Prognostic models for mortality risk in patients requiring ECMO.

PURPOSE: To provide an overview and evaluate the performance of mortality prediction models for patients requiring extracorporeal membrane oxygenation (ECMO) support for refractory cardiocirculatory or respiratory failure. METHODS: A systematic literature search was undertaken to identify studies developing and/or validating multivariable prediction models for all-cause mortality in adults requiring or receiving veno-arterial (V-A) or veno-venous (V-V) ECMO. Estimates of model performance (observed versus expected (O:E) ratio and c-statistic) were summarized using random effects models and sources of heterogeneity were explored by means of meta-regression. Risk of bias was assessed using the Prediction model Risk Of BiAS Tool (PROBAST). RESULTS: Among 4905 articles screened, 96 studies described a total of 58 models and 225 external validations. Out of all 58 models which were specifically developed for ECMO patients, 14 (24%) were ever externally validated. Discriminatory ability of frequently validated models developed for ECMO patients (i.e., SAVE and RESP score) was moderate on average (pooled c-statistics between 0.66 and 0.70), and comparable to general intensive care population-based models (pooled c-statistics varying between 0.66 and 0.69 for the Simplified Acute Physiology Score II (SAPS II), Acute Physiology and Chronic Health Evaluation II (APACHE II) score and Sequential Organ Failure Assessment (SOFA) score). Nearly all models tended to underestimate mortality with a pooled O:E > 1. There was a wide variability in reported performance measures of external validations, reflecting a large between-study heterogeneity. Only 1 of the 58 models met the generally accepted Prediction model Risk Of BiAS Tool criteria of good quality. Importantly, all predicted outcomes were conditional on the fact that ECMO support had already been initiated, thereby reducing their applicability for patient selection in clinical practice. CONCLUSIONS: A large number of mortality prediction models have been developed for ECMO patients, yet only a minority has been externally validated. Furthermore, we observed only moderate predictive performance, large heterogeneity between-study populations and model performance, and poor methodological quality overall. Most importantly, current models are unsuitable to provide decision support for selecting individuals in whom initiation of ECMO would be most beneficial, as all models were developed in ECMO patients only and the decision to start ECMO had, therefore, already been made.

Caracterização do desempenho motor em escolares com transtorno de déficit de atenção com hiperatividade / Characterization of motor performance in students with attention deficit hyperactivity disorder

Objetivos: Caracterizar e comparar o desempenho motor de escolares com Transtorno de Déficit de Atenção com Hiperatividade (TDAH) com o desempenho de escolares com desenvolvimento neuropsicomotor normal e verificar a ocorrência de Transtorno do Desenvolvimento da Coordenação (TDC) nos escolares com TDAH deste estudo. Método: Participaram deste estudo 30 escolares de 1ª a 4ª séries, na faixa etária de 6 a 12 anos de idade, de ambos os gêneros, divididos em 2 grupos: GI - composto de 15 escolares com Transtorno de Déficit de Atenção e Hiperatividade (TDA/H) e GII - composto de 15 escolares com desenvolvimento neuropsicomotor normal. Foi aplicado o Exame Motor para o diagnóstico de Déficit de Atenção, Controle Motor e Percepção (DAMP). Resultados: Os resultados evidenciaram diferença estatisticamente significativa, revelando que o GI apresentou desempenho inferior em provas de habilidades motoras grossa e fina. Conclusão: Os escolares com TDAH deste estudo, por apresentarem desempenho inferior no exame motor, possuem quadro de TDC em comorbidade, não sendo, portanto, os problemas de coordenação aqui evidenciados características do TDAH.

Aims: To characterize and to compare the motor performance of students with Attention-Deficit Hyperactivity Disorder (ADHD) with the performance of students with normal neuropsicomotor development and to verify the occurrence of Disorder Coordination Development (DCD). Method: 30 students from 2nd to 4th grades participated, from both genders, ranging from 6 to 12 years old, distributed in: GI: 15 students with ADHD and GII: 15 students with normal neuropsicomotor development, paired according to gender and age with GI. The Motor Examination was conducted for diagnosisof Deficit of Attention, Motor Control and Perception (DAMP). Results: The results evidenced a significant statistical difference, revealing that GI presented inferior performance in the fine and gross motor skills tests. Conclusion: Once students with ADHD presented inferior performance in the motor examination in this study, they can have DCD as comorbidity, not being, however, the coordination disorders shown here characteristic of ADHD.

Caracterização do desempenho motor em escolares com transtorno de déficit de atenção com hiperatividade / Characterization of motor performance in students with attention deficit hyperactivity disorder

Objetivos: Caracterizar e comparar o desempenho motor de escolares com Transtorno de Déficit de Atenção com Hiperatividade (TDAH) com o desempenho de escolares com desenvolvimento neuropsicomotor normal e verificar a ocorrência de Transtorno do Desenvolvimento da Coordenação (TDC) nos escolares com TDAH deste estudo. Método: Participaram deste estudo 30 escolares de 1ª a 4ª séries, na faixa etária de 6 a 12 anos de idade, de ambos os gêneros, divididos em 2 grupos: GI - composto de 15 escolares com Transtorno de Déficit de Atenção e Hiperatividade (TDA/H) e GII - composto de 15 escolares com desenvolvimento neuropsicomotor normal. Foi aplicado o Exame Motor para o diagnóstico de Déficit de Atenção, Controle Motor e Percepção (DAMP). Resultados: Os resultados evidenciaram diferença estatisticamente significativa, revelando que o GI apresentou desempenho inferior em provas de habilidades motoras grossa e fina. Conclusão: Os escolares com TDAH deste estudo, por apresentarem desempenho inferior no exame motor, possuem quadro de TDC em comorbidade, não sendo, portanto, os problemas de coordenação aqui evidenciados características do TDAH. (AU)

Aims: To characterize and to compare the motor performance of students with Attention-Deficit Hyperactivity Disorder (ADHD) with the performance of students with normal neuropsicomotor development and to verify the occurrence of Disorder Coordination Development (DCD). Method: 30 students from 2nd to 4th grades participated, from both genders, ranging from 6 to 12 years old, distributed in: GI: 15 students with ADHD and GII: 15 students with normal neuropsicomotor development, paired according to gender and age with GI. The Motor Examination was conducted for diagnosisof Deficit of Attention, Motor Control and Perception (DAMP). Results: The results evidenced a significant statistical difference, revealing that GI presented inferior performance in the fine and gross motor skills tests. Conclusion: Once students with ADHD presented inferior performance in the motor examination in this study, they can have DCD as comorbidity, not being, however, the coordination disorders shown here characteristic of ADHD.(AU)

Kinetic parameters estimation in an anaerobic digestion process using successive quadratic programming.

In this work, an optimization method is implemented in an anaerobic digestion model to estimate its kinetic parameters and yield coefficients. This method combines the use of advanced state estimation schemes and powerful nonlinear programming techniques to yield fast and accurate estimates of the aforementioned parameters. In this method, we first implement an asymptotic observer to provide estimates of the non-measured variables (such as biomass concentration) and good guesses for the initial conditions of the parameter estimation algorithm. These results are then used by the successive quadratic programming (SQP) technique to calculate the kinetic parameters and yield coefficients of the anaerobic digestion process. The model, provided with the estimated parameters, is tested with experimental data from a pilot-scale fixed bed reactor treating raw industrial wine distillery wastewater. It is shown that SQP reaches a fast and accurate estimation of the kinetic parameters despite highly noise corrupted experimental data and time varying inputs variables. A statistical analysis is also performed to validate the combined estimation method. Finally, a comparison between the proposed method and the traditional Marquardt technique shows that both yield similar results; however, the calculation time of the traditional technique is considerable higher than that of the proposed method.