Real-time lung ultrasound for the diagnosis of alveolar consolidation and interstitial syndrome in the emergency department

Efficiency of Lung Ultrasonography in the Diagnosis and Follow-up of Viral Pneumonia in Newborn

OBJECTIVE

Lung ultrasonography (LUS) is a useful method for diagnosis of lung diseases such as respiratory distress syndrome, transient tachypnea of the newborn, pneumonia, and pneumothorax in the neonatal period. LUS has become an important tool in the diagnosis and follow-up of lung diseases. LUS is easy to apply at the bedside and is a practical and low-cost method for diagnosing pneumonia.

STUDY DESIGN

This study was conducted in neonatal intensive care unit of Dr. Sami Ulus Obstetrics, Children's Health and Diseases Training and Research Hospital. From September 2019 to April 2020, 50 patients who were diagnosed with viral pneumonia were included in the study. Also, 24 patients with sepsis-related respiratory failure were included in the study as a control group. LUS was performed at the bedside three times, by a single expert, once each before treatment for diagnosis, on discharge, and after discharge in outpatient clinic control.

RESULTS

Before treatment, LUS findings were lung consolidation with air bronchograms (50/50), pleural line abnormalities (35/50), B-pattern (25/50), disappearance of lung sliding (21/50), lung pulse (5/50), and pleural effusion (9/50). During discharge, we found significant changes: lung consolidation with air bronchograms (6/50), pleural line abnormalities (7/50), B-pattern (12/50), and pleural effusion (1/50) (p < 0.05). Outpatient clinic control LUS findings were lung consolidation with air bronchograms (0/50), pleural line abnormalities (0/50), B-pattern (0/50), disappearance of lung sliding (0/50), and pleural effusion (0/50) (p < 0.05). Also, B-pattern image, disappearance of lung sliding, and pleural line abnormalities were higher in control group (p < 0.05).

CONCLUSION

Ultrasound gives no hazard, and the application of bedside ultrasonography is comfortable for the patients. Pneumonia is a serious infection in the neonatal period. Repeated chest radiography may be required depending on the clinical condition of the patient with pneumonia. This study focuses on adequacy of LUS in neonatal pneumonia.

KEY POINTS

· Lung ultrasound is a practical and low-cost method in diagnosing pneumonia.. · Neonatal pneumonia is a very important cause of morbidity and mortality in NICU.. · We can evaluate neonatal pneumonia with combination of clinical presentations and LUS findings..

Optimizing Lung Ultrasound: The Effect of Depth, Gain and Focal Position on Sonographic B-Lines

Ultrasonographic B-lines are artifacts present in alveolar-interstitial syndromes. We prospectively investigated optimal depth, gain, focal position and transducer type for B-line visualization and image quality. B-Lines were assessed at a single rib interspace with curvilinear and linear transducers. Video clips were acquired by changing parameters: depth (6, 12, 18 and 24 cm for curvilinear transducer, 4 and 8 cm for linear transducer), gain (10%, 50% and 90%) and focal position (at the pleural line or half the scanning depth). Clips were scored for B-lines and image quality. Five hundred sixteen clips were obtained and analyzed. The curvilinear transducer improved B-line visualization (63% vs. 37%, p < 0.0001), with higher image quality (3.52 ± 0.71 vs. 3.31 ± 0.86, p = 0.0047) compared with the linear transducer. B-Lines were better visualized at higher gains (curvilinear: gain of 50% vs. 10%, odds ratio = 7.04, 95% confidence interval: 4.03-12.3; gain of 90% vs. 10%, odds ratio = 9.48, 95% confidence interval: 5.28-17.0) and with the focal point at the pleural line (odds ratio = 1.64, 95% confidence interval: 1.02-2.63). Image quality was highest at 50% gain (p = 0.02) but decreased at 90% gain (p < 0.0001) and with the focal point at the pleural line (p < 0.0001). Image quality was highest at depths of 12-18 cm. B-Lines are best visualized using a curvilinear transducer with at least 50% gain and focal position at the pleural line. Gain less than 90% and image depth between 12 and 18 cm improve image quality.

The impact of ultrasound-guided recruitment maneuvers on the risk of postoperative pulmonary complications in patients undergoing general anesthesia

Introduction

Postoperative pulmonary complications are among the most frequent problems in perioperative care. The risk of their development depends not only on the parameters associated with the patient’s initial clinical condition, but also on the employed anesthesia technique, the method of mechanical ventilation, and the type and technique of the surgical procedure. Atelectasis is the most common complication, affecting nearly 90% of the patients undergoing general anesthesia.

Aim

The aim of this study was to determine whether it was possible to positively impact the postoperative period and reduce the frequency of postoperative pulmonary complications via patient-based intraoperative ultrasound-guided recruitment maneuvers.

Methodology

The course of the postoperative period was analyzed in two groups of patients. One of them comprised 100 patients in whom no recruitment maneuvers were performed during general anesthesia. The other group (100 patients) consisted of patients in whom patient-based ultrasound-guided pulmonary recruitment maneuvers were performed.

Results

In the recruitment group, the postoperative hospitalization was statistically significantly shorter (p = 0.003) and the risk of intensive care treatment significantly lower. Additionally, the need for prolonged postoperative mechanical ventilation was reduced, as was the risk of respiratory tract infections.

Conclusions

Intraoperative ultrasound-guided recruitment maneuvers reduce the frequency of postoperative pulmonary complications.

Sonographic Diagnosis of COVID-19: A Review of Image Processing for Lung Ultrasound

The sustained increase in new cases of COVID-19 across the world and potential for subsequent outbreaks call for new tools to assist health professionals with early diagnosis and patient monitoring. Growing evidence around the world is showing that lung ultrasound examination can detect manifestations of COVID-19 infection. Ultrasound imaging has several characteristics that make it ideally suited for routine use: small hand-held systems can be contained inside a protective sheath, making it easier to disinfect than X-ray or computed tomography equipment; lung ultrasound allows triage of patients in long term care homes, tents or other areas outside of the hospital where other imaging modalities are not available; and it can determine lung involvement during the early phases of the disease and monitor affected patients at bedside on a daily basis. However, some challenges still remain with routine use of lung ultrasound. Namely, current examination practices and image interpretation are quite challenging, especially for unspecialized personnel. This paper reviews how lung ultrasound (LUS) imaging can be used for COVID-19 diagnosis and explores different image processing methods that have the potential to detect manifestations of COVID-19 in LUS images. Then, the paper reviews how general lung ultrasound examinations are performed before addressing how COVID-19 manifests itself in the images. This will provide the basis to study contemporary methods for both segmentation and classification of lung ultrasound images. The paper concludes with a discussion regarding practical considerations of lung ultrasound image processing use and draws parallels between different methods to allow researchers to decide which particular method may be best considering their needs. With the deficit of trained sonographers who are working to diagnose the thousands of people afflicted by COVID-19, a partially or totally automated lung ultrasound detection and diagnosis tool would be a major asset to fight the pandemic at the front lines.

Lung Ultrasonography in the Monitoring of Intraoperative Recruitment Maneuvers

Introduction: Postoperative respiratory failure is a serious problem in patients who undergo general anesthesia. Approximately 90% of mechanically ventilated patients during the surgery may develop atelectasis that leads to perioperative complications. Aim: The aim of this study is to determine whether it is possible to optimize recruitment maneuvers with the use of chest ultrasonography, thus limiting the risk of respiratory complications in patients who undergo general anesthesia. Methodology: The method of incremental increases in positive end-expiratory pressure (PEEP) values with simultaneous continuous ultrasound assessments was employed in mechanically ventilated patients. Results: The study group comprised 100 patients. The employed method allowed for atelectasis reduction in 91.9% of patients. The PEEP necessary to reverse areas of atelectasis averaged 17cmH₂O, with an average peak pressure of 29cmH₂O. The average PEEP that prevented repeat atelectasis was 9cmH₂O. A significant improvement in lung compliance and saturation was obtained. Conclusions: Ultrasound-guided recruitment maneuvers facilitate the patient-based adjustment of the process. Consequently, the reduction in ventilation pressures necessary to aerate intraoperative atelectasis is possible, with the simultaneous reduction in the risk of procedure-related complications.

Automatic classification of pediatric pneumonia based on lung ultrasound pattern recognition

Pneumonia is one of the major causes of child mortality, yet with a timely diagnosis, it is usually curable with antibiotic therapy. In many developing regions, diagnosing pneumonia remains a challenge, due to shortages of medical resources. Lung ultrasound has proved to be a useful tool to detect lung consolidation as evidence of pneumonia. However, diagnosis of pneumonia by ultrasound has limitations: it is operator-dependent, and it needs to be carried out and interpreted by trained personnel. Pattern recognition and image analysis is a potential tool to enable automatic diagnosis of pneumonia consolidation without requiring an expert analyst. This paper presents a method for automatic classification of pneumonia using ultrasound imaging of the lungs and pattern recognition. The approach presented here is based on the analysis of brightness distribution patterns present in rectangular segments (here called “characteristic vectors“) from the ultrasound digital images. In a first step we identified and eliminated the skin and subcutaneous tissue (fat and muscle) in lung ultrasound frames, and the “characteristic vectors”were analyzed using standard neural networks using artificial intelligence methods. We analyzed 60 lung ultrasound frames corresponding to 21 children under age 5 years (15 children with confirmed pneumonia by clinical examination and X-rays, and 6 children with no pulmonary disease) from a hospital based population in Lima, Peru. Lung ultrasound images were obtained using an Ultrasonix ultrasound device. A total of 1450 positive (pneumonia) and 1605 negative (normal lung) vectors were analyzed with standard neural networks, and used to create an algorithm to differentiate lung infiltrates from healthy lung. A neural network was trained using the algorithm and it was able to correctly identify pneumonia infiltrates, with 90.9% sensitivity and 100% specificity. This approach may be used to develop operator-independent computer algorithms for pneumonia diagnosis using ultrasound in young children.

Lung ultrasonography score versus chest X-ray score to predict surfactant administration in newborns with respiratory distress syndrome

OBJECTIVES

We aim to verify the diagnostic accuracy of a lung ultrasonography (LUS) score to early predict the need for surfactant therapy in newborns with respiratory distress syndrome (RDS), and to compare it with a chest X-ray score.

METHODS

In this prospective diagnostic accuracy study we included all newborns admitted for respiratory distress and initially treated with nasal CPAP. LUS was performed within 2 h from nasal CPAP positioning and in any case before surfactant administration. A chest X-ray was also performed. A LUS score and an X-ray score were used and compared. Ability of the scores to predict surfactant administration was evaluated through ROC analysis.

RESULTS

In our population of 56 newborns with mean gestational age of 31 weeks (SD 3) and mean birth weight of 1442 g (SD 520), LUS score showed higher AUC than X-ray score in early recognition of infants with respiratory distress syndrome requiring surfactant treatment (0.94; 95%CI, 0.89-0.98; P < 0.001 vs 0.80; 95%CI, 0.74-0.86; P < 0.001). It showed also higher sensitivity (86% vs 82%), higher specificity (88% vs 76%), better positive (83% vs 69%), and negative (91% vs 87%) predictive values.

CONCLUSIONS

LUS is a non-invasive, bedside and reproducible method that could improve the management of neonatal respiratory distress. It is accurate and reliable to early identify patients who will need treatment with surfactant allowing both an early treatment and a reduction of radiation exposure.

Modified Lung Ultrasonographic Technique for Evaluation of Idiopathic Pulmonary Fibrosis: Lateral Decubitus Position

OBJECTIVES

To compare lung ultrasonography (US) in the sitting or supine positions and the lateral decubitus position, with regard to the feasibility, duration, patient convenience, and assessment of B-lines, in patients with idiopathic pulmonary fibrosis.

METHODS

Twenty consecutive patients with idiopathic pulmonary fibrosis were prospectively enrolled. Lung US included scanning of 56 intercostal spaces. Each patient was examined twice by 2 protocols. During protocol 1, patients were examined in the supine and sitting positions for the anterior and dorsal chest, respectively. During protocol 2, patients were examined in the left lateral decubitus position for the evaluation of the right hemithorax and the reverse. Total, anterior, and posterior US scores resulted from the sum of B-lines at the whole, anterior, and posterior chest, respectively. High-resolution computed tomography (CT) was considered the reference standard. The duration of each protocol was recorded. Patients were questioned about which protocol they preferred.

RESULTS

There was no difference regarding feasibility between the protocols. A significant correlation was found between total US scores for both protocols and high-resolution CT findings (P < .0001), with protocol 2 showing a slightly higher correlation. A positive correlation was found between the protocols regarding total, anterior, and posterior US scores (P < .0001). The mean duration of protocol 2 was less than that of protocol 1 (P < .005). Nineteen patients (95%) reported a preference for protocol 2.

CONCLUSIONS

Lung US in the lateral decubitus position seems to be faster and more convenient. There appears to be no difference regarding feasibility and the number of B-lines, whereas it shows slightly higher correlation with high-resolution CT, compared with the sitting or supine positions in patients with idiopathic pulmonary fibrosis.

I-AIM (Indication, Acquisition, Interpretation, Medical Decision-making) Framework for Point of Care Lung Ultrasound

The I-AIM (Indication, Acquisition, Interpretation, Medical decision-making) model is a conceptive framework uniquely applicable to every point of care ultrasound application. We present a systematic comprehensive approach to lung ultrasound based on the I-AIM framework.

Supplemental Digital Content is available in the text.

Point-of-Care Ultrasonography for Primary Care Physicians and General Internists

Point-of-care ultrasonography (POCUS) is a safe and rapidly evolving diagnostic modality that is now utilized by health care professionals from nearly all specialties. Technological advances have improved the portability of equipment, enabling ultrasound imaging to be executed at the bedside and thereby allowing internists to make timely diagnoses and perform ultrasound-guided procedures. We reviewed the literature on the POCUS applications most relevant to the practice of internal medicine. The use of POCUS can immediately narrow differential diagnoses by building on the clinical information revealed by the traditional physical examination and refining clinical decision making for further management. We describe 2 common patient scenarios (heart failure and sepsis) to highlight the impact of POCUS performed by internists on efficiency, diagnostic accuracy, resource utilization, and radiation exposure. Using POCUS to guide procedures has been found to reduce procedure-related complications, along with costs and lengths of stay associated with these complications. Despite several undisputed advantages of POCUS, barriers to implementation must be considered. Most importantly, the utility of POCUS depends on the experience and skills of the operator, which are affected by the availability of training and the cost of ultrasound devices. Additional system barriers include availability of templates for documentation, electronic storage for image archiving, and policies and procedures for quality assurance and billing. Integration of POCUS into the practice of internal medicine is an inevitable change that will empower internists to improve the care of their patients at the bedside.

Lung Ultrasound Will Soon Replace Chest Radiography in the Diagnosis of Acute Community-Acquired Pneumonia

Acute community-acquired pneumonia should be diagnosed early to avoid most complications. The common diagnostic tools were represented by blood tests and chest X-ray with CT scan coming as a second-line exploration. The presence of air in the pulmonary parenchyma has long been thought of as not explorable by ultrasound. However, since the 1990s, several teams have described a semiology of ultrasonography of pulmonary diseases. Moreover, the safety of the technique and the development of mobile and ultra-portable devices have offered it as a first-line examination by a non-radiologist physician. The authors describe in this article ultrasonography as a way of learning the technique, and the main results observed in the literature. In conclusion, they propose it as the first-line examination instead of chest X-ray, and to reserve chest CT scan for complicated cases.

Intraoperative lung ultrasound: A clinicodynamic perspective

In the era of evidence-based medicine, ultrasonography has emerged as an important and indispensable tool in clinical practice in various specialties including critical care. Lung ultrasound (LUS) has a wide potential in various surgical and clinical situations for timely and easy detection of an impending crisis such as pulmonary edema, endobronchial tube migration, pneumothorax, atelectasis, pleural effusion, and various other causes of desaturation before it clinically ensues to critical level. Although ultrasonography is frequently used in nerve blocks, airway handling, and vascular access, LUS for routine intraoperative monitoring and in crisis management still necessitates recognition. After reviewing the various articles regarding the use of LUS in critical care, we found, that LUS can be used in various intraoperative circumstances similar to Intensive Care Unit with some limitations. Except for few attempts in the intraoperative detection of pneumothorax, LUS is hardly used but has wider perspective for routine and crisis management in real-time. If anesthesiologists add LUS in their routine monitoring armamentarium, it can assist to move a step ahead in the dynamic management of critically ill and high-risk patients.

Incremental value of thoracic ultrasound in intensive care units: Indications, uses, and applications

Emergency physicians are required to care for unstable patients with life-threatening conditions, and thus must make decisions that are both quick and precise about unclear clinical situations. There is increasing consensus in favor of using ultrasound as a real-time bedside clinical tool for clinicians in emergency settings alongside the irreplaceable use of historical and physical examinations. B-mode sonography is an old technology that was first proposed for medical applications more than 50 years ago. Its application in the diagnosis of thoracic diseases has always been considered limited, due to the presence of air in the lung and the presence of the bones of the thoracic cage, which prevent the progression of the ultrasound beam. However, the close relationship between air and water in the lungs causes a variety of artifacts on ultrasounds. At the bedside, thoracic ultrasound is based primarily on the analysis of these artifacts, with the aim of improving accuracy and safety in the diagnosis and therapy of the various varieties of pulmonary pathologic diseases which are predominantly “water-rich” or “air-rich”. The indications, contraindications, advantages, disadvantages, and techniques of thoracic ultrasound and its related procedures are analyzed in the present review.

Focused Ultrasound in the Emergency Department for Patients with Acute Heart Failure

The emergency department (ED) plays a key role in the initial diagnosis and management of acute heart failure (AHF). Despite the advent of novel biomarkers and traditional methods of assessment, such as history, examination, and chest X-ray, diagnosis of the dyspnoeic ED patient is, at times, very challenging. Focused cardiac and pulmonary ultrasound has emerged as a valid, facile and efficient method to aid in the initial diagnosis and management of AHF.

Agreement Between the World Health Organization Algorithm and Lung Consolidation Identified Using Point-of-Care Ultrasound for the Diagnosis of Childhood Pneumonia by General Practitioners

PURPOSE

The World Health Organization (WHO) case management algorithm for acute lower respiratory infections has moderate sensitivity and poor specificity for the diagnosis of pneumonia. We sought to determine the feasibility of using point-of-care ultrasound in resource-limited settings to identify pneumonia by general health practitioners and to determine agreement between the WHO algorithm and lung consolidations identified by point-of-care ultrasound.

METHODS

An expert radiologist taught two general practitioners how to perform point-of-care ultrasound over a seven-day period. We then conducted a prospective study of children aged 2 months to 3 years in Peru and Nepal with and without respiratory symptoms, which were evaluated by point-of-care ultrasound to identify lung consolidation.

RESULTS

We enrolled 378 children: 127 were controls without respiratory symptoms, 82 had respiratory symptoms without clinical pneumonia, and 169 had clinical pneumonia by WHO criteria. Point-of-care ultrasound was performed in the community (n = 180), in outpatient offices (n = 95), in hospital wards (n = 19), and in Emergency Departments (n = 84). Average time to perform point-of-care ultrasound was 6.4 ± 2.2 min. Inter-observer agreement for point-of-care ultrasound interpretation between general practitioners was high (κ = 0.79, 95 % CI 0.73-0.81). The diagnosis of pneumonia using the WHO algorithm yielded a sensitivity of 69.6 % (95 % CI 55.7-80.8 %), specificity of 59.6 % (95 % CI 54.0-65.0 %), and positive and negative likelihood ratios of 1.73 (95 % CI 1.39-2.15) and 0.51 (95 % CI 0.30-0.76) when lung consolidation on point-of-care ultrasound was used as the reference.

CONCLUSIONS

The WHO algorithm disagreed with point-of-care ultrasound findings in more than one-third of children and had an overall low performance when compared with point-of-care ultrasound to identify lung consolidation. A paired approach with point-of-care ultrasound may improve case management in resource-limited settings.

Diagnosing acute heart failure in patients with undifferentiated dyspnea: a lung and cardiac ultrasound (LuCUS) protocol

OBJECTIVES

The primary goal of this study was to determine accuracy for diagnosing acutely decompensated heart failure (ADHF) in the undifferentiated dyspneic emergency department (ED) patient using a lung and cardiac ultrasound (LuCUS) protocol. Secondary objectives were to determine if US findings acutely change management and if findings are more accurate than clinical gestalt.

METHODS

This was a prospective, observational study of adult patients presenting to the ED with undifferentiated dyspnea. The intervention consisted of a 12-view LuCUS protocol performed by experienced emergency physician sonographers. The primary objective was measured by comparing US findings to the final diagnosis independently determined by two physicians blinded to the LuCUS result. Acute treatment changes based on US findings were tracked in real time through a standardized data collection form.

RESULTS

Data on 99 patients were analyzed; ADHF was the final diagnosis in 36%. The LuCUS protocol had sensitivity of 83% (95% confidence interval [CI] = 67% to 93%), specificity of 83% (95% CI = 70% to 91%), positive likelihood ratio of 4.8 (95% CI = 2.7 to 8.3), and negative likelihood ratio of 0.20 (95% CI = 0.09 to 0.42). Forty-seven percent of patients had changes in acute management, and 42% had changes in acute treatment. Observed agreement for the LuCUS protocol was 93% between coinvestigators. Overall, accuracy improved by 20% (83% vs. 63%, 95% CI = 8% to 31% for the difference) over clinical gestalt alone.

CONCLUSIONS

The LuCUS protocol may accurately identify ADHF and may improve acute clinical management in dyspneic ED patients. This protocol has improved diagnostic accuracy over clinical gestalt alone.

Lung ultrasound in heart failure: Lessons from re-analysis of Lung Ultrasound 2011 database

Introduction: In the setting of patients presenting with shortness of breath to an Emergency Department a simple lung ultrasound protocol aimed at detecting pulmonary oedema has been shown to have diagnostic accuracy of 85%. This article reviews data from the original study, in an attempt to determine whether adjusting the protocol and/or interpretive criteria would improve results. Method: A large lung ultrasound project provided the dataset. Inter-rater and intertest discrepancies were reviewed. Then original stored images and comments were retrospectively analysed using alternate interpretive criteria. Specific variations included changing the number of B-lines required to define 'wet lung' and assessing other pleural line abnormalities. Where they had been acquired cardiac loops were reviewed in addition to the lung images. Results: The 204 original studies available were reviewed. Some disagreement could be attributed to inexperience and unclear definitions. Adjusting the number of B-lines did not improve diagnostic accuracy. All positive scans, with numerous B-lines were reviewed using more advanced diagnostic criteria (pleural line abnormalities) and the number of false positives was decreased. In cases where cardiac views were available, their inclusion was beneficial. Conclusion: A simple lung ultrasound protocol to assess for 'wet lung' in patients presenting to Emergency Departments provides diagnostic accuracy of around 85% in the hands of relative novices. More advanced interpretation of the same_ultrasound images, and the addition of cardiac views, is likely to further improve diagnostic accuracy.

Use of neonatal chest ultrasound to predict noninvasive ventilation failure

BACKGROUND

Noninvasive ventilation is the treatment of choice for neonatal moderate respiratory distress (RD). Predictors of nasal ventilation failure are helpful in preventing clinical deterioration. Work on neonatal lung ultrasound has shown that the persistence of a hyperechogenic, "white lung" image correlates with severe distress in the preterm infant. We investigate the persistent white lung ultrasound image as a marker of noninvasive ventilation failure.

METHODS

Newborns admitted to the NICU with moderate RD and stabilized on nasal continuous positive airway pressure for 120 minutes were enrolled. Lung ultrasound was performed and blindly classified as type 1 (white lung), type 2 (prevalence of B-lines), or type 3 (prevalence of A-lines). Chest radiograph also was examined and graded by an experienced radiologist blind to the infant's clinical condition. Outcome of the study was the accuracy of bilateral type 1 to predict intubation within 24 hours from scanning. Secondary outcome was the performance of the highest radiographic grade within the same time interval.

RESULTS

We enrolled 54 infants (gestational age 32.5 ± 2.6 weeks; birth weight 1703 ± 583 g). Type 1 lung profile showed sensitivity 88.9%, specificity 100%, positive predictive value 100%, and negative predictive value 94.7%. Chest radiograph had sensitivity 38.9%, specificity 77.8%, positive predictive value 46.7%, and negative predictive value 71.8%.

CONCLUSIONS

After a 2-hour nasal ventilation trial, neonatal lung ultrasound is a useful predictor of the need for intubation, largely outperforming conventional radiology. Future studies should address whether including ultrasonography in the management of neonatal moderate RD confers clinical advantages.

Lung Ultrasound Predicts Well Extravascular Lung Water but Is of Limited Usefulness in the Prediction of Wedge Pressure

Background:

Pulmonary congestion is indicated at lung ultrasound by detection of B-lines, but correlation of these ultrasound signs with pulmonary artery occlusion pressure (PAOP) and extravascular lung water (EVLW) still remains to be further explored. The aim of the study was to assess whether B-lines, and eventually a combination with left ventricular ejection fraction (LVEF) assessment, are useful to differentiate low/high PAOP and EVLW in critically ill patients.

Methods:

The authors enrolled 73 patients requiring invasive monitoring from the intensive care unit of four university-affiliated hospitals. Forty-one patients underwent PAOP measurement by pulmonary artery catheterization and 32 patients had EVLW measured by transpulmonary thermodilution method. Lung and cardiac ultrasound examinations focused to the evaluation of B-lines and gross estimation of LVEF were performed. The absence of diffuse B-lines (A-pattern) versus the pattern showing prevalent B-lines (B-pattern) and the combination with normal or impaired LVEF were correlated with cutoff levels of PAOP and EVLW.

Results:

PAOP of 18 mmHg or less was predicted by the A-pattern with 85.7% sensitivity (95% CI, 70.5 to 94.1%) and 40.0% specificity (CI, 25.4 to 56.4%), whereas EVLW 10 ml/kg or less with 81.0% sensitivity (CI, 62.6 to 91.9%) and 90.9% specificity (CI, 74.2 to 97.7%). The combination of A-pattern with normal LVEF increased sensitivity to 100% (CI, 84.5 to 100%) and specificity to 72.7% (CI, 52.0 to 87.2%) for the prediction of PAOP 18 mmHg or less.

Conclusions:

B-lines allow good prediction of pulmonary congestion indicated by EVLW, whereas are of limited usefulness for the prediction of hemodynamic congestion indicated by PAOP. Combining B-lines with estimation of LVEF at transthoracic ultrasound may improve the prediction of PAOP.

Lung ultrasonography for the diagnosis of severe neonatal pneumonia

BACKGROUND

Lung ultrasonography is useful for the diagnosis of pneumonia in children and adults. This study investigated the lung ultrasound findings in severe neonatal pneumonia.

METHODS

From September 2012 to October 2013, 80 neonates admitted to Bayi Children's Hospital, affiliated with the Beijing Military General Hospital, were divided into two groups: 40 neonates with severe pneumonia according to their medical history, clinical manifestations, and chest radiograph findings and 40 neonates with no lung disease (control group). All subjects underwent bedside lung ultrasound examination in a quiet state. A single expert physician performed all ultrasound examinations. Findings of pleural line abnormalities, B lines, lung consolidation, air bronchograms, bilateral white lung, interstitial syndrome, lung sliding, and lung pulse were compared between the groups.

RESULTS

The lung ultrasound findings associated with infectious pneumonia included large areas of lung consolidation with irregular margins and air bronchograms, pleural line abnormalities, and interstitial syndrome. A large area of lung consolidation with irregular margins had 100% sensitivity and 100% specificity for the diagnosis of neonatal pneumonia.

CONCLUSIONS

Lung ultrasonography is a reliable tool for diagnosing neonatal pneumonia. It is suitable for routine use in the neonatal ICU and may eventually replace chest radiography and CT scanning.

Effectiveness of chest radiography, lung ultrasound and thoracic computed tomography in the diagnosis of congestive heart failure

Hydrostatic pulmonary edema is as an abnormal increase in extravascular water secondary to elevated pressure in the pulmonary circulation, due to congestive heart failure or intravascular volume overload. Diagnosis of hydrostatic pulmonary edema is usually based on clinical signs associated to conventional radiography findings. Interpretation of radiologic signs of cardiogenic pulmonary edema are often questionable and subject. For a bedside prompt evaluation, lung ultrasound (LUS) may assess pulmonary congestion through the evaluation of vertical reverberation artifacts, known as B-lines. These artifacts are related to multiple minimal acoustic interfaces between small water-rich structures and alveolar air, as it happens in case of thickened interlobular septa due to increase of extravascular lung water. The number, diffusion and intensity of B lines correlates with both the radiologic and invasive estimate of extravascular lung water. The integration of conventional chest radiograph with LUS can be very helpful to obtain the correct diagnosis. Computed tomography (CT) is of limited use in the work up of cardiogenic pulmonary edema, due to its high cost, little use in the emergencies and radiation exposure. However, a deep knowledge of CT signs of pulmonary edema is crucial when other similar pulmonary conditions may occasionally be in the differential diagnosis.

Lung ultrasonography for the diagnosis of neonatal lung disease

Ultrasound has recently become an important method for diagnostic examination and monitoring of lung disease. Many lung diseases, such as respiratory distress syndrome, transient tachypnea of the newborn, pneumonia, atelectasis and pneumothorax were diagnosed by chest X-ray or CT scan in the past, but can now easily be diagnosed with lung ultrasound. Lung ultrasound has many advantages over X-ray and CT scan including accuracy, reliability, low-cost and simplicity, as well as the fact that ultrasound incurs no risk of radiation damage. It is therefore feasible and convenient to perform at the bedside in a neonatal ward. This review focuses on features of bedside lung ultrasound and diagnosis features of common lung diseases in newborn infants, culminating in suggestions for improving the application of ultrasound in the neonatal field.

Comparison of a basic lung scanning protocol against formally reported chest x-ray in the diagnosis of pulmonary oedema

Introduction: Brief lung scan protocols have been recommended as a useful adjunct to identify pulmonary oedema in the breathless elderly patient. Some papers quote diagnostic accuracies above that of chest x-ray. Method: We recruited a prospective convenience sample of patients over sixty years of age reporting any breathlessness on presentation to the emergency department. Those who received both bedside lung scan and chest x-ray later had their case notes audited by an expert cardiologist for the cause of their breathlessness at presentation. Admission diagnosis was also extracted. Results: 204 comparative data sets were collected. Compared with cardiologist chart review, delayed expert radiology report had a diagnostic accuracy of 92.2% (95%CI 87.6 to 95.1). Bedside interpretation of lung scan protocol had a diagnostic accuracy of 85.3% (95%CI 79.8 to 89.5). The difference of 6.9% between the two accuracy measures was significant (95%CI 0.69 to 13.1). Admission diagnosis accuracy, which encompasses inexpert x-ray interpretation was 70.2%(95%CI 62.9 to 76.6), significantly less than either lung scan or expert chest x-ray report. Conclusion: For identifying heart failure in breathless patients, urgent chest x-ray with delayed formal report has not been shown to be redundant. Basic lung scan protocols should not yet replace chest x-ray, but may be more reliable in the interim than inexpert clinician interpretation of chest x-rays.

Ex vivo lung sonography: morphologic-ultrasound relationship

Ultrasound (US) interstitial syndrome is a sonographic lung pattern characterized by the presence of acoustic artifacts (B-lines and white lung). The purpose of this study was to demonstrate how interstitial syndrome is determined by acoustic interactions in lungs of variable density and in healthy organs deflated to a nonphysiologic level of density. Normal rabbit lungs were studied ex vivo by US at varying known degrees of inflation, and their histologic appearances were described. In this experimental setting, US interstitial syndrome recognizes a mechanism related to tissue density or porosity. Artifacts (B-lines and white lung) appear in the normal rabbit lung through air-dependent increases in density. As in pathologic conditions, US interstitial syndrome can be reproduced in histologically normal lungs that are deflated to a critical level (>0.45 g/mL) of density, which is not achievable under physiologic conditions.

International evidence-based recommendations for point-of-care lung ultrasound

BACKGROUND

The purpose of this study is to provide evidence-based and expert consensus recommendations for lung ultrasound with focus on emergency and critical care settings.

METHODS

A multidisciplinary panel of 28 experts from eight countries was involved. Literature was reviewed from January 1966 to June 2011. Consensus members searched multiple databases including Pubmed, Medline, OVID, Embase, and others. The process used to develop these evidence-based recommendations involved two phases: determining the level of quality of evidence and developing the recommendation. The quality of evidence is assessed by the grading of recommendation, assessment, development, and evaluation (GRADE) method. However, the GRADE system does not enforce a specific method on how the panel should reach decisions during the consensus process. Our methodology committee decided to utilize the RAND appropriateness method for panel judgment and decisions/consensus.

RESULTS

Seventy-three proposed statements were examined and discussed in three conferences held in Bologna, Pisa, and Rome. Each conference included two rounds of face-to-face modified Delphi technique. Anonymous panel voting followed each round. The panel did not reach an agreement and therefore did not adopt any recommendations for six statements. Weak/conditional recommendations were made for 2 statements, and strong recommendations were made for the remaining 65 statements. The statements were then recategorized and grouped to their current format. Internal and external peer-review processes took place before submission of the recommendations. Updates will occur at least every 4 years or whenever significant major changes in evidence appear.

CONCLUSIONS

This document reflects the overall results of the first consensus conference on "point-of-care" lung ultrasound. Statements were discussed and elaborated by experts who published the vast majority of papers on clinical use of lung ultrasound in the last 20 years. Recommendations were produced to guide implementation, development, and standardization of lung ultrasound in all relevant settings.

Computerised lung sound analysis to improve the specificity of paediatric pneumonia diagnosis in resource-poor settings: protocol and methods for an observational study

INTRODUCTION

WHO case management algorithm for paediatric pneumonia relies solely on symptoms of shortness of breath or cough and tachypnoea for treatment and has poor diagnostic specificity, tends to increase antibiotic resistance. Alternatives, including oxygen saturation measurement, chest ultrasound and chest auscultation, exist but with potential disadvantages. Electronic auscultation has potential for improved detection of paediatric pneumonia but has yet to be standardised. The authors aim to investigate the use of electronic auscultation to improve the specificity of the current WHO algorithm in developing countries.

METHODS

This study is designed to test the hypothesis that pulmonary pathology can be differentiated from normal using computerised lung sound analysis (CLSA). The authors will record lung sounds from 600 children aged ≤5 years, 100 each with consolidative pneumonia, diffuse interstitial pneumonia, asthma, bronchiolitis, upper respiratory infections and normal lungs at a children's hospital in Lima, Peru. The authors will compare CLSA with the WHO algorithm and other detection approaches, including physical exam findings, chest ultrasound and microbiologic testing to construct an improved algorithm for pneumonia diagnosis.

DISCUSSION

This study will develop standardised methods for electronic auscultation and chest ultrasound and compare their utility for detection of pneumonia to standard approaches. Utilising signal processing techniques, the authors aim to characterise lung sounds and through machine learning, develop a classification system to distinguish pathologic sounds. Data will allow a better understanding of the benefits and limitations of novel diagnostic techniques in paediatric pneumonia.

Sonographic diagnosis of pneumothorax

PURPOSE

Over the last decade, the use of ultrasound as a technique to look for pneumothorax has rapidly evolved. This review aims to analyze and synthesize current knowledge on lung ultrasound targeted at the diagnosis of pneumothorax. The technique and its usefulness in different scenarios are explained, and its merits over conventional radiology are highlighted.

METHODS

A systematic literature search (1995-2010) was performed, involving PubMed, to describe the more recent scientific evidence on the topic. Moreover, this review is also a synopsis of experts' opinion and personal clinical experience.

RESULTS AND CONCLUSIONS

Ultrasound diagnosis of pneumothorax relies on the recognition of four sonographic artifact signs: the lung sliding, the B lines, the lung point, and the lung pulse. Combining these few signs, it is possible to accurately rule in or rule out pneumothorax at the bedside in several different clinical scenarios. Sensitivity of a lung ultrasound in the detection of pneumothorax is higher than that of conventional anterior-posterior chest radiography, and similar to that of computerized tomography. A major benefit of a lung ultrasound is that it can be used quickly to diagnose pneumothorax at the bedside in any critical situation, like cardiac arrest and hemodynamically unstable patients. Moreover, it can be used to detect radio-occult pneumothorax and to quantify the extension of the air layer. Advantages in terms of reduced complexity, feasibility at the bedside, and absence of exposure to ionizing radiation make lung ultrasound the method of choice in several common clinical situations.