Department of Critical Care

Thoracic Ultrasound

Detection and management of respiratory diseases are of principal importance to the intensivist and acute care provider. In the most severe cases of respiratory failure, reconciling risk of deterioration with obtaining suitable imaging studies is an all too common predicament. Interestingly, lungs, as historically thought, were impervious to the diagnostic capability of ultrasound and therefore, were described sonographically with indifference. Thanks to the painstaking work by Lichtenstein and many others,1–5 it has emerged as an invaluable tool for the modern acute care provider to detect and manage cardio-respiratory disease in critically ill patients. Not only is it performed with ease, it is inexpensive, reproducible, requires no transport, yet offers a high degree of accuracy and precision in decrypting challenging cases of respiratory failure. Whether it be undifferentiated respiratory failure, 2,6 assessment of volume status, 7–11 consolidation, 12,13 or assessment of pleural effusion,14–17 its’ versatility in detection and management of a myriad of lung pathology is matched only by that of CT. Moreover, mounting evidence has demonstrated diagnostic superiority over chest radiography for life-threatening diseases including pneumothorax and pulmonary edema, especially in the setting of critical illness.1,10,12,15,18,19 International guidelines, published in 2012, provide a summation and critique of evidence for how this technique is best applied. 5

In this section, we will explore the use of critical care ultrasound in approaching the critically ill patient with a variety of cardio-respiratory diseases. We encourage those individuals who care for acutely ill patients to consider exploring this technology and how it can be used to aid clinical decision making. Indications that will be covered in this section include:

1.     Undifferentiated respiratory failure
2.     Volume status assessment
3.     Identification of pneumothorax
4.     Distinguishing consolidation from pleural effusion
5.     Investigating quality and quantity of pleural effusions; procedural guidance
6.     Interrogation of weaning failure

References:
1. Lichtenstein DA. Ultrasound in the management of thoracic disease. Crit Care Med. 2007; 35:S250-S261. 
2. Lichtenstein D. Lung ultrasound in acute respiratory failure an introduction to the BLUE-protocol. Minerva Anestesiol. 2009;75(5):313-317. 
3. Lichtenstein DA, Axler O. Intensive use of general ultrasound in the intensive care unit. Intensive Care Med. 1993;19:353-355.
4. Lichtenstein DA. A-Lines and B-Lines. CHEST J. 2009;136(4):1014. 
5. Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577-591. 
6. Volpicelli G, Lamorte A, Tullio M, et al. Point-of-care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department. Intensive Care Med. 2013;39(7):1290-1298.
7. Lichtenstein DA, Mezière G a, Lagoueyte J-F, Biderman P, Goldstein I, Gepner A. A-lines and B-lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill. Chest. 2009;136(4):1014-1020. 
8. Volpicelli G, Mussa A, Garofalo G, et al. Bedside lung ultrasound in the assessment of alveolar-interstitial syndrome. Am J Emerg Med. 2006;24(6):689-696.
9. Volpicelli G. Interpreting lung ultrasound B-lines in acute respiratory failure. CHEST J. 2014;146(6):e230--e230. 
10. Al Deeb M, Barbic S, Featherstone R, Dankoff J, Barbic D. Point-of-care ultrasonography for the diagnosis of acute cardiogenic pulmonary edema in patients presenting with acute dyspnea: a systematic review and meta-analysis. Acad Emerg Med. 2014;21(8):843-852. 
11. Agricola E, Bove T, Oppizzi M, et al. “Ultrasound comet-tail images”: A marker of pulmonary edema - A comparative study with wedge pressure and extravascular lung water. Chest. 2005;127(5):1690-1695. 
12. Nazerian P, Volpicelli G, Vanni S, et al. Accuracy of lung ultrasound for the diagnosis of consolidations when compared to chest computed tomography. Am J Emerg Med. 2015;33(5):620-625. 
13. Lichtenstein DA, Lascols N, Mezière G, Gepner A. Ultrasound diagnosis of alveolar consolidation in the critically ill. Intensive Care Med. 2004;30:276-281.
14. Eibenberger KL, Dock WI, Ammann ME, Dorffner R, Hörmann MF, Grabenwöger F. Quantification of pleural effusions: sonography versus radiography. Radiology. 1994;191(3):681-684. 
15. Lichtenstein D, Goldstein I, Mourgeon E, Cluzel P, Grenier P, Rouby J-J. Comparative Diagnostic Performances of Auscultation, Chest Radiography, and Lung Ultrasonography in Acute Respiratory Distress Syndrome.; 2004. 
16. Begot E, Grumann A, Duvoid T, et al. Ultrasonographic identification and semiquantitative assessment of unloculated pleural effusions in critically ill patients by residents after a focused training. Intensive Care Med. 2014;40:1475-1480. d
17. Balik M, Plasil P, Waldauf P, et al. Ultrasound estimation of volume of pleural fluid in mechanically ventilated patients. Intensive Care Med. 2006;32(2):318-321. doi:10.1007/s00134-005-0024-2.
18. Kirkpatrick  a W, Sirois M, Laupland KB, et al. Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST). J Trauma. 2004;57(2):288-295. doi:10.1097/01.ruq.0000182460.27116.c0.
19. Ebrahimi A, Yousefifard M, Kazemi HM, et al. Diagnostic accuracy of chest ultrasonography versus chest radiography for identification of pneumothorax: A systematic review and meta-analysis. Tanaffos. 2014;13(4):29-40.