Lung ultrasound monitoring in patients with COVID-19 pneumonia admitted to ICU: interrater agreement among anesthesiologists and intensivists: a two-center retrospective cohort study

INTRODUCTION: The subjectivity of ultrasound is a well-recognized limitation of the technique. This issue is particularly relevant for specialists with varying levels of experience performing routine ultrasound monitoring of intensive care unit patients with coronavirus (COVID-19) pneumonia. To achieve optimal interrater agreement, it is essential to determine which protocol and lung ultrasound (LUS) scale are most effective. OBJECTIVE: To investigate the interrater agreement of a 16-zone protocol using semiquantitative lung ultrasound (LUS) and the LUS NMHC (National Medical-Surgical Center) scales in intensive care unit patients with COVID-19, with assessments performed by both an expert and a novice specialist. MATERIALS AND METHODS: A retrospective analysis was performed on data from 161 hospitalized patients with confirmed COVID-19 pneumonia who underwent both computed tomography and lung ultrasound within 24 hours of admission. Lung ultrasound images were recorded as cine loops and scored by both an expert and a novice reader. The 16-zone protocol was tested using two types of scales, including the original LUS NMHC, to determine which provided the most reliable agreement between specialists with different levels of experience. RESULTS: The 16-zone protocol demonstrated high interrater agreement regardless of the scale used (LUS or LUS NMHC), with a correlation of scores between operators greater than 0.9 (p > 0.001). This strong correlation (R > 0.9, p > 0.001) was consistent regardless of the time elapsed before the cine loops were reviewed by both experts and novices. CONCLUSIONS: The developed 16-zone protocol with the LUS NMHC score for patients with COVID-19 pneumonia shows high interrater agreement among anesthesiologists and intensivists with varying levels of ultrasound experience.