论文部分内容阅读
OBJECTIVE Vibration response imaging (VRI) is a new bedside technology to monitor ventilation by detecting lung sound vibrations.It is currently unknown whether VRI is able to accurately monitor the local distribution of ventilation within the lungs.We therefore compared VRI to electrical impedance tomography (EIT), an established technique used for the assessment of regional ventilation.METHODS For peer review,simultaneous EIT and VRI measurements were performed in the healthy and injured lungs (ALl;induced by saline lavage) at different PEEP levels (0, 5, 10, 15 mbar) in nine piglets.Vibration energy amplitude (VEA) by VRI, and amplitudes of relative impedance changes (rel.△Z) by EIT, were evaluated in seven regions of interest (ROIs).To assess the distribution of VT by VRI and EIT, absolute values were normalized to the VT obtained by simultaneous spirometry measurements.RESULTS Redistribution of ventilation by ALl and PEEP was detected by VRI and EIT.The linear correlation between pooled VT by VEA and rel.△Z was R =0.96.Bland-Altman analysis showed a bias of-1.07±24.71 ml and limits of agreement of-49.05 to +47.36 ml.Within the different ROIs,correlations of VT-distribution by EIT and VRI ranged between R values of0.29 and 0.96.ALl and PEEP did not alter the agreement of VT between VRI and EIT.CONCLUSION Measurements of regional ventilation distribution by VRI are similar to those obtained by EIT.