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Workup and Diagnosis

Definitions

• Recurrent UTI: 2+ UTIs in 6mo or 3+ UTIs in 1yr
• Uncomplicated UTI: UTI without anatomic/functional abnormalities that would increase risk of developing UTI
• Complicated UTI: UTI in setting of anatomic/functional abnormalities, immunocompromised, or MDRO
• "Index" patient: otherwise healthy adult woman w/ uncomplicated UTI, excluding pregnancy, immunocompromixed, anatomic/functional abnormalities, catheters, bacteremia, neurologic disease, post-GU procedures

History

• UTI symptoms: dysuria, frequency, urgency, nocturia, incontinence, hematuria, pneumaturia, fecaluria
• Baseline voiding symptoms: # voids, urgency, straining, incomplete emptying, pelvic pressure, vaginal bulge, dysuria, dyspareunia, GU/pelvic pain
• Bowel symptoms: diarrhea, constipation, fecal incontinence
• Other symptoms: back/flank pain, vaginal discharge/irritation
• UTI hx: frequency, positive cultures, type of bacteria
• Antibiotics: prior usage, complications, allergies
• GU hx: catheter usage, prior GU/pelvic surgery
• GYN hx: menopause status, contraceptive usage, spermicides, E/P products
• Sexual hx: # partners, new partners within past year, post-coital UTIs
• Other hx: travel history, family history of UTI (in 1st degree relative)
• Risk factors for complex UTI: pregnancy, immunocompromised, anatomic/functional abnormalities, neurologic disease

Exam

• Pelvic organ prolapse
• Urethra/bladder: tenderness, diverticulum, cysts, incontinence
• Vaginal mucosa: atrophy, irritation
• Pelvic floor: tone, tenderness, trigger points
• Neuro exam

Adjuncts

• Post-void residual: no threshold for (ab)normal value, confirms patient able to adequately empty
• Confirm diagnosis with positive urine culture
• Persistent negative UCx: pursue workup for OAB, cancer, stones, pelvic floor dysfunction, interstitial cystitis
• Cystoscopy and upper tract imaging: not required in an index (uncomplicated) patient, only find abnormalities in 2-6% of patients (and usually suspected based on history/physical)

Indications for cystoscopy and imaging

• Consider if patient does not respond to adequate UTI treatment or high suspicion, helps to assess anatomic/functional abnormalities that increase risk for UTI
• Imaging choice: renal/bladder US should be first choice, only consider CT if high concern or abnormal findings on US
• VCUG: obtain if VUR is suspected
• MRI: obtain if concern for urethral diverticulum

Management

Antibiotic therapy options

• Self-start therapy: indicated for a reliable patient who will provide UCx and immediately starts taking abx
• Post-coital abx: prescribe if clear pattern related to coitus
• Prophylactic abx: recommended for 6-12mo duration, but risk of abx resistance

Vaginal estrogen

• Benefits: peri/post-menopausal women without obvious contraindications, can help if UTI during breastfeeding, minimal systemic absorption, minimal risk of cancer or thromboembolic events
• 17b-estradiol cream: 2g daily x2 weeks, then 1g 2-3x per week
• Equine estrogen cream: 0.5g daily x2 weeks, then 0.5g 2x per week
• Vaginal tablet (estradiol hemihydrate): 10mcg daily x2 weeks, then 10mcg 2-3x per week
• Vaginal ring (17b): 2mg ring releases 7.5mcg daily for 3mo

Non-abx proven therapies

• Cranberry: proanthocyanidins prevent bacterial adhesion to urothelium, lower rUTI (RR=0.67), tablets are better than juice (sugar), take BID, take 36mg-72mg PAC equivalents
• Increased water intake: benefit if baseline UOP < 1.5L
• Timed voiding: warranted if hx holding urine for long periods

Non-abx less proven therapies

• Methenamine: converted to formaldehyde in urine, take 1g BID, take with 1-4g ascorbic acid (acidified urine increases effects), do not take if CrCl < 50, no benefit if catheter present (needs time to dwell in bladder)
• D-mannose: reportedly reduces rUTI, proper dosing not known
• Doesn't work: post-coital urination, douching, pubic shaving, avoiding thong underwear, oral estrogen, lactobacillus

Antibiotic options

Culture-proven UTI treatment	TMP/SMX DS BID x3 days Nitrofurantoin 100mg BID x5 days Fosfomycin 3g single dose Second line options: beta-lactams, fluoroquinolones
Daily prophylaxis	TMP 100mg QD TMP/SMX SS QD or SS 3x/week Nitrofurantoin 50mg or 100mg QD Cephalexin125mg or 250mg QD Fosfomycin 3g q10d
Post-coital dose	TMP/SMX SS or DS Nitrofurantoin 50mg or 100mg Cephalexin 250mg