title: Clinical review: the role of ultrasound in estimating extra-vascular lung water.
abstract: The estimation of extra-vascular lung water (EVLW) is an essential component in the assessment of critically ill patients. EVLW is independently associated with mortality and its manipulation has been shown to improve outcome. Accurate assessment of lung water is possible with CT and MR imaging but these are impractical for real-time measurement in sick patients and have been superseded by single thermal dilution techniques. While useful, single thermo-dilution requires repeated calibration and is prone to error, suggesting a need for other monitoring methods. Traditionally the lung was not thought amenable to ultrasound examination owing to the high acoustic impedance of air; however, the identification of artefacts in diseased lung has led to increased use of ultrasound as a point of care investigation for both diagnosis and to monitor response to interventions. Following the initial description of B-lines in association with increased lung water, accumulating evidence has shown that they are a useful and responsive measure of the presence and dynamic changes in EVLW. Animal models have confirmed a correlation with lung gravimetry and the utility of B-lines has been demonstrated in many clinical situations and correlated against other established measures of EVLW. With increasing availability and expertise the role of ultrasound in estimating EVLW should be embedded in clinical practice and incorporated into clinical algorithms to aid decision making. This review looks at the evidence for ultrasound as a valid, easy to use, non-invasive point of care investigation to assess EVLW.
authors.forename: Murali
authors.initials: M
authors.lastname: Shyamsundar
authors.forename: Benjamin
authors.initials: B
authors.lastname: Attwood
authors.forename: Liza
authors.initials: L
authors.lastname: Keating
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Walden
mesh_terms: D000818:Animals; D016638:Critical Illness / Q000628:therapy; D015633:Extravascular Lung Water / Q000000981:diagnostic imaging*; D006801:Humans; D014463:Ultrasonography
references.citation: J Am Soc Echocardiogr. 2006 Mar;19(3):356-63
references.pmid: 16500505
references.citation: Am Rev Respir Dis. 1992 May;145(5):990-8
references.pmid: 1586077
references.citation: Am J Respir Crit Care Med. 1997 Nov;156(5):1640-6
references.pmid: 9372688
references.citation: Circ Res. 1965 May;16:482-8
references.pmid: 14289157
references.citation: Crit Care. 2011;15(2):R114
references.pmid: 21492424
references.citation: Am J Physiol Lung Cell Mol Physiol. 2008 Jun;294(6):L1023-31
references.pmid: 18359882
references.citation: Cardiovasc Ultrasound. 2008 Apr 29;6:16
references.pmid: 18442425
references.citation: J Am Coll Cardiol. 1997 Nov 15;30(6):1527-33
references.pmid: 9362412
references.citation: Am J Physiol Heart Circ Physiol. 2011 Nov;301(5):H2161-7
references.pmid: 21873499
references.citation: Am J Physiol Lung Cell Mol Physiol. 2009 Oct;297(4):L547-58
references.pmid: 19617309
references.citation: J Card Fail. 2007 Dec;13(10):830-5
references.pmid: 18068616
references.citation: Am J Emerg Med. 2006 Oct;24(6):689-96
references.pmid: 16984837
references.citation: Am J Emerg Med. 2008 Jun;26(5):585-91
references.pmid: 18534289
references.citation: Chest. 2003 Feb;123(2):436-41
references.pmid: 12576363
references.citation: Chest. 2007 Apr;131(4):1013-8
references.pmid: 17426204
references.citation: N Engl J Med. 2001 Nov 8;345(19):1368-77
references.pmid: 11794169
references.citation: J Ultrasound Med. 1982 Jan-Feb;1(1):1-7
references.pmid: 6152918
references.citation: Best Pract Res Clin Anaesthesiol. 2009 Sep;23(3):299-311
references.pmid: 19862889
references.citation: Crit Care Med. 2010 Sep;38(9):1818-23
references.pmid: 20562696
references.citation: Eur J Echocardiogr. 2007 Dec;8(6):474-9
references.pmid: 17116422
references.citation: Acad Emerg Med. 2009 Mar;16(3):201-10
references.pmid: 19183402
references.citation: Cochrane Database Syst Rev. 2013 Feb 28;(2):CD003408
references.pmid: 23450539
references.citation: Eur J Heart Fail. 2008 Jan;10(1):70-7
references.pmid: 18077210
references.citation: N Engl J Med. 2006 Jun 15;354(24):2564-75
references.pmid: 16714767
references.citation: J Trauma. 2006 Apr;60(4):785-91
references.pmid: 16612298
references.citation: Chest. 2008 Jul;134(1):117-25
references.pmid: 18403664
references.citation: JACC Cardiovasc Imaging. 2010 Jun;3(6):586-94
references.pmid: 20541714
references.citation: Intern Emerg Med. 2013 Aug;8(5):409-15
references.pmid: 21590437
references.citation: Echocardiography. 2008 Jul;25(6):584-90
references.pmid: 18652005
references.citation: Intensive Care Med. 2012 Apr;38(4):577-91
references.pmid: 22392031
references.citation: J Am Soc Echocardiogr. 2006 Apr;19(4):457-63
references.pmid: 16581487
references.citation: Crit Care Med. 2008 Jan;36(1):69-73
references.pmid: 18090369
references.citation: J Am Soc Echocardiogr. 2008 Oct;21(10):1150-5
references.pmid: 18926391
references.citation: Am J Cardiol. 2004 May 15;93(10):1265-70
references.pmid: 15135701
references.citation: Ann Emerg Med. 2006 Sep;48(3):227-35
references.pmid: 16934640
references.citation: Br J Anaesth. 2011 Apr;106(4):482-6
references.pmid: 21205627
references.citation: Chest. 2002 Dec;122(6):2080-6
references.pmid: 12475851
references.citation: Chest. 1985 Nov;88(5):649-52
references.pmid: 3902385
references.citation: Ultrasound Med Biol. 2010 Dec;36(12):2004-10
references.pmid: 21030138
references.citation: J Thorac Imaging. 1988 Jul;3(3):36-43
references.pmid: 3292781
references.citation: Intensive Care Med. 1998 Dec;24(12):1331-4
references.pmid: 9885889
references.citation: Anesthesiology. 1998 Dec;89(6):1313-21
references.pmid: 9856704
references.citation: Chest. 2009 Oct;136(4):1014-1020
references.pmid: 19809049
references.citation: Chest. 2009 Jun;135(6):1433-1439
references.pmid: 19188552
references.citation: Am J Respir Crit Care Med. 2000 Jul;162(1):134-8
references.pmid: 10903232
references.citation: Crit Care Med. 2007 Dec;35(12):2769-74
references.pmid: 17828031
references.citation: Curr Opin Crit Care. 2005 Jun;11(3):264-70
references.pmid: 15928477
references.citation: Chest. 2005 May;127(5):1690-5
references.pmid: 15888847
references.citation: Ann N Y Acad Sci. 1982;384:394-410
references.pmid: 7046565
references.citation: Chest. 2002 Jun;121(6):2000-8
references.pmid: 12065368
references.citation: Intensive Care Med. 2000 Feb;26(2):180-7
references.pmid: 10784306
references.citation: Crit Care Med. 2010 Jan;38(1):114-20
references.pmid: 19789451