Peri-operative changes in serum immune markers after trauma: A systematic review

Introduction: Surgery is a posttraumatic immune stimulus which contributes to the systemic inflammatory response syndrome and multiple organ failure (MOF). Serum markers may facilitate post-injury immune monitoring, predict complications and guide the timing of surgery. Aim: To evaluate whether immune markers increase after surgery in trauma patients, if this is affected by the timing of surgery, and whether immune markers correlate with clinical outcomes. Patients and methods: Systematic review of MEDLINE, Cochrane and EMBASE using a combination of keywords including trauma, biological markers, immune monitoring, and surgical procedures. The last search was performed on 26/11/13. The search considered English language studies enrolling adult trauma patients. Outcomes were perioperative immune markers plus clinical outcomes including mortality, MOF, sepsis. Results: 1612 Articles were identified using the search strategy. 1548 Articles were excluded by title and 40 excluded by abstract, leaving 24 articles for full text review. Of these articles, fifteen studies were eligible for study inclusion. The disparity in interventions and outcome measures precluded combined statistical analysis. The surgical intervention studied was mostly intramedullary nailing of long bone fractures. All articles described a postoperative increase in at least one marker. Interleukin (IL)-6 and IL-10 were consistently elevated and tested in the greatest number of patients. Many studies did not correlate markers with clinical outcomes and few significant associations were demonstrated. Two studies considered the timing of surgery and showed greater increase in IL-6 after "early'' surgery, though definitions of timing were dissimilar. Discussion: An increase in posttraumatic serum cytokines has been demonstrated after surgery, but without consistent clinical associations. The timing of surgery may modulate this increase. Future research directions include confirmation of findings in larger populations, clarifying clinical associations, and evaluation of other surgical interventions. (C) 2014 Elsevier Ltd. All rights reserved.