Clinical Presentations

Question 1

What are some causes of transient or spurious non-visible haematuria?

Answer 1

• urinary tract infection
• menstruation
• vigorous exercise (this normally settles after around 3 days)
• sexual intercourse

Question 2

What are some causes of persistent non-visible haematuria?

Answer 2

• cancer (bladder, renal, prostate)
• stones
• benign prostatic hyperplasia
• prostatitis
• urethritis e.g. Chlamydia
• renal causes: IgA nephropathy, thin basement membrane disease

Question 3

What are the causes of spurious cases of haematuria - (red/orange urine, where blood is not present on dipstick)?

Answer 3

• foods: beetroot, rhubarb
• drugs: rifampicin, doxorubicin

Question 4

How is haematuria tested?

Answer 4

• urine dipstick is the test of choice for detecting haematuria
  
  • persistent non-visible haematuria is often defined as blood being present in 2 out of 3 samples tested 2-3 weeks apart
• renal function, albumin:creatinine (ACR) or protein:creatinine ratio (PCR)
• blood pressure should also be checked
• urine microscopy may be used but time to analysis significantly affects the number of red blood cells detected

Question 5

What is the indication for urgent referral with haematuria?

Answer 5

Urgent referral (i.e. within 2 weeks)

• Aged >= 45 years AND:
• unexplained visible haematuria without urinary tract infection, or
• visible haematuria that persists or recurs after successful treatment of urinary tract infection
• Aged >= 60 years AND have unexplained nonvisible haematuria and either dysuria or a raised white cell count on a blood test

Question 6

What is the indication for a non-urgent referral for haematuria?

Answer 6

• Non-urgent referral
• Aged 60 >= 60 years with recurrent or persistent unexplained urinary tract infection
• Since the investigation (or not) of non-visible haematuria is such as a common dilemma a number of guidelines have been published. They generally agree with NICE guidance, of note:
  
  • patients under the age of 40 years with normal renal function, no proteinuria and who are normotensive do not need to be referred and may be managed in primary care

Question 8

What are some causes of hyperkalaemia?

Answer 8

• acute kidney injury
• drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin**
  
  • *beta-blockers interfere with potassium transport into cells and can potentially cause hyperkalaemia in renal failure patients - remember beta-agonists, e.g. Salbutamol, are sometimes used as emergency treatment
  • **both unfractionated and low-molecular weight heparin can cause hyperkalaemia. This is thought to be caused by inhibition of aldosterone secretion
• metabolic acidosis
• Addison’s
• rhabdomyolysis
• massive blood transfusion
• Foods that are high in potassium:
  
  • salt substitutes (i.e. Contain potassium rather than sodium)
  • bananas, oranges, kiwi fruit, avocado, spinach, tomatoes