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Acute respiratory distress syndrome (ARDS)

Last reviewed: 6 Nov 2023
Last updated: 24 Oct 2023



History and exam

Key diagnostic factors

  • low oxygen saturation
  • acute respiratory failure
More key diagnostic factors

Other diagnostic factors

  • critically ill patient
  • dyspnea
  • increased respiratory rate
  • pulmonary crepitations
  • low lung compliance
  • fever, cough, pleuritic chest pain
  • frothy sputum
Other diagnostic factors

Risk factors

  • sepsis
  • aspiration
  • pneumonia
  • severe trauma
  • blood transfusions
  • lung transplantation
  • pancreatitis
  • history of alcohol misuse
  • burns and smoke inhalation
  • drowning
  • e-cigarette and vaping product use
  • drug overdose
  • cigarette smoking
More risk factors

Diagnostic investigations

1st investigations to order

  • chest x-ray
  • arterial blood gases
  • sputum culture
  • blood culture
  • urine culture
  • amylase and lipase
More 1st investigations to order

Investigations to consider

  • brain natriuretic peptide (BNP)
  • echocardiogram
  • pulmonary artery catheterization
  • bronchoalveolar lavage or endotracheal aspirate
  • CT scan of the thorax
  • viral testing
  • open lung biopsy
More investigations to consider

Treatment algorithm


all patients



Lorraine Ware, MD
Lorraine Ware

Professor of Medicine and Pathology, Microbiology and Immunology


Vanderbilt Medical Scholars Program

Division of Allergy, Pulmonary and Critical Care Medicine

Department of Medicine

Vanderbilt University School of Medicine




LW has received research contract support from CSL Behring, Boehringer Ingelheim and Genentech. She has received consulting fees and/or scientific advisory board fees from CSL Behring, Merck, Foresee, Citius, and Boehringer Ingelheim.


Dr Lorraine Ware would like to gratefully acknowledge Dr Richard Fremont, a previous contributor to this topic.


RF declares that he has no competing interests.

Peer reviewers

Michael A. Matthay, MD

Director of Medicine Critical Care Fellowship

Department of Anesthesia and Perioperative Care

University of California San Francisco



MAM declares that he has no competing interests.

Timothy Evans, MBBS

Professor of Intensive Care Medicine

Royal Brompton Hospital




TE declares that he has no competing interests.

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