Short case — recognising and classifying ARDS

A focused CICM short case on the highest-yield discriminators in ARDS — applying the Berlin definition to classify mild, moderate or severe disease from the gas and the film, and stating the management fork each severity band triggers (lung protection for all; prone and the rescue ladder for severe). Tests whether the candidate can move cleanly from data to syndrome to plan.

Prompt

You are shown a ventilated patient's arterial blood gas and chest X-ray and asked: 'Does this patient have ARDS, and if so how would you classify and manage it?' The gas shows PaO2 54 mmHg on FiO2 0.7 with PEEP 12; the chest film shows bilateral confluent infiltrates that developed over 36 hours after a witnessed aspiration. Talk the examiner through your recognition, classification, and the management it triggers.

Presentation

You are presented with a ventilated patient whose arterial blood gas shows a PaO2 of 54 mmHg on FiO2 0.7 with PEEP 12, and whose chest X-ray shows bilateral confluent infiltrates developing over 36 hours following a witnessed aspiration. The question is whether this is ARDS, how it is classified, and what that classification triggers.^[1]

State the principle first: ARDS is a syndrome defined by four criteria, and once you confirm it you classify it by the PaO2/FiO2 ratio under PEEP — because the severity band decides which therapies you reach for.^[1]

References7Show

[1]Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute Respiratory Distress Syndrome: The Berlin Definition. JAMA, 2012.PMID 22797452
[2]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.PMID 26903337
[3]Brower RG, Matthay MA, Morris A, et al. Ventilation with Lower Tidal Volumes as Compared with Traditional Tidal Volumes for Acute Lung Injury and the Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2000.PMID 10793162
[4]Amato MBP, et al. Driving Pressure and Survival in the Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2015.PMID 25693014
[5]Guérin C, Reignier J, Richard JC, et al. Prone Positioning in Severe Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2013.PMID 23688302
[6]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.
[7]Marino PL The ICU Book. 4th edition, Lippincott Williams & Wilkins, 2014.

Short case — recognising and classifying ARDS

Presentation

References7Show

[1]Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute Respiratory Distress Syndrome: The Berlin Definition. JAMA, 2012.PMID 22797452
[2]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.PMID 26903337
[3]Brower RG, Matthay MA, Morris A, et al. Ventilation with Lower Tidal Volumes as Compared with Traditional Tidal Volumes for Acute Lung Injury and the Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2000.PMID 10793162
[4]Amato MBP, et al. Driving Pressure and Survival in the Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2015.PMID 25693014
[5]Guérin C, Reignier J, Richard JC, et al. Prone Positioning in Severe Acute Respiratory Distress Syndrome. New England Journal of Medicine, 2013.PMID 23688302
[6]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.
[7]Marino PL The ICU Book. 4th edition, Lippincott Williams & Wilkins, 2014.