Complicated UTI & Pyelonephritis Management (IDSA 2025)

Algorithm Steps

1. ▶

   Start

   Suspected Complicated UTI

   Urinary symptoms + signs of upper tract involvement or complicating factors

   1. ●

      Action

      cUTI Definition (IDSA 2025)

      Infection beyond the bladder

      • Pyelonephritis (flank pain, CVA tenderness, fever)
      • UTI in men
      • UTI with anatomic/functional abnormalities
      • Catheter-associated UTI (CAUTI)
      • UTI with sepsis
      1. ●

         Action

         Initial Workup

         Urine culture and labs

         • Urinalysis + Urine culture with susceptibilities
         • Blood cultures if sepsis or immunocompromised
         • BMP (renal function), CBC
         • Review prior urine cultures for resistance patterns
         • Imaging: CT or US if complicated (abscess, obstruction, stones)
         1. ◆

            Decision

            Sepsis Present?

            Assess severity of illness

            • Sepsis: SIRS criteria + infection source
            • Septic shock: Vasopressors required
            • Urosepsis: 20-30% of sepsis cases
            1. ●

               Action

               Urosepsis Management

               Aggressive treatment required

               • IV antibiotics within 1 hour
               • Piperacillin-tazobactam 4.5g IV q6h, OR
               • Meropenem 1g IV q8h (if ESBL risk), OR
               • Ceftriaxone 1-2g IV daily (if low resistance)
               • ADD Vancomycin if gram-positive suspected
               • Source control: Decompress obstruction urgently
               1. ◆

                  Decision

                  Risk for Resistant Organisms?

                  ESBL, Pseudomonas, MDR

                  • Prior resistant isolate
                  • Recent antibiotic use (esp. FQ in past 12 months)
                  • Healthcare exposure, catheter
                  • Travel to high-resistance area
                  1. ●

                     Action

                     ESBL/MDR Coverage

                     Carbapenem or alternative

                     • Ertapenem 1g IV daily (preferred for ESBL)
                     • Meropenem 1g IV q8h (if Pseudomonas risk)
                     • Alternatives if carbapenem-sparing needed:
                     • Aminoglycosides (if susceptible)
                     • Ceftazidime-avibactam, Ceftolozane-tazobactam
                     1. ●

                        Action

                        CAUTI-Specific Management

                        If catheter-associated

                        • Remove or replace catheter (strongly recommended)
                        • Duration: 7 days (if symptoms resolve promptly)
                        • May extend to 10-14 days if slower response
                        • Do NOT treat asymptomatic bacteriuria in catheterized patients
                        1. ●

                           Action

                           Duration of Therapy

                           Shorter courses now recommended

                           • Uncomplicated pyelonephritis: 5-7 days (FQ) or 7 days (other)
                           • Complicated UTI: 7-10 days
                           • CAUTI: 7 days if prompt response
                           • Prostatitis: 14-28 days (if prostate involved)
                           • Do NOT use longer courses routinely
                           1. ◆

                              Decision

                              Clinical Response by 48-72h?

                              Assess for improvement

                              1. ✓

                                 Outcome

                                 Improving

                                 Continue course, step down

                                 • IV to PO transition when appropriate
                                 • Complete antibiotic course
                                 • No routine test of cure culture needed
                              2. ⚠

                                 Warning

                                 Treatment Failure

                                 Persistent symptoms/fever

                                 • Repeat imaging (CT): Rule out abscess, obstruction
                                 • Repeat urine culture
                                 • Consider resistant organism, wrong diagnosis
                                 • Urology consultation if structural issue
                                 • Broaden antibiotic coverage
                  2. ●

                     Action

                     Standard Coverage Adequate

                     Continue empiric or narrow based on culture

                     • Narrow to susceptibility results
                     • Oral step-down when criteria met
                     • De-escalate from broad-spectrum when possible
            2. ◆

               Decision

               Outpatient or Inpatient?

               Based on ability to tolerate PO, severity

               1. ●

                  Action

                  Outpatient Treatment

                  Mild-moderate, can tolerate PO

                  • Fluoroquinolone x5-7 days (if susceptible, no recent FQ use):
                  • Ciprofloxacin 500mg PO BID or Levofloxacin 750mg daily
                  • OR TMP-SMX DS BID x7 days (if susceptible)
                  • OR Amoxicillin-clavulanate 875mg PO BID x7 days
                  • Consider one-time IV ceftriaxone 1g then oral therapy
               2. ●

                  Action

                  Inpatient IV Treatment

                  Cannot tolerate PO, moderate-severe

                  • Ceftriaxone 1-2g IV daily, OR
                  • Ciprofloxacin 400mg IV q12h, OR
                  • Ertapenem 1g IV daily (if ESBL risk)
                  • Step down to oral when afebrile x24-48h, tolerating PO