1 renal tubular acidosis?
There is a failure to excrete H+ ions in the distal tubule of the nephron
What happens to the pH of urine in renal tubular acidosis?
It is increased (alkaline)
How is type 1 renal tubular acidosis treated?
Oral sodium bicarbonate or sodium citrate
Describe what is meant by type 2 renal tubular acidosis?
There is a failure to reabsorb bicarbonate in the proximal tubule of the nephron
Which electrolyte abnormality is seen in both type 1 and 2 renal tubular acidosis?
Hypokalaemia
How is type 2 renal tubular acidosis treated?
High doses of bicarbonate supplementation
Type 4 renal tubular acidosis is due to what?
Hypo-aldosteronism, causing hyperkalaemia
How is type 4 renal tubular acidosis treated?
Treating the underlying cause and correcting the potassium level
Fanconi syndrome is dysfunction of which part of the renal tubule?
Proximal tubule
Fanconi syndrome leads to the loss of what things in the urine?
Amino acids, glucose, phosphate and bicarbonate
What is the most common cause of AKI seen in clinical practice?
Acute tubular necrosis
What are the two main types of acute tubular necrosis?
Ischaemic and nephrotoxic
How does acute tubular necrosis present?
With an AKI
Muddy brown casts in the urine are associated with what diagnosis?
Acute tubular necrosis
How is acute tubular necrosis managed?
Treat the underlying cause and manage supportively
Interstitial nephritis is inflammation of the renal interstitium. What are the two main causes for this?
Direct toxicity or an acute hypersensitivity reaction
What are some examples of drugs known for causing interstitial nephritis?
Antibiotics, NSAIDs, allopurinol, diuretics
Interstitial nephritis usually occurs how long after starting a drug?
15 days
How does interstitial nephritis present?
Mild renal impairment, and systemic features such as a rash, fever and arthralgia
What is a common feature on FBC of someone with interstitial nephritis?
Eosinophilia
What are some features that may be seen on urine microscopy of someone with interstitial nephritis?
Sterile pyuria and white cell casts
A biopsy of interstitial nephritis shows what in the interstitial space?
Oedema and inflammatory cell infiltrate
How is interstitial nephritis managed?
Treat/stop the underlying cause
If there has been no improvement to interstitial nephritis after one week, what medication can be given as a trial for a month?
Prednisolone
Interstitial nephritis may occur associated with what other condition in young females?
Uveitis
Chronic interstitial nephritis is most common in individuals with what?
Abnormal renal anatomy
What is the commonest cause of chronic interstitial nephritis?
Analgesic nephropathy
What are the 3 main clinical features of renal papillary necrosis?
Proteinuria, haematuria and loin pain
What are some causes of renal papillary necrosis?
Pyelonephritis, diabetic/obstructive/analgesic nephropathy, sickle cell anaemia
‘Cup and spill’ appearance on IV urogram is suggestive of what diagnosis?
Renal papillary necrosis
Acute crystal nephropathy (AKI due to acute uric acid precipitation) is usually due to what?
Tumour lysis syndrome
How can the risk of acute crystal nephropathy be reduced in individuals undergoing chemotherapy?
Give allopurinol before chemotherapy
How can the risk of radiocontrast nephropathy be reduced?
Stop other nephrotoxic agents and keep patients hydrated with 0.9% IV saline both pre and post procedure
When does contrast nephropathy typically occur?
2-5 days after administration of contrast dye
A massively raised CK is most suggestive of what diagnosis?
Rhabdomyolysis
What are the two main complications of rhabdomyolysis?
AKI and hyperkalaemia
Tea/cola coloured urine suggests what?
Myoglobinuria
What happens to calcium and phosphate levels in individuals with rhabdomyolysis?
Phosphate is high, calcium is low
What type of acid-base disorder is associated with rhabdomyolysis?
Metabolic acidosis
How is rhabdomyolysis treated initially?
Urgent management of hyperkalaemia and IV fluid therapy
