Renal Flashcards
Q: What are the causes of normal anion gap (hyperchloraemic) metabolic acidosis?
Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
Renal tubular acidosis
Drugs: e.g. acetazolamide
Ammonium chloride injection
Addison’s disease
Q: What conditions are associated with a raised anion gap in metabolic acidosis?
Lactate: shock, hypoxia
Ketones: diabetic ketoacidosis, alcohol
Urate: renal failure
Acid poisoning: salicylates, methanol
Q: What causes metabolic alkalosis?
Metabolic alkalosis may be caused by a loss of hydrogen ions or a gain of bicarbonate, mainly due to problems in the kidney or gastrointestinal tract.
Q: What are the causes of metabolic alkalosis?
Vomiting/aspiration (e.g. peptic ulcer leading to pyloric stenosis, nasogastric suction)
Diuretics
Liquorice, carbenoxolone
Hypokalaemia
Primary hyperaldosteronism
Cushing’s syndrome
Bartter’s syndrome
Congenital adrenal hyperplasia
Q: What are the common causes of respiratory acidosis?
COPD
Decompensation in other respiratory conditions (e.g. life-threatening asthma, pulmonary oedema)
Sedative drugs: benzodiazepines, opiate overdose
Q: What are the common causes of respiratory alkalosis?
Anxiety leading to hyperventilation
Pulmonary embolism
Salicylate poisoning
CNS disorders: stroke, subarachnoid haemorrhage, encephalitis
Altitude
Pregnancy
Q: What percentage of drug-induced acute kidney injury is accounted for by acute interstitial nephritis?
A: Acute interstitial nephritis accounts for 25% of drug-induced acute kidney injury.
Q: What are the common drug causes of acute interstitial nephritis?
Penicillin
Rifampicin
NSAIDs
Allopurinol
Furosemide
Q: What systemic diseases can cause acute interstitial nephritis?
Systemic lupus erythematosus (SLE)
Sarcoidosis
Sjogren’s syndrome
Q: What infections can cause acute interstitial nephritis?
Hanta virus
Staphylococci
Q: What is seen in the histology of acute interstitial nephritis?
A: Marked interstitial oedema and interstitial infiltrate in the connective tissue between renal tubules.
Q: What are the features of acute interstitial nephritis?
Fever
Rash
Arthralgia
Eosinophilia
Mild renal impairment
Hypertension
Q: What are the investigation findings in acute interstitial nephritis?
Sterile pyuria
White cell casts
Q: What are the symptoms of tubulointerstitial nephritis with uveitis (TINU)?
Fever
Weight loss
Painful, red eyes
Q: What is found on urinalysis in tubulointerstitial nephritis with uveitis (TINU)?
A: Urinalysis is positive for leukocytes and protein.
Q: What is one of the best ways to differentiate between acute kidney injury (AKI) and chronic kidney disease (CKD)?
A: Renal ultrasound, as most patients with CKD have bilateral small kidneys.
Q: What are exceptions to the rule of bilateral small kidneys in CKD?
Autosomal dominant polycystic kidney disease
Diabetic nephropathy (early stages)
Amyloidosis
HIV-associated nephropathy
Q: What other feature suggests CKD rather than AKI?
A: Hypocalcaemia (due to lack of vitamin D).
Q: What does acute kidney injury (AKI) describe?
A: AKI describes a reduction in renal function following an insult to the kidneys.
Q: How are the causes of AKI traditionally divided?
A: Causes of AKI are divided into prerenal, intrinsic, and postrenal causes.
Q: What is a major cause of AKI?
A: Ischaemia (lack of blood flow) to the kidneys is a major cause of AKI.
Q: What are some examples of prerenal causes of AKI?
Hypovolaemia secondary to diarrhoea/vomiting
Renal artery stenosis
Q: What are some examples of intrinsic causes of AKI?
Glomerulonephritis
Acute tubular necrosis (ATN)
Acute interstitial nephritis (AIN)
Rhabdomyolysis
Tumour lysis syndrome
Q: What are some examples of postrenal causes of AKI?
Kidney stone in ureter or bladder
Benign prostatic hyperplasia
External compression of the ureter