Microbiology and management of chronic maxillary sinusitis.

OBJECTIVE: Assessment of the microbiology and management of patients who suffered from chronic maxillary sinusitis was studied retrospectively.
DESIGN: Retrospective analysis of microbiology and antimicrobial therapy of 68 patients who underwent the Caldwell-Luc procedure for chronic sinusitis had not received antimicrobials before surgery and whose cultures showed bacterial growth.
SETTING: This study was performed at the Naval Hospital in Bethesda, Md. INTERVENTION: Amoxicillin-clavulanic acid was given to 18 patients, amoxicillin or ampicillin to 25, cefaclor to 17, and erythromycin to eight.
RESULTS: A total of 183 isolates (123 anaerobic and 60 aerobic) were recovered. Anaerobic organisms only were recovered from 35 (51%), specimens, and aerobic or facultative bacteria only in 12 (18%), and mixed aerobic and anaerobic flora in 21 (31%). Thirty-four aerobic and anaerobic beta-lactamase-producing bacteria were isolated from 28 patients. The 18 patients who received amoxicillin-clavulanic acid had the most rapid and complete response to therapy, none required a change in therapy, and surgical drainage was required in one case. Of 25 patients who received amoxicillin or ampicillin, eight required a change of therapy due to clinical failure (32%), including three who also had surgical drainage. Of 17 that received cefaclor, five had an antibiotic change (29%), one with surgical drainage. Of the eight who were treated with erythromycin, three needed antibiotic change (38%), two with surgical drainage. Resistant organisms were recovered from most of the patients that required therapeutic change.
CONCLUSIONS: These findings indicate the major role of aerobic and anaerobic beta-lactamase-producing bacteria organisms in the polymicrobial etiology of chronic maxillary sinusitis and illustrate the superiority of therapy effective against these bacteria.