Lung Ultrasound Integration in Assessment of Patients with Noncritical COVID-19

Abstract

Objectives: Performing lung ultrasound during the clinical assessment of patients with suspicion of noncritical COVID-19 may increase the diagnostic rate of pulmonary involvement over other diagnostic techniques used in routine clinical practice. This study aims to compare complications (readmissions, emergency department [ED] visits, and length of outpatient follow-up) in the first 30 days after ED discharge in patients with confirmed COVID-19 who were managed with versus without lung ultrasound.

Materials and methods: Prospective, observational, analytical study in noncritical patients with confirmed respiratory disease due to SARS-CoV-2, assessed in the ED of a tertiary Spanish hospital in March and April 2020. We compared 2 cohorts, differentiated by the use of lung ultrasound as a diagnostic tool. Complications were assessed (hospital admissions, ED revisits and days of outpatient follow-up) at 30 days postdischarge.

Results: Of the 88 included patients, 31% (n = 27) underwent an initial lung ultrasound, while 61 (68%) did not. In 82.5% of the patients evaluated with ultrasound, the most predominant areas affected were the posterobasal regions, in the form of focalized and confluent B-lines; 70.4% showed pleural irregularity in these same areas. Use of the lung ultrasound was associated with a greater probability of hospital admission (odds ratio 5.63, 95% confidence interval 3.31 to 9.57; p < 0.001). However, it was not significantly associated with mortality or short-term complications.

Conclusions: Lung ultrasound could identify noncritical patients with lung impairment due to SARS-CoV-2, in whom other tests used routinely show no abnormalities. However, it has not shown a prognostic value in these patients and could generate a higher percentage of hospital admissions. More studies are still needed to demonstrate the clear benefit of this use.

Keywords: COVID-19; emergency departments; lung; pneumonia; point-of-care; ultrasonography.

Figure 1

Lung ultrasound in patients with COVID‐19, according to the scoring system devised by Soldati et al. (A) Score 0. A‐lines, regular pleura: pattern of equidistant, horizontal lines (thin arrow), parallel to pleura. Compatible with normal findings. Linear pleural line in the presence of pleural sliding*. (B) Score 1. Irregular focalized/pleural B‐lines: pattern of B‐lines, vertical lines that reach the depth of the field and start at the (discontinuous) pleural line. They appear in patches and alternate with areas of a normal pattern. In the initial phases, they can appear and disappear with breathing (light beam). The pleural line is fragmented*. (C) Score 2. Confluent B‐lines and/or subpleural consolidation: in “white lung” (thick arrow), the B‐lines converge and the pleural irregularity is increased, generating a pattern of consolidation**. (D) Score 3. Translobar consolidation: in severe cases or in the presence of superinfection, subpleural consolidation has a hepatized, tissue‐like appearance.

Figure 2

Participant flow chart.

Figure 3

Distribution of scores, according to the system proposed by Soldati et al. in each of the regions explored by ultrasound in patients with positive RT‐PCR.