Lung ultrasound training: how short is too short? observational study on the effects of a focused theoretical training for novice learners

BACKGROUND

Lung ultrasound has been increasingly used in the last years for the assessment of patients with respiratory diseases; it is considered a simple technique, now spreading from physicians to other healthcare professionals as nurses and physiotherapists, as well as to medical students. These providers may require a different training to acquire lung ultrasound skills, since they are expected to have no previous experience with ultrasound. The aim of the study was to assess the impact of a short theoretical training focused on lung ultrasound pattern recognition in a population of novice nurse learners with no previous experience with ultrasound.

METHODS

We included the nurses attending a critical care advanced course for nurses performed at the University of Pavia. Images' interpretation skills were tested on two slide sets (a 25-clip set focused on B-pattern recognition and a 25-clip set focused on identification of pleural movement as lung sliding, lung pulse, lung point, no movement) before and after three 30-minute teaching modules dedicated to general ultrasound principles, B-lines assessment and lung sliding assessment. A cut off of 80% was considered acceptable for correctly interpreted images after this basic course.

RESULTS

22 nurses were enrolled (age 26.0 [24.0-28.0] years; men 4 (18%)); one nurse had previous experience with other ultrasound techniques, none of them had previous experience with lung ultrasound. After the training, the number of correctly interpreted clips improved from 3.5 [0.0-13.0] to 22.0 [19.0-23.0] (p < 0.0001) for B-pattern and from 0.5 [0.0-2.0] to 8.5 [6.0-12.0] (p < 0.0001) for lung sliding assessment. The number of correct answers for B-pattern recognition was significantly higher than for lung sliding assessment, both before (3.5 [0.0-13.0] vs. 0.5 [0.0-2.0]; p = 0.0036) and after (22.0 [19.0-23.0] vs. 8.5 [6.0-12.0]; p < 0.0001) the training. After the training, nurses were able to correctly recognize the presence or the absence of a B-pattern in 84.2 ± 10.3% of cases; lung sliding was correctly assessed in 37.1 ± 15.3% of cases.

CONCLUSIONS

Lung ultrasound is considered a simple technique; while a short, focused training significantly improves B-pattern recognition, lung sliding assessment may require a longer training for novice learners.

TRIAL REGISTRATION

Not applicable.

Lung Imaging and Artificial Intelligence in ARDS

Artificial intelligence (AI) can make intelligent decisions in a manner akin to that of the human mind. AI has the potential to improve clinical workflow, diagnosis, and prognosis, especially in radiology. Acute respiratory distress syndrome (ARDS) is a very diverse illness that is characterized by interstitial opacities, mostly in the dependent areas, decreased lung aeration with alveolar collapse, and inflammatory lung edema resulting in elevated lung weight. As a result, lung imaging is a crucial tool for evaluating the mechanical and morphological traits of ARDS patients. Compared to traditional chest radiography, sensitivity and specificity of lung computed tomography (CT) and ultrasound are higher. The state of the art in the application of AI is summarized in this narrative review which focuses on CT and ultrasound techniques in patients with ARDS. A total of eighteen items were retrieved. The primary goals of using AI for lung imaging were to evaluate the risk of developing ARDS, the measurement of alveolar recruitment, potential alternative diagnoses, and outcome. While the physician must still be present to guarantee a high standard of examination, AI could help the clinical team provide the best care possible.

Are lung ultrasound features more severe in infants with bronchiolitis and coinfections?

Background

The lung ultrasound (LUS) score can be a useful tool to predict the need for respiratory support and the length of hospital stay in infants with bronchiolitis.

Objective

To compare lung ultrasound features in neonates and infants up to three months of age with bronchiolitis to determine whether LUS scores (range 0-36) differ in infants with coinfections or not.

Methods

Neonates and infants younger than three months admitted to neonatal units from October 2022 to March 2023, who underwent lung ultrasound evaluation on admission, were included in this retrospective study.

Results

We included 60 patients who underwent LUS evaluation at admission. Forty-two infants (70.0%) had a single viral infection. Eighteen infants (30.0%) had a coinfection: fifteen infants (25.0%) had more than one virus at PCR; one infant (1.7%) had both a viral coinfection and a viral-bacteria coinfection; two infants (3.3%) had viral-bacteria coinfection. Infants with a single viral infection and those with coinfections had similar LUS scores globally and in different lung zones. An LUS score higher than 8 was identified to significantly predict the need for any respiratory support (p = 0.0035), whereas an LUS score higher than 13 was identified to significantly predict the need for mechanical ventilation (p = 0.024).

Conclusion

In our small cohort of neonates and infants younger than three months hospitalized with bronchiolitis, we found no statistically significant differences in the LUS score on admission between patients with a single viral infection and those with multiple infections.

Lung ultrasound in a nutshell. Lines, signs, some applications, and misconceptions from a radiologist's point of view

In recent years, lung ultrasound (LUS) has developed rapidly, and it is growing in popularity in various scenarios. It has become especially popular among clinicians. There are constant attempts to introduce it in new fields, with quite a strong resistance in the radiological community. In addition, knowledge regarding lung and LUS has been augmented by the recent COVID-19 pandemic. Unfortunately, this has led to many misconceptions. The aim of this review is to discuss lines, signs, and phenomena that can be seen in LUS in order to create a single, easily available compendium for radiologists and promote consistency in LUS nomenclature. Some simplified suggestions are presented.

Lung Ultrasound Prediction Model for Acute Respiratory Distress Syndrome: A Multicenter Prospective Observational Study

Rationale: Lung ultrasound (LUS) is a promising tool for diagnosis of acute respiratory distress syndrome (ARDS), but adequately sized studies with external validation are lacking. Objectives: To develop and validate a data-driven LUS score for diagnosis of ARDS and compare its performance with that of chest radiography (CXR). Methods: This multicenter prospective observational study included invasively ventilated ICU patients who were divided into a derivation cohort and a validation cohort. Three raters scored ARDS according to the Berlin criteria, resulting in a classification of "certain no ARDS," or "certain ARDS" when experts agreed or "uncertain ARDS" when evaluations conflicted. Uncertain cases were classified in a consensus meeting. Results of a 12-region LUS exam were used in a logistic regression model to develop the LUS-ARDS score. Measurements and Main Results: Three hundred twenty-four (16% certain ARDS) and 129 (34% certain ARDS) patients were included in the derivation cohort and the validation cohort, respectively. With an ARDS diagnosis by the expert panel as the reference test, the LUS-ARDS score, including the left and right LUS aeration scores and anterolateral pleural line abnormalities, had an area under the receiver operating characteristic (ROC) curve of 0.90 (95% confidence interval [CI], 0.85-0.95) in certain patients of the derivation cohort and 0.80 (95% CI, 0.72-0.87) in all patients of the validation cohort. Within patients who had imaging-gold standard chest computed tomography available, diagnostic accuracy of eight independent CXR readers followed the ROC curve of the LUS-ARDS score. Conclusions: The LUS-ARDS score can be used to accurately diagnose ARDS also after external validation. The LUS-ARDS score may be a useful adjunct to a diagnosis of ARDS after further validation, as it showed performance comparable with that of the current practice with experienced CXR readers but more objectifiable diagnostic accuracy at each cutoff.

Evaluation of the prognostic value of lncRNA UCA1 combined with extravascular lung water index and lung ultrasound score in patients with acute lung injury

INTRODUCTION

Acute lung injury (ALI) is a common and rapidly developing critical inflammatory lung disease in clinic. This study investigated the predictive value of lncRNA UCA1, extravascular lung water index (EVLWI), and lung ultrasound score (LUS) in predicting the overall outcome of patients with ALI.

METHODS

Patients with ALI were recruited for detecting the content of UCA1, EVLWI, and LUS. All patients were cataloged into the survival group and death group according to the prognosis. The discrepancy of UCA1, EVLWI, and LUS was compared in the two groups. The prognostic significance of UCA1, EVLWI, LUS, and their combination was estimated by logistic regression and the receiver operating characteristic (ROC) curve.

RESULTS

The levels of UCA1, LUS, and EVLWI were elevated in the death group compared with the survival group. The content of UCA1 was positively correlated with LUS scores and EVLWI scores. UCA1, LUS, and EVLWI were independent indicators of predicting the prognosis of patients with ALI. The ROC curve reflected that UCA1, LUS, and EVLWI could forecast the endpoint events of patients with ALI whereas their combined approach had the highest accuracy.

CONCLUSION

Highly expressed UCA1 is a biomarker in forecasting the outcome of patients with ALI. It had high accuracy in predicting the endpoint of patients with ALI when combined with LUS and EVLWI.

Lung Ultrasound to Determine the Effect of Lower vs. Higher PEEP on Lung Aeration in Patients without ARDS-A Substudy of a Randomized Clinical Trial

BACKGROUND

Ventilation with lower positive end-expiratory pressure (PEEP) may cause loss of lung aeration in critically ill invasively ventilated patients. This study investigated whether a systematic lung ultrasound (LUS) scoring system can detect such changes in lung aeration in a study comparing lower versus higher PEEP in invasively ventilated patients without acute respiratory distress syndrome (ARDS).

METHODS

Single center substudy of a national, multicenter, randomized clinical trial comparing lower versus higher PEEP ventilation strategy. Fifty-seven patients underwent a systematic 12-region LUS examination within 12 h and between 24 to 48 h after start of invasive ventilation, according to randomization. The primary endpoint was a change in the global LUS aeration score, where a higher value indicates a greater impairment in lung aeration.

RESULTS

Thirty-three and twenty-four patients received ventilation with lower PEEP (median PEEP 1 (0-5) cm H₂O) or higher PEEP (median PEEP 8 (8-8) cm H₂O), respectively. Median global LUS aeration scores within 12 h and between 24 and 48 h were 8 (4 to 14) and 9 (4 to 12) (difference 1 (-2 to 3)) in the lower PEEP group, and 7 (2-11) and 6 (1-12) (difference 0 (-2 to 3)) in the higher PEEP group. Neither differences in changes over time nor differences in absolute scores reached statistical significance.

CONCLUSIONS

In this substudy of a randomized clinical trial comparing lower PEEP versus higher PEEP in patients without ARDS, LUS was unable to detect changes in lung aeration.

Multicentre study on the accuracy of lung ultrasound in the diagnosis and monitoring of respiratory sequelae in the medium and long term in patients with COVID-19

Introduction

Lung ultrasound (LUS) has proven to be a more sensitive tool than radiography (X-ray) to detect alveolar-interstitial involvement in COVID-19 pneumonia. However, its usefulness in the detection of possible pulmonary alterations after overcoming the acute phase of COVID-19 is unknown. In this study we proposed studying the utility of LUS in the medium- and long-term follow-up of a cohort of patients hospitalized with COVID-19 pneumonia.

Materials and methods

This was a prospective, multicentre study that included patients, aged over 18 years, at 3 ± 1 and 12 ± 1 months after discharge after treatment for COVID-19 pneumonia. Demographic variables, the disease severity, and analytical, radiographic, and functional clinical details were collected. LUS was performed at each visit and 14 areas were evaluated and classified with a scoring system whose global sum was referred to as the "lung score." Two-dimensional shear wave elastography (2D-SWE) was performed in 2 anterior areas and in 2 posterior areas in a subgroup of patients. The results were compared with high-resolution computed tomography (CT) images reported by an expert radiologist.

Results

A total of 233 patients were included, of whom 76 (32.6%) required Intensive Care Unit (ICU) admission; 58 (24.9%) of them were intubated and non-invasive respiratory support was also necessary in 58 cases (24.9%). Compared with the results from CT images, when performed in the medium term, LUS showed a sensitivity (S) of 89.7%, specificity (E) 50%, and an area under the curve (AUC) of 78.8%, while the diagnostic usefulness of X-ray showed an S of 78% and E of 47%. Most of the patients improved in the long-term evaluation, with LUS showing an efficacy with an S of 76% and E of 74%, while the X-ray presented an S of 71% and E of 50%. 2D-SWE data were available in 108 (61.7%) patients, in whom we found a non-significant tendency toward the presentation of a higher shear wave velocity among those who developed interstitial alterations, with a median kPa of 22.76 ± 15.49) versus 19.45 ± 11.39; p = 0.1).

Conclusion

Lung ultrasound could be implemented as a first-line procedure in the evaluation of interstitial lung sequelae after COVID-19 pneumonia.

Lung Ultrasound in the Evaluation of Lung Disease Severity in Children with Clinically Stable Cystic Fibrosis: A Prospective Cross-Sectional Study

With the increasing longevity of cystic fibrosis (CF), there is a growing need to minimise exposure to ionising radiation in patients who undergo regular imaging tests while monitoring the course of the lung disease. This study aimed to define the role of lung ultrasounds (LUS) in the evaluation of lung disease severity in children with clinically stable CF. LUS was performed on 131 patients aged 5 weeks to 18 years (study group) and in 32 healthy children of an equivalent age range (control group). Additionally, an interobserver study was performed on 38 patients from the study group. In CF patients, the following ultrasound signs were identified: I-lines; Z-lines; single, numerous and confluent B-lines; Am-lines; small and major consolidations; pleural line abnormalities and small amounts of pleural fluid. The obtained results were evaluated against an original ultrasound score. LUS results were correlated with the results of chest X-ray (CXR) [very high], pulmonary function tests (PFTs) [high] and microbiological status [significant]. The interobserver study showed very good agreement between investigators. We conclude that LUS is a useful test in the evaluation of CF lung disease severity compared to routinely used methods. With appropriate standardisation, LUS is highly reproducible.

The value of lung ultrasound in COVID-19 pneumonia, verified by high resolution computed tomography assessed by artificial intelligence

BACKGROUND

Lung ultrasound (LUS) is an increasingly popular imaging method in clinical practice. It became particularly important during the COVID-19 pandemic due to its mobility and ease of use compared to high-resolution computed tomography (HRCT). The objective of this study was to assess the value of LUS in quantifying the degree of lung involvement and in discrimination of lesion types in the course of COVID-19 pneumonia as compared to HRCT analyzed by the artificial intelligence (AI).

METHODS

This was a prospective observational study including adult patients hospitalized due to COVID-19 in whom initial HRCT and LUS were performed with an interval < 72 h. HRCT assessment was performed automatically by AI. We evaluated the correlations between the inflammation volume assessed both in LUS and HRCT, between LUS results and the HRCT structure of inflammation, and between LUS and the laboratory markers of inflammation. Additionally we compared the LUS results in subgroups depending on the respiratory failure throughout the hospitalization.

RESULTS

Study group comprised 65 patients, median 63 years old. For both lungs, the median LUS score was 19 (IQR-interquartile range 11-24) and the median CT score was 22 (IQR 16-26). Strong correlations were found between LUS and CT scores (for both lungs r = 0.75), and between LUS score and percentage inflammation volume (PIV) (r = 0.69). The correlations remained significant, if weakened, for individual lung lobes. The correlations between LUS score and the value of the percentage consolidation volume (PCV) divided by percentage ground glass volume (PGV), were weak or not significant. We found significant correlation between LUS score and C-reactive protein (r = 0.55), and between LUS score and interleukin 6 (r = 0.39). LUS score was significantly higher in subgroups with more severe respiratory failure.

CONCLUSIONS

LUS can be regarded as an accurate method to evaluate the extent of COVID-19 pneumonia and as a promising tool to estimate its clinical severity. Evaluation of LUS in the assessment of the structure of inflammation, requires further studies in the course of the disease.

TRIAL REGISTRATION

The study has been preregistered 13 Aug 2020 on clinicaltrials.gov with the number NCT04513210.

Lung Ultrasound Score in Neonates with Congenital Diaphragmatic Hernia (CDH-LUS): A Cross-Sectional Study

Introduction: The use of a lung ultrasound (LUS) score has been described in the early phases of neonatal respiratory distress syndrome; however, there is still no data regarding the application of the LUS score to neonates with a congenital diaphragmatic hernia (CDH). The objective of this observational cross-sectional study was to explore, for the first time, the postnatal changes in LUS score patterns in neonates with CDH, with the creation of a new specific CDH-LUS score. Methods: We included all consecutive neonates with a prenatal diagnosis of CDH admitted to our Neonatal Intensive Care Unit (NICU) from June 2022 to December 2022 who underwent lung ultrasonography. Lung ultrasonography (LUS) was determined at scheduled time points: (T0) during the first 24 h of life; (T1) at 24-48 h of life; (T2) within 12 h of surgical repair; (T3) a week after the surgical repair. We used a modified LUS score (CDH-LUS), starting from the original 0-3 score. We assigned 4 as a score in the presence of herniated viscera in the hemithorax (liver, small bowel, stomach, or heart in the case of a mediastinal shift) in the preoperative scans or pleural effusions in the postoperative scans. Results: We included in this observational cross-sectional study 13 infants: twelve/13 had a left-sided hernia (2 severe, 3 moderate, and 7 mild cases), while one patient had a right-sided severe hernia. The median CDH-LUS score was 22 (IQR 16-28) during the first 24 h of life (T0), 21 (IQR 15-22) at 24-48 h of life (T1), 14 (IQR 12-18) within 12 h of surgical repair (T2) and 4 (IQR 2-15) a week after the surgical repair (T3). The CDH-LUS significantly dropped over time from the first 24 h of life (T0) to a week after the surgical repair (T3), according to ANOVA for repeated measures. Conclusion: We showed a significant improvement in CDH-LUS scores from the immediate postoperative period, with normal ultrasonographic evaluations a week after surgery in most patients.

One-Year Follow-Up Lung Ultrasound of Post-COVID Syndrome-A Pilot Study

(1) Background: Millions of people worldwide were infected with COVID-19. After the acute phase of the disease, many suffer from prolonged symptoms, the post-COVID syndrome, especially the phenotype with lung residuals. Many open questions regarding lung ultrasound (LUS) have to be answered. One essential question is the means for optimal following-up of patients with post-COVID-19 residuals with LUS; (2) Methods: A retrospective data analysis of patients after acute COVID-19 infection diagnosed with post-COVID syndrome in the state hospital of Steyr and the rehabilitation center of Hochegg was performed. LUS examinations following a 12-zone scanning protocol were performed, and the LUS score quantified comet tail artifacts. A total of 16 patients were evaluated twice with LUS from May 2020 until June 2021. (3) Results: All patients’ reverberation artifacts were reduced over time. The initial LUS score of 17.75 (SD 4.84) points was decreased over the duration of the second rehabilitation to 8,2 (SD 5.94). The difference in the Wilcoxon test was significant (p < 0.001); (4) Conclusions: Lung ultrasound was a valuable tool in the follow-up of post-COVID-syndrome with lung residuals in the first wave of COVID-19. A reduction in reverberation artifacts was demonstrated. Further studies about the clinical significance have to follow.

A Review of COVID-19 Diagnostic Approaches in Computer Vision

Computer vision has proven that it can solve many problems in the field of health in recent years. Processing the data obtained from the patients provided benefits in both disease detection and follow-up and control mechanisms. Studies on the use of computer vision for COVID-19, which is one of the biggest global health problems of the past years, are increasing daily. This study includes a preliminary review of COVID-19 computer vision research conducted in recent years. This review aims to help researchers who want to work in this field.

Time course of lung ultrasound findings in patients with COVID-19 pneumonia and cardiac dysfunction

Background

Lung ultrasound (LUS) is a valuable tool to predict and monitor the COVID-19 pneumonia course. However, the influence of cardiac dysfunction (CD) on LUS findings remains to be studied. Our objective was to determine the effect of CD on LUS in hospitalized patients with COVID-19 pneumonia.

Material and methods

Fifty-one patients with COVID-19 pneumonia participated in the study. Focused echocardiography (FoCUS) was carried out on day 1 to separate patients into two groups depending on whether they had FoCUS signs of CD (CD+ vs CD−). LUS scores, based on the thickness of the pleural line, the B-line characteristics, and the presence or not of consolidations, were obtained three times along the patient’s admission (D1, D5, D10) and compared between CD+ and CD− patients. A correlation analysis was carried out between LUS scores and the ratio of the arterial partial pressure of oxygen to the fraction of the inspired oxygen (P/F ratio).

Results

Twenty-two patients were CD+ and 29 patients were CD−. Among the CD+ patients, 19 were admitted to the intensive care unit (ICU), seven received invasive mechanical ventilation (IMV), and one did not survive. Among the CD− patients, 11 were admitted to the ICU, one received IMV and seven did not survive. CD+ patients showed a significantly lower P/F ratio than CD− patients. However, LUS scores showed no between-group differences, except for fewer subpleural consolidations in the upper quadrants of CD+ than on CD− patients.

Conclusion

In patients with COVID-19, CD contributed to a worse clinical course, but it did not induce significant changes in LUS. Our findings suggest that pathophysiological factors other than those reflected by LUS may be responsible for the differences in clinical condition between CD+ and CD− patients.

Clinical, Laboratory and Lung Ultrasound Assessment of Congestion in Patients with Acute Heart Failure

Congestion is the main cause of hospitalization in patients with acute heart failure (AHF), however its precise assessment by simple clinical evaluation remains elusive. The recent introduction of the lung ultrasound scan (LUS) allowed to physicians to more precisely quantify pulmonary congestion. The aim of this study was to compare clinical congestion (CC) with LUS and B-type natriuretic peptide (BNP) in order to achieve a more complete evaluation and to evaluate the prognostic power of each measurement. Methods: All patients were submitted to clinical evaluation for blood sample analysis and LUS at admission and before discharge. LUS protocol evaluated the number of B-lines for each chest zone by standardized eight site protocol. CC was measured following ESC criteria. The mean difference between admission and discharge congestion logBNP and B-lines values were calculated. Combined end points of death and rehospitalization was calculated over 180 days. Results: 213 patients were included in the protocol; 133 experienced heart failure with reduced ejection fraction (HFrEF), and 83 presented with heart failure with preserved ejection fraction (HFpEF). Patients with HFrEF had a more increased level of BNP (1150 (812−1790) vs. 851 (694−1196); p = 0.002) and B lines total number (32 (27−38) vs. 30 (25−36); p = 0.05). A positive correlation was found between log BNP and Blines number in both HFrEF (r = 0.57; p < 0.001) and HFpEF (r = 0.36; p = 0.001). Similarly, dividing B-lines among tertiles the upper group (B-lines ≥ 36) had an increased clinical congestion score. Among three variables at admission only B-lines were predictive for outcome (AUC 0.68 p < 0.001) but not LogBNP and CC score. During 180 days of follow-up, univariate analysis showed that persistent ΔB-lines <−32.3% (HR 6.54 (4.19−10.20); p < 0.001), persistent ΔBNP < −43.8% (HR 2.48 (1.69−3.63); p < 0.001) and persistent ΔCC < 50% (HR 4.25 (2.90−6.21); p < 0.001) were all significantly related to adverse outcome. Multivariable analysis confirmed that persistent ΔB-lines (HR 4.38 (2.64−7.29); p < 0.001), ΔBNP (HR 1.74 (1.11−2.74); p = 0.016) and ΔCC (HR 3.38 (2.10−5.44); p < 0.001 were associated with the combined end point. Conclusions: a complete clinical laboratory and LUS assessment better recognized different congestion occurrence in AHF. The difference between admission and discharge B-lines provides useful prognostic information compared to traditional clinical evaluation.

The Diagnostic Contribution of Systematic Lung Ultrasonography in Patients Admitted to a Conventional Pulmonology Hospitalization Unit

OBJECTIVE

Although the evidence to date remains limited, we hypothesized that performing protocolized lung ultrasound (LUS) in patients, admitted to a conventional pulmonology hospitalization unit, could improve diagnostic precision. The main objectives of this study were to evaluate the diagnostic contribution and changes in the treatments administered after performing a protocolized LUS in patients hospitalized in a Pulmonology Department ward.

METHODOLOGY

This was a prospective, observational study, which included patients admitted from the Emergency Department to a conventional Pulmonology Department hospitalization unit, after first being evaluated by a pulmonologist. LUS was performed within the first 48 hours of admission. The diagnosis at the time of discharge was used as the reference diagnosis.

RESULTS

A total of 180 patients were included in this study. The admitting diagnoses were the decompensation of an underlying obstructive disease in 60 patients (33.3%), respiratory infection in 93 (51.7%), pulmonary thromboembolism (PE) in 9 (5%), exacerbation of an interstitial lung disease in 14 (7.8%), and other causes in 4 cases (2.2%). Ultrasonography provided new information, unsuspected at the patient's admission, in 117 (65%) of the patients by capturing images suggestive of infection in 63 patients (35%), 1 new case of ILD, 23 (12.7%) cases of cardiogenic edema, and pleural pathology in 19 (10.5%), as well as two tumors and indirect data related to a PE. The use of LUS resulted in the decision to change the already established treatment in 17.2% of the cases.

CONCLUSIONS

LUS provided additive information in more than half of patients that ended up reclassifying or potentially changing diagnosis or treatment. Thus, including LUS in management algorithms could reduce the need for other complementary tests or unnecessary treatments.

Ten Years of Pediatric Lung Ultrasound: A Narrative Review

Lung diseases are the most common conditions in newborns, infants, and children and are also the primary cause of death in children younger than 5 years old. Traditionally, the lung was not thought to be a target for an ultrasound due to its inability to penetrate the gas-filled anatomical structures. With the deepening of knowledge on ultrasound in recent years, it is now known that the affected lung produces ultrasound artifacts resulting from the abnormal tissue/gas/tissue interface when ultrasound sound waves penetrate lung tissue. Over the years, the application of lung ultrasound (LUS) has changed and its main indications in the pediatric population have expanded. This review analyzed the studies on lung ultrasound in pediatrics, published from 2010 to 2020, with the aim of highlighting the usefulness of LUS in pediatrics. It also described the normal and abnormal appearances of the pediatric lung on ultrasound as well as the benefits, limitations, and possible future challenges of this modality.

Coronavirus Disease 2019 Phenotypes, Lung Ultrasound, Chest Computed Tomography and Clinical Features in Critically Ill Mechanically Ventilated Patients

Chest computed tomography (CT) may provide insights into the pathophysiology of coronavirus disease 2019 (COVID-19), although it is not suitable for a timely bedside dynamic assessment of patients admitted to intensive care unit (ICU); therefore, lung ultrasound (LUS) has been proposed as a complementary diagnostic tool. The aims of this study were to investigate different lungs phenotypes in patients with COVID-19 and to assess the differences in CT and LUS scores between ICU survivors and non-survivors. We also explored the association between CT and LUS, and oxygenation (arterial partial pressure of oxygen [PaO₂]/fraction of inspired oxygen [FiO_2]) and clinical parameters. The study included 39 patients with COVID-19. CT scans revealed types 1, 2 and 3 phenotypes in 62%, 28% and 10% of patients, respectively. Among survivors, pattern 1 was prevalent (p < 0.005). Chest CT and LUS scores differed between survivors and non-survivors both at ICU admission and 10 days after and were associated with ICU mortality. Chest CT score was positively correlated with LUS findings at ICU admission (r = 0.953, p < 0.0001) and was inversely correlated with PaO₂/FiO₂ (r = -0.375, p = 0.019) and C-reactive protein (r = 0.329, p = 0.041). LUS score was inversely correlated with PaO₂/FiO₂ (r = -0.345, p = 0.031). COVID-19 presents distinct phenotypes with differences between survivors and non-survivors. LUS is a valuable monitoring tool in an ICU setting because it may correlate with CT findings and mortality, although it cannot predict oxygenation changes.

The role of imaging techniques in understanding and evaluating the long-term pulmonary effects of COVID-19

INTRODUCTION

Limited data exist regarding the long-term pulmonary sequelae of COVID-19. Identifying features utilizing multiple imaging modalities engenders a clearer picture of the illness's long-term consequences.

AREAS COVERED

This review encompasses the common pulmonary findings associated with different imaging modalities during acute and late remission stages of COVID-19 pneumonia.

EXPERT OPINION

Chest x-ray, a common preliminary diagnostic imaging technique, is not optimal for extended care due to limited tissue contrast resolution providing suboptimal assessment of pulmonary pathology and subtle interval changes. Ultrasound may be utilized on a case-by-case basis in certain patient populations, or in countries with limited resources. Chest CT's accessibility, high tissue contrast and spatial resolution make it the foremost modality for long-term COVID-19 follow-up. While MRI can viably monitor extrapulmonary disease due to its lack of radiation and high inherent soft-tissue contrast, it has limited pulmonary utility due to motion artifact and alveolar gas decreasing lung signal. Although 18F-FDG-PET/CT is costly and has limited specificity, it can provide molecular level data and inflammation quantification. Lung perfusion scintigraphy may also explain COVID-19 induced thromboembolic events and persistent dyspnea despite normal structural imaging and testing results. Correlating the long-term pulmonary findings of COVID-19 with each imaging modality is essential in elucidating the post-recovery course.

Lung Ultrasound in the Screening of Pulmonary Interstitial Involvement Secondary to Systemic Connective Tissue Disease: A Prospective Pilot Study Involving 180 Patients

OBJECTIVES

The aim of the study was the assessment of lung ultrasound (LUS) as a screening of pulmonary interstitial involvement secondary to systemic connective tissue diseases.

METHODS

A prospective study was conducted on the study group comprising 180 patients diagnosed with different systemic connective tissue diseases. Each patient underwent lung ultrasound (LUS), high-resolution chest computed tomography (HRCT), and echocardiography (ECHO). Each imaging examination was blinded and performed by an independent operator. LUS was conducted with convex and linear transducers.

RESULTS

The sensitivity and specificity of LUS as compared to HRCT in detecting pulmonary interstitial involvement in the study group were 99.3% and 96.4%, respectively; positive predictive value (PPV) 0.7, negative predictive value (NPV) 3.6. Abnormalities indicating interstitial lung disease (ILD) with fibrosis were most frequently localized bilaterally in the lower fields of the lungs, assessed in the dorsal view.

CONCLUSIONS

LUS is an efficient imaging modality that can detect pulmonary interstitial involvement in patients with systemic connective tissue disease with a high sensitivity and specificity. Further prospective studies conducted on a larger population are deemed necessary.

First diagnosis of multisystem inflammatory syndrome in children (MIS-C): an analysis of PoCUS findings in the ED

Children with multisystem inflammatory syndrome (MIS-C) tend to develop a clinical condition of fluid overload due both to contractile cardiac pump deficit and to endotheliitis with subsequent capillary leak syndrome. In this context, the ability of point-of-care ultrasound (PoCUS) to simultaneously explore multiple systems and detect polyserositis could promote adequate therapeutic management of fluid balance. We describe the PoCUS findings in a case-series of MIS-C patients admitted to the Emergency Department. At admission 10/11 patients showed satisfactory clinical condition without signs and symptoms suggestive for cardiovascular impairment/shock, but PoCUS showed pathological findings in 11/11 (100%). In particular, according to Rapid Ultrasound in SHock (RUSH) protocol, cardiac hypokinesis was detected in 5/11 (45%) and inferior vena cava dilatation in 3/11 (27%). Peritoneal fluid was reported in 6/11 cases (54%). Lung ultrasound (LUS) evaluation revealed an interstitial syndrome in 11/11 (100%), mainly localized in posterior basal lung segments. We suggest PoCUS as a useful tool in the first evaluation of children with suspected MIS-C for the initial therapeutic management and the following monitoring of possible cardiovascular deterioration.

Results from a Spanish national survey on the application of ultrasound in pulmonology services

Background

This was an observational, cross-sectional, and multicentre study carried out from October to December 2020, through a survey sent to Spanish Society of Pulmonology and Thoracic Surgery members in public hospitals with different levels of complexity. Our objective was to complete a national analysis of clinical practice, organisation, infrastructure, the services portfolio, teaching, and research activity related to ultrasound.

Results

Data from 104 hospitals were analysed. Ultrasound was used in 56.7% of cases, both in the area of bronchopleural techniques and on conventional wards, with no differences between centres. Lung ultrasound (LUS) was performed more often in the procedures area in intermediate-complexity centres compared to high- and low-complexity centres (36% vs. 31% and 6.25%, respectively). More high-complexity centres had three or more ultrasound scanners than intermediate-complexity centres (38% vs. 16%); 43% of low-complexity centres shared their ultrasound equipment with other specialties. Fewer than 6% of centres did not have an ultrasound machine. LUS was most often used during the treatment of pleural effusion (91.3%), in the differential diagnosis of dyspnoea (51.9%), and to rule out iatrogenic pneumothorax (50.9%). Only 5.7% of the centres had a pulmonologist specialised in LUS. Finally, fewer than 35% of the hospitals were teaching centres and fewer than 18% participated in research projects.

Conclusions

The use and availability of LUS has grown in pulmonology services, however, still relatively few pulmonologists are specialised in its use. Moreover, teaching and research activity in this field is scarce. Strategies are necessary to improve physicians’ skill at using LUS and to promote its use, with the ultimate goal of improving healthcare activity.

Role of Lung Ultrasound in Predicting Clinical Severity and Fatality in COVID-19 Pneumonia

Background: Lung ultrasound (LUS) is a useful imaging method for identifying COVID-19 pneumonia. The aim of this study was to explore the role of LUS in predicting the severity of the disease and fatality in patients with COVID-19. Methods: This was a single-center, follow-up study, conducted from 1 November 2020, to 22 March 2021. The LUS protocol was based on the assessment of 14 lung zones with a total score up to 42, which was compared to the disease severity and fatality. Results: A total of 133 patients with COVID-19 pneumonia confirmed by RT-PCR were enrolled, with a median time from hospital admission to lung ultrasound of one day. The LUS score was correlated with clinical severity at hospital admission (Spearman’s rho 0.40, 95% CI 0.24 to 0.53, p < 0.001). Patients with higher LUS scores were experiencing greater disease severity; a high flow nasal cannula had an odds ratio of 1.43 (5% CI 1.17–1.74) in patients with LUS score > 29; the same score also predicted the need for mechanical ventilation (1.25, [1.07–1.48]). An LUS score > 30 (1.41 [1.18–1.68]) and age over 68 (1.26 [1.11–1.43]) were significant predictors of fatality. Conclusions: LUS at hospital admission is shown to have a high predictive power of the severity and fatality of COVID-19 pneumonia.

Lung Ultrasound Examination in Patients with SARS-CoV-2 Infection: Multicenter Study

BACKGROUND

The COVID-19 pandemic has, by necessity, contributed to rapid advancements in medicine. Owing to the necessity of following strict anti-epidemic sanitary measures when taking care of infected patients, the accessibility of standard diagnostic methods may be limited. Consequently, the significance and potential of bedside diagnostic modalities increase, including lung ultrasound (LUS).

METHOD

Multicenter registry study involving adult patients with confirmed COVID-19, for whom LUS was performed.

RESULTS

A total of 228 patients (61% males) qualified for the study. The average age was 60 years (±14), 40% were older than 65 years of age. In 130 from 173 hospitalized patients, HRCT (high-resolution computed tomography) was performed. In 80% of patients, LUS findings indicated interstitial pneumonia. In hospitalized patients multifocally located single B-lines, symmetrical B-lines, and areas of white lung were significantly more frequent as compared to ambulatory patients. LUS findings, both those indicating interstitial syndrome and consolidations, were positively correlated with HRCT images. As compared to HRCT, the sensitivity and specificity of LUS in detecting interstitial pneumonia were 97% and 100%, respectively.

CONCLUSIONS

As compared to HRCT, LUS is characterized by a very high sensitivity and specificity in detecting interstitial pneumonia in COVID-19 patients. Potentially, LUS can be a particularly useful diagnostic modality for COVID-19 patients pneumonia.

Validity of Lung Ultrasound: Is an Image Worth More Than a Thousand Sounds?

Introduction: There is debate as to whether lung-ultrasound (LUS) can replace lung-auscultation (LA) in the assessment of respiratory diseases. Methodology: The diagnostic validity, safety, and reliability of LA and LUS were analyzed in patients admitted in a pulmonary ward due to decompensated obstructive airway diseases, decompensated interstitial diseases, and pulmonary infections, in a prospective study. Standard formulas were used to calculate the diagnostic sensitivity, specificity, and accuracy. The interobserver agreement with respect to the LA and LUS findings was evaluated based on the Kappa coefficient (ᴋ). Results: A total of 115 patients were studied. LUS was more sensitive than the LA in evaluating pulmonary infections (93.59% vs. 77.02%; p = 0.001) and more specifically in the case of decompensated obstructive airway diseases (95.6% vs. 19.10%; p = 0.001). The diagnostic accuracy of LUS was also greater in the case of pulmonary infections (75.65% vs. 60.90%; p = 0.02). The sensitivity and specificity of the combination of LA and LUS was 95.95%, 50% in pulmonary infections, 76.19%, 100% in case of decompensated obstructive airway diseases, and (100%, 88.54%) in case of interstitial diseases. (ᴋ) was 0.71 for an A-pattern, 0.73 for pathological B-lines, 0.94 for condensations, 0.89 for pleural-effusion, 0.63 for wheezes, 0.38 for rhonchi, 0.68 for fine crackles, 0.18 for coarse crackles, and 0.29 for a normal LA. Conclusions: There is a greater interobserver agreement in the interpretation of LUS-findings compared to that of LA-noises, their combined use improves diagnostic performance in all diseases examined.

Clinical Impact of Vertical Artifacts Changing with Frequency in Lung Ultrasound

Background: This study concerns the application of lung ultrasound (LUS) for the evaluation of the significance of vertical artifact changes with frequency and pleural line abnormalities in differentiating pulmonary edema from pulmonary fibrosis. Study Design and Methods: The study was designed as a diagnostic test. Having qualified patients for the study, an ultrasound examination was performed, consistent with a predetermined protocol, and employing convex and linear transducers. We investigated the possibility of B-line artifact conversion depending on the set frequency (2 MHz and 6 MHz), and examined pleural line abnormalities. Results: The study group comprised 32 patients with interstitial lung disease (ILD) (and fibrosis) and 30 patients with pulmonary edema. In total, 1941 cineloops were obtained from both groups and analyzed. The employment of both types of transducers (linear and convex) was most effective (specificity 91%, specificity 97%, positive predictive value (PPV) 97%, negative predictive value (NPV) 91%, LR(+) 27,19, LR(−) 0.097, area under curve (AUC) = 0.936, p = 7 × 10⁻⁶). Interpretation: The best accuracy in differentiating the etiology of B-line artifacts was obtained with the use of both types of transducers (linear and convex), complemented with the observation of the conversion of B-line artifacts to Z-line.

Dynamic assessment of lung injury by ultrasound in patients with acute paraquat poisoning

Objective

To investigate the value of ultrasound in the dynamic assessment of lung injury after acute paraquat poisoning.

Methods

A prospective observational study was performed on patients with paraquat poisoning from admission to day 28 or discharge. Ultrasound assessment of the lungs was performtyed every 48 hours. The correlation of the lung ultrasound score (LUS) with other indicators was analyzed.

Results

Twenty-six patients were enrolled, with an average age of 46 ± 16 years. The average toxic dose was 95 ± 51 mL. The intensive care unit (ICU) stay averaged 9 ± 8 days, and the 28-day mortality was 88.5%. There was a significant negative correlation between LUS and oxygenation index (rho = −0.896) and a significant positive correlation between LUS and carbon dioxide concentration (rho = 0.567). Lung ultrasound and computed tomography imaging correlated closely.

Conclusion

Lung ultrasound can reflect changes in lung status in patients with paraquat poisoning and can be used to evaluate lung injury in these patients.

Trial registration: ChiCTR, ChiCTR-DDD-16010211. Registered 21 December 2016, http://www.chictr.org.cn/listbycreater.aspx.

Consensus on the Application of Lung Ultrasound in Pneumonia and Bronchiolitis in Children

This evidence-based consensus aims to establish the role of point-of-care lung ultrasound in the management of pneumonia and bronchiolitis in paediatric patients. A panel of thirteen experts form five Polish tertiary pediatric centres was involved in the development of this document. The literature search was done in PubMed database. Statements were established based on a review of full-text articles published in English up to December 2019. The development of this consensus was conducted according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluations)-adopted and Delphi method. Initially, 22 proposed statements were debated over 3 rounds of on-line discussion and anonymous voting sessions. A total of 17 statements were agreed upon, including four statements referring to general issues, nine referring to pneumonia and four to bronchiolitis. For five statements experts did not achieve an agreement. The evidence supporting each statement was evaluated to assess the strength of each statement. Overall, eight statements were rated strong, five statements moderate, and four statements weak. For each statement, experts provided their comments based on the literature review and their own experience. This consensus is the first to establish the role of lung ultrasound in the diagnosis and management of pneumonia and bronchiolitis in children as an evidence-based method of imaging.

COVID-19 Assessment with Bedside Lung Ultrasound in a Population of Intensive Care Patients Treated with Mechanical Ventilation and ECMO

The COVID-19 pandemic has increased the need for an accessible, point-of-care and accurate imaging modality for pulmonary assessment. COVID-19 pneumonia is mainly monitored with chest X-ray, however, lung ultrasound (LUS) is an emerging tool for pulmonary evaluation. In this study, patients with verified COVID-19 disease hospitalized at the intensive care unit and treated with ventilator and extracorporal membrane oxygenation (ECMO) were evaluated with LUS for pulmonary changes. LUS findings were compared to C-reactive protein (CRP) and ventilator settings. Ten patients were included and scanned the day after initiation of ECMO and thereafter every second day until, if possible, weaned from ECMO. In total 38 scans adding up to 228 cineloops were recorded and analyzed off-line with the use of a constructed LUS score. The study indicated that patients with a trend of lower LUS scores over time were capable of being weaned from ECMO. LUS score was associated to CRP (R = 0.34; p < 0.03) and compliance (R = 0.60; p < 0.0001), with the strongest correlation to compliance. LUS may be used as a primary imaging modality for pulmonary assessment reducing the use of chest X-ray in COVID-19 patients treated with ventilator and ECMO.

High Levels of Variation Within Gene Sequences of Olea europaea L

Gene sequence variation in cultivated olive (Olea europaea L. subsp. europaea var. europaea), the most important oil tree crop of the Mediterranean basin, has been poorly evaluated up to now. A deep sequence analysis of fragments of four genes, OeACP1, OeACP2, OeLUS and OeSUT1, in 90 cultivars, revealed a wide range of polymorphisms along all recognized allele forms and unexpected allele frequencies and genotype combinations. High linkage values among most polymorphisms were recorded within each gene fragment. The great sequence variability corresponded to a low number of alleles and, surprisingly, to a small fraction of genotype combinations. The distribution, frequency, and combination of the different alleles at each locus is possibly due to natural and human pressures, such as selection, ancestrality, or fitness. Phylogenetic analyses of allele sequences showed distant and complex patterns of relationships among cultivated olives, intermixed with other related forms, highlighting an evolutionary connection between olive cultivars and the O. europaea subspecies cuspidata and cerasiformis. This study demonstrates how a detailed and complete sequence analysis of a few gene portions and a thorough genotyping on a representative set of cultivars can clarify important issues related to sequence polymorphisms, reconstructing the phylogeny of alleles, as well as the genotype combinations. The identification of regions representing blocks of recombination could reveal polymorphisms that represent putatively functional markers. Indeed, specific mutations found on the analyzed OeACP1 and OeACP2 fragments seem to be correlated to the fruit weight.

Lung Ultrasound as a New Technique for Diagnosis of Neonatal Respiratory Diseases

Point-of-care ultrasound in the NICU is becoming more commonplace and is now used for a number of indications. Over the past ten years, the use of ultrasound as an alternative to a chest x-ray for the diagnosis of neonatal lung disease has been explored, and protocols were developed to refine the interpretation of ultrasound images in neonatal lung disease. The purpose of this column is to briefly explain the physics of ultrasound and describe the application of ultrasound to neonatal lung assessment.

Combined use of lung ultrasound, B-type natriuretic peptide, and echocardiography for outcome prediction in patients with acute HFrEF and HFpEF

BACKGROUND

Lung ultrasound (LUS) can be used to assess pulmonary congestion by imaging B-lines ('comets') for patients with acute heart failure (AHF).

OBJECTIVES

Investigate relationship of B-lines, plasma concentrations of B-type natriuretic peptide (BNP), and echocardiographic left ventricular (LV) function measured at admission and discharge and their relationship to prognosis for AHF with preserved (HFpEF) or reduced (HFrEF) LV ejection fraction.

METHODS

Patients with AHF had the above tests done at admission and discharge. The primary outcome was re-hospitalization for heart failure or death at 6 months.

RESULTS

Of 162 patients enrolled, 95 had HFrEF and 67 had HFpEF, median age was 80 [77-85] years, and 85 (52%) were women. The number of B-lines at admission (median 31 [27-36]) correlated with respiratory rate (r = 0.75; p < 0.001), BNP (r = 0.43; p < 0.001), clinical congestion score (r = 0.25; p = 0.001), and systolic pulmonary artery pressure (r = 0.42; p < 0.001). At discharge, B-lines were also correlated with BNP (r = 0.69; p < 0.001) and congestion score (r = 0.57; p < 0.001). B-line count at discharge predicted outcome (AUC 0.83 [0.77-0.90]; univariate HR 1.12 [1.09-1.16]; p < 0.001; multivariable HR 1.16 [1.11-1.21]; p < 0.001). Results were similar for HFpEF and HFrEF.

CONCLUSIONS

LUS appears a useful method to assess severity and monitor the resolution of lung congestion. At hospital admission, B-lines are strongly related to respiratory rate, which may be a key component of the sensation of dyspnea. Measurement of lung congestion at discharge provides prognostic information for patients with either HFpEF or HFrEF.

Lung ultrasonography to diagnose community-acquired pneumonia in children

Background

Early diagnosis of community-acquired pneumonia (CAP) is essential to reduce the total burden of this disease. Traditionally, chest radiography (CR) is used to identify true CAP. However, CR is not a perfect diagnostic test for CAP. The use of lung ultrasonography (LUS) has been suggested as an alternative to overcome the problems associated with CR and increase the feasibility and accuracy of CAP diagnosis. LUS has largely been used for the diagnosis of several lung problems, including CAP, in adult patients with satisfactory results. Experience with LUS in children has grown over recent years. The main aim of this paper is to discuss the advantages and limits of LUS in the diagnosis of paediatric CAP.

Discussion

The presence of a consolidation pattern during LUS may represent pneumonia or atelectasis, although this conclusion is operator dependent. An overall agreement between LUS and CR was observed in most of the studies that were examined. In most reports where a disagreement between the two methods was found, CR was not able to identify the cases that were correctly diagnosed by LUS, particularly when CR was performed only with postero-anterior/antero-posterior projection and consolidation was observed in lung areas that are poorly visualized by CR. However, the lack of standardized LUS methods is problematic. Finally, the real advantage of LUS for the diagnosis of CAP in children remains unclear.

Summary

LUS is an interesting diagnostic modality that appears a useful first imaging test in children with suspected CAP. However, the methods used to perform LUS in children are not precisely standardized, and the diagnosis of interstitial CAP is inaccurate. Further studies are needed before LUS can be routinely used in everyday paediatric practice.

Lung real time three-dimensional imaging in critically ill ventilated patients: a global diagnosis concordance study

Lung ultrasound (LUS) increases clinical diagnosis performance in intensive care unit (ICU). Real-time three-dimensional (3-D) imaging was compared with two-dimensional (2-D) LUS by assessing the global diagnosis concordance. In this single center, prospective, observational, pilot study, one trained operator performed a 3-D LUS immediately after a 2-D LUS in eight areas of interest on the same areas in 16 ventilated critically ill patients. All cine loops were recorded on a computer without visible link between 2-D and 3-D exams. Two experts blindly reviewed cine loops. Four main diagnoses were proposed: normal lung, consolidation, pleural effusion and interstitial syndrome. Fleiss κ and Cohen's κ values were calculated. In 252 LUS cine loops, the concordance between 2-D and 3-D exams was 83.3% (105/126), 77.6% (99/126) and 80.2% (101/126) for the trained operator and the experts respectively. The Cohen's κ coefficient value was 0.69 [95% Confidence Interval (CI) 0.58-0.80] for expert 1 meaning a substantial agreement. The inter-rater reliability was very good (Fleiss' κ value = 0.94 [95% CI 0.87-1.0]) for 3-D exams. The Cohen's κ was excellent for pleural effusion (κ= 0.93 [95% CI 0.76-1.0]), substantial for normal lung diagnosis (κ = 0.68 [95% CI 0.51-0.86]) and interstitial syndrome (κ = 0.62 [95% CI 0.45-0.80]) and fair for consolidation diagnoses (κ = 0.47 [95% CI 0.30-0.64]). In ICU ventilated patients, there was a substantial concordance between 2-D and 3-D LUS with a good inter-rater reliability. However, the diagnosis concordance for lung consolidation is poor.

A Novel Gel Pad Laryngeal Ultrasound for Vocal Cord Evaluation

BACKGROUND

Laryngeal ultrasound (LUS) is a new method for vocal cord evaluation in patients with risk of vocal cord palsy (VCP). However, the previously described LUS reportedly had a high failure rate of vocal cord visualization in male patients. A novel gel pad LUS was devised to overcome the limitations of the previous method.

METHODS

A total of 482 (100 male) consecutive LUS and direct laryngoscopy examinations were performed in thyroidectomy and other neck surgery patients. The conventional LUS and gel pad LUS were used for all patients. Findings were independently cross-validated with direct laryngoscopy.

RESULTS

The conventional LUS and gel pad LUS methods had a 93.4% and 99.0% visualization rate, respectively, with a sensitivity of 98.0% for both methods, and a specificity of 99.7% and 99.8%, respectively. Among the 482 patients, 51 patients had VCP and 91 patients had diffuse thyroid cartilage calcification interrupting LUS.

CONCLUSION

The new gel pad LUS method significantly enhances the visualization of vocal cords in patients who have diffuse thyroid cartilage calcification interrupting LUS and, therefore, the overall efficacy of LUS as a perioperative diagnostic tool for VCP.

Ultrasound Assessment of Lower Uterine Segment Thickness During Pregnancy, Labour, and the Postpartum Period

OBJECTIVES

To evaluate the normal ranges of lower uterine segment (LUS) thickness throughout pregnancy in women without a previous cesarean and to evaluate the relationship between ultrasound and intraoperative LUS thickness.

METHODS

We assessed LUS thickness using transabdominal and transperineal longitudinal scan at each week of gestation, during labour, and in the postpartum period in 1000 pregnant women without previous CS. Secondly, we assessed LUS thickness immediately before CS (using ultrasound) and intraoperatively (using ophthalmic calipers) immediately before delivery of the fetus in 35 women with a previous CS and 29 women without previous CS undergoing elective CS before labour.

RESULTS

We performed 20 307 LUS thickness measurements in between 119 and 944 women at each week of gestation, in 944 women during labour, and in 936 women after delivery. We observed a strong relationship between transabdominal and transperineal ultrasound (P < 0.001) and an inverse correlation between LUS thickness and gestational age (P < 0.001), with a mean thickness of 5.1 ± 1.4 mm at 20 weeks, 3.6 ± 1.3 mm at 30 weeks, and 2.3 ± 0.6 mm at 40 weeks of gestation. In women undergoing elective CS, we observed a strong relationship between antepartum and intraoperative LUS thickness (P < 0.001), with mean thicknesses of 2.2 ± 0.7 mm in 28 women without thinning of LUS; 0.8 ± 0.1 mm in four women with grade II uterine scar dehiscence; and 0.4 ± 0.1 mm in three women with grade III dehiscence. A LUS myometrial thickness less than 1.2 mm could have predicted all grade II and grade III uterine scar dehiscences without false-positive cases.

CONCLUSION

LUS thickness decreases with gestational age and correlates strongly with the intraoperative LUS thickness in women with a previous CS.

Lung ultrasound for the evaluation of pulmonary congestion in outpatients: a comparison with clinical assessment, natriuretic peptides, and echocardiography

OBJECTIVES

The aim of this study was to define the performance of lung ultrasound (LUS) compared with clinical assessment, natriuretic peptides, and echocardiography, to evaluate decompensation in patients with systolic heart failure (HF) in an outpatient clinic.

BACKGROUND

Evaluation of pulmonary congestion in chronic HF is challenging. LUS has been recently proposed as a reliable tool for the semiquantification of extravascular lung water through assessment of B-lines.

METHODS

This was a cohort study of patients with moderate to severe systolic HF. Receiver-operating characteristic (ROC) analyses were performed to compare LUS with a previously validated clinical congestion score (CCS), amino-terminal portion of B-type natriuretic peptide (NT-proBNP), E/e' ratio, chest x-ray, and 6-min walk test.

RESULTS

Ninety-seven patients were enrolled. Decompensation was present in 57.7% of patients when estimated by CCS, 68% by LUS, 53.6% by NT-proBNP, and 65.3% by E/e' ≥15. The number of B-lines was correlated to NT-proBNP (r = 0.72; p < 0.0001), E/e' (r = 0.68; p < 0.0001), and CCS (r = 0.43; p < 0.0001). In ROC analyses, considering as reference for decompensation a combined method (E/e' ≥ 15 and/or NT-proBNP >1,000 pg/ml), LUS yielded a C-statistic of 0.89 (95% confidence interval: 0.82 to 0.96), providing the best accuracy with a cutoff ≥ 15 B-lines (sensitivity 85%, specificity 83%). A systematic approach using CCS, E/e', NT-proBNP, chest x-ray, and 6-min walk test in different combinations as reference for decompensation also corroborated this cutoff and found a similar accuracy for LUS.

CONCLUSIONS

In an HF outpatient clinic, B-lines were significantly correlated with more established parameters of decompensation. A B-line ≥15 cutoff could be considered for a quick and reliable assessment of decompensation in outpatients with HF.