Lung ultrasound in acute respiratory distress syndrome and beyond

The application value of lung ultrasound scoring in assessing disease severity: Evaluation of small-scale outbreaks of COVID-19

PURPOSE

This study explored the use of transthoracic lung ultrasound for evaluating COVID-19 patients, compared it with computed tomography (CT), and examined its effectiveness using 8 and 12 lung regions.

METHODS

A total of 100 patients with COVID-19 and 40 healthy volunteers were assessed using 12 regions (bilateral upper/lower regions of the anterior/lateral/posterior chest) and simplified 8 zones (bilateral upper/lower regions of the anterior/lateral chest) transthoracic lung ultrasound. The relationships between ultrasound, CT, and clinical indicators were analyzed to evaluate the diagnostic value of ultrasound scores in COVID-19.

RESULTS

Increased disease severity correlated with increased 8- and 12-zone ultrasound and CT scores (all p < 0.05). The modified 8-zone method strongly correlated with the 12-zone method (Pearson's r = 0.908, p < 0.05). The 8- and 12-zone methods correlated with CT scoring (correlation = 0.568 and 0.635, respectively; p < 0.05). The intragroup correlation coefficients of the 8-zone, 12-zone, and CT scoring methods were highly consistent (intragroup correlation coefficient = 0.718, p < 0.01). The 8-zone ultrasound score correlated negatively with oxygen saturation (rs  = 0.306, p < 0.05) and Ca (rs  = 0.224, p < 0.05) and positively with IL-6 (rs  = 0.0.335, p < 0.05), erythrocyte sedimentation rate (rs  = 0.327, p < 0.05), alanine aminotransferase (rs  = 0.230, p < 0.05), and aspartate aminotransferase (rs  = 0.251, p < 0.05). The 12-zone scoring method correlated negatively with oxygen saturation (rs  = 0.338, p < 0.05) and Ca (rs  = 0.245, p < 0.05) and positively with IL-6 (rs  = 0.354, p < 0.05) and erythrocyte sedimentation rate (rs  = 0.495, p < 0.05).

CONCLUSION

Lung ultrasound scores represent the clinical severity and have high clinical value for diagnosing COVID-19 pneumonia. The 8-zone scoring method can improve examination efficiency and reduce secondary injuries caused by patient movement.

Lung ultrasound score and in-hospital mortality of adults with acute respiratory distress syndrome: a meta-analysis

BACKGROUND

Lung ultrasound (LUS) score could quantitatively reflect the lung aeration, which has been well applied in critically ill patients. The aim of the systematic review and meta-analysis was to evaluate the association between LUS score at admission and the risk of in-hospital mortality of adults with acute respiratory distress syndrome (ARDS).

METHODS

Toachieve the objective of this meta-analysis, we conducted a thorough search of PubMed, Embase, Cochrane Library, and the Web of Science to identify relevant observational studies with longitudinal follow-up. We employed random-effects models to combine the outcomes, considering the potential influence of heterogeneity.

RESULTS

Thirteen cohort studies with 1,022 hospitalized patients with ARDS were included. Among them, 343 patients (33.6%) died during hospitalization. The pooled results suggested that the LUS score at admission was higher in non-survivors as compared to survivors (standardized mean difference = 0.73, 95% confidence interval [CI]: 0.55 to 0.91, p < 0.001; I2 = 25%). Moreover, a high LUS score at admission was associated with a higher risk of in-hospital mortality of patients with ARDS (risk ratio: 1.44, 95% CI: 1.14 to 1.81, p = 0.002; I2 = 46%). Subgroup analyses showed consistent results in studies with LUS score analyzed with 12 or 16 lung regions, and in studies reporting mortality during ICU or within 1-month hospitalization.

CONCLUSION

Our findings suggest that a high LUS score at admission may be associated with a high risk of in-hospital mortality of patients with ARDS.

Lung Ultrasound and Pleural Artifacts: A Pictorial Review

Lung ultrasound is a well-established diagnostic approach used in detecting pathological changes near the pleura of the lung. At the acoustic boundary of the lung surface, it is necessary to differentiate between the primary visualization of pleural parenchymal pathologies and the appearance of secondary artifacts when sound waves enter the lung or are reflected at the visceral pleura. The aims of this pictorial essay are to demonstrate the sonographic patterns of various pleural interface artifacts and to illustrate the limitations and pitfalls of the use of ultrasound findings in diagnosing any underlying pathology.

Delivery systems of therapeutic nucleic acids for the treatment of acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) is a devastating inflammatory lung disease with a high mortality rate. ALI/ARDS is induced by various causes, including sepsis, infections, thoracic trauma, and inhalation of toxic reagents. Corona virus infection disease-19 (COVID-19) is also a major cause of ALI/ARDS. ALI/ARDS is characterized by inflammatory injury and increased vascular permeability, resulting in lung edema and hypoxemia. Currently available treatments for ALI/ARDS are limited, but do include mechanical ventilation for gas exchange and treatments supportive of reduction of severe symptoms. Anti-inflammatory drugs such as corticosteroids have been suggested, but their clinical effects are controversial with possible side-effects. Therefore, novel treatment modalities have been developed for ALI/ARDS, including therapeutic nucleic acids. Two classes of therapeutic nucleic acids are in use. The first constitutes knock-in genes for encoding therapeutic proteins such as heme oxygenase-1 (HO-1) and adiponectin (APN) at the site of disease. The other is oligonucleotides such as small interfering RNAs and antisense oligonucleotides for knock-down expression of target genes. Carriers have been developed for efficient delivery for therapeutic nucleic acids into the lungs based on the characteristics of the nucleic acids, administration routes, and targeting cells. In this review, ALI/ARDS gene therapy is discussed mainly in terms of delivery systems. The pathophysiology of ALI/ARDS, therapeutic genes, and their delivery strategies are presented for development of ALI/ARDS gene therapy. The current progress suggests that selected and appropriate delivery systems of therapeutic nucleic acids into the lungs may be useful for the treatment of ALI/ARDS.

Use of Cardio-Pulmonary Ultrasound in the Neonatal Intensive Care Unit

Cardiopulmonary ultrasound (CPUS), the combination of lung ultrasound (LUS) and targeted neonatal echocardiography (TnECHO)AA, may offer a more appropriate approach to the challenging neonatal cardiovascular and respiratory disorders. This paper reviews the possible use of CPUS in the neonatal intensive care unit (NICU).

Recent ultrasound advancements for the manipulation of nanobiomaterials and nanoformulations for drug delivery

Recent advances in ultrasound (US) have shown its great potential in biomedical applications as diagnostic and therapeutic tools. The coupling of US-assisted drug delivery systems with nanobiomaterials possessing tailor-made functions has been shown to remove the limitations of conventional drug delivery systems. The low-frequency US has significantly enhanced the targeted drug delivery effect and efficacy, reducing limitations posed by conventional treatments such as a limited therapeutic window. The acoustic cavitation effect induced by the US-mediated microbubbles (MBs) has been reported to replace drugs in certain acute diseases such as ischemic stroke. This review briefly discusses the US principles, with particular attention to the recent advancements in drug delivery applications. Furthermore, US-assisted drug delivery coupled with nanobiomaterials to treat different diseases (cancer, neurodegenerative disease, diabetes, thrombosis, and COVID-19) are discussed in detail. Finally, this review covers the future perspectives and challenges on the applications of US-mediated nanobiomaterials.

Undifferentiated Dyspnea with Point-of-Care Ultrasound, Primary Emergency Physician Compared with a Dedicated Emergency Department Ultrasound Team

BACKGROUND

Emergency physicians (EPs) perform critical actions while operating with diagnostic uncertainty. Point-of-care ultrasound (POCUS) is useful in evaluation of dyspneic patients. In prior studies, POCUS is often performed by ultrasound (US) teams without patient care responsibilities.

OBJECTIVES

This study evaluates the effectiveness of POCUS in narrowing diagnostic uncertainty in dyspneic patients when performed by treating EPs vs. separate US teams.

METHODS

This multicenter, prospective noninferiority cohort study investigated the effect of a POCUS performing team in patient encounters for dyspnea. Before-and-after surveys assessing medical decision-making were administered to attending physicians. Primary outcome was change in most likely diagnosis after POCUS. This was assessed for noninferiority between encounters where the primary or US team performed POCUS. Secondary outcomes included change in differential diagnosis, confidence in diagnosis, interventions considered, and image quality.

RESULTS

There were 156 patient encounters analyzed. In the primary team group, most likely diagnosis changed in 40% (95% confidence interval 28-52%) of encounters vs. 32% (95% confidence interval 22-41%) in the US team group. This was noninferior using an a priori specified margin of 20% (p < .0001). Post-POCUS differential decreased by a mean 1.8 diagnoses and was equivalent within a margin of 0.5 diagnoses between performing teams (p = 0.034). Other outcomes were similar between groups.

CONCLUSION

POCUS performed by primary teams was noninferior to POCUS performed by US teams for changing the most likely diagnosis, and equivalent when considering mean reduction in number of diagnoses. POCUS performed by treating EPs reduces cognitive burden in dyspneic patients.

A Comparison of Lung Ultrasound and Computed Tomography in the Diagnosis of Patients with COVID-19: A Systematic Review and Meta-Analysis

Background Lung ultrasound (LUS) and computed tomography (CT) can both be used for diagnosis of interstitial pneumonia caused by coronavirus disease 2019 (COVID-19), but the agreement between LUS and CT is unknown. Purpose to compare the agreement of LUS and CT in the diagnosis of interstitial pneumonia caused by COVID-19. Materials and Methods We searched PubMed, Cochrane library, Embase, Chinese Biomedicine Literature, and WHO COVID-19 databases to identify studies that compared LUS with CT in the diagnosis of interstitial pneumonia caused by COVID-19. We calculated the pooled overall, positive and negative percent agreements, diagnostic odds ratio (DOR) and the area under the standard receiver operating curve (SROC) for LUS in the diagnosis of COVID-19 compared with CT. Results We identified 1896 records, of which nine studies involving 531 patients were finally included. The pooled overall, positive and negative percentage agreements of LUS for the diagnosis of interstitial pneumonia caused by COVID-19 compared with CT were 81% (95% confidence interval [CI] 43–99%), 96% (95% CI, 80–99%, I² = 92.15%) and 80% (95%CI, 60–92%, I² = 92.85%), respectively. DOR was 37.41 (95% CI, 9.43–148.49, I² = 63.9%), and the area under the SROC curve was 0.94 (95% CI, 0.92–0.96). The quality of evidence for both specificity and sensitivity was low because of heterogeneity and risk of bias. Conclusion The level of diagnostic agreement between LUS and CT in the diagnosis of interstitial pneumonia caused by COVID-19 is high. LUS can be therefore considered as an equally accurate alternative for CT in situations where molecular tests are not available.

Ultrasound and Microbubbles for Targeted Drug Delivery to the Lung Endothelium in ARDS: Cellular Mechanisms and Therapeutic Opportunities

Acute respiratory distress syndrome (ARDS) is characterized by increased permeability of the alveolar–capillary membrane, a thin barrier composed of adjacent monolayers of alveolar epithelial and lung microvascular endothelial cells. This results in pulmonary edema and severe hypoxemia and is a common cause of death after both viral (e.g., SARS-CoV-2) and bacterial pneumonia. The involvement of the lung in ARDS is notoriously heterogeneous, with consolidated and edematous lung abutting aerated, less injured regions. This makes treatment difficult, as most therapeutic approaches preferentially affect the normal lung regions or are distributed indiscriminately to other organs. In this review, we describe the use of thoracic ultrasound and microbubbles (USMB) to deliver therapeutic cargo (drugs, genes) preferentially to severely injured areas of the lung and in particular to the lung endothelium. While USMB has been explored in other organs, it has been under-appreciated in the treatment of lung injury since ultrasound energy is scattered by air. However, this limitation can be harnessed to direct therapy specifically to severely injured lungs. We explore the cellular mechanisms governing USMB and describe various permutations of cargo administration. Lastly, we discuss both the challenges and potential opportunities presented by USMB in the lung as a tool for both therapy and research.

Acute respiratory distress syndrome (ARDS) as an adverse event following immunization: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term “Acute Respiratory Distress Syndrome – ARDS” to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated in this final manuscript.

The Role of Imaging in the Management of Suspected or Known COVID-19 Pneumonia. A Multidisciplinary Perspective

Coronavirus disease (COVID-19) is an illness caused by a novel coronavirus that has rapidly escalated into a global pandemic leading to an urgent medical effort to better characterize this disease biologically, clinically, and by imaging. In this review, we present the current approach to imaging of COVID-19 pneumonia. We focus on the appropriate use of thoracic imaging modalities to guide clinical management. We also describe radiologic findings that are considered typical, atypical, and generally not compatible with COVID-19. Furthermore, we review imaging examples of COVID-19 imaging mimics, such as organizing pneumonia, eosinophilic pneumonia, and other viral infections.

Lung sonographic findings in COVID-19 patients

Objective

The objective of this study was to describe the lung sonographic findings of COVID-19 patients prospectively and investigate its association with disease severity.

Methods

This study was conducted in an emergency department and included consecutively enrolled laboratory confirmed COVID-19 patients. Lung sonography findings were described in all the included patients and analysed with respect to the clinical severity of the patients.

Results

106 patients were included in the study. Common sonographic findings in COVID-19 patients were pleural line irregularity or shredding (70% of patients), followed by B – profile (59%), pleural line thickening (33%), occasional B – lines (26%), sub-pleural consolidations (35%), deep consolidations (6%), spared areas (13%), confluent B – lines or waterfall sign (14%) and pleural effusion (9%). These findings tended to be present more bilaterally and in lower lung zones. Sonographic characteristics like bilateral lung involvement, B – profile, spared areas and confluent B – lines or waterfall sign were significantly associated (p < 0.01) with clinical severity (more frequent with increasing disease severity).

Conclusion

The lung sonographic findings of COVID-19 were found more bilaterally and in lower lung zones, and specific findings like B – profile, pleural thickening, spared areas and confluent B – lines or waterfall sign were associated with severe COVID-19.

Pulmonary complications of acute pancreatitis

Introduction: Acute pancreatitis is an inflammatory condition of the pancreas, which runs a severe course in 20% of patients, wherein it is associated with high mortality. It is associated with several pleuro-pulmonary complications with variable severity that may occur either in isolation but are frequently present in combination. Clinicians need to be aware of these complications for early and appropriate management.Areas covered: We performed a systematic search of the PUBMED database (1970-2019) to identify relevant articles focusing on pleuro-pulmonary complications that may occur in patients with acute pancreatitis. We also retrieved articles describing the pathophysiological mechanisms and treatment approach of the various complications.Expert opinion: Acute pancreatitis is usually a self-limiting disease, but the development of organ failure during the course worsens the clinical outcome. Pulmonary complications usually occur early in the course of acute pancreatitis. Clinicians need to recognize the various pulmonary complications of acute pancreatitis, early during the disease, and manage them appropriately and aggressively to improve outcomes.

The role of point-of-care ultrasound in pediatric acute respiratory distress syndrome: emerging evidence for its use

Pediatric acute respiratory distress syndrome (PARDS) remains an important cause of significant morbidity and mortality. The 2015 PALICC definition of PARDS requires chest imaging to diagnose the presence of new pulmonary infiltrate(s). Traditionally chest radiography or computerised tomography have been used. However, these carry the limitations of exposure to ionizing radiation, need to transfer the critically unwell child, lag-time with clinical correlation and lack of immediate results. The use of point of care ultrasound (POCUS) has been well established in adult emergency medicine and critical care. Furthermore, the adult literature clearly demonstrates that lung POCUS is a safe and validated tool, which is highly sensitive and specific when compared to chest radiography for differentiating the causes of respiratory failure, including ARDS. Whilst pediatric specific data is limited, it has been shown that the signs seen in adults are reproducible in critically ill neonates and children. Furthermore, the numerous benefits of POCUS in the paediatric setting are compelling and include lack of ionizing radiation, immediate feedback, promoting time at the bedside of the critically unwell child, and ease of serial assessments. This review article presents the emerging evidence demonstrating that lung POCUS can be used not only to support the diagnosis of pediatric ARDS, but also to assess for complications, monitor progression and thus guide management. We hope it will stimulate much needed collaborative research into this exciting field of imaging and its applications to PARDS and beyond.

Chest radiography versus lung ultrasound for identification of acute respiratory distress syndrome: a retrospective observational study

Background

Lung ultrasound may be a reasonable alternative to chest radiography for the identification of acute respiratory distress syndrome (ARDS), but the diagnostic performance of lung ultrasound for ARDS is uncertain. We therefore analyzed the clinical outcomes of ARDS diagnosed according to the Berlin Definition, using either chest radiography (Berlin-CXR) or lung ultrasound (Berlin-LUS) as an alternative imaging method.

Methods

This was a retrospective observational study in a 20-bed medical intensive care unit (ICU). Patients who required noninvasive ventilation or invasive ventilation for hypoxemic respiratory failure on ICU admission from August 2014 to March 2017 were included. Both chest radiography and lung ultrasound were performed routinely upon ICU admission. Comparisons were made using either the Berlin-CXR or Berlin-LUS definitions to diagnose ARDS with respect to the patient characteristics and clinical outcomes for each definition. ICU and hospital mortality were the main outcome measures for both definitions.

Results

The first admissions of 456 distinct patients were analyzed. Compared with the 216 patients who met the Berlin-CXR definition (ICU mortality 19.4%, hospital mortality 36.1%), 229 patients who met the Berlin-LUS definition (ICU mortality 22.7%, hospital mortality 34.5%) and 79 patients who met the Berlin-LUS but not the Berlin-CXR definition (ICU mortality 21.5%, hospital mortality 29.1%) had similar outcomes. In contrast, the 295 patients who met either definition had higher mortality than the 161 patients who did not meet either definition (ICU mortality 20.0% versus 12.4%, P = 0.041; hospital mortality 34.2% versus 24.2%, P = 0.027). Compared with Berlin-CXR, Berlin-LUS had a positive predictive value of 0.66 (95% confidence interval 0.59–0.72) and a negative predictive value of 0.71 (0.65–0.77). Among the 216 Berlin-CXR ARDS patients, 150 patients (69.4%) also fulfilled Berlin-LUS definition.

Conclusions

For the identification of ARDS using the Berlin definition, both chest radiography and lung ultrasound were equally related to mortality. The Berlin definition using lung ultrasound helped identify patients at higher risk of death, even if these patients did not fulfill the conventional Berlin definition using chest radiography. However, the moderate overlap of patients when chest imaging modalities differed suggests that chest radiography and lung ultrasound should be complementary rather than used interchangeably.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2105-y) contains supplementary material, which is available to authorized users.

Bedside sonography assessment of extravascular lung water increase after major pulmonary resection in non-small cell lung cancer patients

Background

Extra vascular lung water (EVLW) following pulmonary resection increases due to fluid infusion and rises in capillary surface and permeability of the alveolar capillary membranes. EVLW increase clinically correlates to pulmonary oedema and it may generate impairments of gas exchanges and acute lung injury. An early and reliable assessment of postoperative EVLW, especially following major pulmonary resection, is useful in terms of reducing the risk of postoperative complications. The currently used methods, though satisfying these criteria, tend to be invasive and cumbersome and these factors might limit its use. The presence and burden of EVLW has been reported to correlate with sonographic B-line artefacts (BLA) assessed by lung ultrasound (LUS). This observational study investigated if bedside LUS could detect EVLW increases after major pulmonary resection. Due to the clinical association between EVLW increase and impairment of gas exchange, secondary aims of the study included investigating for associations between any observed EVLW increases and both respiratory ratio (PaO₂/FiO₂) and fluid retention, measured by brain natriuretic peptide (BNP).

Methods

Overall, 74 major pulmonary resection patients underwent bedside LUS before surgery and at postoperative days 1 and 4, in the inviolate hemithorax which were divided into four quadrants. BLA were counted with a four-level method. The respiratory ratio PaO₂/FiO₂ and fluid retention were both assessed.

Results

BLA resulted being increased at postoperative day 1 (OR 9.25; 95% CI, 5.28-16.20; P<0.0001 vs. baseline), and decreased at day 4 (OR 0.50; 95% CI, 0.31-0.80; P=0.004 vs. day 1). Moreover, the BLA increase was associated with both increased BNP (OR 1.005; 95% CI, 1.003-1.008; P<0.0001) and body weight (OR 1.040; 95% CI, 1.008-1.073; P=0.015). Significant inverse correlations were observed between the BLA values and the PaO₂/FiO₂ respiratory ratios.

Conclusions

Our results suggest that LUS, due to its non-invasiveness, affordability and capacity to detect increases in EVLW, might be useful in better managing postoperative patients.