Use of single dose pre-operative antibiotics in abdominal surgery at the University teaching hospital, Lusaka

Abstract

The objective of the study was to assess the efficacy of a single dose pre-operative antibiotic prophylaxis as compared to post-operative antibiotics in prevention of surgical site infection in elective abdominal surgery at the University Teaching Hospital Lusaka It was a prospective randomized case control study. 80 patients undergoing clean or clean contaminated abdominal surgery were recruited using a non-probability convenience sampling method and divided into two groups: study and control. The confidence interval was 95 percent and p Value 0.05.The study consisted of 41 while the control consisted of 39 patients. Study patients were given a single dose of prophylactic antimicrobials (ceftriaxone and metronidazol) before their surgery, while Control patients were given postoperative antimicrobial treatment with triple antibiotics (crystalline penicillin, gentamicin and metronidazol) after surgery. Results: Mean age was 38.48+12.48 years in study and 38.05+13.90 years in control. There was no significant difference in the proportion of male and female patients in both groups (p=0.343). Statistical analysis showed no significant difference in the proportion of early postoperative surgical site infections between the two groups: 7.3 and 10.3 percent for study and control respectively with p=0.642. The surgical site infection rate in the all studied patients was 8.7 percent. E. coli was the commonest organism cultured from the wound discharge in our study (43 percent) followed by Staphylococcus aureus and proteus mirabilis (14 percent for each). Three of our cases having postoperative wound infection showed no growth. There was no significant difference between the two groups regarding mean operating time and duration of stay in hospital. There was no statistically significant difference in the proportion of surgical site infections between the group of patients receiving pre-operative single dose prophylactic antibiotic and the group of those who received triple antibiotic treatment post-operatively. The small sample size may explain this unexpected result that is at variance with literature in this field. However the use of a single preoperative prophylactic antibiotic was much more cost-effective than the use of combined triple antimicrobials in the postoperative period. A larger study is recommended for more definitive conclusions to be made. We recommend the UTH to adopt the practice of pre-operative prophylaxis in patients undergoing major abdominal surgery.