Bruce L. Dalkin
I Urinary Tract Infections
* Bacteriuria is the presence of bacteria in the bladder. It can occur with or without pyuria and can be symptomatic or asymptomatic.
* Pyelonephritis is a clinical syndrome with fever, chills, and flank pain accompanied by bacteriuria and pyuria.
* Cystitis is an inflammatorycondition of the bladder. It can be bacterial or nonbacterial (e.g., radiation, interstitial, fungal causes).
* Reinfection signifies recurrent infection with different bacteria from outside the urinary tract.
* Relapse indicates recurrent infection caused by the same bacterial strain from a focus within the urinary tract.
* Prophylactic antimicrobial therapy refers to prevention ofreinfection of the urinary tract by administration of antimicrobial therapy.
* Suppressive antimicrobial therapy is used to suppress an existing urinary tract infection (UTI) that cannot be eradicated.
* Ascending infection. Most UTIs are thought to result from ascending colonization from the introitus in women or from the periurethral area in men. Fecal flora are the most commonpathogens, including Escherichia coli, other gram-negative rods, and entercocci. Other pathogens include staphycoccal species.
* Incidence. UTIs are more common in women than in men, possibly because women have a shorter urethra. There may also be a protective effect of the prostatic urethra in men. Newer concepts of bacterial adherence factors in the bladder are being investigated.
* Cystitis symptoms include:
* Urinary frequency
* Cloudy or foul-smelling urine
* Pyelonephritis symptoms include all of the symptoms of cystitis plus fever, chills, and flank pain.
* Pyuria. The presence of white blood cells in the urine indicates inflammation.* Bacteriuria. The detection of bacteria in the urine may require a Gram stain.
* Nitrate reduction. Nitrate in the urine is reduced to nitrite in the presence of bacteria.
* Leukocyte esterase. White blood cells contain esterases that can be detected in the urine.
* Urine culture is performed on a split agar disposable plate and determines the presence of bacteria inthe urine. The common quantization for infection is â‰¥10-5 bacteria. However, lower numbers present in symptomatic patients may signify infection.
* Choice of antimicrobial agent
* Uncomplicated cystitis. Good results have been obtained with ampicillin, amoxicillin, first-generation cephalosporins, fluoroquinolones, nitrofurantoin, and trimethoprim-sulfamethoxazole.Regional differences in antibiotic resistance exist and should dictate choice of antimicrobial agent.
* Complicated UTI. Fluoroquinolones or parenteral regimens are recommended for initial empirical therapy of a UTI associated with significant anatomic or structural abnormality of the urinary tract or with acute pyelonephritis or prostatitis.
* Duration of therapy
* Uncomplicatedcystitis therapy lasts for 1â€“3 days.
* Complicated UTI therapy lasts for 7â€“14 days.
* Acute prostatitis therapy is given over 14â€“28 days.
* Pyelonephritis therapy lasts for 14â€“21 days.
F Serious complications of a UTI
* Renal papillary necrosis. Sloughing of the renal papillae is frequently seen in diabetic patients. This sloughing can cause ureteral obstruction andhydronephrosis.
* Pyonephrosis is infected hydronephrosis associated with infectious destruction of renal parenchyma. Usually, the patient is very ill and has a fever and chills.
* Cause. Obstruction (e.g., ureteral calculus) with infection
* Ureteral catheter drainage
* Percutaneous nephrostomy tube, if a ureteral catheter is not possible