Valor preditivo da variação de pressão de pulso para resposta a infusão de fluidos em pacientes ventilados com estratégia protetora
Data
2012-10-31
Autores
Freitas, Flavio Geraldo Rezende de 
Orientadores
Machado, Flávia Ribeiro
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivos. A aplicabilidade da variação de pressão de pulso (ΔPP) em predizer a resposta à infusão de fluidos em pacientes sob estratégia ventilatória invasiva protetora é incerta na pratica clínica. Desenhamos esse estudo para avaliar a acurácia deste parâmetro em pacientes sépticos ventilando com baixos volumes correntes (6ml.kg-1). Métodos. Foram incluídos quarenta pacientes após a fase de ressuscitação da sepse grave e choque séptico que estavam ventilados com volume corrente de 6ml.kg-1. O ΔPP foi calculado automaticamente no baseline e após prova de volume (7ml.kg-1). Pacientes que apresentaram incremento do debito cardíaco acima de 15% foram considerados respondedores. O valor preditivo do ΔPP e das variáveis estáticas (pressão
atrial direita e pressão ocluída de artéria pulmonar) foi avaliado através da análise da curva ROC (receiver operating characteristics). Resultados. Trinta e quatro pacientes apresentavam características consistentes com lesão pulmonar aguda ou síndrome de angústia respiratória aguda (LPA / SDRA) e foram ventilados com altos níveis de PEEP [10.0 (10.0-13.5)]. Dezenove pacientes foram considerados respondedores. A pressão atrial direita e pressão ocluída de artéria pulmonar aumentaram significativamente e o ΔPP diminuiu
significativamente após infusão de fluidos. O desempenho do ΔPP [área da curva ROC: 0,91 (0,82-1,0)] foi superior a pressão atrial direita [área da curva ROC: 0,73 (0,59-0,90)] e a pressão ocluída de artéria pulmonar [área da curva ROC: 0,58 (0,40-0,76)]. A análise da curva ROC revelou que o melhor ponto de corte para o ΔPP foi de 6,5%, com uma sensibilidade de 0,89, especificidade de 0,90, valor preditivo positivo de 0,89 e valor preditivo negativo de 0,90. Conclusão. O ΔPP automatizado prediz com exatidão a resposta à infusão de fluidos
em pacientes sépticos ventilados com baixos volumes correntes.
Background. The applicability of pulse pressure variation (ΔPP) to predict fluid responsiveness using lung-protective ventilation strategies is uncertain in clinical practise. We designed this study to evaluate the accuracy of this parameter in predicting the fluid responsiveness of septic patients ventilated with low tidal volumes (6ml.kg-1). Methods. Forty patients after the resuscitation phase of severe sepsis and septic shock who were mechanically ventilated with 6ml.kg-1 were included. The ΔPP was obtained automatically at baseline and after a standardised fluid challenge (7ml.kg-1). Patients whose cardiac output increased by more than 15% were considered fluid responders. The predictive values of ΔPP and static variables (right atrial pressure and pulmonary artery occlusion pressure) were evaluated through a receiver operating characteristic (ROC) curve analysis. Results. Thirty-four patients had characteristics consistent with acute lung injury or acute respiratory distress syndrome (ALI/ARDS) and were ventilated with high levels of PEEP [10.0 (10.0-13.5)]. Nineteen patients were considered fluid responders. The right atrial pressure and pulmonary capillary occlusion pressure significantly increased, and ΔPP significantly decreased after volume expansion. The ΔPP performance [ROC curve area: 0.91 (0.82-1.0)] was better than that of the right atrial pressure [ROC curve area: 0.73 (0.59-0.90)] and pulmonary artery occlusion pressure [ROC curve area: 0.58 (0.40-0.76)]. The ROC curve analysis revealed that the best cut-off for ΔPP was 6.5%, with a sensitivity of 0.89, specificity of 0.90, positive predictive value of 0.89 and negative predictive value of 0.90. Conclusions. Automatised ΔPP accurately predicted fluid responsiveness in septic patients ventilated with low tidal volumes.
Background. The applicability of pulse pressure variation (ΔPP) to predict fluid responsiveness using lung-protective ventilation strategies is uncertain in clinical practise. We designed this study to evaluate the accuracy of this parameter in predicting the fluid responsiveness of septic patients ventilated with low tidal volumes (6ml.kg-1). Methods. Forty patients after the resuscitation phase of severe sepsis and septic shock who were mechanically ventilated with 6ml.kg-1 were included. The ΔPP was obtained automatically at baseline and after a standardised fluid challenge (7ml.kg-1). Patients whose cardiac output increased by more than 15% were considered fluid responders. The predictive values of ΔPP and static variables (right atrial pressure and pulmonary artery occlusion pressure) were evaluated through a receiver operating characteristic (ROC) curve analysis. Results. Thirty-four patients had characteristics consistent with acute lung injury or acute respiratory distress syndrome (ALI/ARDS) and were ventilated with high levels of PEEP [10.0 (10.0-13.5)]. Nineteen patients were considered fluid responders. The right atrial pressure and pulmonary capillary occlusion pressure significantly increased, and ΔPP significantly decreased after volume expansion. The ΔPP performance [ROC curve area: 0.91 (0.82-1.0)] was better than that of the right atrial pressure [ROC curve area: 0.73 (0.59-0.90)] and pulmonary artery occlusion pressure [ROC curve area: 0.58 (0.40-0.76)]. The ROC curve analysis revealed that the best cut-off for ΔPP was 6.5%, with a sensitivity of 0.89, specificity of 0.90, positive predictive value of 0.89 and negative predictive value of 0.90. Conclusions. Automatised ΔPP accurately predicted fluid responsiveness in septic patients ventilated with low tidal volumes.
Descrição
Citação
FREITAS, Flavio Geraldo Rezende de. Valor preditivo da variação de pressão de pulso para resposta a infusão de fluidos em pacientes ventilados com estratégia protetora. São Paulo, 2012. 60 f. Tese (Doutorado em Medicina Translacional) – Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2012.