Neutrophil oxidative burst capacity for peri-operative immune monitoring in trauma patients

Background: Post injury immune dysfunction can result in serious complications. Measurement of biomarkers may guide the optimal timing of surgery in clinically borderline patients and therefore prevent complications. Aim: peri-operative measurement of neutrophil oxidative burst capacity as an indicator of the immune response to major orthopaedic surgical procedures. Methods: Prospective cohort study of trauma patients aged ≥16 yrs with pelvic, acetabular, femoral shaft or tibial shaft fractures requiring surgical intervention. Blood samples were taken immediately pre-op and at 30 min, 7, 24 and 72–96 h post-operatively. Neutrophil oxidative burst capacity was measured both with and without stimulation by formyl-methionyl-leucyl-phenylalanine (fMLP, a chemotactic factor). Clinical outcomes measured were mortality, length of stay, MOF, pneumonia, acute respiratory distress syndrome (ARDS) and sepsis. Results: 100 consecutive orthopaedic trauma patients were enrolled over a 16 month period. 78% were male, with a mean age of 42 ± 18 years and an average ISS of 19 ± 13. Neutrophil oxidative burst capacity was significantly elevated at 7 h (p = 0.006) and 24 h (p = 0.022) post operatively. Patients who developed infective complications (pneumonia and sepsis) had higher levels of oxidative burst capacity pre-operatively (pneumonia: 1.52 ± 0.93 v 0.99 ± 0.66 p = 0.032, sepsis: 1.39 ± 0.86 v 0.97 ± 0.56 p = 0.024) and at 24 h post op (pneumonia: 2.72 ± 2.38 v 1.12 ± 0.63 p = <0.001, sepsis: 2.16 ± 2.09 v 1.10 ± 0.54 p =