Urinary Tract Infection Flashcards
What is the defintion of a UTI?
presence of a pure growth of >105 organisms per mL of fresh MSU
What are the 3 types of UTI?
- Urethritis – affects the urethra
- Cystitis – affects the bladder
- Pyelonephritis – affects the kidney
What is the most common cause of UTI?
Escherichia coli
What are RF for UTIs?
- Sexual intercourse
- Pregnancy
- Immunosuppression
- Catheterization
- Urinary tract obstruction (BPH, calculi)
- Female as shorter urethra and shorter distance between urethral + anal opening
What are the storage symptoms of a UTI?
- Increased frequency
- Urgency
- Dysuria
- Foul-smelling
What are the symptoms of acute pyelonephritis?
- flank pain
- fever
- malaise
What is the 1st line investigation for UTI?
urine dip
What would the urine dip show for a UTI?
+ve leucocytes and nitrites
What is the gold standard investigation for UTI?
MSU and MC&S – Gold standard:
1. Identify bacteria
What would MSU and MC&S show in pyelonephritis?
white cell casts
When do you do blood cultures in a UTI?
systemically unwell and risk or urosepsis
What is the management for UTIs?
empirical antibiotics (nitrofurantoin)
What is a UTI characterised by?
presence of >100,000 of colony-forming units per millilitre of urine. UTI may affect bladder (cystitis), kidney (pyelonephritis) or prostate (prostatitis).
What is the aetiology of UTIs?
- Escherichia coli (80%)
- Staphylococcus saprophyticus
- Klebsiella pneumoniae
- Proteus mirabilis
- Enterocci
What are RF for UTIs?
- Age >50 /Sex
- Urine outflow obstruction (BPH, stones, strictures etc.)
- Catheters (HAI)
- Diabetes Mellitus
- Pregnancy
- Immunosupression
What are white cell casts strong indicators of?
pyelonephritis
What are upper UTIs?
- Kidneys
2. Pyelonephritis
What is the aeitology of upper UTIs?
Ascending faecal bacteria
OR
Descending bacteremia
What is the presentation of an upper UTI?
- Costo-vertebral angle tenderness
- Flank pain
- Fever
- N&V
- Urinary Sx
- Acute confusion: elderly
What is a lower UTI?
- Bladder (cystitis)
2. Urethra (urethritis)
What is the aeitology of lower UTIs?
faecal bacteria
E.Choli, Klebsiella Pneumoniae, Proteus mirabilis
What is the presentation of a lower UTI?
- Urgency
- Dysuria
- Frequency
- Suprapubic pain
- Foul smelling urine
What are Ix for cystitis?
- If young woman with typical symptoms clinical Dx
- Clean catch
- Suprapubic aspiration
What is clean catch?
- Midstream urine sample
2. Avoids contamination with bacteria from outer meatus
When is suprapubic aspiration indicated?
in patients with indwelling catheter (urine in bladder should have no bacteria)
What bloods are done in pyelonephritis?
- FBC (Leukocytosis w/ neutrophilia)
- Renal function tests
- Urinalysis (WBC casts on microscopy)
- Urine culture
What imaging is done in pyelonephritis?
- Renal USS (Hypoechoic mass)
2. Abdominal CT (Localised hypodense symptoms, signs of obstruction)
What is abdo uss done?
exclude urinary tract obstruction or renal stones
What are most causative organisms?
- Gram-negative enteric organisms produce urinary nitrite and represent the most common uropathogens
- Enterococcus, a less common uropathogen, does not produce nitrite and has a unique antibiotic resistance pattern.
What makes a UTI complicated?
- Men
- pregnant women
- indwelling catheters
- uncontrolled diabetes mellitus
- urethral strictures
- recent urological procedures
- immuno compromised
What is the 1st line treatment for uncomplicated lower UTI?
1st line: Nitrofurantoin:
50mg x4/day for 3 days
Trimethoprim:
200mg x2/day for 3 days
What is important to remeber with Trimethoprim?
tetarogenic
What is 2nd line for lower uncomplicated UTI?
- if no improvement in symptoms
1. Pivmecillinam
2. Fosfomycin
What is the 1st line treatment for lower complicated UTI (men)?
Nitrofurantoin:
50mg x4/day for 7days
Trimethoprim:
200mg x2/day for 7 days
What is the 1st line treatment for lower complicated UTI (pregnant women)?
1st line:
Nitrofurantoin:
50mg x4/day for 7days
What is the 2nd line treatment for lower complicated UTI (pregnant)?
- amoxicillin
2. cefalexin
How do you check if complicated UTI?
- structural or functional condition of genitourinary tract
OR - underlying disease
For upper UTIs how do you administer medication?
IV if unable to take oral antibiotics or severely unwell (i.e:. Sepsis concern)
What is the 1st line oral treatment for uncomplicated upper UTI or complicated upper UTI (men)?
- Cefalexin
- Co-amoxiclav
- Trimethoprim
- Ciprofloxacin
What is the 1st line IV treatment for uncomplicated upper UTI or complicated upper UTI (men)?
- Co-amoxiclav
- Cefuroxime
- Ceftriaxone
- Ciprofloxacin
- Gentamicin
What is the 1st line oral treatment for complicated upper UTI (pregnant)?
Cefalexin
What is the 1st line IV treatment for complicated upper UTI (pregnant)?
Cefuroxime
What are the key antibiotics for UTI?
- Trimethoprim (avoid in pregnancy) / Nitrofurantoin
- Pyelonephritis – Cefalexin 1st line