Anthony W. Chow

Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America.

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003-2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Management of Anaerobic Infections

Anaerobic infections are reviewed with emphasis on management. Most anaerobic pulmonary infections respond to penicillin G, even when Bacteroides fragilis (penicillin-resistant) is present. Clindamycin is suitable in penicillin-sensitive patients. Intraabdominal infections have a complex flora usually involving anaerobes, especially B. fragilis. It is desirable to use antimicrobial therapy to cover potential pathogens of all types. Surgical drainage and debridement are extremely important considerations. Anaerobic bacteria were found in 72% of 200 patients with female genital tract infections and were the exclusive isolates in 30%. Surgical therapy is primary, but antimicrobial and anticoagulant therapy are also important. A variety of soft-tissue infections involve anaerobes. Surgery is the major therapeutic approach. Anaerobic endocarditis is uncommon but may be difficult to manage. Chloramphenicol is ordinarily the drug of choice for brain abscess. New antimicrobial agents, which are under investigation and are promising, include new penicillins, new cephalosporins, new tetracyclines, and metronidazole.

Neonatal scalp abscess and fetal monitoring: factors associated with infection.

Forty-two of 929 (4.5 per cent) newborn infants prospectively studied following continuous, direct fetal heart rate monitoring during labor developed a scalp abscess at the site of electrode application during the neonatal period. Factors associated with infection with the use of a multivariate analysis were duration of monitoring (p less than 0.01) and high-risk indications for monitoring (p less than 0.01). Of the 42 infected neonates, 33 had complete bacteriologic studies. Microorganisms were isolated from all the infection tended to be polymicrobial, most commonly containing both aerobes and anaerobes. Staphylococcus epidermidis, Streptococcus, Peptostreptococcus, and Peptococcus were the predominant isolates. These data indicate that scalp abscess complicating intrapartum fetal monitoring may be nosocomial importance, and infants monitored should be closely observed in order to prevent more serious infectious complications.

Randomized, Double-Blind, Multicenter Trial Comparing Clinafloxacin with Imipenem as Empirical Monotherapy for Febrile Granulocytopenic Patients

In a double-blind, multicenter trial, 541 febrile granulocytopenic patients were randomized to receive either intravenous (iv) clinafloxacin (200 mg every 12 h) or i.v. imipenem (500 mg every 6 h) as empirical monotherapy. More baseline pathogens were susceptible to clinafloxacin (259 [99%] of 262 organisms) than to imipenem (253 [95%] of 265; P=.03). Initial favorable clinical response rates for clinafloxacin (88 [32%] of 272 patients) and imipenem (89 [33%] of 269) were similar. After addition of other antimicrobial agents, overall response rates were 259 (95%) of 272 for clinafloxacin and 251 (93%) of 269 for imipenem. During the study, only 13 clinafloxacin (5%) and 18 imipenem (7%) recipients died. Both drugs were generally well tolerated. Drug-related skin rash occurred more often with clinafloxacin (11% vs. 6%; P=.07), whereas nausea (2% vs. 5%; P=.16), Clostridium-difficile-associated diarrhea (3% vs. 8%; P=.02), and seizures (0% vs. 2%; P=.06) occurred more often with imipenem. These results suggest that clinafloxacin and imipenem have similar efficacy as empirical monotherapy in febrile granulocytopenic patients.

Antimicrobial therapy of postpartum endomyometritis: II. Prospective, randomized trial of mezlocillin versus ampicillin

Seventy patients with postpartum endomyometritis were treated with either intravenous mezlocillin (16 gm/day) or ampicillin (8 gm/day) in a prospective, randomized, double-blind comparison. Endocervical dilatation was routinely performed. Clindamycin (2 gm/day) was added if patients failed to improve within 48 hours of beginning therapy. Pretreatment clinical and microbiologic profiles were comparable in the two groups. Bacteremia was documented in 21 patients (30%). Anaerobic cocci and Bacteroides spp. (non-B. fragilis) comprised 19 of 29 (65%) blood isolates. Thirty of 33 mezlocillin-treated patients (91%) and 30 of 37 ampicillin-treated patients (81%) responded to initial therapy (P greater than 0.4). Resolution was noted after the addition of clindamycin in all ten nonresponders; two of these patients also required surgical wound debridement. Objective parameters of clinical response were not significantly different in the two treatment groups. Side effects of mezlocillin therapy were minimal. We conclude that mezlocillin and ampicillin are equally effective and safe for therapy of postpartum endomyometritis. That mezlocillin was not superior to ampicillin, despite expanded activity against B. fragilis and members of Enterobacteriaceae, suggests that these pathogens are less important than was previously considered in postpartum endomyometritis.

Cytosine Arabinoside Therapy for Herpes Simplex Encephalitis—Clinical Experience with Six Patients

Two neonates and four adults with herpes simplex virus (HSV) encephalitis were treated with cytosine arabinoside (Ara-C). A low dose of 40 to 160 mg per m2 per day was given for 4 to 6 days by continuous intravenous infusion and, except in two cases, by intrathecal administration. In one patient, idoxuridine (IUdR) at the dose of 1 g every 4 h was also administered after 4 days of Ara-C therapy. Both neonates and two of four adults survived. Their clinical improvement was closely related in time to the onset of therapy with Ara-C (cases 1, 2, 3) and with IUdR (case 4). In one adult who died on the 27th day of illness of a massive pulmonary embolus, postmortem examination of the brain did not disclose viral inclusions, and viral culture was negative. In the other patient who died, however, brain culture postmortem was still positive for HSV despite 4 days of Ara-C therapy. Ara-C, in addition to IUdR, may be effective in HSV encephalitis treatment, but double-blind, controlled studies appear to be necessary with these agents.

Clinical and microbiologic risk evaluation for post—cesarean section endometritis by multivariate discriminant analysis: Role of intraoperative mycoplasma, aerobes, and anaerobes

The clinical and microbiologic risk factors for postpartum endometritis were studied prospectively in 77 patients undergoing cesarean section without antibiotic prophylaxis at Harbor-University of California at Los Angeles Medical Center. Intraoperative cultures were obtained from the amniotic fluid, lower uterine segment, and abdominal wound for isolation of genital mycoplasmas, aerobes, and anaerobes. Postsection endometritis developed in 21 (27%) patients and was significantly associated with presence of either high-virulence bacteria (predominantly, coliforms, streptococci, anaerobic cocci, and bacteroides) (35% to 60% versus 10% to 24%; p less than 0.05) or Ureaplasma urealyticum (15% to 42% versus 0% to 10%; p less than 0.05) at any site compared with afebrile women. Multivariate analysis identified primary cesarean section, younger maternal age, presence of ruptured membranes, and presence of Ureaplasma as significant risk factors independent of other confounding variables (p less than 0.01). It is suggested that genital mycoplasmas could play a primary role in some cases of postsection endometritis or that they are cofactors or markers for the presence of other high-virulence aerobic and anaerobic bacteria.

Combined use of gentamicin and carbenicillin.

Abstract High concentrations of carbenicillin can decrease the antibacterial activity of gentamicin in vitro over a period of time. Experiments in dogs and humans with normal renal function show th...

Antimicrobial therapy of postpartum endomyometritis

Seventy patients with postpartum endomyometritis were treated with either intravenous mezlocillin (16 gm/day) or ampicillin (8 gm/day) in a prospective, randomized, double-blind comparison. Endocervical dilatation was routinely performed. Clindamycin (2 gm/day) was added if patients failed to improve within 48 hours of beginning therapy. Pretreatment clinical and microbiologic profiles were comparable in the two groups. Bacteremia was documented in 21 patients (30%). Anaerobic cocci and Bacteroides spp. (non- B. fragilis ) comprised 19 of 29 (65%) blood isolates. Thirty of 33 mezlocillin-treated patients (91%) and 30 of 37 ampicillin-treated patients (81%) responded to initial therapy (P>0.4). Resolution was need after the addition of clindamycin in all ten nonresponders; two of these patients also required surgical wound debridement. Objective parameters of clinical response were not significantly different in the two treatment groups. Side effects of mezlocillin therapy were minimal. We conclude that mezlocillin and ampicillin are equally effective and sate for therapy of postpartum endomyometritis. That mezlocillin was not superior to ampicillin, despite expanded activity against B. fragilis end members of Enterobacteriaceae , suggests that these pathogens are less important than was previously considered in postpartum endomyometritis.

Bacteriology of acute pelvic inflammatory disease: Suboptimal survival of Neisseria gonorrhoeae in a nonbuffered transport system

In our earlier study, Neisseria gonorrhoeae was infrequently isolated while Bacteroides fragilis was totally absent from cul-de-sac aspirates of patients with acute pelvic inflammatory disease (PID). Twenty additional women were studied to further elucidate the bacteriology of this disease. Recovery rate of N. gonorrhoeae from cul-de-sac aspirates collected in selective transport medium (Transgrow) was 25 per cent among patients with gonococcal PID, compared to only 8 per cent when specimens were collected in a nonselective transport system (Anaport). In vitro studies confirmed a detrimental effect of the Anaport for survival of N. gonorrhoeae during transport. This suboptimal survival was primarily related to low pH of the transport system under prereduced conditions, and could be corrected when pH of the transport vial was preadjusted and maintained between 6 and 7. B. fragilis was again absent from the cul-de-sac in all patients, while streptococci, peptococci, and peptostreptococci remained the most predominant isolates. These data may explain the empiric observations that penicillin and tetracycline are effective in most cases of acute PID.