title: Association between different indexations of extravascular lung water (EVLW) and PaO2/FiO2: a two-center study in 231 patients.
abstract: BACKGROUND
  Variability of body weight (BW) and height calls for indexation of volumetric hemodynamic parameters. Extravascular lung water (EVLW) has formerly been indexed to actual BW (BW(act)) termed EVLW-index (EVLWI). In overweight patients indexation to BW(act) might inappropriately lower indexed EVLWI(act). Several studies suggest indexation of EVLWI to predicted BW (EVLWI(pred)). However, data regarding association of EVLWI(act) and EVLW(pred) to mortality and PaO2/FiO2 are inconsistent. Two recent studies based on biometric database-analyses suggest indexation of EVLWI to height (EVLWI(height)). Therefore, our study compared the association of un-indexed EVLW, EVLWI(height), EVLW(pred) and EVLWI(act) to PaO2/FiO2 and Oxygenation index (OI = mean airway pressure*FiO2*/PaO2).
  
  
  METHODS
  A total of 2119 triplicate transpulmonary thermodilutions (TPTDs; PiCCO; Pulsion Medical-Systems, Germany) were performed in 50 patients from the evaluation, and 181 patients from the validation groups. Correlations of EVLW and EVLWI to PaO2/FiO2, OI and ROC-AUC-analyses regarding PaO2/FiO2<200 mmHg (primary endpoint) and OI>10 were performed.
  
  
  RESULTS
  In the evaluation group, un-indexed EVLW (AUC 0.758; 95%-CI: 0.637-0.880) and EVLWI(height) (AUC 0.746; 95%-CI: 0.622-0.869) provided the largest ROC-AUCs regarding PaO2/FiO2<200 mmHg. The AUC for EVLWI(pred) was smaller (0.713). EVLWI(act) provided the smallest AUC (0.685). This was confirmed in the validation group: EVLWI(height) provided the largest AUC (0.735), EVLWI(act) (0.710) the smallest. In the merged data-pool, AUC was significantly greater for EVLWI(height) (0.729; 95%-CI: 0.674-0.784) compared to all other indexations including EVLWI(act) (ROC-AUC 0.683, p = 0.007) and EVLWI(pred) (ROC-AUC 0.707, p = 0.015). The association of EVLW(I) was even stronger to OI compared to PaO2/FiO2. In the merged data-pool, EVLWI(height) provided the largest AUC regarding "OI>10" (0.778; 95%-CI: 0.713-0.842) compared to 0.739 (95%-CI: 0.669-0.810) for EVLWI(act) and 0.756 (95%-CI: 0.688-0.824) for EVLWI(pred).
  
  
  CONCLUSIONS
  Indexation of EVLW to height (EVLWI(height)) improves the association of EVLW(I) to PaO2/FiO2 and OI compared to all other indexations including EVLWI(pred) and EVLWI(act). Also considering two recent biometric database analyses, EVLWI should be indexed to height.
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Huber
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Höllthaler
authors.affiliation: Institut für Medizinische Epidemiologie und Statistik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Umgelter
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Franzen
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Saugel
authors.affiliation: Department of Intensive Care, Ziekenhuis Netwerk Antwerpen, Antwerpen, Belgium.
authors.forename: Colin
authors.initials: C
authors.lastname: Cordemans
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, München, Germany.
authors.forename: Roland M
authors.initials: RM
authors.lastname: Schmid
authors.affiliation: Department of Intensive Care, Ziekenhuis Netwerk Antwerpen, Antwerpen, Belgium.
authors.forename: Manu L N G
authors.initials: ML
authors.lastname: Malbrain
mesh_terms: D000328:Adult; D001699:Biometry / Q000379:methods*; D001784:Blood Gas Analysis / Q000379:methods; D001827:Body Height; D001835:Body Weight; D015633:Extravascular Lung Water; D005260:Female; D006305:Health Status Indicators; D006439:Hemodynamics; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D012372:ROC Curve; D012128:Respiratory Distress Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D012129:Respiratory Function Tests
references.citation: Ann Pharmacother. 2000 Sep;34(9):1066-9
references.pmid: 10981254
references.citation: J Appl Physiol. 1960 May;15:377-82
references.pmid: 14425845
references.citation: Am Rev Respir Dis. 1992 May;145(5):990-8
references.pmid: 1586077
references.citation: JAMA. 2006 Apr 5;295(13):1549-55
references.pmid: 16595758
references.citation: Crit Care Med. 2013 Apr;41(4):990-8
references.pmid: 23388510
references.citation: Respir Med. 1989 Mar;83(2):123-5
references.pmid: 2602596
references.citation: Crit Care. 2005 Apr;9(2):R74-82
references.pmid: 15774053
references.citation: Am Rev Respir Dis. 1987 Sep;136(3):662-8
references.pmid: 3307570
references.citation: J Pediatr. 1961 Nov;59:710-4
references.pmid: 13881039
references.citation: Eur Respir J. 2005 Sep;26(3):511-22
references.pmid: 16135736
references.citation: Crit Care Med. 2004 Sep;32(9):1981
references.pmid: 15343044
references.citation: Crit Care Med. 2013 Feb;41(2):472-80
references.pmid: 23263578
references.citation: Crit Care. 2010;14(5):R162
references.pmid: 20819213
references.citation: Crit Care Med. 2006 Jun;34(6):1647-53
references.pmid: 16625129
references.citation: Respir Med. 1990 Jan;84(1):47-55
references.pmid: 2371421
references.citation: Ann Intensive Care. 2012 Jul 5;2 Suppl 1:S15
references.pmid: 22873416
references.citation: Crit Care. 2004 Dec;8(6):R451-8
references.pmid: 15566591
references.citation: Crit Care Med. 2008 Jan;36(1):69-73
references.pmid: 18090369
references.citation: J Clin Invest. 1958 Jul;37(7):1049-60
references.pmid: 13563634
references.citation: Crit Care Med. 2006 May;34(5):1437-43
references.pmid: 16557161
references.citation: Am Rev Respir Dis. 1983 Nov;128(5):949-52
references.pmid: 6638686
references.citation: Eur Respir J. 1995 Mar;8(3):492-506
references.pmid: 7789503
references.citation: Crit Care Med. 2008 Jan;36(1):151-8
references.pmid: 18007266
references.citation: Intensive Care Med. 1999 Feb;25(2):216-9
references.pmid: 10193551
references.citation: Crit Care Med. 2008 Jun;36(6):1803-9
references.pmid: 18496374
references.citation: Chest. 2002 Dec;122(6):2080-6
references.pmid: 12475851
references.citation: Intensive Care Med. 2006 Sep;32(9):1315-21
references.pmid: 16741694
references.citation: J Crit Care. 2012 Aug;27(4):376-83
references.pmid: 22591571
references.citation: Crit Care Med. 2006 Mar;34(3):738-44
references.pmid: 16521268
references.citation: Am Rev Respir Dis. 1983 Sep;128(3):501-6
references.pmid: 6614644
references.citation: Intensive Care Med. 2008 Nov;34(11):1999-2009
references.pmid: 18670756
references.citation: Thorax. 1977 Aug;32(4):486-96
references.pmid: 929491
references.citation: Intensive Care Med. 2013 Jan;39(1):146-50
references.pmid: 23160768
references.citation: Crit Care. 2012 Feb 27;16(1):114
references.pmid: 22369761
references.citation: J Crit Care. 2003 Dec;18(4):253-8
references.pmid: 14691899
references.citation: Crit Care. 2012 Dec 12;16(2):417
references.pmid: 22424187
references.citation: Crit Care. 2012 Jan 03;16(1):R1
references.pmid: 22214612
references.citation: Ann Intensive Care. 2012 Jul 05;2(Suppl 1 Diagnosis and management of intra-abdominal hyperten):S1
references.pmid: 22873410
references.citation: Crit Care Med. 2010 Jan;38(1):114-20
references.pmid: 19789451
references.citation: Chest. 2006 Sep;130(3):827-33
references.pmid: 16963682