Lung Ultrasound Severity Index: Development and Usefulness in Patients with Suspected SARS-Cov-2 Pneumonia-A Prospective Study

Pragmatic evaluation of point of care lung ultrasound for the triage of COVID-19 patients using a simple scoring matrix: Intraclass-classification and predictive value

BACKGROUND

The value of routine bedside lung ultrasound (LUS) for predicting patient disposition during visits to the Emergency Department (ED) is difficult to quantify. We hypothesized that a simplified scoring of bedside-acquired LUS images for the triage of acute respiratory symptoms in the ED would be associated with patient disposition.

METHODS

For this observational pragmatic study, we reviewed prospectively-collected bedside LUS images from patients presenting to the ED with acute respiratory symptoms. We agreed on a simplified LUS scoring approach (0-3). At least three reviewers blindly assessed the available LUS images for each patient and determined the worst score for each patient and the presence of individual LUS findings. The worst LUS score was used to classify patients' LUS-suggested hospital admission risk. We evaluated the agreement between reviewers and the predictive value of LUS findings for patient disposition.

RESULTS

204 patients were eligible, and 126 sets of images were available and scored. The most common LUS finding were isolated B-lines (63.5 % of LUS images), pleural thickening/irregularity (48.4 %), and diffuse B-lines (43.7 %). The patients' worst LUS score were 2 (43.5 %), 3 (26.1 %), 1 (20.7 %), and 0 (9.8 %). There was good agreement among reviewers on the worst LUS score (intra-class correlation coefficient 0.830, 95 % confidence interval (0.772-0.875)) and the LUS-suggested disposition (ICC 0.882, 95 % CI (0.846, 0.911)).

CONCLUSION

A simplified scoring of bedside-acquired LUS images from patients with acute respiratory symptoms at the emergency department reliably predicts patient disposition.

Sensitivity of Lung Point-of-Care Ultrasound (POCUS) to Predict Oxygen Requirements in Emerging Viral Infections

OBJECTIVES

The prognostic characteristics of lung point-of-care ultrasound (L-POCUS) to predict respiratory decompensation in patients with emerging infections remains unstudied. Our objective was to examine whether scored lung ultrasounds predict hypoxia among a nonhypoxic, ambulatory population of patients with COVID-19.

METHODS

This was a diagnostic case-control study. Three academic emergency departments across the United States collected a convenience sample of nonhypoxic subjects with COVID-19, scored subjects' hemithorax at 7 locations using lung ultrasound, and followed outcomes for 40 days. We defined cases as hypoxia (≤91% by pulse oxygenation) from 2 hours after index presentation to day 40. Follow-up was by telephone plus home pulse oximeter and by chart review. We conducted a logistic regression to test the association between L-POCUS scores and hypoxia. To evaluate lung ultrasound score prediction of a hypoxic event, we calculated sensitivity and specificity at optimal cut off scores and report receiver operating characteristic curve and area under the curve.

RESULTS

We enrolled 163 subjects but excluded 15 (3 duplicate entries; 12 lost to follow up). Median age was 41 years (interquartile range [IQR] 31-56); 83 (56%) were female, and median body mass index was 29 (IQR 25-35). We classified 47 of 148 as hypoxic cases (32%, 95% confidence interval [CI]: 25-40), leaving 101 controls. L-POCUS scores associated with hypoxia by logistic regression (odds ratio = 1.05, 95% CI: 1.02-1.08), with a 5% increase in odds of hypoxia for each 1-unit increase in L-POCUS score. The optimal cut-off score was 15 (sensitivity, 0.60; specificity, 0.73) and the area under the curve was 0·66 (95% CI 0·58-0·75). The correctly classified proportion was 69% (95% CI: 61-76).

CONCLUSIONS

Among nonhypoxic COVID-19 patients, higher L-POCUS rubric scores were associated with hypoxia but no scoring threshold strongly predicts hypoxia at 40 days.

Point-of-care ultrasound use in COVID-19: a narrative review

Background and Objective

The coronavirus disease 2019 (COVID-19) pandemic that began in early 2020 resulted in significant mortality from respiratory tract infections. Existing imaging modalities such as chest X-ray (CXR) lacks sensitivity in its diagnosis while computed tomography (CT) scan carries risks of radiation and contamination. Point-of-care ultrasound (POCUS) has the advantage of bedside testing with higher diagnostic accuracy. We aim to describe the various applications of POCUS for patients with suspected severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the emergency department (ED) and intensive care unit (ICU).

Methods

We performed literature search on the use of POCUS in the diagnosis and management of COVID-19 in MEDLINE, Embase and Scopus databases using the following search terms: "ultrasonography", "ultrasound", "COVID-19", "SARS-CoV-2", "SARS-CoV-2 variants", "emergency services", "emergency department" and "intensive care units". Search was performed independently by two reviewers with any discrepancy adjudicated by a third member.

Key Content and Findings

Lung POCUS in patients with COVID-19 shows different ultrasonographic features from pulmonary oedema, bacterial pneumonia, and other viral pneumonia, thus useful in differentiating between these conditions. It is more sensitive than CXR, and more accessible and widely available than CT scan. POCUS can be used to diagnose COVID-19 pneumonia, screen for COVID-19-related pulmonary and extrapulmonary complications, and guide management of ICU patients, such as timing of ventilator weaning based on lung POCUS findings.

Conclusions

POCUS is a useful and rapid point-of-care modality that can be used to aid in diagnosis, management, and risk stratification of COVID-19 patients in different healthcare settings.

Lung Ultrasound and High-Resolution Computed Tomography in Suspected COVID-19 Patients Admitted to the Emergency Department: A Comparison

Objective

To analyze the diagnostic accuracy of lung ultrasonography (LUS) and high-resolution computed tomography (HRCT), to detect COVID-19.

Materials and Methods

This study recruited all patients admitted to the emergency medicine unit, due to a suspected COVID-19 infection, during the first wave of the COVID-19 pandemic. These patients also who underwent a standardized LUS examination and a chest HRCT. The signs detected by both LUS and HRCT were reported, as well as the sensitivity, specificity, positive predictive value, and negative predictive value for LUS and HRCT.

Results

This cohort included 159 patients, 101 (63%) were diagnosed with COVID-19. COVID-19 patients showed more often confluent subpleural consolidations and parenchymal consolidations in lower lung regions of LUS. They also had "ground glass" opacities and "crazy paving" on HRCT, while pleural effusion and pulmonary consolidations were more common in non-COVID-19 patients. LUS had a sensitivity of 0.97 (95% CI 0.92-0.99) and a specificity of 0.24 (95% CI 0.07-0.5) for COVID-19 lung infections. HRCT abnormalities resulted in a 0.98 sensitivity (95% CI 0.92-0.99) and 0.1 specificity (95% CI 0.04-0.23) for COVID-19 lung infections.

Conclusion

In this cohort, LUS proved to be a noninvasive, diagnostic tool with high sensitivity for lung abnormalities that were likewise detected by HRCT. Furthermore, LUS, despite its lower specificity, has a high sensitivity for COVID-19, which could prove to be as effective as HRCT in excluding a COVID-19 lung infection.

All B-lines are equal, but some B-lines are more equal than others

In this pictorial essay the theme of the differential diagnosis between the different causes of lung interstitial disease will be discussed, which can be detected on lung ultrasound as B lines. In particular, from the experience obtained during the covid-19 pandemic, the term B line may appear too simplified, and new data in the literature show that it is necessary to update the terminology and the differential diagnosis of this ultrasound sign.