RESUMO
STUDY DESIGN: Retrospective comparative study. OBJECTIVES: The aim of this study was to compare the efficacy of prophylactic antibiotics in spinal surgery for the occurrence of postoperative surgical site infection (SSI) and host immune reactions depending on various administration regimens and protocols. SUMMARY OF LITERATURE REVIEW: The superiority of one regimen or protocol of prophylactic antibiotics over others for SSI in spinal surgery has not been clearly demonstrated. We designed a controlled clinical trial to compare the occurrence of SSI with the changes of hematologic results depending on prophylaxis regimens and protocols. MATERIALS AND METHODS: Between January 2007 and February 2011, two hundred consecutive patients who had undergone thoracolumbar/lumbar surgery for degenerative or traumatic disease were included. Postoperative protocol was altered for each group of fifty consecutive patients; 1st generation cephalosporins for 5-days (group A), 2nd generation cephalosporins for 5-days (group B), 1st generation cephalosporins for 3-days (group C), and 2nd generation cephalosporins for 3-days (group D). Preoperative antibiotic prophylaxis was administrated within 1 hour prior to surgical incision with the same trial antibiotics. Intraoperative bacterial culture was performed from the surgical site. The occurrences of SSI were evaluated as either incisional or organ/space SSI. Serial changes in hematologic inflammatory markers (WBC, ESR, CRP) and DIC markers (fibrinogen, FDP, D-dimer) were compared until postoperative 2 weeks. RESULTS: The study groups were homogeneous regarding age, sex, body mass index, estimated blood loss, diabetes mellitus, smoking, diagnosis, baseline laboratory values, and type of surgery including instrumentation. Overall, 13 cases of incisional SSI (6.5%) and 3 cases (1.5%) of organ/space SSI occurred. There was no difference in the occurrence of incisional and organ/space SSI among the 4 groups (P=0.690, 0.799). Laboratory results revealed that postoperative changes in hematologic inflammatory markers and DIC markers were not influenced by prophylaxis regimens and protocols (all P>0.05). CONCLUSIONS: The occurrences of SSI and host immune responses were not influenced by postoperative antibiotics regimens and protocols. Hematologic investigation revealed that host immune responses did not depend on the type of prophylactic antibiotics.