Newly Published
Critical Care Medicine  |   December 2018
Outcomes of Patients Presenting with Mild Acute Respiratory Distress Syndrome: Insights from the LUNG SAFE Study
Author Notes
  • From the Interdepartmental Division of Critical Care Medicine (T.P., J.G.L., E.F., L.J.B.), Department of Anesthesia (J.G.L.), and Institute of Health Policy, Management and Evaluation (E.F.), University of Toronto, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute (T.P., J.G.L., L.J.B.) and Department of Anesthesia (J.G.L.), St. Michael’s Hospital, Toronto, Canada; Department of Critical Care Medicine, Hospital Israelita Albert Einstein, São Paulo, Brazil (A.S.N.); Department of Intensive Care (A.S.N., M.J.S.) and Laboratory of Experimental Intensive Care and Anesthesiology (M.J.S.), Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Department of Clinical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy (P.P.) and San Martino Policlinico Hospital, Istituto di Ricovero e Cura a Carattere Scientifico for Oncology, Genoa, Italy (P.P.); Department of Anaesthesia, School of Medicine, and Regenerative Medicine Institute at CÚRAM Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland (J.G.L.); Critical Care Area, Parc Tauli Hospital University, Autonomous University of Barcelona, Barcelona, Spain (C.D.H.); Respiratory Diseases Network Biomedical Investigation Center, Barcelona, Spain (C.D.H., J.A.L., A.A.); Critical Care Department, University Hospital of Getafe, Madrid, Spain (J.A.L.); European University, Madrid, Spain (J.A.L.); School of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy (G.B.); Department of Emergency and Intensive Care, San Gerardo Hospital, Monza, Italy (G.B.); Department of Medicine, University Health Network and Mount Sinai Hospital, Toronto, Canada (E.F.); Department of Anesthesia, Critical Care and Emergency Medicine, Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico Milan, Milan, Italy (A.P.); Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy (A.P.); Mahidol–Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand (M.J.S.); Critical Care Department, Parc Tauli Health Corporation University, Autonomous University of Barcelona, Sabadell and Intensive Care Department, University Hospitals Sagrado Corazon-General de Cataluña, Quiron Salut, Barcelona-Sant Cugat del Valles, Spain (A.A.).
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • Part of the work presented in this article has been presented at the American Thoracic Society meeting in Washington, D.C., May 23, 2017.
    Part of the work presented in this article has been presented at the American Thoracic Society meeting in Washington, D.C., May 23, 2017.×
  • M.J.S. and A.A. contributed equally to this article.
    M.J.S. and A.A. contributed equally to this article.×
  • Submitted for publication April 25, 2018. Accepted for publication October 5, 2018.
    Submitted for publication April 25, 2018. Accepted for publication October 5, 2018.×
  • *The LUNG SAFE investigators are listed in the appendix.
    The LUNG SAFE investigators are listed in the appendix.×
  • Correspondence: Address correspondence to Dr. Pham: Interdepartmental Division of Critical Care Medicine, University of Toronto, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada. taiopham@gmail.com. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Critical Care Medicine / Critical Care / Respiratory System
Critical Care Medicine   |   December 2018
Outcomes of Patients Presenting with Mild Acute Respiratory Distress Syndrome: Insights from the LUNG SAFE Study
Anesthesiology Newly Published on December 3, 2018. doi:10.1097/ALN.0000000000002508
Anesthesiology Newly Published on December 3, 2018. doi:10.1097/ALN.0000000000002508
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Hospital mortality in acute respiratory distress syndrome is approximately 40%, but mortality and trajectory in “mild” acute respiratory distress syndrome (classified only since 2012) are unknown, and many cases are not detected

What This Article Tells Us That Is New:

  • Approximately 80% of cases of mild acute respiratory distress syndrome persist or worsen in the first week; in all cases, the mortality is substantial (30%) and is higher (37%) in those in whom the acute respiratory distress syndrome progresses

Background: Patients with initial mild acute respiratory distress syndrome are often underrecognized and mistakenly considered to have low disease severity and favorable outcomes. They represent a relatively poorly characterized population that was only classified as having acute respiratory distress syndrome in the most recent definition. Our primary objective was to describe the natural course and the factors associated with worsening and mortality in this population.

Methods: This study analyzed patients from the international prospective Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) who had initial mild acute respiratory distress syndrome in the first day of inclusion. This study defined three groups based on the evolution of severity in the first week: “worsening” if moderate or severe acute respiratory distress syndrome criteria were met, “persisting” if mild acute respiratory distress syndrome criteria were the most severe category, and “improving” if patients did not fulfill acute respiratory distress syndrome criteria any more from day 2.

Results: Among 580 patients with initial mild acute respiratory distress syndrome, 18% (103 of 580) continuously improved, 36% (210 of 580) had persisting mild acute respiratory distress syndrome, and 46% (267 of 580) worsened in the first week after acute respiratory distress syndrome onset. Global in-hospital mortality was 30% (172 of 576; specifically 10% [10 of 101], 30% [63 of 210], and 37% [99 of 265] for patients with improving, persisting, and worsening acute respiratory distress syndrome, respectively), and the median (interquartile range) duration of mechanical ventilation was 7 (4, 14) days (specifically 3 [2, 5], 7 [4, 14], and 11 [6, 18] days for patients with improving, persisting, and worsening acute respiratory distress syndrome, respectively). Admissions for trauma or pneumonia, higher nonpulmonary sequential organ failure assessment score, lower partial pressure of alveolar oxygen/fraction of inspired oxygen, and higher peak inspiratory pressure were independently associated with worsening.

Conclusions: Most patients with initial mild acute respiratory distress syndrome continue to fulfill acute respiratory distress syndrome criteria in the first week, and nearly half worsen in severity. Their mortality is high, particularly in patients with worsening acute respiratory distress syndrome, emphasizing the need for close attention to this patient population.