Urinary Tract Infection

• November 11, 2022
• Tony Guo
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Urinary Tract Infection

• Most common bacterial infection in women
• May be caused by a variety of disorders
  • Bacterial infection most common
• Bladder and its contents are free of bacteria in majority of healthy people
• Minority of healthy individuals have some bacteria colonizing in bladder
  • Called asymptomatic bacteriuria and does not justify treatment
• Escherichia coli  (E. coli) most common pathogen
• Other causes of UTIs
  • Enterococcus
  • Klebsiella
  • Enterobacter
  • Proteus
  • Pseudomonas
  • Staphylococcus
  • Serratia
  • Candida albicans
• Counts of 105 CFU/mL or more indicate significant UTI
• Counts as low as 102 CFU/mL in a person with signs/symptoms are indicative of UTI
• Fungal and parasitic infections may cause UTIs
• Patients at risk
  • Immunosuppressed
  • Diabetic
  • Have kidney problems
  • Have undergone multiple antibiotic courses
  • Have traveled to developing countries
• Classification of UTI
  • Upper versus lower
    • Upper urinary tract 
      • Renal parenchyma, pelvis, and ureters
      • Typically causes fever, chills, flank pain
      • Example 
        • Pyelonephritis: inflammation of renal parenchyma and collecting system
    • Lower urinary tract 
      • Usually no systemic manifestations
      • Examples
        • Cystitis: inflammation of bladder
        • Urethritis: inflammation of urethra
    • Urosepsis
      • UTI that has spread systemically
      • Life-threatening condition requiring emergent treatment
  • Complicated versus uncomplicated 
    • Complicated UTI
      • Coexists with presence of
        • Obstruction or stones
        • Catheters
        • Abnormal GU tract
        • Diabetes/neurologic disease
        • Resistance to antibiotics
        • immunocompromised
        • Pregnancy-induced changes
        • Recurrent infection

Etiology and Pathophysiology

• Urinary tract above urethra normally sterile
• Defense mechanisms exist to maintain sterility/prevent UTIs
  • Complete emptying of bladder
  • Ureterovesical junction competence
  • Ureteral peristaltic activity
• Defense mechanisms
  • Acidic pH (less than 6.0)
  • High urea concentration
  • Abundant glycoproteins
• Predisposing factors to UTI:
  • Factors increasing urinary stasis
    • Intrinsic obstruction (stone, tumor of urinary tract, urethral stricture, BPH)
    • Extrinsic obstruction (tumor, ibrosis compressing urinary tract)
    • Urinary retention (e.g., neurogenic bladder)
    • Renal impairment
  • Foreign bodies such as:
    • Urinary tract calculi
    • Catheters (indwelling, external condom catheter, ureteral stent, nephrostomy tube, intermittent catheterization)
    • Urinary tract instrumentation (cystoscopy)
  • Anatomic factors
    • Congenital defects leading to obstruction or urinary stasis
    • Fistula (abnormal opening) exposing urinary stream to skin, vagina, or fecal stream
    • Shorter female urethra and colonization from normal vaginal flora
    • Obesity
  • Compromising immune response factors
    • Aging
    • Human immunodeficiency virus infection
    • Diabetes mellitus
  • Functional disorders
    • Constipation
    • Voiding dysfunction with detrusor sphincter dyssynergia
  • Other factors
    • Pregnancy
    • Menopause
    • Multiple sex partners (women)
    • Use of spermicidal agents, contraceptive diaphragm (women), bubble baths, feminine sprays
    • Poor personal hygiene
    • Habitual delay of urination (“nurse’s bladder,” “teacher’s bladder”)
• Gram-negative bacilli normally found in GI tract: common cause
• Urologic instrumentation allows bacteria to enter urethra and bladder
• Organisms introduced via ascending route from urethra that originated from the perineum
• Contributing factor: 
  • Sexual intercourse promotes “milking” of bacteria from perineum and vagina
    • May cause minor urethral trauma
• Less common routes 
  • Bloodstream
  • Lymphatic system
• Catheter-associated urinary tract infections (CAUTI) are the most common HAI 
  • Causes
    • Often: E. coli
    • Less frequently: Pseudomonas species
  • Most are underrecognized and undertreated

Clinical Manifestations

• Painful urination
• Abdominal or back pain
• Fever
• Sepsis
• Decreased kidney function in some cases of pyelonephritis
• Symptoms related Storage:
  • Urinary frequency 
    • Abnormally frequent (more often than  every 2 hours)
  • Urgency
    • Sudden, strong desire to void immediately
  • Incontinence
    • Loss or leakage or urine
  • Bladder storage
    • Nocturia
      • Waking up two or more times at night to void
      • May be diurnal or nocturnal depending on sleep schedule
    • Nocturnal enuresis
      • Loss of urine during sleep
  • Bladder emptying
    • Weak stream
    • Hesitancy
      • Difficulty starting the urine stream
      • Delay between initiation of urination (because of urethral sphincter relaxation) and beginning of low of urine
      • Diminished urinary stream
    • Intermittency
      • Interruption of urinary stream during voiding
    • Post-void dribbling
      • Urine loss after completion of voiding
    • Urinary retention
      • Inability to empty urine from bladder
      • Caused by atonic bladder or obstruction of urethra
      • Can be acute or chronic
    • Dysuria
      • Painful or difficulty voiding
  • Flank pain, chills, and fever indicate infection of upper tract 
    • Pyelonephritis
  • In older adults
    • Symptoms often absent 
    • Nonlocalized abdominal discomfort rather than dysuria
    • Cognitive impairment possible
    • Fever less likely

• Diagnostic Studies
  • History and physical examination
  • Dipstick urinalysis 
    • Identify presence of nitrites, WBCs, and leukocyte esterase
  • Urine culture
    • Urine for culture and sensitivity (if indicated)
      • Clean-catch sample preferred
      • Specimen by catheterization or suprapubic needle aspiration more accurate
      • Determine bacteria susceptibility to antibiotics
  • Imaging studies 
    • Ultrasound
    • CT scan (CT urogram)

• Drug Therapy
  • Antibiotics
    • Selected on empiric therapy or results of sensitivity testing
    • Uncomplicated cystitis
      • Short-term course (typically 3 days)
    • Complicated UTIs 
      • Long-term treatment (7 to 14 days or more)
    • Trimethoprim/sulfamethoxazole 
    • Used to treat uncomplicated or initial UTI
      • Inexpensive
      • Taken twice a day
    • Nitrofurantoin (Macrodantin)
      • Given three or four times a day
      • Long-acting preparation (Macrobid) is taken twice daily
    • Ampicillin, amoxicillin, cephalosporins
      • Treat uncomplicated UTI
    • Fluoroquinolones
      • Treat complicated UTIs
      • Example: ciprofloxacin (Cipro)
  • Antifungals
    • Amphotericin or fluconazole
      • UTIs secondary to fungi
  • Urinary analgesic
    • Phenazopyridine
      • Used in combination with antibiotics
      • Provides soothing effect on urinary tract mucosa
      • Stains urine reddish orange 
        • Can be mistaken for blood and may stain underclothing

Nursing Managment

• Nursing Assessment
  • Subjective Data
    • Important Health Information
      • Past health history: 
        • Previous urinary tract infection. 
        • Urinary calculi, reflux, strictures, or retention. 
        • Neurogenic bladder, pregnancy, benign prostatic hyperplasia, bladder cancer, sexually transmitted infection.
      • Medications: Antibiotics, anticholinergics, antispasmodics
      • Surgery or other treatments: 
        • Recent urologic instrumentation (catheterization, cystoscopy)
    • Functional Health Patterns
      • Health perception–health management: 
        • Urinary hygiene practices.
      • Lassitude, malaise
      • Nutritional-metabolic: 
        • Nausea, vomiting, anorexia. Chills
      • Elimination: 
        • Urinary frequency, urgency, hesitancy. Dysuria, nocturia
      • Cognitive-perceptual: 
        • Suprapubic or low back pain, costovertebral tenderness, bladder spasms, dysuria, burning on urination
      • Sexuality-reproductive: Multiple sex partners (women), use of spermicidal agents or contraceptive diaphragm (women)
  • Objective Data
    • General
      • Fever, chills, dysuria
      • Atypical presentation in older adults: afebrile, absence of dysuria, loss of appetite, altered mental status
    • Urinary
      • Hematuria. Cloudy, foul-smelling urine. Tender, enlarged kidney
    • Possible Diagnostic Findings
      • Leukocytosis. UA positive for bacteria, pyuria, RBCs, WBCs, and nitrites. Positive urine culture. Ultrasound, CT scan (CT urogram), VCUG, and cystoscopy indicating urinary tract abnormalities
• Nursing Diagnoses
  • Impaired urinary elimination related to the effects of UTI
  • Infection
  • Risk for urge urinary incontinence
  • Acute pain: dysuria related to inflammatory process in bladder
  • Readiness for enhanced health management
• Nursing Planning
  • Patient will have
    • Relief from lower urinary tract symptoms (LUTS)
    • No upper urinary tract involvement
    • No recurrence
• Nursing implementation
  • Health Promotion 
    • Recognize individuals at risk
      • Debilitated persons
      • Older adults
      • Underlying diseases (HIV, diabetes)
      • Taking immunosuppressive drug or corticosteroids
    • Emptying bladder regularly and completely
      • Evacuating bowel regularly
      • Wiping perineal area front to back
      • Drinking adequate fluids (person’s weight in pounds/2)
        • 20% of fluid comes from food
    • Cranberry juice or cranberry tablets may reduce number of UTIs
    • Avoid unnecessary catheterization and early removal of indwelling catheters
    • Aseptic technique must be followed during instrumentation procedures
    • Routine and thorough perineal care for all hospitalized patients
    • Answer call lights and offer bedpan or urinal at frequent intervals
  • Prevention of CAUTI
    • Avoidance of unnecessary catheterization
    • Early removal of indwelling catheters
    • Follow aseptic technique for procedures
    • Handwashing before and after patient contact
    • Wear gloves for care of urinary catheters