Acoustic monitoring of one-lung ventilation with vibration response imaging

Introduction

Inadvertent endobronchial intubation and one-lung ventilation (OLV) with a standard endotracheal tube may lead to serious complications, such as a nonventilated lung, pneumothorax and hypoxemia. Auscultation of breath sounds was found to be inaccurate for the detection of OLV with a high margin, up to 60% error [1]. Vibration response imaging (VRI) is a novel technology that measures vibration energy from the lungs and displays regional intensity in both visual and graphic format. The time from the start of the procedure to display takes less than 1.5 minutes. We investigated the effectiveness of VRI to detect OLV using a double-lumen endotracheal tube in lung surgery patients.

Methods

Double-lumen tubes were placed at the time of surgery. Tracheal and endobronchial lumens were alternately clamped to produce unilateral lung ventilation of the right and left lungs. VRI was performed after each occlusion. Two images were excluded a priori (prior to analysis) due to technical failure (external artifact).

Results

The right and left lung distribution of vibration intensity is shown in Figure 1. The mean percentage change of vibration intensity clearly demonstrates the increased vibration in ventilated lungs (89.1 ± 5.47% vs 10.9 ± 5.4%, P < 0.05) (Figure 2).

Figure 1.

Figure 2.

Conclusion

Auscultation is insensitive to endobronchial intubation and chest radiography may not be immediately available. VRI offers the potential to rapidly and noninvasively determine endobronchial intubation. Currently VRI is performed in the sitting position, but the capability of supine imaging will soon be available.