UTI Flashcards
Symptoms and signs of lower/simple UTI
-Bladder ‘cystitis’
• Urinary frequency
• Urinary urgency
• Dysuria
• Suprapubic tenderness
• Gross Haematuria
Symptoms and signs of complicated UTI
-Kidneys/ ureteric obstruction (stones)
• Often cystitis Sx (not always) with
addition of:
• Systemic symptoms
• Fever, rigors, lethargy
• Loin pain/ paravertebral tenderness
Examples of uropathogens
-Enterobacteriaceae
• Escherichia coli (75-95% cystitis)
• P-fimbriated E.coli= virulent as adheres to epithelium
• Klebsiella Spp.
• Proteus Spp.
• Staphylococci saprophyticus- young women
-Recent antimicrobials, hospitalisation and urinary
catheters
• Pseudomonas Spp, Enterococcus Spp, and
Staphylococci Spp
Describe urinalysis
-Detect
=Leukocyte esterase released by leukocytes indicating pyuria (white blood cells in urine)
=Nitrites- produced by some Enterobacteriaceae by breaking
down nitrates
* Can modestly improve diagnosis but cannot adequately rule out infection.
* Do not use urinalysis in asymptomatic/elderly/catheterised patients
Describe urine culture
• Confirm the presence of bacteriuria and to provide antibiotic susceptibility.
• Mid stream urine routine
• Out-with pregnant women only perform culture of urine on symptomatic patients.
• ≥ 100 000 cfu/ml of a single strain of bacteria confirms bacteriuria, however recent studies have suggested ≥1000 cfu/ml of E. coli can represent infection in
symptomatic patients1
.
• Mixed cultures usually indicate contamination.
Types of lower urinary tract infections
-Cystitis in women and men
-Asymptomatic bacteriuria
-Recurrent UTI
Why is cystitis more common in adult women?
-Anatomy
=Shorter distance from anus to urethra
Risk factors for cystitis in adult women
• Sexual activity
• Recent UTI
• Diabetes mellitus
• Urinary tract abnormalities
• Post-menopause
Clinical symptoms of acute cystitis in women
• Dysuria
• Urinary frequency
• Urinary urgency
• Suprapubic pain
• Haematuria (sometimes)
• Explore alternative diagnosis if vaginal discharge/itch present (STDs, thrush, urethritis)
Investigations for acute cystitis in women <65 years
-In women with 3 or more symptoms of cystitis
• Treat empirically. No further investigations required.
-Urinalysis:
• use to guide treatment decisions mild or 2 symptoms or less or atypical symptoms.
• Be wary of using urinalysis in elderly patients
-MSU:
• Risk of multidrug resistant pathogens, to guide treatment in patients who do not respond to first line antibiotics.
How common is acute cystitis in men?
• Much less common in men between 16-50 years due to anatomical differences.
• Elderly males: risk increases = elderly women, in part due to outflow obstruction (prostate).
-Same symptoms
Evaluation of cystitis in men
• Systemic upset/costovertebral tenderness upper urinary tract infection.
• Prostatitis- pelvic/perineal pain, obstructive symptoms (dribbling and hesitancy).
• Chronic prostatitis-recurrent infections.
• STIs and urethritis in all sexually active men.
Describe diagnosis of cystitis in men
There is no evidence to suggest the best method for diagnosing UTI in men.
• All men with suspected UTI should be regarded as complicated.
• Send urine for culture in all suspected cases.
• All men with recurrent UTIs should be referred for Urological investigation.
Antibiotics treatment of acute cystitis
-Empirical treatment: Nitrofurantoin (low level resistance in E. coli, high concentrations in urine) or Trimethoprim
=Women: 3 days
=Men: 7 days
-Nitrofurantoin: Avoid in renal failure (eGFR <45 ml/min) due to concerns regarding toxicity.
-Second line therapy: in treatment failure use antibiotic susceptibility from urine cultures to guide therapy.
Diagnosis and treatment of asymptomatic bacteriuria
-Laboratory confirmed bacteriuria:
• 2 x specimens with at least 100 000 cfu/ml of a pure culture for women, only 1 required for men.
=Common especially in elderly patients
DO NOT TREAT
• there is no benefit in terms of morbidity/mortality from treating UNLESS Pregnant or in Renal Transplant.
What is considered a recurrent UTI?
-3 or more laboratory confirmed urinary tract infections within year.
-Consider underlying causes and risk factors. History and examination
What should be assessed for in recurrent UTI for causes?
-Constipation
-Uterine prolapse
-Atrophic vaginitis (post-menopausal)
-Diabetes
-Prostatitis
-Relating to sexual intercourse
-Sexually transmitted diseases
Investigations for recurrent UTI
-Check renal function
-Urinary tract USS
Treatment for recurrent UTI
-Non-antibiotic approaches:
• Consider cranberry supplements in women- evidence is lacking but some may benefit from this.
-Antibiotic approaches:
• Post-intercourse antibiotic e.g. trimethoprim single dose
• Standby antibiotics- 3 day course dependant on known susceptibilities
• Prophylactic antibiotics- 3- 6 months course, stop and assess. Specialist input only. Trimethoprim preferred.
• Promotes resistance. Evidence for benefit is not strong.
What is acute pyelonephritis?
Infection causing inflammation of the kidneys
=E Coli most common
-Risk factors
=Obstruction
=Immunosuppression
=DM
=Pregnancy
Clinical presentation of acute pyelonephritis
-Cystitis symptoms
• Systemic illness – fever, rigors, marked fatigue.
• Loin pain/costovertebral tenderness- often unilateral
• Fever and flank pain pyelonephritis.
• Sepsis and no localizing symptoms pyelonephritis in differential
• Pelvic/perineal pain in men- ? prostatitis
• Discharge/itch- ?pelvic inflammatory disease, urethritis
Examination findings of acute pyelonephritis
• Fever
• SIRS and SEPSIS 6
• Costovertebral tenderness.
• Suprapubic tenderness.
• Caution if significant abdominal tenderness/guarding consider reasons for acute surgical abdomen.
Investigations for acute pyelonephritis
-All patients: Urine culture.
-Urinalysis- absence of pyuria may indicate alternative diagnosis if atypical presentation.
-Inpatients:
=Blood cultures, FBC, UECs, LFTs, CRP, (lactate if sepsis).
Indications for renal tract ultrasound/ CT in acute pyelonephritis
• Severely unwell
• Persisting clinical symptoms (48-72 hours)
• Urinary tract obstruction or Acute Kidney Injury
• Recurrence of symptoms.
Urinary stones in complicated urinary tract infection
• Patients with urinary stones, history of urological surgery e.g., ureteric stents are at increased risk of both upper urinary tract infections and complications.
• Perform imaging
• Seek prompt urological input for related upper urinary tract infections.
• Surgical management aimed at relieving the obstruction
Who should be admitted in acute pyelonephritis?
• If septic, at higher risk of complications (e.g. diabetic), unable to take oral medication or concerns re urinary tract obstruction.
Empiric antibiotic therapy for pyelonephritis
• IV amoxicillin 1g TDS and IV gentamicin (NHS Lothian calculator)
• Oral options include:
=cotrimoxazole, co-amoxiclav and ciprofloxacin.
=Do not use nitrofurantoin (inability to achieve high levels in systemic circulation).
• Review with culture results
• 7 to 14 days in acute pyelonephritis.
• Do not continue gentamicin >72 hours without specialist input.
• All male patients with upper urinary tract infections should be referred for urological investigation.
Risks and incidence of UTI in catheterised patients
• Patients with indwelling urinary catheters are at a significantly elevated risk for UTI.
• 75% of healthcare acquired UTIs are in patients with urinary catheter
• Do not rely on classical symptoms or signs for predicting the likelihood of symptomatic UTI.
Signs and symptoms of UTI in catheterised patients
• New fever, rigors, delirium.
• Flank pain
• Pelvic discomfort
• Acute haematuria
• In patients whom catheter has been removed- dysuria, urgency, suprapubic pain
Investigations for UTI in catheterised patients
-Do not perform urine dipstick on catheterised patients.
-Send urine for culture.
-Send bloods and blood cultures.
-Do not treat asymptomatic bacteriuria.
-Catheters become colonised very rapidly after insertion, 80% of urinary catheters are colonized at 1 month.
Antibiotic management for UTI in catheterised patients
• IV gentamicin dose as per NHS Lothian calculator.
• Change urinary catheter, consider the need for ongoing catheterisation.
• Monitor daily decision for ongoing antibiotic therapy
• 7 day course of antibiotic therapy for males and females with symptomatic catheter associated UTI with prompt resolution of symptoms.
• Do not continue gentamicin for longer than 72 hours without specialist input
• Review with urine culture results and refine antibiotic choice.
Why is diagnosis of UTI more difficult in elderly patients?
• Non-specific symptoms- delirium, abdominal pain, loss of diabetic control.
• High rates of bacteriuria
Management of UTI in elderly patients
• Urinary tract infection based upon full clinical assessment.
• Urine dipstick is not routinely recommended in this age group due to difficulties with interpretation.
• Extra care with antibiotic prescribing due to increased risk of adverse effects and Clostridiodes difficile infection.
