Comparison of Linear and Sector Array Probe for Handheld Lung Ultrasound in Invasively Ventilated ICU Patients

Nanon F.L Heijnen,Iwan C.C Van Der Horst,Lieuwe D.J Bos,Chiara Almondo,Luigi Pisani,Laura A Hagens,Dennis C.J.J Bergmans,Ronny M Schnabel,Marcus J Schultz,Juliette De Vos,Marry R Smit

doi:10.1016/j.ultrasmedbio.2020.08.016

Abstract

International guidelines do not recommend a specific probe for assessment of lung aeration using lung ultrasound (LUS). The aim of this study was to assess the concordance between linear and sector array probes of a handheld ultrasound device in assessment of lung aeration in invasively ventilated intensive care unit patients. This study included intensive care unit patients who were expected to be ventilated for longer than 24 h. A 12-region LUS exam was performed with a linear and a sector array probe. In each image, the LUS aeration score and number of B-lines were determined. Adding the LUS aeration scores of all regions resulted in a global LUS aeration score. Agreement between the two probes was calculated using intra-class correlation coefficients (ICCs). A total of 30 LUS exams were performed in 19 patients, resulting in a total of 328 pairs of images. Twenty-nine pairs of images were excluded from analysis because the images from the linear probe could not be scored. ICCs calculated for the remaining images revealed good concordance the LUS aeration scores for individual images (ICC = 0.73, 95% confidence interval 0.67–0.78), number of B-lines (ICC = 0.79, 95% confidence interval 0.72–0.83) and global LUS aeration score (ICC = 0.74, 95% confidence interval 0.52–0.87). In conclusion, there is good concordance between linear and sector array probes of a handheld ultrasound device in assessment of lung aeration patterns in mechanically ventilated intensive care unit patients. However, in roughly 10% of the images acquired using the linear probe, the aeration pattern could not be scored.

Highlights

Lung imaging is an essential part of intensive care because it facilitates the diagnosis of pulmonary disease, monitoring of therapy and titration of ventilation (Kruisselbrink et al 2017; Mayo et al 2019)
Volume 46, Number 12, 2020 probe is recommended for the evaluation of pneumothorax and pleural effusion by international guidelines (Volpicelli et al 2012), but it is rarely available in the intensive care unit (ICU)
For the sector array probe, all lung ultrasound (LUS) images could be scored, while for the linear probe, in 29 LUS images (8.8%) the investigator was unable to score the aeration pattern owing to the lack of A-lines, B-lines or a consolidation despite the presence of a clear pleural line (Fig. 1a)

Summary

Introduction

Lung imaging is an essential part of intensive care because it facilitates the diagnosis of pulmonary disease, monitoring of therapy and titration of ventilation (Kruisselbrink et al 2017; Mayo et al 2019). A-lines are horizontal artifacts indicating a normally aerated lung, while B-lines are hyperechoic vertical artifacts that suggest lung tissue with diminished aeration. Complete loss of lung aeration will present as a real anatomic image of consolidation (Lichtenstein 2014). These LUS patterns are commonly used to semi-quantify lung aeration in people who are critically ill, and they correlate well with aeration measured in chest CT (Chiumello et al 2018)

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