protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            App.Current.ContextoAtual = ctx;
            if (App.Current.AtendimentoAtual < 0)
            {
                Web.Atendimento atendimento = new Web.Atendimento
                                                  {
                                                      PacienteId = App.Current.PacienteAtual,
                                                      MedicoId = 1,
                                                      Horario = DateTime.Now
                                                  };

                ctx.Atendimentos.Add(atendimento);
                var submitOperation = ctx.SubmitChanges();
                submitOperation.Completed += (s, ex) =>
                                                 {
                                                     if (submitOperation.HasError)
                                                     {
                                                         MessageBox.Show(submitOperation.Error.Message);
                                                         return;
                                                     }
                                                     if (submitOperation.ChangeSet.Count() == 0)
                                                     {
                                                         MessageBox.Show("Erro ao carregar atendimento");
                                                         return;
                                                     }
                                                     App.Current.AtendimentoAtual = ((Web.Atendimento)submitOperation.ChangeSet.AddedEntities.First()).Id;
                                                     ObtemAtendimentoAtual();
                                                 };
            }
            else
                ObtemAtendimentoAtual();
        }
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            App.Current.ContextoAtual = ctx;
            if (App.Current.AtendimentoAtual < 0)
            {
                Web.Atendimento atendimento = new Web.Atendimento
                {
                    PacienteId = App.Current.PacienteAtual,
                    MedicoId   = 1,
                    Horario    = DateTime.Now
                };

                ctx.Atendimentos.Add(atendimento);
                var submitOperation = ctx.SubmitChanges();
                submitOperation.Completed += (s, ex) =>
                {
                    if (submitOperation.HasError)
                    {
                        MessageBox.Show(submitOperation.Error.Message);
                        return;
                    }
                    if (submitOperation.ChangeSet.Count() == 0)
                    {
                        MessageBox.Show("Erro ao carregar atendimento");
                        return;
                    }
                    App.Current.AtendimentoAtual = ((Web.Atendimento)submitOperation.ChangeSet.AddedEntities.First()).Id;
                    ObtemAtendimentoAtual();
                };
            }
            else
            {
                ObtemAtendimentoAtual();
            }
        }