Ahad Alhassan Saud Abdulaziz Al Saud
King Saud University Medical City, Kingdom of Saudi Arabia
Aim: We studied whether any aortic flow changes could be observed in the early stage of septic (warm) shock.
Patients and Methods: Computed tomography data and image reconstruction software packages to analyze patient-specific aortic flow patterns based on computational fluid dynamics models (non-Newtonian Navier-Stokes equations) were used. Boundary conditions were extracted from hemodynamic monitoring of trauma patients. Ten stable trauma patients [35 ± 9.9 years of age, 6 males, injury severity score (ISS) 26 ± 3.9] served as controls. Ten trauma septic patients [37 ± 8.7 years of age, 5 males, ISS 27 ± 4.2] were studied. Hemodynamic monitoring was performed using a pulmonary artery catheter.
Results: In warm shock, the model depicted: 1. increased asymmetry of the three-dimensional aortic vortex (Dean number increased 77%), 2. reduction of secondary flow in the peripheral blood vessels (Reynolds number increased 78%), 3. Increased aortic wall shear stress; while no pathology in aortic flow geometry was documented (Womersley number unchanged).
Conclusion: In warm shock, a severely distorted aortic vortex may be responsible for reduction of secondary flow to peripheral arteries and increased aortic wall shear stress.