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The effect of C1-esterase inhibitor on systemic inflammation in trauma patients with a femur fracture - The CAESAR study: study protocol for a randomized controlled trial

Marjolein Heeres13*, Tjaakje Visser1, Karlijn JP van Wessem1, Anky HL Koenderman2, Paul FW Strengers2, Leo Koenderman3 and Luke PH Leenen1

Author Affiliations

1 Department of Trauma Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3508 GA, Utrecht, The Netherlands

2 Sanquin Blood Supply Foundation, Plesmanlaan 125, 1066 CX, Amsterdam, The Netherlands

3 Department of Respiratory Medicine, University Medical Centre Utrecht, Heidelberglaan 100, 3508 GA, Utrecht, The Netherlands

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Trials 2011, 12:223  doi:10.1186/1745-6215-12-223

Published: 11 October 2011



Systemic inflammation in response to a femur fracture and the additional fixation is associated with inflammatory complications, such as acute respiratory distress syndrome and multiple organ dysfunction syndrome. The injury itself, but also the additional procedure of femoral fixation induces a release of pro-inflammatory cytokines such as interleukin-6. This results in an aggravation of the initial systemic inflammatory response, and can cause an increased risk for the development of inflammatory complications. Recent studies have shown that administration of the serum protein C1-esterase inhibitor can significantly reduce the release of circulating pro-inflammatory cytokines in response to acute systemic inflammation.


Attenuation of the surgery-induced additional systemic inflammatory response by perioperative treatment with C1-esterase inhibitor of trauma patients with a femur fracture.


The study is designed as a double-blind randomized placebo-controlled trial. Trauma patients with a femur fracture, Injury Severity Score ≥ 18 and age 18-80 years are included after obtaining informed consent. They are randomized for administration of 200 U/kg C1-esterase inhibitor intravenously or placebo (saline 0.9%) just before the start of the procedure of femoral fixation. The primary endpoint of the study is Δ interleukin-6, measured at t = 0, just before start of the femur fixation surgery and administration of C1-esterase inhibitor, and t = 6, 6 hours after administration of C1-esterase inhibitor and the femur fixation.


This study intents to identify C1-esterase inhibitor as a safe and potent anti-inflammatory agent, that is capable of suppressing systemic inflammation in trauma patients. This might facilitate early total care procedures by lowering the risk of inflammation in response to the surgical intervention. This could result in increased functional outcomes and reduced health care related costs.

Trial registration NCT01275976 (January 12th 2011)

ARDS; C1-esterase inhibitor; Complication; Femur; Fracture; Inflammation; Interleukin-6; Intramedullary fixation; MODS; Trauma