Variation of Left Ventricular Outflow Tract Velocity Time Integral at Different Positive End-Expiratory Pressure Levels Can Predict Fluid Responsiveness in Mechanically Ventilated Critically Ill Patients.

OBJECTIVES

To explore whether the variation of left ventricular outflow tract velocity time integral (LVOT VTI) between positive end-expiratory pressure (PEEP) 10 cmHO and PEEP 0 cmHO can predict fluid responsiveness in mechanically ventilated critically ill patients.

DESIGN

An observational study.

SETTING

A tertiary hospital intensive care unit.

PARTICIPANTS

A total of 79 critically ill patients who were on controlled mechanical ventilation.

INTERVENTIONS

Transthoracic echocardiography was performed at different PEEP levels and was also performed before and after passive leg raising (PLR).

MEASUREMENTS AND MAIN RESULTS

The patients were classified as the fluid responders (n = 45) and the fluid nonresponders (n = 34) according to the LVOT VTI change after PLR (ΔVTI). The difference of LVOT VTI between PEEP 10 cmHO and PEEP 0 cmHO (ΔVTI) was much higher in responders than in nonresponders (17.9% v 2.1%, p < 0.001). The ΔVTI and ΔVTI were correlated among all patients (r = 0.582, p < 0.001). The receiver operating characteristic curve analysis revealed that the ΔVTI was a good predictor of fluid responsiveness, with an area under the curve of 0.935 (95% confidence interval: 0.885-0.986, p < 0.001), and the optimal cutoff value was 10.5%.

CONCLUSIONS

Variation of LVOT VTI between PEEP 10 cmHO and PEEP 0 cmHO can be used to predict fluid responsiveness in critically ill patients on controlled mechanical ventilation.