From the Guidelines
Complicated urinary tract infections (UTIs) should be managed with empiric broad-spectrum antibiotics, such as a combination of amoxicillin plus an aminoglycoside, a second-generation cephalosporin plus an aminoglycoside, or an intravenous third-generation cephalosporin, as recommended by the European Association of Urology guidelines 1.
Definition and Epidemiology
A complicated UTI is an infection occurring in the presence of a functional or anatomical abnormality of the urinary tract, or in a host with compromised defenses. These infections affect approximately 20-30% of all UTI cases, with higher prevalence in hospitalized patients, the elderly, pregnant women, and those with urological abnormalities.
Pathophysiology and Clinical Signs
The pathophysiology typically involves bacterial ascension from the urethra to the bladder and potentially to the kidneys, with common pathogens including E. coli, Klebsiella, Pseudomonas, Proteus, and Enterococcus species. Risk factors include urinary catheterization, recent urological procedures, structural abnormalities, immunosuppression, diabetes, and pregnancy. Clinical signs include:
- Fever
- Flank pain
- Dysuria
- Frequency
- Urgency
- Suprapubic pain
- Sometimes altered mental status in elderly patients
Management
Management requires empiric broad-spectrum antibiotics initially, with subsequent adjustment based on culture results.
- For mild to moderate cases, oral options are not recommended as first line, instead intravenous third-generation cephalosporin as empirical treatment for complicated UTI with systemic symptoms is recommended 1.
- Severe cases require intravenous therapy with options like piperacillin-tazobactam, ceftriaxone, or meropenem for 10-14 days.
- Ciprofloxacin should only be used if the local resistance rate is <10% when the entire treatment is given orally, the patient does not require hospitalisation, and the patient has anaphylaxis to b-lactam antimicrobials 1.
- Do not use ciprofloxacin and other fluoroquinolones for empirical treatment of complicated UTI in patients from urology departments or when patients have used fluoroquinolones in the last 6 mo 1.
- Any underlying anatomical abnormalities should be addressed, and follow-up urine cultures are recommended to confirm resolution.
- Patients with recurrent complicated UTIs may benefit from urological evaluation to identify and correct structural abnormalities contributing to infection.
From the Research
Definition of Complicated UTI
- A complicated urinary tract infection (cUTI) occurs in the setting of a functionally or structurally abnormal genitourinary tract 2.
- Many different abnormalities may lead to a designation of complicated urinary tract infection, and these abnormalities will have different influences on the frequency of infection and likelihood of relapse or reinfection 2.
Epidemiology of Complicated UTI
- Complicated urinary tract infections (cUTIs) are a major cause of hospital admissions and are associated with significant morbidity and health care costs 3.
- cUTIs are more common in patients with anatomic and functional abnormalities of the genitourinary tract 3.
- The high prevalence of UTIs continues to the in-patient setting where genitourinary infections are the most common nosocomial infection 4.
Pathophysiology of Complicated UTI
- The microbiology of complicated urinary tract infection is characterised by a greater variety of organisms and increased likelihood of antimicrobial resistance compared with acute uncomplicated urinary tract infection 2.
- Escherichia coli is the most common bacteria identified in UTIs, but the prevalence of other organisms increases in complicated UTIs 4.
Clinical Signs of Complicated UTI
- Patients presenting with a suspected UTI should be screened for the presence of complicating factors, such as anatomic and functional abnormalities of the genitourinary tract 3.
- Urinalysis and culture and sensitivity testing are essential in diagnosing cUTIs 3.
- Blood cultures are appropriate in some clinical settings, especially in severe cases of cUTIs 3.
Management of Complicated UTI
- Treatment of cUTIs can be challenging due to the increased prevalence of antimicrobial resistance and the lack of well-designed clinical trials 3.
- Empiric treatment for serious cUTIs should include broad-spectrum antibiotics such as carbapenems or piperacillin-tazobactam 3.
- Fluoroquinolones, trimethoprim-sulfamethoxazole, and nitrofurantoin are still appropriate empiric options for mild lower cUTIs, but should be used with caution due to increasing resistance 3.
- Once organisms and susceptibilities are identified, treatment should be targeted accordingly, and the duration of treatment can range from 1 to 4 weeks based on the clinical situation 3.
- Extended release ciprofloxacin has been shown to be as safe and effective as conventional treatment with ciprofloxacin twice daily for cUTIs and acute uncomplicated pyelonephritis 5.