Sonographic diagnosis of pneumonia and bronchopneumonia

Lung Ultrasonography Accuracy for Diagnosis of Adult Pneumonia: Systematic Review and Meta-Analysis

BACKGROUND

Pneumonia is a ubiquitous health condition with severe outcomes. The advancement of ultrasonography techniques allows its application in evaluating pulmonary diseases, providing safer and accessible bedside therapeutic decisions compared to chest X-ray and chest computed tomography (CT) scan. Because of its aforementioned benefits, we aimed to confirm the diagnostic accuracy of lung ultrasound (LUS) for pneumonia in adults.

METHODS

A systematic literature search was performed of Medline, Cochrane and Crossref, independently by two authors. The selection of studies proceeded based on specific inclusion and exclusion criteria without restrictions to particular study designs, language or publication dates and was followed by data extraction. The gold standard reference in the included studies was chest X-ray/CT scan or both.

RESULTS

Twenty-nine (29) studies containing 6702 participants were included in our meta-analysis. Pooled sensitivity, specificity and PPV were 92% (95% CI: 91-93%), 94% (95% CI: 94 to 95%) and 93% (95% CI: 89 to 96%), respectively. Pooled positive and negative likelihood ratios were 16 (95% CI: 14 to 19) and 0.08 (95% CI: 0.07 to 0.09). The area under the ROC curve of LUS was 0. 9712.

CONCLUSIONS

LUS has high diagnostic accuracy in adult pneumonia. Its contribution could form an optimistic clue in future updates considering this condition.

Implementing an interprofessional point-of-care ultrasound protocol for dyspneic patients in an emergency department as a blended learning concept-Feasibility of Employing Thoracic Ultrasound in Shortness of Breath

Objective

Dyspnea is a common symptom in the Emergency Department, with a wide variety of differential diagnoses. Previous research has demonstrated the diagnostic accuracy of Point-of-Care Ultrasound (POCUS) in this field of interest. Our goal was to better establish sonography in our emergency department with a practicable and time effective method. Therefore, we implemented a sonography protocol in an interprofessional emergency team using blended learning as a modern didactic approach and evaluated the learning and teaching success. We named the study FETUS, which stands for "Feasibility of Employing Thoracic Ultrasound in Shortness of Breath."

Methods

A demonstration of the POCUS protocol was given, followed by individual supervision during clinical routine. A written manual, a pocket card, and further materials for personal training supplemented the training. A post-training questionnaire measured several parameters regarding the training, e.g., subjective skill-acquisition or media use.

Results

32 medical and nursing staff participated in this study, 14 of whom completed the questionnaire. All training modalities offered were well received. A pre-post comparison of subjective sonographic competence shows a significant increase in both medical and nursing staff.The other items surveyed also indicate the success of the intervention undertaken.

Conclusion

The use of different media as a blended learning approach can support the implementation of new measures in the ongoing working routine within an interprofessional team.

Diagnostic Value of Bedside Lung Ultrasonography in Pneumonia

Bedside lung ultrasonography (LUS) is a reliable method for the diagnosis of pneumonia. No common consensus exists in the literature regarding the effectiveness of LUS findings, except consolidation, for the diagnosis of pneumonia. The primary objective of this study was to investigate the effectiveness of LUS for the diagnosis of pneumonia, and the secondary objective was to investigate the use of LUS findings, except consolidation, for the diagnosis of pneumonia. A total of 127 patients with clinically suspected pneumonia were evaluated in the study. The sensitivity and specificity of LUS were 98.0% and 95.8%, respectively. In the cases where consolidation was not determined in LUS but B-3 line positivity or a diffuse interstitial pattern was present, the sensitivity and specificity were 93.3% and 88.2%, respectively. When consolidation was not observed in LUS, the presence of B-3 line positivity or diffuse interstitial pattern could be used for the diagnosis of pneumonia.

Systematic review and meta-analysis for the use of ultrasound versus radiology in diagnosing of pneumonia

Background

Physicians are increasingly using point of care lung ultrasound (LUS) for diagnosing pneumonia, especially in critical situations as it represents relatively easy and immediately available tool. They also used it in many associated pathological conditions such as consolidation, pleural effusion, and interstitial syndrome with some reports of more accuracy than chest X-ray. This systematic review and meta-analysis are aimed to estimate the pooled diagnostic accuracy of ultrasound for the diagnosis of pneumonia versus the standard chest radiological imaging.

Methods and main results

A systematic literature search was conducted for all published studies comparing the diagnostic accuracy of LUS against a reference Chest radiological exam (C X-ray or Chest computed Tomography CT scan), combined with clinical criteria for pneumonia in all age groups. Eligible studies were required to have a Chest X-ray and/or CT scan at the time of clinical evaluation. The authors extracted qualitative and quantitative information from eligible studies, and calculated pooled sensitivity and specificity and pooled positive/negative likelihood ratios (LR). Twenty studies containing 2513 subjects were included in this meta-analysis. The pooled estimates for lung ultrasound in the diagnosis of pneumonia were, respectively, as follows: Overall pooled sensitivity and specificity for diagnosis of pneumonia by lung ultrasound were 0.85 (0.84–0.87) and 0.93 (0.92–0.95), respectively. Overall pooled positive and negative LRs were 11.05 (3.76–32.50) and 0.08 (0.04–0.15), pooled diagnostic Odds ratio was 173.64 (38.79–777.35), and area under the pooled ROC (AUC for SROC) was 0.978.

Conclusion

Point of care lung ultrasound is an accurate tool for the diagnosis of pneumonia. Considering being easy, readily availability, low cost, and free from radiological hazards, it can be considered as important diagnostic strategy in this condition.

Thoracic Ultrasound: What Non-radiologists Need to Know

Purpose of review

The aim of this review is to provide the theoretical and practical knowledge essential for non-radiologists to develop the skills necessary to apply thoracic ultrasound as an extension of clinical assessment and intervention.

Recent findings

Issues relating to training and competence are discussed and a library of thoracic ultrasound videos is provided to illustrate artefacts, pleural, parenchymal and pneumothorax pathology as well as important pitfalls to consider. Novel and future diagnostic applications of thoracic ultrasound in the setting of acute cardiorespiratory pathology including consolidation, acute interstitial syndromes and pulmonary embolism are explored.

Summary

Thoracic ultrasound requires an understanding of imaging artefact specific to lung and pleura and a working knowledge of machine knobology for image optimisation and interpretation. Ultrasound is a valuable tool for the practicing chest clinician providing diagnostic information for the assessment of pleural and parenchymal disease and increased safety and cost effectiveness of thoracic interventions.

Electronic supplementary material

The online version of this article (doi:10.1007/s13665-017-0164-1) contains supplementary material, which is available to authorized users.

Role of Arrival Time Difference Between Lesions and Lung Tissue on Contrast-Enhanced Sonography in the Differential Diagnosis of Subpleural Pulmonary Lesions

OBJECTIVES

The purpose of this study was to explore the diagnostic value of the arrival time difference between lesions and surrounding lung tissue on contrast-enhanced sonography of subpleural pulmonary lesions.

METHODS

A total of 110 patients with subpleural pulmonary lesions who underwent both conventional and contrast-enhanced sonography and had a definite diagnosis were enrolled. After contrast agent injection, the arrival times in the lesion, lung, and chest wall were recorded. The arrival time differences between various tissues were also calculated.

RESULTS

Statistical analysis showed a significant difference in the lesion arrival time, the arrival time difference between the lesion and lung, and the arrival time difference between the chest wall and lesion (all P < .001) for benign and malignant lesions. Receiver operating characteristic curve analysis revealed that the optimal diagnostic criterion was the arrival time difference between the lesion and lung, and that the best cutoff point was 2.5 seconds (later arrival signified malignancy). This new diagnostic criterion showed superior diagnostic accuracy (97.1%) compared to conventional diagnostic criteria.

CONCLUSIONS

The individualized diagnostic method based on an arrival time comparison using contrast-enhanced sonography had high diagnostic accuracy (97.1%) with good feasibility and could provide useful diagnostic information for subpleural pulmonary lesions.

Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis

Background

Guidelines do not currently recommend the use of lung ultrasound (LUS) as an alternative to chest X-ray (CXR) or chest computerized tomography (CT) scan for the diagnosis of pneumonia. We conducted a meta-analysis to summarize existing evidence of the diagnostic accuracy of LUS for pneumonia in adults.

Methods

We conducted a systematic search of published studies comparing the diagnostic accuracy of LUS against a referent CXR or chest CT scan and/or clinical criteria for pneumonia in adults aged ≥18 years. Eligible studies were required to have a CXR and/or chest CT scan at the time of evaluation. We manually extracted descriptive and quantitative information from eligible studies, and calculated pooled sensitivity and specificity using the Mantel-Haenszel method and pooled positive and negative likelihood ratios (LR) using the DerSimonian-Laird method. We assessed for heterogeneity using the Q and I² statistics.

Results

Our initial search strategy yielded 2726 articles, of which 45 (1.7%) were manually selected for review and 10 (0.4%) were eligible for analyses. These 10 studies provided a combined sample size of 1172 participants. Six studies enrolled adult patients who were either hospitalized or admitted to Emergency Departments with suspicion of pneumonia and 4 studies enrolled critically-ill adult patients. LUS was performed by highly-skilled sonographers in seven studies, by trained physicians in two, and one did not mention level of training. All studies were conducted in high-income settings. LUS took a maximum of 13 minutes to conduct. Nine studies used a 3.5-5 MHz micro-convex transducer and one used a 5–9 MHz convex probe. Pooled sensitivity and specificity for the diagnosis of pneumonia using LUS were 94% (95% CI, 92%-96%) and 96% (94%-97%), respectively; pooled positive and negative LRs were 16.8 (7.7-37.0) and 0.07 (0.05-0.10), respectively; and, the area-under-the-ROC curve was 0.99 (0.98-0.99).

Conclusions

Our meta-analysis supports that LUS, when conducted by highly-skilled sonographers, performs well for the diagnosis of pneumonia. General practitioners and Emergency Medicine physicians should be encouraged to learn LUS since it appears to be an established diagnostic tool in the hands of experienced physicians.

Performance comparison of lung ultrasound and chest x-ray for the diagnosis of pneumonia in the ED

OBJECTIVE

The aim of our study was to assess the potential of bedside lung ultrasound examination by the attending emergency physician in the diagnosis of acute pneumonia.

MATERIAL AND METHODS

This observational single-center study was conducted between January 2010 and June 2012 in the emergency unit of a general hospital, and analyzed 144 adult patients. The ultrasound examination was performed by one of five trained emergency physicians, and a chest radiograph interpreted by a radiologist. The primary end point was the diagnosis of hospital discharge.

RESULTS

We found a sensitivity of 0.95 for the ultrasound examination against 0.6 for radiography (P < .05). The negative predictive value was 0.67 against 0.25 for radiography (P < .05).

CONCLUSION

These results exhort to promote the use of thoracic ultrasound in the first-line diagnosis of pneumonia.

Evaluation of lung ultrasound for the diagnosis of pneumonia in the ED

OBJECTIVES

The aim of this study is to assess the ability of bedside lung ultrasound (US) to confirm clinical suspicion of pneumonia and the feasibility of its integration in common emergency department (ED) clinical practice.

METHODS

In this study we performed lung US in adult patients admitted in our ED with a suspected pneumonia. Subsequently, a chest radiograph (CXR) was carried out for each patient. A thoracic computed tomographic (CT) scan was made in patients with a positive lung US and a negative CXR. In patients with confirmed pneumonia, we performed a follow-up after 10 days to evaluate clinical conditions after antibiotic therapy.

RESULTS

We studied 49 patients: pneumonia was confirmed in 32 cases (65.3%). In this group we had 31 (96.9%) positive lung US and 24 (75%) positive CXR. In 8 (25%) cases, lung US was positive with a negative CXR. In this group, CT scan always confirmed the US results. In one case, US was negative and CXR positive. Follow-up turned out to be always consistent with the diagnosis.

CONCLUSION

Considering that lung US is a bedside, reliable, rapid, and noninvasive technique, these results suggest it could have a significant role in the diagnostic workup of pneumonia in the ED, even if no sensitivity nor specificity can be inferred from this study because the real gold standard is CT, which could not be performed in all patients.

Contrast enhanced ultrasonography (CEUS) in peripheral lung lesions: A study of 60 cases

INTRODUCTION

The authors report their experience in 60 patients with infectious and neoplastic peripheral pulmonary lesions studied by conventional radiology, B-Mode ultrasound (US) and computed tomography (CT). In view of the particular pulmonary vascularization (consisting of both pulmonary and bronchial arteries) the patients underwent also contrast enhanced ultrasound (CEUS) using a II-generation contrast agent, SonoVue (sulphur hexafluoride microbubbles surrounded by a phospholipid shell).

METHODS AND RESULTS

In this study, the sensitivity of CEUS reached 95% in the characterization of peripheral pulmonary lesions, which is similar to the sensitivity of CT (97%). The method used in this case-study was free of significant side effects.

DISCUSSION

This preliminary clinical experience seems to confirm the possibility of using SonoVue enhanced US to make a differential diagnosis between infectious and neoplastic lesions based on a qualitative and quantitative assessment, by evaluating the enhancement pattern (homogeneous or inhomogeneous), arrival time of the contrast agent in the lesion, the possibility to identify the pulmonary arteries and time of contrast agent elimination.