Lung Ultrasound in Patients With SARS-COV-2 Pneumonia: Correlations With Chest Computed Tomography, Respiratory Impairment, and Inflammatory Cascade

Lung ultrasound score in dogs and cats: A reliability study

BACKGROUND

Lung ultrasound (LUS) is a noninvasive tool for examining respiratory distress patients. The lung ultrasound score (LUSS) can be used to quantify and monitor lung aeration loss with good reliability.

HYPOTHESIS/OBJECTIVES

Assess the reliability of a new LUSS among raters with different levels of experience and determine how well the same raters agree on identifying patterns of LUS abnormalities.

ANIMALS

Forty LUS examinations of dogs and cats and 320 videos were reviewed from a digital database.

METHODS

Retrospective reliability study with post hoc analysis. Protocolized LUS were randomly selected; intrarater and interrater reliability of the LUSS and pattern recognition agreement among 4 raters with different levels of experience in LUS were tested.

RESULTS

The intrarater intraclass correlation coefficient (ICC) single measurement, absolute agreement, and 2-way mixed effects model was 0.967 for the high-experience rater (H-Exp), 0.963 and 0.952 for the medium-experience raters (M-Exp-1; M-Exp-2), and 0.950 for the low-experience rater (L-Exp). The interrater ICC average measurement, absolute agreement, and 2-way random effects model among the observers was 0.980. The Fleiss' kappa (k) values showed almost perfect agreement (k = 1) among raters in identifying pleural effusion and translobar tissue-like pattern, strong agreement for A-lines (k = 0.881) and B-lines (k = 0.806), moderate agreement (k = 0.693) for subpleural loss of aeration, and weak agreement (k = 0.474) for irregularities of the pleural line.

CONCLUSIONS AND CLINICAL IMPORTANCE

Our results indicate excellent intra- and interrater reliability for LUS scoring and pattern identification, providing a foundation for the use of the LUSS in emergency medicine and intensive care.

Clinical and functional status of patients with severe COVID-19 pneumonia: an observational study at 2-3 months following discharge

Introduction

Critically ill COVID-19 patients present long-term sequelae that affect their everyday life. This study aimed to describe the clinical and functional status of patients with severe COVID-19 pneumonia at 2-3 months post discharge from a Spanish critical care unit.

Methods

We collected retrospective data from 58 patients admitted to the critical care unit with diagnosis of severe respiratory failure due to COVID-19. Only patients who required invasive (IMV) or noninvasive ventilation (NIV) during their hospital stay were included. The following data were collected 2-3 months after hospital discharge: respiratory signs and symptoms, lung ultrasound (LUS) and diaphragm ultrasound images, blood test analysis, lung function parameters (spirometry and DLCO), exercise capacity (6 min walk test and sit-to-stand test), level of physical activity and health-related quality of life.

Results

We found clinical symptoms and lung structural alterations in LUS images of 26 patients (48.1%). Those presenting LUS abnormalities had longer length of stay in hospital (p = 0.026), functional alterations in spirometry (p < 0.01) and decreased diaphragm excursion (p = 0.029). No significant alterations were observed in blood test analysis, exercise capacity, level of physical activity and health-related quality of life.

Conclusions

A significant part of the patients admitted to a critical care unit continue to present clinical symptoms, pulmonary morphological abnormalities, and lung function alterations 2-3 months post discharge. This study corroborates that assessing the functional status of the survivors is essential to monitor the evolution of pulmonary sequelae.

Assessment of respiratory function and exercise tolerance at 4-6 months after COVID-19 infection in patients with pneumonia of different severity

BACKGROUND

The evaluation of COVID-19 systemic consequences is a wide research field in which respiratory function assessment has a pivotal role. However, the available data in the literature are still sparse and need further strengthening.

AIM

To assess respiratory function 4-6 months after hospital discharge based on lung disease severity in patients who overcome COVID-19 pneumonia.

METHODS

Patients hospitalised either in the Internal Medicine Department (IMD) for moderate to severe disease or in the Intensive Care Unit (ICU) for critical disease underwent spirometry with maximal flow-volume curve, lung volumes, lung diffusion capacity (DL_CO ) and six-minute walking test (6-MWT).

RESULTS

Eighty-eight patients were analysed: 40 from the IMD and 48 from the ICU. In both cohorts, there was a greater prevalence of male patients. In the IMD cohort, 38% of patients showed at least one altered respiratory parameter, while 62% in the ICU cohort did so (P < 0.05). Total lung capacity (TLC) and DL_CO were the most frequently altered parameters: 15% and 33% from IMD versus 33% and 56% from ICU, respectively (P < 0.05). In IMD patients, 5% had only restrictive deficit, 22% had only lung diffusion impairment and 10% had both. In ICU patients, 6% had only restrictive deficit, 29% had only lung diffusion impairment and 27% had both (P < 0.05). ICU patients showed a higher frequency of abnormal 6-MWT (P < 0.05).

CONCLUSION

Lung function tests and 6-MWT are highly informative tools for monitoring the negative consequences of COVID-19 pneumonia, which were more frequent and more complex in patients discharged from ICU.

Risk factors for impaired pulmonary diffusion function in convalescent COVID-19 patients: A systematic review and meta-analysis

BACKGROUND

The long-term prognosis of COVID-19 survivors remains poorly understood. It is evidenced that the lung is the main damaged organ in COVID-19 survivors, most notably in impairment of pulmonary diffusion function. Hence, we conducted a meta-analysis of the potential risk factors for impaired diffusing capacity for carbon monoxide (DLCO) in convalescent COVID-19 patients.

METHODS

We performed a systematic search of PubMed, Web of Science, Embase, and Ovid databases for relevant studies from inception until January 7, 2022, limited to papers involving human subjects. Studies were reviewed for methodological quality. Fix-effects and random-effects models were used to pool results. Heterogeneity was assessed using I². The publication bias was assessed using the Egger's test. PROSPERO registration: CRD42021265377.

FINDINGS

A total of eighteen qualified articles were identified and included in the systematic review, and twelve studies were included in the meta-analysis. Our results showed that female (OR: 4.011; 95% CI: 2.928-5.495), altered chest computerized tomography (CT) (OR: 3.002; 95% CI: 1.319-6.835), age (OR: 1.018; 95% CI: 1.007-1.030), higher D-dimer levels (OR: 1.012; 95% CI: 1.001-1.023) and urea nitrogen (OR: 1.004;95% CI: 1.002-1.007) were identified as risk factors for impaired DLCO.

INTERPRETATION

Pulmonary diffusion capacity was the most common impaired lung function in recovered patients with COVID-19. Several risk factors, such as female, altered chest CT, older age, higher D-dimer levels and urea nitrogen are associated with impairment of DLCO. Raising awareness and implementing interventions for possible modifiable risk factors may be valuable for pulmonary rehabilitation.

FUNDING

This work was financially supported by Emergency Key Program of Guangzhou Laboratory (EKPG21-29, EKPG21-31), Incubation Program of National Science Foundation for Distinguished Young Scholars by Guangzhou Medical University (GMU2020-207).

What Is COVID 19 Teaching Us about Pulmonary Ultrasound?

In lung ultrasound (LUS), the interactions between the acoustic pulse and the lung surface (including the pleura and a small subpleural layer of tissue) are crucial. Variations of the peripheral lung density and the subpleural alveolar shape and its configuration are typically connected to the presence of ultrasound artifacts and consolidations. COVID-19 pneumonia can give rise to a variety of pathological pulmonary changes ranging from mild diffuse alveolar damage (DAD) to severe acute respiratory distress syndrome (ARDS), characterized by peripheral bilateral patchy lung involvement. These findings are well described in CT imaging and in anatomopathological cases. Ultrasound artifacts and consolidations are therefore expected signs in COVID-19 pneumonia because edema, DAD, lung hemorrhage, interstitial thickening, hyaline membranes, and infiltrative lung diseases when they arise in a subpleural position, generate ultrasound findings. This review analyzes the structure of the ultrasound images in the normal and pathological lung given our current knowledge, and the role of LUS in the diagnosis and monitoring of patients with COVID-19 lung involvement.