INFECTION AFTER HYSTERECTOMY TABLE I. Potential pathogens recovered from operative site infections Aerobic bacteria Gram-positive cocci Enterococcus faecalis Streptococcus agalactiae Streptococcus sp. Staphylococcus aureus Staphylococcus epidermidis Gram-negative bacilli Acinetobacter sp. Citrobacter sp. Enterobacter sp. Escherichia coli Haemophilus influenzae Klebsiella sp. Proteus sp. Pseudomonas sp. Anaerobic bacteria Gram-positive cocci Peptostreptococcus sp. Gram-negative bacilli Prevotella bivius Prevotella sp. Bacteroides fragilis group B. caccae B. distasonis B. melaninogenicus B. ovatus B. thetaiotaomicron B. uniformis Fusobacterium sp. Gram-positive bacilli Clostridium sp. Bifidobacterium sp. Eubacterium spo Lactobacillus sp. Propionibacterium sp. Gram-negative cocci Veillonella parvula tween these variables, with modifications by me- chanical or antimicrobial applications, which results in the development of a clinically important opera- tive site infection. Hysterectomy has been classified as a "clean contaminated" procedure because of the lower re- productive tract flora and its introduction into the operative site at surgery. There is little risk of con- tamination of pelvic tissues until vaginal transec- tion. That the entire procedure is carried out in a contaminated field would explain why reported in- fection rates following vaginal hysterectomy were higher than those after abdominal hysterectomy, and why antimicrobial prophylaxis was more pre- dictably effective in preventing operative site in- fection in women undergoing vaginal hysterec- tomy. The following is one classification for the types of infection that can develop following hysterec- tomy. Temperature elevation alone is not the hall- mark of operative site infection requiring antimi- crobial therapy. Vagina/cuff ce//u/itis undoubtedly happens after every hysterectomy, irrespective of surgical approach. The vaginal surgical margin is erythematous, edematous, and hyperemic early fol- lowing surgery, and there are purulent vaginal se- cretions. This occurs with or without prophylaxis, HEMSELL and is not usually, but may be associated with tem- perature elevation and/or symptoms. If unassoci- ated with symptoms and signs of infection, it does not require treatment and disappears spontane- ously. This physiologic response to incision may or may not contribute to recurring temperature eleva- tion in an asymptomatic patient, febrile morbidity, which usually occurs during the first 48 h after sur- gery. If symptoms develop, they are primarily cen- tral, lower abdominal and pelvic discomfort, and there is tenderness at the vaginal surgical margin on bimanual examination without evidence of para- metrial involvement. This may not be clinically evident until after the patient is discharged from the hospital. Pelvic cellulitis, or lateral extension of cuff cellu- litis, is the result of the inability of physician and host to control the inflammatory response to the vaginal surgical margin. Inflammation spreads lat- erally to the parametrial region(s), and is associated with lower abdominal, pelvic, back, and/or leg pain and recurring temperature elevation, usually >38C, which begins 48-72 h after surgery. At ex- amination, there is lower abdominal tenderness, which is usually more pronounced on one side. No distinct masses are palpable at bimanual examina- tion, although pelvic tissue tenderness is obvious and corresponds to tender area(s) discovered at ab- dominal examination. If a tender mass is palpable in the operative site of a woman with posthysterectomy pelvic infec- tion, there arc several possibilities. The patient may have a phlegmon, an area of intense cellulitis and microabscesses. This tender, indurated area is usually not diagnosed by sonography, but may be identified by a pelvic computerized tomographic (CT) scan, or magnetic resonance imaging. A pelvic abscess also may complicate cellulitis. The most fre- quent location for this more fluctuant tender mass is just above the vaginal surgical margin; it is fre- quently referred to as a cuff abscess. Vaginal probe sonography is more sensitive than transabdominal sonography for identifying such an abscess. An ab- scess may also develop laterally in the extraperito- heal space or in retained adnexa. If the patient has an infected hematoma or abscess that is above the vaginal surgical margin, draining that site by open- ing the vaginal cuff will facilitate cure. This can usually be done in a treatment room and does not require another operative procedure. If abscesses INFECTIOUS DISEASES IN OBSTETRICS AND GYNECOLOGY 53