Amputation in emergency situations: indications, techniques and Médecins Sans Frontières France's experience in Haiti

PURPOSE: The decision to amputate is always difficult but becomes even harder in emergency situations, which usually present extra complicating factors. MSF EXPERIENCE: These include human factors (related to both the surgeon and the patient); poor or nonexistent medical facilities, especially in war conditions or resource-poor countries; and cultural and religious considerations. Médecins Sans Frontières (MSF) has developed a quick medical and logistical response that relies on surgical protocols adapted to emergency situations, together with complete "kits" of medical equipment, supplies and inflatable facilities. CONCLUSION: Our response to Haiti's 2010 earthquake relied on these tools but also highlighted the need to develop more detailed protocols that will help our teams on the ground

Numerical modeling of two-phase flows using the two-fluid two-pressure approach

The present paper is devoted to the computation of two-phase flows using the two-fluid approach. The overall model is hyperbolic and has no conservative form. No instantaneous local equilibrium between phases is assumed, which results in a two-velocity twopressure model. Original closure laws for interfacial velocity and interfacial pressure are proposed. These closures allow to deal with discontinuous solutions such as shock waves and contact discontinuities without ambiguity for the definition of Rankine-Hugoniot jump relations. Each field of the convective system is investigated, providing that the maximum principle for the volume fraction and the positivity of densities and internal energies are ensured when focusing on the Riemann problem. Two Finite Volume methods are presented, based on the Rusanov scheme and on an approximate Godunov scheme. Relaxation terms are taken into account using a fractional step method. Eventually, numerical tests illustrate the ability of both methods to compute two-phase flows

On the use of symmetrizing variables for vacuum

The paper is devoted to the computation of shallow-water equations (or Euler equations) when the flow may include dry areas. This is achieved with the help of some symmetrizing variables

On the use of symmetrizing variables for vacuum

The paper is devoted to the computation of shallow-water equations (or Euler equations) when the flow may include dry areas. This is achieved with the help of some symmetrizing variables

Numerical modeling of two-phase flows using the two-fluid two-pressure approach

The present paper is devoted to the computation of two-phase flows using the two-fluid approach. The overall model is hyperbolic and has no conservative form. No instantaneous local equilibrium between phases is assumed, which results in a two-velocity twopressure model. Original closure laws for interfacial velocity and interfacial pressure are proposed. These closures allow to deal with discontinuous solutions such as shock waves and contact discontinuities without ambiguity for the definition of Rankine-Hugoniot jump relations. Each field of the convective system is investigated, providing that the maximum principle for the volume fraction and the positivity of densities and internal energies are ensured when focusing on the Riemann problem. Two Finite Volume methods are presented, based on the Rusanov scheme and on an approximate Godunov scheme. Relaxation terms are taken into account using a fractional step method. Eventually, numerical tests illustrate the ability of both methods to compute two-phase flows