title: Lung ultrasound predicts well extravascular lung water but is of limited usefulness in the prediction of wedge pressure.
abstract: BACKGROUND
  Pulmonary congestion is indicated at lung ultrasound by detection of B-lines, but correlation of these ultrasound signs with pulmonary artery occlusion pressure (PAOP) and extravascular lung water (EVLW) still remains to be further explored. The aim of the study was to assess whether B-lines, and eventually a combination with left ventricular ejection fraction (LVEF) assessment, are useful to differentiate low/high PAOP and EVLW in critically ill patients.
  
  
  METHODS
  The authors enrolled 73 patients requiring invasive monitoring from the intensive care unit of four university-affiliated hospitals. Forty-one patients underwent PAOP measurement by pulmonary artery catheterization and 32 patients had EVLW measured by transpulmonary thermodilution method. Lung and cardiac ultrasound examinations focused to the evaluation of B-lines and gross estimation of LVEF were performed. The absence of diffuse B-lines (A-pattern) versus the pattern showing prevalent B-lines (B-pattern) and the combination with normal or impaired LVEF were correlated with cutoff levels of PAOP and EVLW.
  
  
  RESULTS
  PAOP of 18 mmHg or less was predicted by the A-pattern with 85.7% sensitivity (95% CI, 70.5 to 94.1%) and 40.0% specificity (CI, 25.4 to 56.4%), whereas EVLW 10 ml/kg or less with 81.0% sensitivity (CI, 62.6 to 91.9%) and 90.9% specificity (CI, 74.2 to 97.7%). The combination of A-pattern with normal LVEF increased sensitivity to 100% (CI, 84.5 to 100%) and specificity to 72.7% (CI, 52.0 to 87.2%) for the prediction of PAOP 18 mmHg or less.
  
  
  CONCLUSIONS
  B-lines allow good prediction of pulmonary congestion indicated by EVLW, whereas are of limited usefulness for the prediction of hemodynamic congestion indicated by PAOP. Combining B-lines with estimation of LVEF at transthoracic ultrasound may improve the prediction of PAOP.
authors.affiliation: From the Department of Emergency Medicine (G.V., E.B., V.S., M.F.F.) and Intensive Care Unit (G.R.), San Luigi Gonzaga University Hospital, Torino, Italy; Intensive Care Unit (S.S., E.C.) and Radiology Department (L.L.), Città della salute e della scienza, Molinette University Hospital, Torino, Italy; Department of Emergency Medicine (G.C.) and Intensive Care Unit (A.A.), Vittorio Emanuele University Hospital, Catania, Italy; and Intensive Care Unit, Maggiore della Carità University Hospital, Novara, Italy (M.T.).
authors.forename: Giovanni
authors.initials: G
authors.lastname: Volpicelli
authors.forename: Stefano
authors.initials: S
authors.lastname: Skurzak
authors.forename: Enrico
authors.initials: E
authors.lastname: Boero
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Carpinteri
authors.forename: Marco
authors.initials: M
authors.lastname: Tengattini
authors.forename: Valerio
authors.initials: V
authors.lastname: Stefanone
authors.forename: Luca
authors.initials: L
authors.lastname: Luberto
authors.forename: Antonio
authors.initials: A
authors.lastname: Anile
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cerutti
authors.forename: Giulio
authors.initials: G
authors.lastname: Radeschi
authors.forename: Mauro F
authors.initials: MF
authors.lastname: Frascisco
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness; D004452:Echocardiography; D015633:Extravascular Lung Water / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000502:physiology; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D055815:Young Adult