What is acute respiratory distress syndrome (ARDS)?

Acute respiratory distress syndrome (ARDS) is characterized by a massive reaction of the lungs to various damaging factors such as sepsis, pneumonia infection, trauma, etc.[1] The respiratory system itself is then no longer able to ensure adequate gas exchange. Very often, patients with ARDS must therefore be subjected to invasive mechanical ventilation (IMV). In many cases a sufficient pulmonary gas exchange cannot be maintained despite maximum ventilatory support.[2]

Source: Shutterstock ID 216914668

Some facts about ARDS:

  • ARDS patients account for about 10% of all patients treated in the intensive care unit (ICU).[2]
  • Unfortunately, the mortality rate for patients with ARDS is still very high, with mortality rates of 34.9% for patients with mild ARDS, 40.3% for moderate ARDS cases and 46.1% for severe cases.[2]
  • Significantly worse prognosis for ARDS patients with aggressive, non-protective invasive mechanical ventilation (IMV).[2-6]

ECMO’s primary scope in ARDS is adequate gas exchange, to replace the temporarily compromised lung function for oxygenation of the blood and removal of carbon dioxide. Usually, a veno-venous cannulation is used. VV ECMO only “by-passes” the native lungs but does not provide any circulation support.[7]

References:

[1] Ranieri, V. M. et al. (2012). Acute respiratory distress syndrome: the Berlin Definition. JAMA, 307(23), 2526-2533

[2] Bellani, G. et al. (2016). Epidemiology, Patterns of Care, and Mortality for Patients With Acute Respiratory Distress Syndrome in Intensive Care Units in 50 Countries. JAMA, 315(8), 788-800

[3] Villar, J. (2011). What is the acute respiratory distress syndrome?. Respir Care, 56(10), 1539-1545

[4] Eachempati, S. R. et al. (2007). Outcomes of acute respiratory distress syndrome (ARDS) in elderly patients. J Trauma, 63(2), 344-350

[5] Vasilyev, S. et al. (1995). Hospital survival rates of patients with acute respiratory failure in modern respiratory intensive care units. An international, multicenter, prospective survey . Chest, 107(4), 1083-1088

[6] Ferguson, N. D. et al. (2005). Acute respiratory distress syndrome: underrecognition by clinicians and diagnostic accuracy of three clinical definitions. Crit Care Med, 33(10), 2228-2234

[7] Sangalli, F. et al. (2014). ECMO – Extracorporeal Life Support in Adults. Milano, Italy: Springer