NC.com

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, low risk of breast cancer recurrence (can discuss with patient's oncologist if concerned), low risk for DVT/PE
• 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

Antibiotics

Recommendations

• Trimethoprim/Sulfamethoxazole: DS BID x3 days, covers most uropathogens
• Nitrofurantoin: 100mg BID x5 days, covers E coli and S saprophyticus
• Fosfomycin: 3g single dose, covers VRE, ESBL GNRs, consider fosfomycin susceptibility testing prior to starting IV antibiotics
• Second line: beta-lactams, fluoroquinolones

Prophylaxis

• TMP: 100mg QD
• TMP/SMX: SS QD, SS 3x/week
• Nitrofurantoin (monohydrate): 50mg QD, 100mg QD
• Cephalexin: 125mg QD, 250 QD
• Fosfomycin: 3g q10d

Post-Coital Antibiotics

• TMP/SMX: SS or DS
• Nitrofurantoin: 50mg or 100mg
• Cephalexin: 250mg