Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol.
ABSTRACT: BACKGROUND: This study assesses the potential of lung ultrasonography to diagnose acute respiratory failure. METHODS: This observational study was conducted in university-affiliated teaching-hospital ICUs. We performed ultrasonography on consecutive patients admitted to the ICU with acute respiratory failure, comparing lung ultrasonography results on initial presentation with the final diagnosis by the ICU team. Uncertain diagnoses and rare causes (frequency<2%) were excluded. We included 260 dyspneic patients with a definite diagnosis. Three items were assessed: artifacts (horizontal A lines or vertical B lines indicating interstitial syndrome), lung sliding, and alveolar consolidation and/or pleural effusion. Combined with venous analysis, these items were grouped to assess ultrasound profiles. RESULTS: Predominant A lines plus lung sliding indicated asthma (n=34) or COPD (n=49) with 89% sensitivity and 97% specificity. Multiple anterior diffuse B lines with lung sliding indicated pulmonary edema (n=64) with 97% sensitivity and 95% specificity. A normal anterior profile plus deep venous thrombosis indicated pulmonary embolism (n=21) with 81% sensitivity and 99% specificity. Anterior absent lung sliding plus A lines plus lung point indicated pneumothorax (n=9) with 81% sensitivity and 100% specificity. Anterior alveolar consolidations, anterior diffuse B lines with abolished lung sliding, anterior asymmetric interstitial patterns, posterior consolidations or effusions without anterior diffuse B lines indicated pneumonia (n=83) with 89% sensitivity and 94% specificity. The use of these profiles would have provided correct diagnoses in 90.5% of cases. CONCLUSIONS: Lung ultrasound can help the clinician make a rapid diagnosis in patients with acute respiratory failure, thus meeting the priority objective of saving time.
Project description:Subpleural consolidations have been found in lung ultrasound in patients with COVID-19, possibly deriving from pulmonary embolism (PE). The diagnostic utility of impact of lung ultrasound in critical-ill patients with COVID-19 for PE diagnostics however is unclear. We retrospectively evaluated all SARS-CoV2-associated ARDS patients admitted to our ICU between March 8th and May 31th 2020. They were enrolled in this study, when a lung ultrasound and a computed tomography pulmonary angiography (CTPA) were documented. In addition, wells score was calculated to estimate the probability of PE. The CTPA was used as the gold standard for the detection of PE. Twenty out of 25 patients met the inclusion criteria. In 12/20 patients (60%) (sub-) segmental PE were detected by CT-angiography. Lung ultrasound found subpleural consolidations in 90% of patients. PE-typical large supleural consolidations with a size ≥ 1 cm were detectable in 65% of patients and were significant more frequent in patients with PE compared to those without (p = 0.035). Large consolidations predicted PE with a sensitivity of 77% and a specificity of 71%. The Wells score was significantly higher in patients with PE compared to those without (2.7 ± 0.8 and 1.7 ± 0.5, respectively, p = 0.042) and predicted PE with an AUC of 0.81. When combining the two modalities, comparing patients with considered/probable PE using LUS plus a Wells score ≥ 2 to patients with possible/unlikely PE in LUS plus a Wells score < 2, PE could be predicted with a sensitivity of 100% and a specificity of 80%. Large consolidations detected in lung ultrasound were found frequently in COVID-19 ARDS patients with pulmonary embolism. In combination with a Wells score > 2, this might indicate a high-risk for PE in COVID-19.
Project description:<h4>Introduction</h4>Ultrasonography is being increasingly utilized in acute care settings with expanding applications. Pneumothorax evaluation by ultrasonography is a fast, safe, easy and inexpensive alternative to chest radiographs. In this review, we provide a comprehensive analysis of the current literature comparing ultrasonography and chest radiography for the diagnosis of pneumothorax.<h4>Methods</h4>We searched English-language articles in MEDLINE, EMBASE and Cochrane Library dealing with both ultrasonography and chest radiography for diagnosis of pneumothorax. In eligible studies that met strict inclusion criteria, we conducted a meta-analysis to evaluate the diagnostic accuracy of pleural ultrasonography in comparison with chest radiography for the diagnosis of pneumothorax.<h4>Results</h4>We reviewed 601 articles and selected 25 original research articles for detailed review. Only 13 articles met all of our inclusion criteria and were included in the final analysis. One study used lung sliding sign alone, 12 studies used lung sliding and comet tail signs, and 6 studies searched for lung point in addition to the other two signs. Ultrasonography had a pooled sensitivity of 78.6% (95% CI, 68.1 to 98.1) and a specificity of 98.4% (95% CI, 97.3 to 99.5). Chest radiography had a pooled sensitivity of 39.8% (95% CI, 29.4 to 50.3) and a specificity of 99.3% (95% CI, 98.4 to 100). Our meta-regression and subgroup analyses indicate that consecutive sampling of patients compared to convenience sampling provided higher sensitivity results for both ultrasonography and chest radiography. Consecutive versus nonconsecutive sampling and trauma versus nontrauma settings were significant sources of heterogeneity. In addition, subgroup analysis showed significant variations related to operator and type of probe used.<h4>Conclusions</h4>Our study indicates that ultrasonography is more accurate than chest radiography for detection of pneumothorax. The results support the previous investigations in this field, add new valuable information obtained from subgroup analysis, and provide accurate estimates for the performance parameters of both bedside ultrasonography and chest radiography for pneumothorax evaluation.
Project description:BACKGROUND:Thoracic ultrasound is helpful to evaluate lung pathology in patients with acute dyspnea. Several studies have demonstrated the efficacy of point-of-care ultrasound in patients with extrapulmonary TB and HIV co-infection. This retrospective, open-label case-control study explores the role of lung ultrasound in the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in HIV-positive patients. In particular, it highlights the potential role of specific sonographic features that may be unique to this population. METHODS:The record of all HIV-positive patients admitted from 1.1.2013 to 31.6.2017 to the Department of Infectious Diseases and Tropical Medicine of san Bortolo Hospital, Vicenza, Italy, with a discharge diagnosis of acute lung injury (ALI) and who received point-of-care ultrasound of the chest for clinical purposes was included in the analysis. The patients were scanned according with the evidence-based recommendation. RESULTS:Of 273 HIV-positive patients whose records were reviewed, 81 (29.6%) were diagnosed with ALI. Complete documentation was available for 24 patients, of which 14 (58.3%) had microbiologically confirmed PJP (PJP+) and 10 (41.7%) had other conditions (PJP-). B-lines, subpleural consolidations, and cystic changes were significantly more frequent in patients with PJP (14/14 vs. 6/10, p = 0.0198; 14/14 vs. 4/10, p = 0.0016; 8/14 vs. 0/10, p = 0.0019, respectively). In particular, B-lines and subpleural consolidations were present in all PJP+ patients in our cohort giving a sensitivity of 100%, but their specificity was low (45 and 60%, respectively). On the contrary, the presence of consolidations with cystic changes had a very high specificity for PJP (100%), but low sensitivity (57%). Pleural effusions and consolidations with linear air bronchograms were not observed in PJP+ patients. CONCLUSIONS:B-lines, subpleural consolidations, and cystic changes are suggestive of PJP. Lung consolidation with air bronchograms and pleural effusion should prompt suspicion of other etiologies. These findings have the potential to be useful in the daily management of HIV-positive patients in resource-limited settings where other diagnostic tools are rarely available.
Project description:<h4>Background and aim</h4>Lung ultrasound (LUS) is a convenient imaging modality in the setting of coronavirus disease-19 (COVID-19) because it is easily available, can be performed bedside and repeated over time. We herein examined LUS patterns in relation to disease severity and disease stage among patients with COVID-19 pneumonia.<h4>Methods</h4>We performed a retrospective case series analysis of patients with confirmed SARS-CoV-2 infection who were admitted to the hospital because of pneumonia. We recorded history, clinical parameters and medications. LUS was performed and scored in a standardized fashion by experienced operators, with evaluation of up to 12 lung fields, reporting especially on B-lines and consolidations.<h4>Results</h4>We included 96 patients, 58.3% men, with a mean age of 65.9 years. Patients with a high-risk quick COVID-19 severity index (qCSI) were older and had worse outcomes, especially for the need for high-flow oxygen. B-lines and consolidations were located mainly in the lower posterior lung fields. LUS patterns for B-lines and consolidations were significantly worse in all lung fields among patients with high versus low qCSI. B-lines and consolidations were worse in the intermediate disease stage, from day 7 to 13 after onset of symptoms. While consolidations correlated more with inflammatory biomarkers, B-lines correlated more with end-organ damage, including extrapulmonary involvement.<h4>Conclusions</h4>LUS patterns provide a comprehensive evaluation of patients with COVID-19 pneumonia that correlated with severity and dynamically reflect disease stage. LUS patterns may reflect different pathophysiological processes related to inflammation or tissue damage; consolidations may represent a more specific sign of localized disease, whereas B-lines seem to be also dependent upon generalized illness due to SARS-CoV-2 infection.
Project description:<h4>Background:</h4> The objectives were to perform an analysis of lung ultrasonography (LUS) findings in severely ill patients with novel coronavirus disease-2019 (COVID-19) and to compare the accuracy with high-resolution computed tomography (HRCT) of the thorax. <h4>Methods:</h4> Sixty-two intensive care unit (ICU) patients with COVID-19 were evaluated during their hospital stay. LUS was performed with convex and linear transducers using a designated ultrasonography machine placed in the COVID-19 ICU. The thorax was scanned in 12 areas. Initial LUS was performed on admission and follow-up LUS was done in 7 (mean) days. At the time of the initial LUS, HRCT was performed in 28/62 patients and a chest radiography in 19/62 patients. <h4>Results:</h4> On admission, LUS detected pleural line thickening (>6 lung areas) in 49/62, confluent B-lines in 38/62, and separate B-lines in 34/62, consolidation in 12/62, C prime profile in 19/62, and pleural and cardiac effusions in 4/62 and 1/62, respectively. The single beam “torchlight” artifact was seen in 16/62, which may possibly be a variation of the B-line which has not been described earlier. Follow-up LUS detected significantly lower rates (P < 0.05) of abnormalities. <h4>Conclusion:</h4> Ultrasound demonstrated B-lines, variable consolidations, and pleural line irregularities. This study also sheds light on the appearance of the C prime pattern and “torchlight” B-lines which were not described in COVID-19 earlier. LUS findings were significantly reduced by the time of the follow-up scan, insinuating at a rather slow but consistent reduction in some COVID-19 lung lesions. However, the lung ultrasound poorly correlated with HRCT as a diagnostic modality in COVID-19 patients.
Project description:The goal of this study was to examine the ability of emergency physicians who are not experts in emergency ultrasound (US) to perform lung ultrasonography and to identify B-lines. The hypothesis was that novice sonographers are able to perform lung US and identify B-lines after a brief intervention. In addition, the authors examined the diagnostic accuracy of B-lines in undifferentiated dyspneic patients for the diagnosis of acute heart failure syndrome (AHFS), using an eight-lung-zone technique as well as an abbreviated two-lung-zone technique.This was a prospective, cross-sectional study of patients who presented to the emergency department (ED) with acute dyspnea from May 2009 to June 2010. Emergency medicine (EM) resident physicians, who received a 30-minute training course in thoracic US examinations, performed lung ultrasonography on patients presenting to the ED with undifferentiated dyspnea. They attempted to identify the presence or absence of sonographic B-lines in eight lung fields based on their bedside US examinations. An emergency US expert blinded to the diagnosis and patient presentation, as well as to the residents' interpretations of presence of B-lines, served as the criterion standard. A secondary outcome determined the accuracy of B-lines, using both an eight-lung-zone and a two-lung-zone technique, for predicting pulmonary edema from AHFS in patients presenting with undifferentiated dyspnea. Two expert reviewers who were blinded to the US results determined the clinical diagnosis of AHFS.A cohort of 66 EM resident physicians performed lung US on 380 patients with a range of 1 to 28 examinations, a mean of 5.8 examinations, and a median of three examinations performed per resident. Compared to expert interpretation, lung US to detect B-lines by inexperienced sonographers achieved the following test characteristics: sensitivity 85%, specificity 84%, positive likelihood ratio (+LR) 5.2, negative likelihood ratio (-LR) 0.2, positive predictive value (PPV) 64%, and negative predictive value (NPV) 94%. Regarding the secondary outcome, the final diagnosis was AHFS in 35% of patients (134 of 380). For novice sonographers, one positive lung zone (i.e., anything positive) had a sensitivity of 87%, a specificity of 49%, a +LR of 1.7, a -LR of 0.3, a PPV of 50%, and an NPV of 88% for predicting AHFS. When all eight lung zones were determined positive (i.e., totally positive) by novice sonographers, the sensitivity was 19%, specificity was 97%, +LR was 5.7, -LR was 0.8, PPV was 76%, and NPV was 68% for predicting AHFS. The areas under the curve for novice and expert sonographers were 0.77 (95% CI = 0.72 to 0.82) and 0.76 (95% CI = 0.71 to 0.82), respectively.Novice sonographers can identify sonographic B-lines with similar accuracy compared to an expert sonographer. Lung US has fair predictive value for pulmonary edema from acute heart failure in the hands of both novice and expert sonographers.
Project description:<h4>Objectives</h4>Lung ultrasound (LUS) can accurately diagnose several pulmonary diseases, including pneumothorax, effusion, and pneumonia. LUS may be useful in the diagnosis and management of COVID-19.<h4>Methods</h4>This study was conducted at two United States hospitals from 3/21/2020 to 6/01/2020. Our inclusion criteria included hospitalized adults with COVID-19 (based on symptomatology and a confirmatory RT-PCR for SARS-CoV-2) who received a LUS. Providers used a 12-zone LUS scanning protocol. The images were interpreted by the researchers based on a pre-developed consensus document. Patients were stratified by clinical deterioration (defined as either ICU admission, invasive mechanical ventilation, or death within 28 days from the initial symptom onset) and time from symptom onset to their scan.<h4>Results</h4>N = 22 patients (N = 36 scans) were included. Eleven (50%) patients experienced clinical deterioration. Among N = 36 scans, only 3 (8%) were classified as normal. The remaining scans demonstrated B-lines (89%), consolidations (56%), pleural thickening (47%), and pleural effusion (11%). Scans from patients with clinical deterioration demonstrated higher percentages of bilateral consolidations (50 versus 15%; P = .033), anterior consolidations (47 versus 11%; P = .047), lateral consolidations (71 versus 29%; P = .030), pleural thickening (69 versus 30%; P = .045), but not B-lines (100 versus 80%; P = .11). Abnormal findings had similar prevalences between scans collected 0-6 days and 14-28 days from symptom onset.<h4>Discussion</h4>Certain LUS findings may be common in hospitalized COVID-19 patients, especially for those that experience clinical deterioration. These findings may occur anytime throughout the first 28 days of illness. Future efforts should investigate the predictive utility of these findings on clinical outcomes.
Project description:<h4>Background</h4>Pulmonary embolism (PE) is a potentially life-threatening condition. Although computed tomography pulmonary angiography (CTPA) is the reference standard for diagnosis, its early diagnosis remains a challenge, and the concerns about the radiation exposures further limit the general use of CTPA. The primary aim of this meta-analysis was to evaluate the overall diagnostic accuracy of transthoracic lung ultrasound (TLS) in the diagnosis of PE.<h4>Methods</h4>PubMed, Web of science, OvidSP, ProQuest, EBSCO, Cochrane Library and Clinicaltrial.gov were searched systematically. The quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and hierarchical summary receiver operating characteristic (HSROC) curves were used to examine the TS performance. The Bayes analysis was used to calculate the post-test probability of PE. Publication bias was assessed with Deeks funnel plot.<h4>Results</h4>The results indicated that the sensitivity, specificity, PLR and NLR were 0.85 (95% confidence interval (CI), 0.78 to 0.90), and 0.83 (95% CI, 0.73 to 0.90). And the DOR and HSROC were 28.82 (95% CI, 17.60 to 47.21), 0.91(95% CI, 0.88, 0.93).<h4>Conclusions</h4>The present meta-analysis suggested that transthoracic lung ultrasonography is helpful in diagnosing pulmonary embolism. Although the application of transthoracic lung ultrasound may change some patients' diagnostic processes, it is inappropriate to generally use transthoracic ultrasonography in diagnosing pulmonary embolism currently.
Project description:INTRODUCTION:Current recommendations for diagnostic imaging for moderately to severely ill patients with suspected coronavirus disease 2019 (COVID-19) include chest radiograph (CXR). Our primary objective was to determine whether lung ultrasound (LUS) B-lines, when excluding patients with alternative etiologies for B-lines, are more sensitive for the associated diagnosis of COVID-19 than CXR. METHODS:This was a retrospective cohort study of all patients who presented to a single, academic emergency department in the United States between March 20 and April 6, 2020, and received LUS, CXR, and viral testing for COVID-19 as part of their diagnostic evaluation. The primary objective was to estimate the test characteristics of both LUS B-lines and CXR for the associated diagnosis of COVID-19. Our secondary objective was to evaluate the proportion of patients with COVID-19 that have secondary LUS findings of pleural abnormalities and subpleural consolidations. RESULTS:We identified 43 patients who underwent both LUS and CXR and were tested for COVID-19. Of these, 27/43 (63%) tested positive. LUS was more sensitive (88.9%, 95% confidence interval (CI), 71.1-97.0) for the associated diagnosis of COVID-19 than CXR (51.9%, 95% CI, 34.0-69.3; p = 0.013). LUS and CXR specificity were 56.3% (95% CI, 33.2-76.9) and 75.0% (95% CI, 50.0-90.3), respectively (p = 0.453). Secondary LUS findings of patients with COVID-19 demonstrated 21/27 (77.8%) had pleural abnormalities and 10/27 (37%) had subpleural consolidations. CONCLUSION:Among patients who underwent LUS and CXR, LUS was found to have a higher sensitivity than CXR for the evaluation of COVID-19. This data could have important implications as an aid in the diagnostic evaluation of COVID-19, particularly where viral testing is not available or restricted. If generalizable, future directions would include defining how to incorporate LUS into clinical management and its role in screening lower-risk populations.
Project description:BACKGROUND:Ultrasonography is a suitable modality that can potentially improve patient care, saving time and lives. PURPOSE:This article has evaluated the caveats and pitfalls of point-of-care ultrasonography in the diagnosis of pneumothorax, hemothorax and contusion. MATERIALS AND METHODS:This prospective study was performed in 157 patients with blunt chest trauma in 3 university hospitals. Ultrasonography was performed by 2 board-certified emergency medicine specialists and an emergency medicine resident PGY-3 after passing the training process successfully. RESULTS:The false-negative cases were not significantly correlated with accompanying traumatic injuries. Lung ultrasonography accompanied by chest physical examination show accuracy 91.8. Point-of-care ultrasonography (PoCUS) showed sensitivity 75.0%, specificity 100%, positive-predictive value (PPV) of 100% and a negative-predictive value (NPV) of 94.9% for the diagnosis of pneumothorax. For hemothorax, bedside PoCUS had a sensitivity of 45.4%, specificity of 100%, PPV of 100% and NPV of 91.8%. PoCUS was assessed 58.1% sensitive and 100% specific for detecting lung contusion with positive-predictive value (PPV) of 100% and a negative-predictive value (NPV) of 86.3%. Performing US resulted in no false-positive cases. CONCLUSIONS:Point-of-care ultrasonography was highly sensitive to detect pneumothorax and can be beneficial for the disposition of stable patients and to detect PTX in unstable patients before transferring to the operating room. It is also moderately appropriate for the diagnosis of hemothorax and lung contusion compared to the gold standard, CT scan. It is essential to consider the false-negative and false-positive instances of lung ultrasound in various situations to enhance management and disposition of blunt thoracic injuries.