Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (246 page)

   Although there are no biochemical or hematologic markers of the disorder, ureteral obstruction is assessed by measurements of BUN and serum creatinine concentration. Both are usually elevated in correlation with the presence and extent of obstruction.

   The inflammatory level of the disorder is assessed by measurement of the erythrocyte sedimentation rate and C-reactive protein, both of which are elevated in the majority of patients at presentation.

   Antinuclear antibodies may be found in up to 60% of cases.

   Anemia is found in up to 38% of cases.

Suggested Readings

Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis.
Lancet.
2006;367:241–251.

van Bommel EF, Jansen I, Hendriksz TR, et al. Idiopathic retroperitoneal fibrosis: prospective evaluation of incidence and clinicoradiologic presentation.
Medicine
(Baltimore)
.
2009;88:193–201.

INFECTIONS

URINARY TRACT INFECTIONS
*

Urinary tract infections (UTIs) are among the most common infections encountered in both outpatient and inpatient settings.

   Definitions and Key Concepts

   Most UTIs are restricted to infection of the bladder (cystitis), though infection may occur in any area of the urinary tract, from the kidney to urethra.

   Most UTIs are caused by uropathogenic organisms from the gastrointestinal or vaginal florae that colonize the periurethral mucosa. Organisms are able to ascend through the urethra to the bladder by various mechanisms.

   Acute cystitis that occurs in healthy (including no history suggestive of urinary tract abnormality), premenopausal, nonpregnant women is classified as
uncomplicated
. All other UTIs are classified as
complicated
.

   Uncomplicated cystitis rarely progresses to severe infection. The goal of antibiotic therapy of uncomplicated cystitis is for amelioration of symptoms.

   Most UTIs are caused by a single uropathogenic species. Polymicrobial infections may occur in patients with anatomical abnormalities or foreign bodies, but suspect colonization or culture contamination for cultures that yield growth of more than two different species.

   Etiology:
E. coli
causes >75% of all uncomplicated UTIs. Most other UTIs are caused by other enteric gram-negative bacilli (e.g.,
K. pneumoniae
and
P. mirabilis
) and gram-positive cocci (e.g.,
Enterococcus
species,
S. saprophyticus
, Group B streptococcus). Resistant organisms (e.g.,
C. albicans
,
P. aeruginosa
) are usually associated with nosocomial and health care– related UTIs.