Navegando por Palavras-chave "haemodynamics"

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    Predictive value of pulse pressure variation for fluid responsiveness in septic patients using lung-protective ventilation strategies
    (Oxford Univ Press, 2013-03-01) Freitas, Flavio Geraldo Rezende [UNIFESP]; Bafi, Antonio Tonete [UNIFESP]; Nascente, A. P. M. [UNIFESP]; Assuncao, M. [UNIFESP]; Mazza, B. [UNIFESP]; Azevedo, L. C. P. [UNIFESP]; Machado, F. R. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The applicability of pulse pressure variation (PP) to predict fluid responsiveness using lung-protective ventilation strategies is uncertain in clinical practice. We designed this study to evaluate the accuracy of this parameter in predicting the fluid responsiveness of septic patients ventilated with low tidal volumes (TV) (6 ml kg(1)).Forty patients after the resuscitation phase of severe sepsis and septic shock who were mechanically ventilated with 6 ml kg(1) were included. the PP was obtained automatically at baseline and after a standardized fluid challenge (7 ml kg(1)). Patients whose cardiac output increased by more than 15 were considered fluid responders. the predictive values of PP and static variables [right atrial pressure (RAP) and pulmonary artery occlusion pressure (PAOP)] were evaluated through a receiver operating characteristic (ROC) curve analysis.Thirty-four patients had characteristics consistent with acute lung injury or acute respiratory distress syndrome and were ventilated with high levels of PEEP [median (inter-quartile range) 10.0 (10.013.5)]. Nineteen patients were considered fluid responders. the RAP and PAOP significantly increased, and PP significantly decreased after volume expansion. the PP performance [ROC curve area: 0.91 (0.821.0)] was better than that of the RAP [ROC curve area: 0.73 (0.590.90)] and pulmonary artery occlusion pressure [ROC curve area: 0.58 (0.400.76)]. the ROC curve analysis revealed that the best cut-off for PP 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.Automatized PP accurately predicted fluid responsiveness in septic patients ventilated with low TV.
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    Signal-morphology impedance cardiography during incremental cardiopulmonary exercise testing in pulmonary arterial hypertension
    (Wiley-Blackwell, 2012-09-01) Ferreira, Eloara M. [UNIFESP]; Ota-Arakaki, Jaquelina S. [UNIFESP]; Barbosa, Priscila B. [UNIFESP]; Siqueira, Ana Cristina B. [UNIFESP]; Bravo, Daniela M. [UNIFESP]; Kapins, Carlos Eduardo B. [UNIFESP]; Silva, Celia Maria C. [UNIFESP]; Nery, Luiz Eduardo [UNIFESP]; Alberto Neder, J. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Background Haemodynamic responses to exercise are related to physical impairment and worse prognosis in patients with pulmonary arterial hypertension (PAH). It is clinically relevant, therefore, to investigate the practical usefulness of non-invasive methods of monitoring exercise haemodynamics in this patient population. Methods Using a novel impedance cardiography (ICG) approach that does not require basal impedance estimations and relies on a morphological analysis of the impedance signal (Signal-Morphology-ICG (TM)), stroke volume (SV) and cardiac index (CI) were evaluated in 50 patients and 21 age-matched controls during a ramp-incremental cardiopulmonary exercise testing. Results Technically unacceptable readings were found in 12 of 50 (24%) patients. in the remaining subjects, early decrease (N = 9) or a plateau in SV (N = 8) and Delta (peak-unloaded exercise) SV <10 ml were markers of more advanced PAH (P<0.05). Delta CI = 1.5-fold and early estimated lactate threshold were the only independent predictors of a severely reduced peak oxygen uptake ((V) over dotO(2)) in patients (R-2 = 0.71, P<0.001). the finding of Delta CI = 1.5-fold plus peak (V) over dot O-2 < 50% predicted was associated with a number of clinical and functional markers of disease severity (P<0.001). in addition, abnormal SV responses and Delta CI = 1.5-fold were significantly related to 1-year frequency of PAH-related adverse events (death and balloon atrial septostomy, N = 8; P<0.05). Conclusions Qualitative and semi-quantitative signal-morphology impedance cardiography (TM) (PhysioFlow (TM)) during incremental exercise provided clinically useful information to estimate disease severity and short-term prognosis in patients with PAH in whom acceptable impedance signals could be obtained.