Outcome of acute hypoxaemic respiratory failure: insights from the LUNG SAFE Study

Abstract

Background: Current incidence and outcome of patients with acute hypoxaemic respiratory failure requiring mechanical ventilation in the intensive care unit (ICU) are unknown, especially for patients not meeting criteria for acute respiratory distress syndrome (ARDS).

Methods: An international, multicentre, prospective cohort study of patients presenting with hypoxaemia early in the course of mechanical ventilation, conducted during four consecutive weeks in the winter of 2014 in 459 ICUs from 50 countries (LUNG SAFE). Patients were enrolled with arterial oxygen tension/inspiratory oxygen fraction ratio ≤300 mmHg, new pulmonary infiltrates and need for mechanical ventilation with a positive end-expiratory pressure of ≥5 cmH2O. ICU prevalence, causes of hypoxaemia, hospital survival and factors associated with hospital mortality were measured. Patients with unilateral versus bilateral opacities were compared.

Findings: 12 906 critically ill patients received mechanical ventilation and 34.9% with hypoxaemia and new infiltrates were enrolled, separated into ARDS (69.0%), unilateral infiltrate (22.7%) and congestive heart failure (CHF; 8.2%). The global hospital mortality was 38.6%. CHF patients had a mortality comparable to ARDS (44.1% versus 40.4%). Patients with unilateral-infiltrate had lower unadjusted mortality, but similar adjusted mortality compared to those with ARDS. The number of quadrants on chest imaging was associated with an increased risk of death. There was no difference in mortality comparing patients with unilateral-infiltrate and ARDS with only two quadrants involved.

Interpretation: More than one-third of patients receiving mechanical ventilation have hypoxaemia and new infiltrates with a hospital mortality of 38.6%. Survival is dependent on the degree of pulmonary involvement whether or not ARDS criteria are reached.

Trial registration: ClinicalTrials.gov NCT02010073.

Conflict of interest statement

Conflict of interest: T. Pham has nothing to disclose. Conflict of interest: A. Pesenti reports personal fees from Maquet, Novalung/Xenios, Baxter, Gilead and Boehringer Ingelheim, outside the submitted work. Conflict of interest: G. Bellani reports grants and personal fees from Draeger Medical, personal fees from Getinge, Hamilton, GE Healthcare, Dimar SRL, Intersurgical and Flowmeter SPA, outside the submitted work. Conflict of interest: G. Rubenfeld has nothing to disclose. Conflict of interest: E. Fan reports personal fees from ALung Technologies, Getinge and MC3 Cardiopulmonary, grants, personal fees and non-financial support from Fresenius Medical Care, outside the submitted work. Conflict of interest: G. Bugedo has nothing to disclose. Conflict of interest: J.A. Lorente has nothing to disclose. Conflict of interest: A.D.V. Fernandes has nothing to disclose. Conflict of interest: F. Van Haren has nothing to disclose. Conflict of interest: A. Bruhn has nothing to disclose. Conflict of interest: F. Rios has nothing to disclose. Conflict of interest: A. Esteban has nothing to disclose. Conflict of interest: L. Gattinoni has nothing to disclose. Conflict of interest: A. Larsson reports grants from the Swedish Heart and Lung Foundation, during the conduct of the study. Conflict of interest: D.F. McAuley reports personal fees from consultancy for GlaxoSmithKline, Boehringer Ingelheim and Bayer, outside the submitted work; in addition, his institution has received funds from grants from the UK NIHR, Wellcome Trust, Innovate UK, NI HSC R&D Division, NI Chest Heart and Stroke, and MRC; is one of four named inventors on a patent US8962032 covering the use of sialic acid-bearing nanoparticles as anti-inflammatory agents issued to his institution, The Queen's University of Belfast (http://www.google.com/patents/US8962032); and is a Director of Research for the Intensive Care Society and NIHR EME Programme Director. Conflict of interest: M. Ranieri has nothing to disclose. Conflict of interest: B.T. Thompson reports personal fees from Bayer, Thetis and Novartis, outside the submitted work. Conflict of interest: H. Wrigge reports personal fees for consultancy from Dräger Medical, personal fees for advisory board work from Liberate Medical, grants and personal fees for lectures from InfectoPharm, personal fees for lectures from MSD and GE, outside the submitted work. Conflict of interest: L.J. Brochard reports grants from Medtronic Covidien, grants and non-financial support from Fisher Paykel, non-financial support from Air Liquide, Sentec and Philips, other (patent) from General Electric, outside the submitted work. Conflict of interest: J.G. Laffey reports grants and personal fees from Baxter, grants and non-financial support from Aerogen and Factor Biosciences, outside the submitted work.

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