We believe that a similar protocol could possibly be applied to our anesthetized patients. Lung ultrasound has a higher diagnostic yield than chest during X-ray for most of the aforementioned conditions [59]; it is easier to carry out and less time consuming. However, it has some limitations when used in patients with subcutaneous emphysema, pleural calcifications, and in the obese [5]. Current and potential applications of lung ultrasound are as follows.diagnosis of pneumothorax;diagnosis of interstitial syndrome;diagnosis and differentiation of underlying cause of Pleural effusion, and selecting the optimal puncture site for pleurocentesis;diagnosis of pulmonary consolidation and pneumonia;diagnosis of atelectasisdiagnosis of pulmonary edema and differentiate it from acute respiratory distress syndrome (ARDS); diagnosis of pulmonary embolism;monitoring of lung disease (severity, progress, and response to therapy); optimizing mechanical ventilation.
A high frequency (7.5 to 10MHz) transducer is an appropriate choice for detecting pleural line abnormalities, while lower frequency (3.5MHz) convex and microconvex transducers can be used to diagnose pleural effusions and lung parenchymal abnormalities. [5]. B- and M-mode may be used during lung ultrasound scanning and the produced sonographic images are a virtual interplay of two elements: air and fluid. Lung ultrasound interprets mainly the presence or absence of various artifacts since air is an acoustic barrier.7.1.
Normal Lung Aeration Patterns Reflect Specific Sonographic Signs [5] (Figures 3(a) and 3(b))Figure 3Normal lung ultrasound: (a) 2D ��red arrows�� point to the pleura, where the normal ��sliding sign�� should be seen, while the ��yellow arrows�� represent the A-lines that are normal reverberation from the pleura. …��Lung sliding�� signs are sliding of visceral and parietal layers of pleura with respiration. Seashore sign is a complex picture of parallel lines signifying the static thoracic wall and sandy ��granulous�� pattern, which reflect the normal pulmonary parenchyma.A-lines are a basic artifact of normally aerated lung. 7.2. Pathological Lung Signs and Patterns Include the following [5]B-lines represent discrete laser-like vertical hyperechoic lines that arise from the pleural line and extend to the bottom of the screen.
These lines are consistent with interlobular pulmonary edema and can be found in both ARDS and cardiogenic pulmonary edema. Dynamic and static air bronchograms which consist Cilengitide of hyperechoic punctiform elements within the lung parenchyma can be used to diagnose consolidation and atelectasis, respectively. Lung pulse is an early and dynamic diagnostic sign of complete atelectasis, in which US perceives the vibrations of heart activity, along with the absence of lung sliding [60].The International Liaison Committee on Lung Ultrasound (ILC-LUS) has recommended the following signs for the detection of various lung abnormalities [59].