Lecturer of chest diseasesa, Al-Azhar University
Non invasive imaging using sonography for diagnosis of pneumonia
Chest radiography is the method of choice to diagnose pneumonia; howevere it utilizes radiation. In our study we used chest ultrasound as cheap, non invasive tool to diagnose pneumonia. The results proved to be accurate and sensitive as other imaging modalities
Abstract: This study assesses the potential of lung ultrasonography to diagnose acute respiratory failure.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.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.Lung ultrasound can help the clinician make a rapid diagnosis in patients with acute respiratory failure, thus meeting the priority objective of saving time.
Pub.: 12 Apr '08, Pinned: 25 Aug '17
Abstract: The objective of this study was to identify the relationship between a dynamic lung artifact, the dynamic air bronchogram, within alveolar consolidation and the diagnosis of pneumonia vs resorptive atelectasis.This prospective study was undertaken within the medical ICU of a university-affiliated teaching hospital. The sample comprised 52 patients with proven pneumonia (pneumonia group) and 16 patients with proven resorptive atelectasis (atelectasis group). All patients had alveolar consolidation with air bronchograms on lung ultrasound, were mechanically ventilated, and received fibroscopy and bacteriological tests. The air bronchogram dynamic was analyzed within the ultrasound area of consolidation.The air bronchograms in the pneumonia group yielded the dynamic air bronchogram in 32 patients and a static air bronchogram in 20. In the atelectasis group, air bronchograms yielded a dynamic air bronchogram in 1 out of 16 patients. With regard to pneumonia vs resorptive atelectasis in patients with ultrasound-visible alveolar consolidation with air bronchograms, the dynamic air bronchogram had a specificity of 94% and a positive predictive value of 97%. The sensitivity was 61%, and the negative predictive value 43%.In patients with alveolar consolidation displaying air bronchograms on an ultrasound, the dynamic air bronchogram indicated pneumonia, distinguishing it from resorptive atelectasis. Static air bronchograms were seen in most resorptive atelectases and one third of cases of pneumonia. This finding increases the understanding of the pathophysiology of lung diseases within the clinical context and decreases the need for fibroscopy in practice.
Pub.: 20 Feb '09, Pinned: 25 Aug '17
Abstract: The aim of this prospective, multicenter study was to define the accuracy of lung ultrasound (LUS) in the diagnosis of community-acquired pneumonia (CAP).Three hundred sixty-two patients with suspected CAP were enrolled in 14 European centers. At baseline, history, clinical examination, laboratory testing, and LUS were performed as well as the reference test, which was a radiograph in two planes or a low-dose CT scan in case of inconclusive or negative radiographic but positive LUS findings. In patients with CAP, follow-up between days 5 and 8 and 13 and 16 was scheduled.CAP was confirmed in 229 patients (63.3%). LUS revealed a sensitivity of 93.4% (95% CI, 89.2%-96.3%), specificity of 97.7% (95% CI, 93.4%-99.6%), and likelihood ratios (LRs) of 40.5 (95% CI, 13.2-123.9) for positive and 0.07 (95% CI, 0.04-0.11) for negative results. A combination of auscultation and LUS increased the positive LR to 42.9 (95% CI, 10.8-170.0) and decreased the negative LR to 0.04 (95% CI, 0.02-0.09). We found 97.6% (205 of 211) of patients with CAP showed breath-dependent motion of infiltrates, 86.7% (183 of 211) an air bronchogram, 76.5% (156 of 204) blurred margins, and 54.4% (105 of 193) a basal pleural effusion. During follow-up, median C-reactive protein levels decreased from 137 mg/dL to 6.3 mg/dL at days 13 to 16 as did signs of CAP; median area of lesions decreased from 15.3 cm2 to 0.2 cm2 and pleural effusion from 50 mL to 0 mL.LUS is a noninvasive, usually available tool used for high-accuracy diagnosis of CAP. This is especially important if radiography is not available or applicable. About 8% of pneumonic lesions are not detectable by LUS; therefore, an inconspicuous LUS does not exclude pneumonia.
Pub.: 16 Jun '12, Pinned: 25 Aug '17
Abstract: This study investigated the clinical relevance of early general chest ultrasonography (ie, heart and lung recordings) in patients in the ICU with acute respiratory failure (ARF).We prospectively compared this diagnostic approach (ultrasound) to a routine evaluation established from clinical, radiologic, and biologic data (standard). Subjects were patients consecutively admitted to the ICU of a university teaching hospital during a 1-year period. Inclusion criteria were age ≥ 18 years and the presence of severe ARF criteria to justify ICU admission. We compared the diagnostic approaches and the final diagnosis determined by a panel of experts.Seventy-eight patients were included (age, 70 ± 18 years; sex ratio, 1). Three patients given two or more simultaneous diagnoses were subsequently excluded. The ultrasound approach was more accurate than the standard approach (83% vs 63%, respectively; P < .02). Receiver operating characteristic curve analysis showed greater diagnostic performance of ultrasound in cases of pneumonia (standard, 0.74 ± 0.12; ultrasound, 0.87 ± 0.14; P < .02), acute hemodynamic pulmonary edema (standard, 0.79 ± 0.11; ultrasound, 0.93 ± 0.08; P < .007), decompensated COPD (standard, 0.8 ± 0.09; ultrasound, 0.92 ± 0.15; P < .05), and pulmonary embolism (standard, 0.65 ± 0.12; ultrasound, 0.81 ± 0.17; P < .04). Furthermore, we found that the use of ultrasound data could have significantly improved the initial treatment.The use of cardiothoracic ultrasound appears to be an attractive complementary diagnostic tool and seems able to contribute to an early therapeutic decision based on reproducible physiopathologic data.
Pub.: 15 May '13, Pinned: 25 Aug '17
Abstract: Lung ultrasonography is useful for the diagnosis of pneumonia in children and adults. This study investigated the lung ultrasound findings in severe neonatal pneumonia.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.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.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.
Pub.: 17 May '14, Pinned: 25 Aug '17
Abstract: It has been suggested that the complementary use of echocardiography could improve the diagnostic accuracy of lung ultrasonography (LUS) in patients with acute respiratory failure (ARF). Nevertheless, the additional diagnostic value of echocardiographic data when coupled with LUS is still debated in this setting. The aim of the current study was to compare the diagnostic accuracy of LUS and an integrative cardiopulmonary ultrasound approach (thoracic ultrasonography [TUS]) in patients with ARF.We prospectively recruited patients consecutively admitted for ARF to the ICU of a university teaching hospital over a 12-month period. Inclusion criteria were age ≥ 18 years and the presence of criteria for severe ARF justifying ICU admission. We compared both LUS and TUS approaches and the final diagnosis determined by a panel of experts using machine learning methods to improve the accuracy of the final diagnostic classifiers.One hundred thirty-six patients were included (age, 68 ± 15 years; sex ratio, 1). A three-dimensional partial least squares and multinomial logistic regression model was developed and subsequently tested in an independent sample of patients. Overall, the diagnostic accuracy of TUS was significantly greater than LUS (P < .05, learning and test sample). Comparisons between receiver operating characteristic curves showed that TUS significantly improves the diagnosis of cardiogenic edema (P < .001, learning and test samples), pneumonia (P < .001, learning and test samples), and pulmonary embolism (P < .001, learning sample).This study demonstrated for the first time to our knowledge a significantly better performance of TUS than LUS in the diagnosis of ARF. The value of the TUS approach was particularly important to disambiguate cases of hemodynamic pulmonary edema and pneumonia. We suggest that the bedside use of artificial intelligence methods in this setting could pave the way for the development of new clinically relevant integrative diagnostic models.
Pub.: 22 Aug '14, Pinned: 25 Aug '17
Abstract: This review article describes two protocols adapted from lung ultrasound: the bedside lung ultrasound in emergency (BLUE)-protocol for the immediate diagnosis of acute respiratory failure and the fluid administration limited by lung sonography (FALLS)-protocol for the management of acute circulatory failure. These applications require the mastery of 10 signs indicating normal lung surface (bat sign, lung sliding, A-lines), pleural effusions (quad and sinusoid sign), lung consolidations (fractal and tissue-like sign), interstitial syndrome (lung rockets), and pneumothorax (stratosphere sign and the lung point). These signs have been assessed in adults, with diagnostic accuracies ranging from 90% to 100%, allowing consideration of ultrasound as a reasonable bedside gold standard. In the BLUE-protocol, profiles have been designed for the main diseases (pneumonia, congestive heart failure, COPD, asthma, pulmonary embolism, pneumothorax), with an accuracy > 90%. In the FALLS-protocol, the change from A-lines to lung rockets appears at a threshold of 18 mm Hg of pulmonary artery occlusion pressure, providing a direct biomarker of clinical volemia. The FALLS-protocol sequentially rules out obstructive, then cardiogenic, then hypovolemic shock for expediting the diagnosis of distributive (usually septic) shock. These applications can be done using simple grayscale machines and one microconvex probe suitable for the whole body. Lung ultrasound is a multifaceted tool also useful for decreasing radiation doses (of interest in neonates where the lung signatures are similar to those in adults), from ARDS to trauma management, and from ICUs to points of care. If done in suitable centers, training is the least of the limitations for making use of this kind of visual medicine.
Pub.: 03 Jun '15, Pinned: 25 Aug '17
Abstract: Lung ultrasound (LUS) is as an easily accessible, radiation-free imaging technique that might be used as a diagnostic tool in community-acquired pneumonia (CAP). The aim of the study was to evaluate the usefulness and accuracy of LUS in the diagnosis and monitoring of childhood CAP. One hundred six consecutive children aged between 1 and 213 (median 52.5) months referred to the hospital with suspicion of CAP were enrolled. All patients underwent LUS on the day of admission, followed by chest radiograph (CXR). Lung ultrasound was also performed in 25 children between 5th-7th and 31 children between 10th-14th day after admission. Radiographic signs of pneumonia were demonstrated in 76 children, while lung ultrasound revealed pulmonary abnormalities consistent with pneumonia in 71 children. LUS gave false negative results in 5 patients with parahilar pulmonary infiltrates demonstrated by CXR. Almost perfect overall agreement between LUS and CXR was found in terms of pneumonia diagnosis (Cohen kappa coefficient of 0.89). The diagnostic performance of LUS in demonstration of lung involvement was as follows: sensitivity of 93.4%, specificity of 100%, positive predictive value of 100%, negative predictive value of 85.7% and accuracy of 95.3%. Our study showed that LUS is a sensitive and highly specific diagnostic method in children with CAP. Therefore, LUS may be considered as the first imaging test in children with suspicion of CAP. A diagnostic algorithm of CAP which includes LUS should be validated in prospective studies. Lung ultrasound can also be used to follow-up resolution of pneumonic lesions.
Pub.: 04 Jul '15, Pinned: 25 Aug '17
Abstract: Lung ultrasound (LUS) has been successfully applied for monitoring aeration in ventilator-associated pneumonia (VAP) and to diagnose and monitor community-acquired pneumonia. However, there is as yet no scientific evidence about whether LUS reliably improves VAP diagnosis.
Pub.: 22 Dec '15, Pinned: 25 Aug '17
Abstract: Chest x-ray (CXR) is the test of choice for diagnosing pneumonia. Lung ultrasound (LUS) has been shown to be accurate for diagnosing pneumonia in children and may be an alternative to CXR. Our objective was to determine the feasibility and safety of substituting LUS for CXR when evaluating children with suspected pneumonia.
Pub.: 26 Feb '16, Pinned: 25 Aug '17
Abstract: This study aimed to explore the value of a real-time comparative observation method using contrast-enhanced ultrasound (CEUS) for discriminating between bronchial and pulmonary arterial phases in diagnosing lung diseases. Forty-nine patients with 50 pulmonary lesions (45 peripheral lesions and five central lesions with obstructive atelectasis, including 36 malignant tumors, five tuberculomas, four inflammatory pseudotumors and five pneumonia lesions) detected via computed tomography and visible on ultrasonography were enrolled in this study. The arterial phases were determined by comparing contrast agent arrival time (AT) in the peripheral lung lesion with that in adjacent lung tissue, referred to as a real-time comparative observation method. Detection rates of this observation method were 100% (50/50) for pulmonary arterial phase and 88% (44/50) for bronchial arterial phase. Using the instrument's built-in graphing and analysis software, a time-intensity curve was constructed based on a chosen region of interest within the lesion where enhancement was the most obvious. Commonly used perfusion indicators in CEUS, such as AT, time-to-peak and peak intensity, were obtained from the time-intensity curve. Percutaneous puncture biopsies were performed under ultrasound guidance, and specimens of all 50 lesions were examined pathologically. AT was significantly shorter in patients with pneumonia than in those with malignant tumors or chronic inflammation (p < 0.05), whereas no difference was seen between those with malignant tumors and those with chronic inflammation. No significant differences in time-to-peak or peak intensity were seen among those with various lung diseases (p > 0.05). This is the first description of a real-time comparative observation method using CEUS for determining the arterial phases in the lungs. This method is accurate, simple to perform and provides a direct display. It is expected to become a practical and feasible tool for diagnosing lung diseases.
Pub.: 14 Apr '16, Pinned: 25 Aug '17
Abstract: Ultrasound elastography has shown promising result in the diagnosis of various diseases; however, its application for pulmonary diseases has yet to be clarified. This study aimed to assess the application and feasibility of ultrasound elastography in various pulmonary lesions and diseases. We enrolled 45 patients with radiographic evidence of pneumonia, tumors or obstructive pneumonitis, and 70 ultrasonic lesions were identified (eight necrosis, 17 atelectasis, seven consolidation and 38 tumors). Ultrasound elastography was performed and the strain ratio, which is the ratio of strain of the reference tissue to an equally measuring region of interest of a lesion, was measured. The strain ratio was significantly different among lesions with different ultrasound morphologies (1.03 ± 0.71 [necrosis] vs. 2.51 ± 1.14 [atelectasis] vs. 19.98 ± 15.59 [consolidation] vs. 36.19 ± 20.18 [tumor]; p < 0.05). The strain ratio of primary lung cancer was also significantly different from pneumonia (p = 0.023) and metastatic lung cancer (p = 0.015). In conclusion, transthoracic ultrasound elastography can differentiate pulmonary lesions with different ultrasound morphologies. ClinicalTrials.gov Identifier: NCT02636985.
Pub.: 12 Oct '16, Pinned: 25 Aug '17
Abstract: We investigated if contrast-enhanced ultrasound (CEUS) may differentiate community acquired pneumonia (CAP) from lung cancer (LC). Among 1374 patients admitted in a 5-year period for lung opacities, 728 (329 CAP and 399 LC) were investigated by CEUS, comparing the time of appearance, disappearance, duration and pattern of distribution of contrast enhancement (CE). The patients with CAP and LC did not differ in terms of age, time of CE appearance, disappearance and duration or CE distribution. Our data show that the timing and pattern of CE detected by chest CEUS does not distinguish between CAP and LC and overly optimistic beliefs on this matter should be abandoned.
Pub.: 16 Oct '16, Pinned: 25 Aug '17
Abstract: Some studies suggest that lung ultrasound could be useful for diagnosing pneumonia; moreover, it has a more favorable safety profile and lower cost than chest X-ray (CXR) and computed tomography (CT). The aim of this study is to assess the accuracy of bedside lung ultrasound for diagnosing pneumonia in adults through a systematic review and meta-analysis.We searched MEDLINE, Scopus, The Cochrane Library, Web of Science, DARE, HTA Database, Google Scholar, LILACS, ClinicalTrials.gov, TESEO and OpenGrey. In addition, we reviewed the bibliographies of relevant studies. Two researchers independently selected studies that met the inclusion criteria. Quality of the studies was assessed in accordance with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The summary receiver operating characteristics (SROC) curve and a pooled estimation of the diagnostic odds ratio (DOR) was estimated using using a bivariate random-effects analysis. The sources of heterogeneity were explored using predefined subgroup analyses and bivariate meta-regression.Sixteen studies (2359 participants) were included. There was significant heterogeneity of both sensitivity and specificity according to Q test, without clear evidence of threshold effect. The area under the SROC curve was 0.93, with a DOR at the optimal cutpoint of 50 (95% confidence interval (CI): 21, 120). A tendency towards a higher area under the SROC curve in high quality studies was detected, however these differences were not significant after applying the bivariate meta-regression.Lung ultrasound can help to accurately diagnose pneumonia, and it may be promising as an adjuvant resource to traditional approaches.
Pub.: 08 Nov '16, Pinned: 25 Aug '17
Abstract: Pneumonia is a leading cause of morbidity and mortality in children worldwide; however, its diagnosis can be challenging, especially in settings where skilled clinicians or standard imaging are unavailable. We sought to determine the diagnostic accuracy of lung ultrasound when compared to radiographically-confirmed clinical pediatric pneumonia.Between January 2012 and September 2013, we consecutively enrolled children aged 2-59 months with primary respiratory complaints at the outpatient clinics, emergency department, and inpatient wards of the Instituto Nacional de Salud del Niño in Lima, Peru. All participants underwent clinical evaluation by a pediatrician and lung ultrasonography by one of three general practitioners. We also consecutively enrolled children without respiratory symptoms. Children with respiratory symptoms had a chest radiograph. We obtained ancillary laboratory testing in a subset.Final clinical diagnoses included 453 children with pneumonia, 133 with asthma, 103 with bronchiolitis, and 143 with upper respiratory infections. In total, CXR confirmed the diagnosis in 191 (42%) of 453 children with clinical pneumonia. A consolidation on lung ultrasound, which is our primary endpoint for pneumonia, had a sensitivity of 88.5%, specificity of 100%, and an area under-the-curve of 0.94 (95% CI 0.92-0.97) when compared to radiographically-confirmed clinical pneumonia. When any abnormality on lung ultrasound was compared to radiographically-confirmed clinical pneumonia the sensitivity increased to 92.2% and the specificity decreased to 95.2%, with an area under-the-curve of 0.94 (95% CI 0.91-0.96).Lung ultrasound had high diagnostic accuracy for the diagnosis of radiographically-confirmed pneumonia. Added benefits of lung ultrasound include rapid testing and high inter-rater agreement. Lung ultrasound may serve as an alternative tool for the diagnosis of pediatric pneumonia.
Pub.: 15 Jun '17, Pinned: 25 Aug '17
Abstract: 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.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.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).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.
Pub.: 25 Apr '14, Pinned: 25 Aug '17