RESUMO
OBJECTIVE: The authors hypothesized that variations in electrocardiographically derived R-wave amplitude might be correlated with mechanical ventilation-induced variations in stroke volume as determined by transesophageal echocardiography. DESIGN: Observational prospective study. SETTING: Single university hospital. PARTICIPANTS: Thirty-four patients undergoing coronary artery bypass surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Respiratory R-wave variations in lead II (ΔRII) were correlated with aortic velocity time integral variations (r = 0.82, p < 0.0001). Respiratory R-wave variations in leads III and aVF and pulse pressure variation also were correlated with aortic velocity time integral variations (r = 0.49, p = 0.015; r = 0.61, p = 0.0016; and r = 0.72, p < 0.0001, respectively). R-wave respiratory variations in lead V(5) were not correlated with aortic velocity time integral variations. ΔRII was correlated with pulse pressure variation (r = 0.71, p < 0.0001). A ΔRII cutoff value of 15% accurately predicted stroke volume variations >15%, with a specificity of 92%, a sensitivity of 86%, a positive likelihood ratio of 11.1, a negative likelihood ratio of 0.15, a positive predictive value of 95%, and a negative predictive value of 80%. CONCLUSIONS: ΔRII is correlated with stroke volume variations as determined by transesophageal echocardiography in mechanically ventilated patients and can identify the stroke volume variation cutoff of 15%, previously determined to be the cutoff for volume responsiveness.
Assuntos
Ponte de Artéria Coronária , Monitorização Intraoperatória/métodos , Mecânica Respiratória/fisiologia , Volume Sistólico/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aorta/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Ecocardiografia Transesofagiana/métodos , Eletrocardiografia/métodos , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Respiração ArtificialRESUMO
We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.
