Routine clinical markers of the magnitude of the systemic inflammatory response after elective operation: a systematic review

Operative injury to the body from all procedures causes a stereotypical cascade of neuroendocrine, cytokine, myeloid, and acute phase responses. This response has been examined commonly by the use of cortisol, interleukin-6 (IL-6), white cell count, and C-reactive protein (CRP). We aimed to determine which markers of the systemic inflammatory response were useful in determining the magnitude of injury after elective operations.

A systematic review of the literature was performed using surgery, endocrine response, systemic inflammatory response, cortisol, IL-6, white cell count, and CRP. For each analyte the studies were grouped according to whether the operative injury was considered to be minor, moderate, or major and then by the operative procedure.

A total of 164 studies were included involving 14,362 patients. The IL-6 and CRP responses clearly were associated with the magnitude of operative injury and the invasiveness of the operative procedure. For example, the peak CRP response increased from 52 mg/L with cholecystectomy to 123 mg/L with colorectal cancer resection, 145 mg/L with hip replacement, 163 mg/L after abdominal aortic aneurysm repair, and 189 mg/L after open cardiac surgery. There also appeared to be a difference between minimally invasive/laparoscopic and open procedures such as cholecystectomy (27 vs 80 mg/L), colorectal cancer resection (97 vs 133 mg/L), and aortic aneurysm repair (132 vs 180 mg/L).

Peak IL-6 and CRP concentrations consistently were associated with the magnitude of operative injury and operative procedure. These markers may be useful in the objective assessment of which components of Enhanced Recovery after Surgery are likely to improve patient outcome and to assess the possible impact of operative injury on immune function.