Perioperative Antimicrobial Prophylaxis in Neurosurgery: Clinical Trial of Systemic Flomoxef Administration and Saline Containing Gentamicin for Irrigation

The efficacy of a new protocol consisting of a prophylactic antibiotic regimen of peri and postoperative intravenous administration of flomoxef and irrigation of the operative field with saline containing gentamicin was assessed by comparing infection rates in two consecutive series of patients who underwent neurosurgical procedures. Group A received postoperative flomoxef administration, with saline containing no antibiotics for irrigation, from July 1988 to December 1989. Group B received the new protocol from January 1990 to December 1991. For further evaluation, this protocol was continued in most patients who underwent surgery from January 1992 through December 1993 (Group C). Only adult or adolescent patients who underwent clean neurosurgical procedures were included. The number of patients and procedures in each group were: 76 patients (97 procedures) in Group A, 103 (133) in Group B, and 107 (137) in Group C. There were no significant differences between Groups A and B in age, sex, clinical category, coexistent disease, clinical outcome, surgical procedures, general anesthesia, emergency operation, steroid administration, and the timing (season), duration, and frequency of surgery. Meningitis developed in three patients and subcutaneous infection in one in Group A. None of the patients in Group B experienced postoperative infection. This difference in infection rates (4.1% vs. 0%) was statistically significant (p = 0.0305). Furthermore, no postoperative infections developed in the Group C patients. The most appropriate interval for multiple dose administration was determined by analyzing intraoperative time-related changes in the serum flomoxef concentration during surgery in 21 recent patients. Serum flomoxef concentrations fell below therapeutic levels (3.0μg/ml) by the 6th post-administration hour in 70% of patients. We conclude that this antibiotic regimen significantly reduces the postoperative infection rate following neurosurgical procedures. Multiple dose administration of flomoxef is recommended when the duration of surgery is 6 hours or more.