UTI and Renal Disease

Question 1

What investigations must be conducted for suspected renal kidney disease

Answer 1

Blood pressure and urine dipstick

Question 2

What can be identified on a urine dipstick

Answer 2

Protein, blood, glucose, ketones, white cells, nitrites

Question 3

How can dipstick inaccuracies occur

Answer 3

• Extreme exercise can cause proteinuria and haematuria
• Menstruation, indwelling catheters (always have infection)
• Protein levels change during the day

Question 4

What are host (human) factors that cause UTI

Answer 4

• Shorter urethra in females
• Obstruction - enlarged prostate, pregnancy, stones, tumours
• Neurological problems - incomplete emptying, residual urine
• Ureteric reflux - ascending infection from bladder

Question 5

What bacterial factors can cause UTI

Answer 5

• Fimbriae allow attachment to host epithelium
• K antigen permits production of polysaccharide capsule
• Haemolysins damage host membranes and cause renal damage
• Urease breaks down urea, creating a favourable environment for bacterial growth

Question 6

What is the most common bacteria in UTI

Answer 6

E. coli

Question 7

Describe the most common lower and upper UTI disease and how they present

Answer 7

• Lower UTI - cystitis
  - Present with dysuria, frequency, urgency, low grade fever
• Upper UTI - pyelonephritis
  - Present with fever, loin pain, and may have dysuria

Question 8

Distinguish between uncomplicated and complicated UTI

Answer 8

• Uncomplicated - defines as infection by a usual organism (E. coli) in a patient with a normal urinary tract and normal urinary function
  
  • Most non-pregnant women
• Complicated - UTI when one or more factors are present that predispose the person to persistent infection, recurrent infection or treatment failure
  
  • Abnormal urinary tract - vesicoureteric reflux, indwelling catheter
  • Virulent organism - Staph aureus
  • Impaired host defences - poorly controlled diabetes, immunosuppression
  • Impaired renal function

Question 9

Describe the investigations in complicated and uncomplicated UTI

Answer 9

• Uncomplicated UTI -
  no need to culture urine
• Complicated UTIs require urine culture
  
  • MSU - midstream specimen of urine
    
    • Avoid contamination from urethral opening
  • Catheter samples
  • Supra-pubic aspiration

Question 10

Describe the findings of urine testing

Answer 10

• Turbidity - cloudy would suggest UTI
• Dipstick testing - leucocyte esterase, nitrite, haematuria, proteinuria
  
  • Useful to exclude UTI if dipstick testing is negative and:
    
    • Over 3 years old
    • Men with mild/non-specific symptoms
    • Elderly women
  • Cannot confirm UTI with a positive dipstick testing as:
    
    • Older patients without features of infection - asymptomatic bacteriuria
    • Catheterised patients

Question 11

Describe asymptomatic bacteriuria

Answer 11

• Common in elderly patients
• Generally have pyuria (white blood cells in urine)
  
  • Will have positive dipstick, however no risk of increased morbidity
• Leads to unnecessary antibiotic treatment
• Only requires action in pregnancy

Question 12

What treatment should be given to uncomplicated, complicated and pyelonephritis

Answer 12

• 3 day course of antibiotics for uncomplicated UTI
  
  • Trimethoprim or nitrofurantoin to treat cystitis
• 5-7 day course for complicated lower UTI
  
  • Trimethoprim, nitrofurantoin
  • Post treatment follow up cultures
• 14 day course for acute pyelonephritis
  
  • Use agent with systemic activity (not nitrofurantoin)
    
    • Co-amoxiclav
    • Ciproflaxacin as a 7 day course
  • Possibly IV initially unless good oral absorption and patient well enough

Question 13

Explain how vesicoureteric reflux can occur

Answer 13

• Obstruction or abnormalities of the urinary tract can be due to pregnancy, transplant kidney, renal tract stones, indwelling catheters
• In children, structural issues more likely
• Repeated pyelonephritis in childhood can cause renal scarring
• All cause blockage of the bladder sphincter, therefore bladder more difficult to constrict
  - Increases pressure within bladder, causing reflux into kidney through ureter

Question 14

Describe how TB can effect urinary tract

Answer 14

• Calcification of the kidneys
• Caseous mass and abscess within kidney, which can burst through ureter down to bladder
• Strictures and beading of ureter

Question 15

Describe how schistosomiasis affects urinary tract

Answer 15

• Shistosoma haematobium associated with lower urinary tract disease
  
  • Chronic cystitis, calcification of the bladder, bladder cancer
• Other strains of shistosoma can cause GI hepatosplenic disease which can lead to glomerulonephritis

Question 16

List some systemic infections that can cause GN

Answer 16

• Post-infectious GN
• Endocarditis
• Hepatitis B and C
• HIV
• Immune mediated - immune reactions commonly affect the kidney

Question 17

Why are vaccinations given to patients with chronic kidney disease

Answer 17

• All patients with advanced CKD recommended vaccines as they are severely immunocompromised
• Influenza vaccine, hepatitis B vaccine