Abstract
Introduction
Long bone surgery and marrow instrumentation represent significant surgical insults, and may cause severe local and systemic sequelae following both planned and emergent surgery. Preconditioning is a highly conserved evolutionary endogenous protective mechanism, but finding a clinically safe and acceptable method of induction has proven difficult. Glutamine, a known inducer of the heat shock protein (HSP) response, offers pharmacological modulation of injury through clinically acceptable preconditioning. This effect has not been previously demonstrated in an orthopaedic model.
Aims
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.
Methods
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, and
Glutamine preconditioning 24 hours prior to trauma. Trauma consisted of bilateral femoral fracture following intramedullary instrumentation. Blood samples were taken just prior to the insult, and at an interval four hours following this. The animals were then sacrificed, bronchioalveolar lavage (BAL) performed and skeletal muscle and lung harvested for evaluation.
Results
Glutamine pretreated rats had lower CK levels at 4 hours than those treated with normal saline. Renal dysfunction was less in pre-treated animal, and there was a significant reduction in neutrophil infiltration into BAL fluid. Finally 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 than the group receiving glutamine one hour before trauma.
Conclusion
This data suggests that preconditioning with a single bolus of intravenous glutamine prior to planned orthopaedic intervention may afford local and end-organ protection.
