Glutamine preconditioning protects against local and systemic injury induced by orthopaedic surgery

Long bone surgery represents a significant surgical insults, and may cause severe local and systemic sequalae following both planned and emergent surgery. Glutamine offers pharmacological modulation of injury through clinically acceptable preconditioning. This effect has not been previously demonstrated in an orthopaedic model.

The aim of the study was to test the hypothesis that glutamine preconditioning protects against the local and systemic effects of long bone trauma in a rodent model.

Thirty two adult male Sprague-Dawley rats were randomised into four groups: Control group which received trauma without preconditioning; Normal Saline preconditioning 1 hour before trauma; Glutamine preconditioning 1 hour before trauma; Glutamine preconditioning 24 hours prior to trauma. Trauma consisted of bilateral femoral fracture following intramedullary instrumentation. Blood samples were taken before the insult, and at an interval four hours following this. Bronchioalveolar lavage (BAL) was performed, with skeletal muscle and lung harvested for evaluation.

Glutamine pre-treated rats had lower Creatine Kinase levels, less creatinine elevation, and a significant reduction in neutrophil infiltration into BAL fluid. Glutamine pre-treated rats showed less muscle and lung oedema. This effect was more pronounced for the group which received glutamine 24 hours before trauma.

Preconditioning with a single bolus of intravenous glutamine prior to planned orthopaedic intervention affords loco-regional and distal organ protection. We believe these finding have significant implications for elective orthopaedic surgery where significant soft tissue and long bone manipulation is anticipated.