Urinary 8 - UTIs Flashcards
Name the normal defence mechanisms of the body against UTIs:
- Antimicrobial secretions
- Regular flushing during micturition
What factors may predispose someone to UTIs?
- Shorter urethra (women)
- Obstruction (enlarged prostate, pregnancy, stones, tumours)
- Neurological (incomplete emptying = residual urine)
- Vesicoureteric reflux
Name 4 factors which may obstruct the urinary tract:
- Enlarged prostate
- Pregnancy
- Stones
- Tumours
Which antigens allow some E coli to produce a polysaccharide capsule, to protect it against host defences?
K antigen
What is the importance of K antigens to E coli survival in the urinary tract?
Allows E coli to produce a polysaccharide coat, to resist host defences ie antibacterial secretions.
Name 3 types of UTI associated with the lower urinary tract:
- Bacterial cystitis
- Abacterial cystitis
- Prostatitis
Name 2 types of UTI associated with the upper urinary tract:
- Acute pyelonephritis
- Chronic interstitial nephritis
List the symptoms associated with cystitis:
- Increased freq. of urination
- Dysuria (pain or burning sensation on urination)
- Low grade fever
How can you tell bacterial and abacterial cystitis apart?
Bacteriuria test
List the symptoms associated with Prostatitis:
- Fever
- Dysuria (pain or burning sensation on urination)
- Increased freq. of urination
- Perineal and low back pain
List the symptoms associated with Acute Pyelonephritis:
- Increased freq. of urination
- Dysuria (pain or burning sensation on urination)
- Fever
- Loin pain
List the symptoms associated with Acute Interstitial Nephritis:
- Fever
- Haematuria
- Drowsiness
- Confusion
- Nausea
- Fluid retention
- Change in urine output
Define uncomplicated infection:
Infection with a typical organism in a patient with normal urinary tract, and normal urinary function.
May occur in men and women of any age, however men, children and pregnant women are usually treated as complicated.
Define complicated infection:
When 1+ factors present which predispose a patient to persistent/recurrent infection, or treatment failure:
- Atypical virulent organism (S aureus)
- Abnormal urinary tract (catheter, vesicoureteric reflux)
- Impaired host defences
- Impaired renal function
What are the most common pathogens causing UTIs?
Gram negative rod bacteria
- Enterobacteriaceae: E coli, Klebsiella, Salmonella, Shigella
Which 2 types of bacteria are more likely to cause UTIs in a hospitalised patient?
- Staph. aureus
- Pseudomonas
Describe the investigation of a UTI:
MSU:
- Turbidity
- Dipstick testing (Leukocyte esterase, Nitrite, Haemat-/Protein-uria)
- Microscopy
- Culture
What are the 3 main factors a dipstick tests urine for to exclude a UTI?
1) Leukocyte esterase
2) Nitrite
3) Haemat-/Protein-uria
Explain ‘sterile pyuria’:
Presence of WBCs in urine, but no bacteria present
List some causes of Sterile Pyuria:
- Recent course of Antibiotics
- Urethritis (chlamydia/gonorrhoea)
- Neoplasm
- Vaginal infection/inflammation
- Urinary TB
- Chemicals
How should uncomplicated cystitis be treated?
- Increased water intake
- Address underlying disorders
- 3 day course of oral antibiotic (Trimethoprim or Nitrofurantoin)
How should complicated cystitis be treated?
- Increased water intake
- Address underlying disorders
- 5-7 day course or oral antibiotic (Trimethoprim or Nitrofurantoin, or Cephalexin)
- Post-treatment cultures for children/pregnant women
Name 2 antibiotics used to treat cystitis:
- Trimethoprim
- Nitrofurantoin
- Cephalexin
What class of antibiotic is Nitrofurantoin?
Aminoglycoside
What class of antibiotic is Trimethoprim, and how do they work?
Dihydrofolate Reductase Inhibitors
- Inhibit synthesis of Thymidine, Purines and amino acids (inhibit folate acid synthesis)
What class of antibiotic is Cephalexin, and how do they work?
Beta-lactam (Cephalosporins)
- Inhibit cell wall synthesis by expressing beta-lactamase genes
Describe acute sepsis management:
Sepsis 6:
- Give high flow O2
- Take blood sample (ABG)
- Start fluid challenge
- Give IV antibiotics (Meropenem)
- Measure urine output
- Measure lactate
How should acute pyelonephritis be treated?
- Increased water intake
- Address underlying disorders
- 10-14 day course of oral/IV antibiotic (Co-Amoxiclav, Gentamicin, Ciprofloxacin)
At what point should treatment be started if a catheterised patient has a UTI?
If systemic symptoms are present
What prophylaxis is available for people prone to UTIs, with no treatable underlying condition?
Single nightly dose of Trimethoprim or Nitroofurantoin
