Ultraschall in der Medizin : Organ der Deutschen Gesellschaft für Ultraschall in der Medizin, [der] Österreichischen Gesellschaft für Ultraschall in der Medizin, [der] Schweizerischen Gesellschaft für Ultraschall in Medizin und Biologie
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Comparative Study Controlled Clinical Trial
Ultrasound assessment of inferior vena cava collapsibility is not a valid measure of preload changes during triggered positive pressure ventilation: a controlled cross-over study.
Respiratory changes in the diameter of the inferior vena cava (IVC) have been validated as a measure of volume status and preload responsiveness during spontaneous breathing and mechanical ventilation. However, many intensive care patients are ventilated with triggered positive pressure ventilation (PPV). In this setting, there is no evidence regarding IVC collapsibility (IVCc) as a surrogate for preload. We aimed to elucidate the effects of increasing levels of triggered PPV and of varying preload conditions on the IVCc. ⋯ The compiled results of this study show that IVCc cannot be held as a valid measure of preload status during PPV. This may be explained by systematic alterations in other determinants for IVCc. Comparison of methods encourages the use of sagittal 2-dimensional echocardiography for dynamic imaging of the IVC. Sagittal M-mode and transverse 2-dimensional echocardiography overestimate IVCc as compared to sagittal 2-dimensional echocardiography.