Urinary Tract Infection Flashcards
Definition of asymptomatic bacteriuria
Persistent colonisation of the urinary tract by significant numbers of bacteria without urinary symptoms
Definition of acute cystitis
Acute infection of the urinary bladder. Distinguished from asymptomatic bacteriuria by the presence of symptoms such as dysuria, urgency, frequency, nocturia, haematuria and suprapubic discomfort in afebrile women with no evidence of systemic illness.
Definition of pyelonephritis
Infection of one or both kidneys usually caused by bacteria from the bladder. Defined by significant bacteriuria in the presence of systemic illness and symptoms such as flank or renal angle pain, pyrexia, rigor, nausea and vomiting.
What is the incidence of UTI in pregnancy. Which factors in pregnancy predispose to UTI
In pregnancy, the overall incidence of UTI is approximately 8%. Urinary stasis, compromised ureteric valves and vesicoureteral reflux can all contribute to an increased incidence of UTI.
Risk factors for UTI
History of recurrent cystitis, renal tract abnormalities (duplex system, scarred kidneys, ureteric damage and stones), diabetes (70% of women develop glycosuria during pregnancy), bladder emptying problems e.g multiple sclerosis, sexual activity.
What are the causative organisms for UTI in pregnancy
- Most common cause of UTI is Escherichia coli- gram negative, anaerobic, rod-shaped bacetria found in faeces which is easily spread to the bladder
- Klebsiella pneumoniae (gram-negative anaerobic rod)
- Enterococcus, pseudomonas aeruginosa, Staph sarpophticus
- Candida
Complications of UTI
Increases the risk of preterm delivery. Additionally they increase the risk of other adverse outcomes including low birth weight and PET.
Presentation of UTI
Lower urinary tract infections present with:
* Dysuria (pain, stinging or burning when passing urine), suprapubic pain or discomfort, increased urinary frequency, urgency, incontinence, haematuria
Pyelonephritis presents with:
* Fever (more prominent than in lower UTIs), loin, suprapubic or back pain (this may be bilateral or unilateral), looking or feeling generally unwell, vomiting, loss of appetite, haematuria, renal angle tenderness on examination
Investigations for UTI
- Urine dip: check for the presence of nitrites (produced by gram-negative bacteria such as E.coli from nitrates which are present in urine), leukocytes (nitrites is a more accurate indication of infection)
Midstream urine (MSU) sample:
* Send for microscopy, culture and sensitivities- UTI is defined by labs as the presence of >105 colony forming units
* Often ‘heavy mixed growth’ will be reported- associated with symptoms and may be treated or repeat MSU after a week
When should women be admitted with UTI
If there are any features of serious or systemic illness such as sepsis or pyelonephritis
When should you seek specialist advice for management of UTI
- Recurrent lower UTI
- Catheter associated UTI
- Atypical bacteria
- An underlying structural or functional abnormality or where there is co-morbidity, underlying malignancy, or renal disease.
Management of an uncomplicated first lower UTI in pregnancy
- Give advice on self-care measures: Simple analgesia such as paracetamol can be used for pain relief. Encourage intake of enough fluids to avoid dehydration
- Send an MSU for MC&S before antibiotics are taken
- Advise women to seek urgent review at any time if symptoms worsen or fail to improve within 48 hours of starting antibiotics
- Send urine for culture once treatment is completed to ensure clearance of infection
Offer an immediate antibiotic prescription taking account of previous urine culture and susceptibility results, previous antibiotic use (which may have le to resistant bacteria) and local resistance patterns:
* As 1st line consider: NITROFURANTION (avoid at term- risk of neonatal haemolysis) 100mg modified release twice per day for 7 days
* As 2nd line (no improvement in lower UTI symptoms after 1st course has been taken for at least 48hrs or when 1st choice is unsuitable): Amoxicillin (500mg three times daily), Cefalexin (500mg TDS)
* Trimethoprim needs to be avoided in the first trimester since it works as a folate antagonist- causes congenital malformations, neural tube defects
Management of asymptomatic bacteriuria
Seek specialist advice if the woman is at risk of a complicated UTI
Offer an immediate antibiotic prescription to pregnant women with asymptomatic bacteriuria:
Consider urine culture and susceptibility results and previous antibiotic use and choose from:
* Nitrofurantoin (avoid at term) 100 mg modified-release twice a day for 7 days if eGFR >45ml/minute.
* Amoxicillin (only if culture results available and susceptible) 500 mg three times a day for 7 days.
* Cefalexin 500 mg twice a day for 7 days.
Management of suspected pyelonephritis
Admit to hospital if they have any symptoms or signs suggesting a more serious illness or condition (e.g sepsis). Consider referring for specialist advice
Admit to hospital if it is severe, or they have any signs or symptoms suggestive of a more serious illness or condition:
* Significant tachycardia, hypotension, or breathlessness.
* Marked signs of illness (such as impaired level of consciousness, perfuse sweating, rigors, pallor, significantly reduced mobility).
* A temperature greater than 38°C or less than 36°C
For pregnant women who do not require hospital admission prescribe Cefalexin 500mg TDS for 7-10 days
Review culture and sensitivity results when they become available, and change the antibiotic if indicated. If the bacteria are resistant and symptoms are not already improving, use a narrow-spectrum antibiotic wherever possible
Reassess the person if symptoms worse at any time, or do not start to improve within 48 hours of taking the antibiotic
Urgent management:
* IV fluids, opiate analgesia, IV antibiotics (cefalexin), monitor foetal CTG
