What are the main clinical features of Acute respiratory distress syndrome?

• dyspnoea
• elevated respiratory rate
• bilateral lung crackles
• low oxygen saturations

What is the management of Acute respiratory distress syndrome?

• due to the severity of the condition patients are generally managed in ITU
• oxygenation/ventilation to treat the hypoxaemia
• general organ support e.g. vasopressors as needed
• treatment of the underlying cause e.g. antibiotics for sepsis
• certain strategies such as prone positioning and muscle relaxation have been shown to improve outcome in ARDS

What are the main causes of Acute respiratory distress syndrome?

• infection: sepsis, pneumonia
• massive blood transfusion
• trauma
• smoke inhalation
• acute pancreatitis
• Covid-19
• cardio-pulmonary bypass

What is the pathophysiology of Acute respiratory distress syndrome?

increased permeability of alveolar capillaries leading to fluid accumulation in the alveoli, i.e. non-cardiogenic pulmonary oedema

What are the common complications of Acute respiratory distress syndrome?

mortality of around 40%

What is the diagnostic criteria of Acute respiratory distress syndrome?

• acute onset (within 1 week of a known risk factor)
• pulmonary oedema: bilateral infiltrates on chest x-ray ('not fully explained by effusions, lobar/lung collapse or nodules)
• non-cardiogenic (pulmonary artery wedge pressure needed if doubt)
• pO2/FiO2 < 40kPa (300 mmHg)