BACKGROUND: We present our experience after the introduction of Advanced Trauma Life Support (ATLS)©, Trauma Team (TT) and Preperitoneal Pelvic Packing (PPP) protocols for the treatment of hemodynamically unstable pelvic blunt trauma. METHODS: This is a retrospective study with historical controls: before (Control Group, CG) and after (Study Group SG) the introduction of the protocol. A single physician managed the CG and angiography was the emergency manoeuvre. A team with ATLS guidelines and PPP as an emergency manoeuvre managed the SG. Data were collected retrospectively. Patients were divided into two groups: before and after the introduction of protocols. RESULTS: From January 2007 to October 2014, 36 patients were treated at our Centre. We consider patients from January 2007 to August 2011 (19 patients, CG) and from September 2011 to October 2014 (17 patients, SG). Median age was 54 years (43-69) in the CG vs. 47 (40-63) in the SG (p = 0.43), median initial SBP 90 mmHg (85-103) in the CG 94 (69-103) in the SG, (p = 0.60), heart rate was 90 (80-110) in the CG and 110 (95-130) in the SG, (p = 0.09). Median Injury Severity Score was 33 (21-41) in the CG and 34 (26-41) in the SG (p = 0.29). Time from arrival in the Emergency Department to first therapeutic manoeuvre was 132 minutes (109-180) in the CG and 87 minutes (51-204) in the SG (p = 0.4). The difference in mortality was statistically significant: 64.7% (11/17) in the CG and 23.5% (4/17) in the SG (p = 0.02). CONCLUSIONS: The introduction of protocols changed our approach in hemodynamically unstable pelvic trauma, achieving a remarkable improvement in early mortality.

Analisamos o comportamento quântico de um sistema descrito por um potencial assimétrico unidimensional constituído por um degrau junto a (i) uma barreira linear ou (ii) uma barreira exponencial. Resolvemos a equação dos valores próprios da energia por meio do método da representação integral, classificando as soluções independentes como classes de equivalência de caminhos homotópicos no plano complexo. Discutimos a estrutura dos estados ligados como função da altura U 0 do degrau e estudamos a propagação de um pacote de onda pontiagudo refletido pela barreira. Para ambos os casos linear e exponencial fornecemos uma fórmula explícita para para o retardo τ ( E ) como função da energia de pico E. Exibimos o comportamento ressonante de τ ( E ) para energias próximas de U 0. Ao analisar o comportamento assintótico para grandes energias das funções próprias do espectro contínuo, mostramos também que, como esperado, τ ( E ) se aproxima do valor clássico para E → ∞, divergindo assim para o caso linear e zerando para o caso exponencial.

We analyze the quantum-mechanical behavior of a system described by a one-dimensional asymmetric potential constituted by a step plus (i) a linear barrier or (ii) an exponential barrier. We solve the energy eigenvalue equation by means of the integral representation method, classifying the independent solutions as equivalence classes of homotopic paths in the complex plane. We discuss the structure of the bound states as function of the height U 0 of the step and we study the propagation of a sharp-peaked wave packet reflected by the barrier. For both the linear and the exponential barrier we provide an explicit formula for the delay time τ ( E ) as a function of the peak energy E. We display the resonant behavior of τ ( E ) at energies close to U 0. By analyzing the asymptotic behavior for large energies of the eigenfunctions of the continuous spectrum we also show that, as expected, τ ( E ) approaches the classical value for E → ∞, thus diverging for the step-linear case and vanishing for the step-exponential one.