Definition of Complicated UTI per IDSA Guidelines
A complicated urinary tract infection (UTI) occurs when an individual has host-related factors or specific anatomic or functional abnormalities in the urinary tract that make the infection more challenging to eradicate compared to an uncomplicated infection. 1
Factors That Define a Complicated UTI
Anatomical and Structural Abnormalities
- Obstruction at any site in the urinary tract 1
- Presence of foreign bodies (including indwelling catheters) 1
- Incomplete voiding 1
- Vesicoureteral reflux 1
- Recent history of instrumentation 1
- Urinary tract diverticula or fistulae 1
Host-Related Factors
- Male gender (all UTIs in men are considered complicated) 1
- Pregnancy 1
- Diabetes mellitus 1
- Immunosuppression 1
- Healthcare-associated infections 1
- Voiding dysfunction 1
Microbiological Factors
- Infections with ESBL-producing organisms 1
- Multidrug-resistant organisms 1
- Broader microbial spectrum than uncomplicated UTIs 1
- Common pathogens include E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp. 1
Clinical Considerations
Treatment Implications
- Requires longer treatment duration (7-14 days) compared to uncomplicated UTIs 1
- Men with UTIs typically need 14 days of treatment when prostatitis cannot be excluded 1
- Requires management of the underlying urological abnormality or complicating factor 1
- Often necessitates broader antimicrobial coverage due to increased risk of resistant organisms 1
Diagnostic Approach
- Urine culture and susceptibility testing should always be performed before initiating therapy 1
- Initial empiric therapy should be tailored based on local resistance patterns and patient factors 1
- Characterization of the underlying genitourinary abnormality is essential 2
Important Distinctions
Uncomplicated vs. Complicated UTI
- Uncomplicated UTI occurs in patients without structural or functional abnormalities and without relevant comorbidities 1
- Repeated episodes of pyelonephritis should prompt consideration of a complicated etiology 1
- Catheter-associated UTIs (CA-UTIs) are always considered complicated 1
Clinical Pitfalls to Avoid
- Failure to identify and address the underlying abnormality will likely result in early post-treatment recurrence 2
- Inadequate antimicrobial coverage may lead to treatment failure due to higher likelihood of resistant organisms 1
- Not recognizing that male UTIs, regardless of other factors, should be managed as complicated infections 3
- Overlooking the need for longer treatment duration in complicated UTIs compared to uncomplicated cases 1
By understanding these defining characteristics of complicated UTIs, clinicians can better identify high-risk patients and implement appropriate management strategies to improve outcomes and reduce recurrence.