Overall, 10% to 15% of patients admitted to the intensive care unit meet the criteria for ARDS, with an increased incidence among mechanically ventilated patients.[2]Frutos-Vivar F, Esteban A. Epidemiology of acute lung injury and acute respiratory distress syndrome. Curr Opin Crit Care. 2004 Feb;10(1):1-6.
http://www.ncbi.nlm.nih.gov/pubmed/15166842?tool=bestpractice.com
[3]Summers C, Singh NR, Worpole L, et al. Incidence and recognition of acute respiratory distress syndrome in a UK intensive care unit. Thorax. 2016 Nov;71(11):1050-1.
https://thorax.bmj.com/content/71/11/1050.full
http://www.ncbi.nlm.nih.gov/pubmed/27552782?tool=bestpractice.com
[4]Bellani G, Laffey JG, Pham T, et al. Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries. JAMA. 2016 Feb 23;315(8):788-800.
https://jamanetwork.com/journals/jama/fullarticle/2492877
http://www.ncbi.nlm.nih.gov/pubmed/26903337?tool=bestpractice.com
The incidence of ARDS is estimated at 64 cases in 100,000 people, or 190,000 cases per year in the US. This incidence rate is 2 to 40 times greater than previous estimates, which probably does not represent a rising incidence but rather a historical under-estimation.[5]Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med. 2005 Oct 20;353(16):1685-93.
http://www.ncbi.nlm.nih.gov/pubmed/16236739?tool=bestpractice.com
The incidence of ARDS may be higher in the US than in Europe and other developed countries, although evidence suggests that rates in the US may be declining.[6]MacCullum NS, Evans TW. Epidemiology of acute lung injury. Curr Opin Crit Care. 2005 Feb;11(1):43-9.
http://www.ncbi.nlm.nih.gov/pubmed/15659944?tool=bestpractice.com
[7]Li G, Malinchoc M, Cartin-Ceba R, et al. Eight-year trend of acute respiratory distress syndrome: a population-based study in Olmsted County, Minnesota. Am J Respir Crit Care Med. 2011 Jan 1;183(1):59-66.
https://www.atsjournals.org/doi/full/10.1164/rccm.201003-0436OC
http://www.ncbi.nlm.nih.gov/pubmed/20693377?tool=bestpractice.com
Critical illness, cigarette smoking, and alcohol use are predisposing factors for ARDS.[8]Moss M, Parsons PE, Steinberg KP, et al. Chronic alcohol abuse is associated with an increased incidence of acute respiratory distress syndrome and severity of multiple organ dysfunction in patients with septic shock. Crit Care Med. 2003 Mar;31(3):869-77.
http://www.ncbi.nlm.nih.gov/pubmed/12626999?tool=bestpractice.com
[9]Simou E, Leonardi-Bee J, Britton J. The effect of alcohol consumption on the risk of ARDS: a systematic review and meta-analysis. Chest. 2018 Jul;154(1):58-68.
https://journal.chestnet.org/article/S0012-3692(17)33280-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29288645?tool=bestpractice.com
[10]Moazed F, Hendrickson C, Jauregui A, et al. Cigarette smoke exposure and acute respiratory distress syndrome in sepsis: epidemiology, clinical features, and biologic markers. Am J Respir Crit Care Med. 2022 Apr 15;205(8):927-35.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9838633
http://www.ncbi.nlm.nih.gov/pubmed/35050845?tool=bestpractice.com
Long-term exposure to ambient air pollutants also increases risk of developing ARDS.[11]Reilly JP, Zhao Z, Shashaty MGS, et al. Exposure to ambient air pollutants and acute respiratory distress syndrome risk in sepsis. Intensive Care Med. 2023 Aug;49(8):957-65.
http://www.ncbi.nlm.nih.gov/pubmed/37470831?tool=bestpractice.com
[12]Reilly JP, Zhao Z, Shashaty MGS, et al. Low to moderate air pollutant exposure and acute respiratory distress syndrome after severe trauma. Am J Respir Crit Care Med. 2019 Jan 1;199(1):62-70.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6353017
http://www.ncbi.nlm.nih.gov/pubmed/30067389?tool=bestpractice.com
[13]Ware LB, Zhao Z, Koyama T, et al. Long-term ozone exposure increases the risk of developing the acute respiratory distress syndrome. Am J Respir Crit Care Med. 2016 May 15;193(10):1143-50.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872663
http://www.ncbi.nlm.nih.gov/pubmed/26681363?tool=bestpractice.com
Sex, ethnicity, and race have not been definitively associated with the incidence of ARDS.
The mortality of ARDS is approximately 30% to 50%, although mortality in large clinical trials seems to be steadily decreasing.[3]Summers C, Singh NR, Worpole L, et al. Incidence and recognition of acute respiratory distress syndrome in a UK intensive care unit. Thorax. 2016 Nov;71(11):1050-1.
https://thorax.bmj.com/content/71/11/1050.full
http://www.ncbi.nlm.nih.gov/pubmed/27552782?tool=bestpractice.com
[5]Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med. 2005 Oct 20;353(16):1685-93.
http://www.ncbi.nlm.nih.gov/pubmed/16236739?tool=bestpractice.com
[14]Cochi SE, Kempker JA, Annangi S, et al. Mortality trends of acute respiratory distress syndrome in the United States from 1999 to 2013. Ann Am Thorac Soc. 2016 Oct;13(10):1742-51.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122485
http://www.ncbi.nlm.nih.gov/pubmed/27403914?tool=bestpractice.com
The distinction between mild (PaO₂/FiO₂ 200-300), moderate (PaO₂/FiO₂ 100-200), and severe (PaO₂/FiO₂ ≤100) ARDS has been associated with clinical outcomes.[1]Matthay MA, Arabi Y, Arroliga AC, et al. A new global definition of acute respiratory distress syndrome. Am J Respir Crit Care Med. 2024 Jan 1;209(1):37-47.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10870872
http://www.ncbi.nlm.nih.gov/pubmed/37487152?tool=bestpractice.com
Ongoing research suggests there are at least two discrete ARDS sub-phenotypes, although the clinical implications of this are under investigation.[15]Calfee CS, Delucchi K, Parsons PE, et al. Subphenotypes in acute respiratory distress syndrome: latent class analysis of data from two randomised controlled trials. Lancet Respir Med. 2014 Aug;2(8):611-20.
http://www.ncbi.nlm.nih.gov/pubmed/24853585?tool=bestpractice.com
[16]Famous KR, Delucchi K, Ware LB, et al. Acute respiratory distress syndrome subphenotypes respond differently to randomized fluid management strategy. Am J Respir Crit Care Med. 2017 Feb 1;195(3):331-8.
https://www.atsjournals.org/doi/full/10.1164/rccm.201603-0645OC
http://www.ncbi.nlm.nih.gov/pubmed/27513822?tool=bestpractice.com
[17]Calfee CS, Delucchi KL, Sinha P, et al. Acute respiratory distress syndrome subphenotypes and differential response to simvastatin: secondary analysis of a randomised controlled trial. Lancet Respir Med. 2018 Sep;6(9):691-8.
http://www.ncbi.nlm.nih.gov/pubmed/30078618?tool=bestpractice.com