We conducted a prospective study of all spontaneously breathing adult patients consecutively admitted to our bed clinical-surgical ICU for ARF. This research was approved by the institutional ethics committee Protocol no. After attending 5 hours of theoretical training and performing 10 supervised LUS examinations, 4 non-ultrasound experts participated in the study.
They were blinded to patient medical history and were not involved in diagnostic or therapeutic decisions. All patients were placed in a semirecumbent position and were evaluated with the same curvilinear probe with a range of MHz Toshiba Tosbee r ; Toshiba, Tokyo, Japan. As a rule, LUS was performed within 20 minutes of admission, by one non-ultrasound expert.
Each patient underwent a bedside chest X-ray at admission, which was interpreted by a radiologist unblinded to medical history. The initial clinical evaluation and diagnosis were performed by the physicians responsible for patient care. They were blinded to the LUS results but were aware of the chest X-ray results. The main diagnoses, including pneumonia, acute hemodynamic lung edema, obstructive lung disease i.
Emergency Ultrasound of the Chest
Patients with a multiple diagnosis or rare diseases were excluded from the analysis, as in the original BLUE protocol study. LUS images were recorded for each of six quadrants in each hemithorax upper and lower parts of the anterior, lateral, and posterior chest wall, delimited by anterior and posterior axillary lines. A profile A-lines : white hyperechoic horizontal lines that are static and appear at regular intervals. B profile B-lines : hyperechoic vertical artifacts that move in synchrony with the respiratory cycle.
C profile: consolidation image appearing as a tissue structure containing white points consisting of lung parenchyma. To identify normal lung aeration, lung sliding is a key ultrasound finding. It corresponds to the regular movement of the pleural line described as a shimmering or bright white line in regular cycles in synchrony with each respiratory movement.
In accordance with the BLUE protocol Table 1 , 15 a normal profile bilateral lung sliding with A-lines should be combined with screening for leg vein thrombosis. Deep venous thrombosis was sought using the same probe. A positive finding was the visualization of anatomic echoic intraluminal thrombosis or the absence of compression of femoral or popliteal veins. If there were signs of leg vein thrombosis, pulmonary embolism was the diagnosis; otherwise, the normal pattern was suggestive of respiratory dysfunction due to obstructive lung disease i.
However, for this diagnosis, it was necessary to identify the lung point the point where it is possible to identify both normal lung sliding and its absence. A B profile characterized by symmetric bilateral B-lines suggested hemodynamic lung edema. The AB profile was characterized by asymmetric findings between the hemithoraces, suggestive of pulmonary infection as the etiology of ARF. The diagnostic performance of LUS as measured against each final diagnosis was assessed by calculation of sensitivity, specificity, and predictive values by using a standard formula.
The completeness and accuracy of reporting was assessed with the Standards of Reporting of Diagnostic Accuracy checklist. As previously described, 5 patients with rare diagnoses were excluded from the final analysis 2 patients with pulmonary fibrosis, 1 patient with hypersensitivity pneumonitis, 1 with leptospirosis, and 1 with abdominal compartment syndrome.
The baseline characteristics of the patients are shown in Table 2. The mean hospital length of stay before ICU admission was 7. Fifteen patients were admitted for hemodynamic lung edema, and 4 were admitted for obstructive lung disease. There was only one patient with pulmonary embolism in this patient, LUS was normal as expected, but it was not possible to identify deep vein thrombosis and none with pneumothorax.
The sensibility, specificity, and predictive values are shown in Table 3. Pulmonary embolism and pneumothorax were not included because the number of patients with these conditions was insufficient to perform diagnostic performance analysis. Agreements between the 2 methods were 0.
- Connecting Partnerships to Excellence (Educating Science Teachers).
- Vivir el perdón. Un curso para comprender el significado del perdón y aprender a vivirlo (Spanish Edition);
- The value of lung ultrasound monitoring in H1N1 acute respiratory distress syndrome?
- Ultrasound and Respiratory Distress.
- Emergency Ultrasound of the Chest - FullText - Respiration , Vol. 87, No. 2 - Karger Publishers.
The main result of the present study is that bedside LUS performed by physicians who are not ultrasound experts allows the correct diagnosis of the most common causes of ARF pneumonia and hemodynamic lung edema with good sensitivity and specificity, as measured against the final diagnosis. Indeed, the diagnostic accuracy of LUS was higher than was that of chest X-ray.
The primary concern that led us to perform the present study was operator bias, since different operators could interpret ultrasonographic patterns of lung differently. Gaining competence in a skill over time is a well-recognized process, which has also been demonstrated for LUS. Recently, Silva et al. This finding indicates that the use of LUS data could have significantly improved the initial diagnosis.
Indeed, bedside LUS has been shown to have superior accuracy when evaluating patients with atelectasis, pneumothorax, pneumonia, or acute respiratory distress syndrome, compared with chest X-ray. In an attempt to increase concordance, all patients were evaluated in the same position and with the same probe.
There is no recommendation for the duration of LUS training. With this training method, our operators were able to individually achieve substantial diagnostic agreement kappa coefficient, 0. Bedside LUS is rapidly becoming integral to the evaluation of critically ill patients. However, it is still not widely used in Brazil. Costs are often regarded as major barriers.
The main limitations of this study are its small sample size and the fact that it was conducted in a single center. Because our results are based mainly on the diagnoses of pneumonia and hemodynamic lung edema, further studies are needed to validate the BLUE protocol in the diagnosis of other causes of ARF. In addition, intra- and inter-operator variabilities were not assessed. Furthermore, as we followed the original BLUE protocol, our study did not incorporate the diagnosis of pleural effusion as an etiology of ARF, although LUS has great potential in the diagnosis of this pattern.
After a brief training period, physicians are able to diagnose the main causes of ARF with accuracy. We would like to thank Dr. Charlotte Arbelot for having kindly authorized the reproduction of images from her personnel database. Thoracic ultrasonography for the pulmonary specialist. Comparative diagnostic performances of auscultation, chest radiography, and lung ultrasonography in acute respiratory distress syndrome. Clinical review: Bedside lung ultrasound in critical care practice.
Crit Care. Deep impact of ultrasound in the intensive care unit: the "ICU-sound" protocol. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. Sensitivity and specificity were calculated. A total 50 patients were evaluated. BLUE protocol was successful in average BLUE performed in emergency department is equivalent to computed tomography scan. BLUE protocol aids in making diagnosis and saves time and cost; avoids the side effects related to radiation.
Emergency Ultrasound: Focused Ultrasound for Respiratory Distress: The BLUE Protocol
Point-of-care ultrasonography USG is emerging as an important bedside tool. The objective of this study is to determine the accuracy of the BLUE protocol in giving a correct diagnosis in patients presenting with acute respiratory distress in the emergency department. This was an observational study over a period of 2 months carried out at emergency medicine department of a tertiary care hospital in Ahmedabad.
Micromax ultrasound system, sonosite was used to evaluate the patients. Both low frequency 2—5 MHz curvilinear probe and high frequency 5—10 MHz linear probe were used to get best possible findings. Patients were examined in either supine or semirecumbent position. Areas of each chest were divide in anterior sternum to anterior axillary line , lateral between anterior and posterior axillary line , and posterolateral alveolar pleural syndrome PLAPS point. PLAPS point was observed at posterior region after minimal turning of the patient to opposite side. Each was further divided in the upper zone and lower zone roughly by horizontal line passing through nipple , respectively.
Each lung was thus divided in 6 zones. Ultrasound findings such as artifacts A line, B line , lung sliding, alveolar consolidation or pleural effusion, and venous analysis were recorded for each zone. Venous analysis was carried out after performing lung ultrasound in selected patients showing A profile. Venous analysis to visualize echogenic thrombus was carried out with high-frequency linear probe over internal jugular vein, subclavian vein, femoral vein, iliac veins, superior venacava, and inferior venacava.
Combined results were noted in the pro forma to select diagnosis according to BLUE protocol. Treating units were blinded by the findings of ultrasound. The patient was prospectively followed and results of various investigations such as computed tomography CT scan, two-dimensional echo, chest X-ray, and other specific tests which were used by the treating unit to reach diagnosis were recorded [ Table 1 ]. USG findings were correlated with final diagnosis made by the treating unit. Sensitivity and specificity were calculated for the each profile observed.
Totally 50 patients of acute respiratory distress were evaluated with mean age of Two rib shadows are shown in figure, hyper echoic pleura is seen, suggesting of normal lung ultrasound image. Normal sea-shore pattern of lung on M-mode. M-mode shows horizontal lines suggestive of the chest wall and granular pattern suggestive of lungs. Chronic obstructive pulmonary disease COPD was diagnosed in 14 patients. A profile was found in 14 patients with A lines are shown in Figure 3.
A lines are the repetitive horizontal artifacts arising from the pleural line generated by subpleural air, which, either intraalveolar normal or abnormal pneumothorax , blocks ultrasound waves. Interstitial syndrome was diagnosed in 13 patients. B profile was found in 12 patients with Normal profile was found in one case.
B lines are shown in Figure 4. B lines reflect the coexistence of fluid and air. Fluid at the subpleural interlobular septum surrounded by air-filled alveoli gives B lines. Pneumonia was diagnosed in 17 patients.
The C profile was found in 9 patients with Normal profile was seen in one case. Figure 5 shows pneumonia with irregular pleura. Consolidation which does not invade the whole lobe, will generate a shredded Shred Sign , fractal boundary between the consolidation and the underlying aerated lung.
Bedside lung ultrasound in emergency (approach) | Radiology Reference Article | ohyqukecew.cf
Lung sliding may be present or absent. Pulmonary embolism was found in one patient showing A profile plus venous thrombosis. Pneumothorax was found in 5 patients. Barcode sign was observed. Figure 6 is suggestive of pneumothorax. Ultrasound findings of absent lung sliding with stratosphere sign on M-mode suggests pneumothorax.
The lung point not featured here confidently rules in the diagnosis. Figure 7 shows Pleural effusion on M-mode. Ultrasound suggestive of pleural effusion anechoic. The inspiratory shift of the lung line toward the pleural line is called the sinusoid sign visualized on M-mode.
Profiles observed were as shown below in Table 2. Ultrasound Accuracy of various profiles is as shown in Table 3. The B profile anterior interstitial syndrome with lung sliding indicated pulmonary edema. The A profile plus venous thrombosis indicated pulmonary embolism.
The pleural line is superficial. Most acute disorders reach it; acute interstitial changes involve deep as well as subpleural areas; most The high-acoustic impedance gradient between air and fluid generates artifacts. Air stops ultrasounds, and fluid facilitates their transmission.
Regularly spaced B lines suggest septal or interstitial edema. Crowded or coalescent B lines are suggestive of alveolar edema. Inhomogeneous B lines with pleural abnormalities irregularly spaced suggest acute respiratory distress syndrome, pleural fibrosis, or some other condition. The appearance of ultrasound images depends on the relative aeration of alveoli.
Lung sliding may be abolished because of inflammatory exudates. Fully formed consolidation appears solid liver-like, suggestive of tissue sign. Normal profile is found mostly in pulmonary embolism. Venous scans improved sensitivity of diagnosis. Pulmonary embolism was proved by high-resolution CT thorax. M-mode shows horizontal lines, stratosphere sign. Lung point indicates junction of normal lung and pneumothorax.
In our study, BLUE protocol was successful in average Comparision of Efficacy is as shown in Table 4. Stefano Parlamento et al. The limitation of this study was its small sample size and the fact that it was conducted in a single center. Micro convex probe with small footprint gives better visualization. It was unavailable in our setting and thus linear probe and curvilinear probes were used.