Urinary Tract Infections for NP
Urinary Tract Infections for the Nurse Practitioner Licensing Exam
- Definition:
- Urinary tract infections (UTIs) involve microbial infection of the urethra, bladder, ureters, or kidneys. UTIs are categorized into lower UTI (cystitis) and upper UTI (pyelonephritis) depending on the infection site.
- Etiology:
- The most common pathogen is Escherichia coli (75-95% of cases). Other pathogens include:
- Staphylococcus saprophyticus, Proteus mirabilis, Klebsiella pneumoniae, and Enterococcus.
- Fungal UTIs (typically caused by Candida) are more common in patients with indwelling catheters or those who are immunocompromised.
- Risk Factors:
- Female anatomy (shorter urethra) increases the risk of UTIs.
- Sexual activity and postmenopausal changes (decreased estrogen).
- Urinary stasis due to obstruction (e.g., benign prostatic hyperplasia [BPH], kidney stones) or vesicoureteral reflux.
- Catheterization and diabetes (impaired immune function).
- Clinical Features:
- Lower UTI (Cystitis):
- Dysuria: Painful urination.
- Urinary frequency and urgency: Frequent need to void with urgency.
- Suprapubic pain and possibly hematuria.
- Upper UTI (Pyelonephritis):
- Fever, chills, and flank pain.
- Nausea, vomiting, and systemic symptoms.
- Diagnosis:
- Urinalysis: Positive nitrites (indicative of gram-negative bacteria) and leukocyte esterase (indicating pyuria).
- Urine culture: Confirms diagnosis, especially in complicated or recurrent cases (≥10⁵ CFU/mL).
- Imaging (e.g., ultrasound) may be needed in recurrent or complicated cases to evaluate for obstruction or abscess.
- Management:
- Uncomplicated UTI:
- First-line antibiotics: Nitrofurantoin (5 days), trimethoprim-sulfamethoxazole (TMP-SMX) (3 days), or fosfomycin (single dose).
- Hydration and symptomatic relief with phenazopyridine (short-term).
- Complicated UTI:
- Longer antibiotic courses (7-14 days) and tailored therapy based on urine culture.
- IV antibiotics for severe pyelonephritis or urosepsis.
- Recurrent UTI:
- Consider prophylactic antibiotics in frequent cases, along with behavioral modifications (e.g., hydration, post-coital voiding).
Key Points
- UTIs are mainly caused by Escherichia coli, affecting the bladder (cystitis) or kidneys (pyelonephritis).
- Diagnosis is based on urinalysis and confirmed by urine culture, especially for complicated cases.
- Uncomplicated UTIs are treated with short courses of antibiotics, while complicated infections require longer therapy and possibly IV antibiotics.
- Prevention of recurrent UTIs includes behavioral modifications and prophylactic antibiotics in selected cases.