Influence of surgical intervention in the immune response of severely injured patients.

Abstract

Primary events such as severe injury and elective surgery cause a deterioration of the immune response measurable by reduction of expression of HLA-DR on monocytes or ex vivo LPS-induced TNFalpha production. The further influence of secondary surgery after severe injury on the immune response remains unresolved. Prospective observation study. Surgical intensive care unit of an university hospital. Sixteen severely injured patients with an ISS >25 points. On day 1 after trauma and immediately before secondary surgery, mean fluorescence intensity (MFI) of HLA-DR expression on monocytes and TNFalpha ex vivo synthesis was significantly reduced compared to healthy donors. Overall, surgical intervention during the second week after trauma caused no further reduction of HLA-DR expression on monocytes and of the ex vivo TNFalpha-synthesis. However, major surgery such as intramedullary nailing or pelvic osteosynthesis caused reduction of the HLA-DR expression and TNFalpha-synthesis, whereas, minor surgical interventions such as osteosynthesis on peripheral joints exhibited no significant effects on the immune response. Surgical intervention performed to clear septic foci normalised immune response by elevating HLA-DR expression on monocytes and ex vivo TNFalpha synthesis. Severe injury caused elevated serum IL-10 levels, whereas secondary surgery did not induce a further increase in serum IL-10 levels. This study shows that initial trauma as well as major secondary surgery causes a suppression of immune functions, whereas minor secondary surgery does not cause significant immune disturbance.