Introduction
Urinary tract infections are common, and can affect both males and females at any
age. Clinical symptoms can vary widely, ranging from lower tract complaints of frequency,
urgency, dysuria, to septic shock. Although modern antibiotics are quite effective in
treating UTIs, occasionally patients will succumb to infections of the solid organs of the
urinary tract. Therefore, urinary tract infections, especially associated with a febrile
response, should not be taken lightly, and aggressive management is necessary.
Sources of the
UTI
The ascending route of bacterial entry is the typical means of developing an
infection, however, hematogenous and lymphatic channels can rarely provide the path to the
urinary system. Infections are at times associated with indwelling catheters,
urolithiasis, impaired bladder function, bladder outlet obstruction or vesicoureteral
reflux. In these instances, treating the infection without addressing the actual problem
may be less than satisfactory and a urology consultation should be considered.
Organisms
The most common organisms isolated are the gram negative enteric bacteria, with E.
coli being cultured in approximately 85 percent of community acquired infections.
Other organisms include Enterobacter, Proteus, Klebsiella, Pseudomonas
and Enterococcus species to name a few. Gram positive organisms such as
Staphylococcal and Streptococcal species, as well as atypical organisms must be suspected
in those patients that do not respond to the antimicrobials most commonly used to treat
the usual offenders.
Management of uncomplicated UTIs
Uncomplicated, or isolated, infrequent urinary tract infections are not associated
with anatomic or physiologic abnormalities. The clinical manifestations include frequency,
urgency, dysuria, nocturia, hematuria, small volume voiding, suprapubic or lower abdominal
pain. A minimal diagnostic work-up is necessary, and an adequate history, physical
examination, urinalysis, and culture will reveal the diagnosis will yield an accurate
assessment in the overwhelming majority of cases. This will also assist in identifying
less common etiologies of conditions that could present with similar complaints. The
differential diagnosis includes sexually transmitted diseases, vaginitis, trauma or sexual
abuse, urothelial tumor, retained foreign bodies, and an overactive bladder. Treatment of
uncomplicated UTIs for 3 days (in women) or 30 days (in men) with an appropriate broad
spectrum antibiotic oral medication such as Septra
(TMP/SMX), Nitrofurantoin, or
Amoxicillin is generally adequate and can be tailored according to sensitivity patterns of
the organisms cultured. Fluoroquinolones are also very effective, however, are much more
costly, and nonjudicious use for uncomplicated UTIs and other community-acquired
infections is promoting drug resistance in the United States. Therefore this class of
antibiotics should be reserved for those patients with treatment failures or multiple drug
allergies to sulfa or penicillin derivatives. Follow-up cultures should be obtained 1 to 2
weeks after treatment is completed to ensure urine sterility.
Management of
recurrent
infections
Treatment failures are typically secondary to drug resistance, reinfection, or
bacterial persistence. Underdosing and non-compliance to treatment recommendations may
also contribute to unsuccessful therapy. Prophylactic antibiotics may be necessary for
patients with frequent, recurrent infections, and studies have shown that one half of a
typical dose at bedtime significantly reduces reinfection rates. Patients failing multiple
adequate courses of antibiotics may need urinary tract imaging or functional studies to
rule out complicating pathology. These may include intravenous urogram, computed
tomography, magnetic resonance imaging, ultrasound, cystoscopy, or cystometrogram and can
be done in coordination with a urologic consultation.
Management of complicated UTIs
Complicated urinary tract infections pose a significant health risk and can result
in increased morbidity and mortality if inadequately treated or if treatment is delayed.
Acute pyelonephritis has historically been universally treated with intravenous
antibiotics. Patients present with symptoms of fevers, chills, flank pain, pyuria, and
bacteruria. The gram-negative organisms are again the most common organisms recovered, and
treatment should be directed with broad-spectrum agents to empirically treat these
bacteria until urine and blood culture and sensitivity results are available. Outpatient
treatment has been proven safe for patients who are hemodynamically stable, and 14-day
treatment is recommended. Patients with known anatomic or functional abnormalities require
an additional 7 days of therapy to eradicate the infection. Non-responders to oral or
parenteral medications, or those whos condition deteriorates, should undergo upper
tract imaging to rule out a perinephric abscess or obstructed collecting system, both of
which require immediate drainage.
Pregnancy
Pregnancy is associated with physiologic changes such as hydronephrosis, increased
renal size, and anterosuperior bladder displacement, which increase the incidence of acute
pyelonephritis when compared to non-pregnant females. This places the mother and unborn
fetus at great risk for antenatal complications. Sepsis, preterm labor, infant
prematurity, and fetal demise are outcomes that can be avoided with the routine use of
screening urine cultures in asymptomatic gravid women and treating all with bacteruria.
Prostatitis
Prostatitis is a common disorder, which accounts for approximately 25 percent of
visits for men presenting for urologic evaluation of lower urinary tract symptoms. Most
prostatitis is uncomplicated and can be treated adequately with a 30-day course of
antibiotics as stated above. Acute febrile prostatitis accounts for less than five percent
of all patients with prostatitis. Fevers, chills, rigors, frequency, urgency, dysuria,
difficulty emptying the bladder, or even acute urinary retention are all common
complaints. Temperature elevations to 1040 and a distended, tender lower
abdomen are frequently encountered on physical examination. Prostate massage should be
avoided in the acutely infected patient as this could result in severe pain,
bacteremia, and unrecoverable urosepsis. Urine and blood cultures must be obtained before
starting antibiotic therapy, and treatment should then begin empirically with broad
spectrum agents such as ampicillin or vancomycin and an aminoglycocide until culture and
sensitivity results are available. Hospitalization along with intravenous hydration,
bladder drainage, and hemodynamic stabilization are imperative for the septic patient.
Four weeks of treatment is required, however, most patients when afebrile and stable, can
continue treatment with oral medications as an outpatient according to organism
sensitivities. Persistent spiking fevers despite appropriate antibiotic coverage
necessitates an investigation for a prostatic abscess, as antibiotics alone are typically
inadequate. Surgical drainage by a urologist is necessary if an abscess is discovered.
Chronic Prostatitis
Chronic prostatitis can be debilitating to those afflicted and is at
times a difficult condition to treat. Diagnosis is made by demonstrating > 10 white
blood cells per high powered field light microscopy and bacteria in the expressed
prostatic secretions and VB3 urine culture. The VB3 (or voided
bladder-3) specimen is obtained by collecting the first 5-10 milliliters of urine voided
after a vigorous prostate massage. This will produce colony counts ten-fold higher than
the midstream clean-catch specimen (VB2). Four to six week of treatment is
successful in the majority of cases, TMP/SMX or a Fluoroquinolone being the medications of
choice due to their penetrability into the prostatic tissue. Treatment duration may be
extended to 12 weeks and occasionally 6 months of once a day suppression if cure is not
achieved with the initial treatment.
Submitted by CAPT M. Melanie Haluszka, MC, USN, LCDR Brian K.
Auge, MC, USN, and LT Timothy F. Donahue, MC, USNR, National Naval Medical Center,
Bethesda (1999).