Acute respiratory distress syndrome

Definition

Acute respiratory distress syndrome (ARDS) is a severe condition characterized by rapid onset of widespread inflammation in the lungs, leading to impaired gas exchange and decreased oxygenation of the blood. It can occur due to various triggers, including trauma, pneumonia, and sepsis, resulting in significant respiratory failure. Understanding ARDS is crucial because it involves complex pathophysiological processes that can significantly impact patient outcomes.

5 Must Know Facts For Your Next Test

1. ARDS is classified into mild, moderate, and severe categories based on the degree of hypoxemia and oxygenation impairment.
2. The Berlin Definition of ARDS provides specific criteria, including timing of onset, chest imaging findings, and the exclusion of other causes of respiratory failure.
3. Common risk factors for developing ARDS include pneumonia, aspiration of gastric contents, and systemic inflammatory response syndrome (SIRS).
4. Management of ARDS typically includes supportive care such as oxygen therapy and mechanical ventilation, along with treating the underlying cause.
5. Survivors of ARDS often experience long-term effects, including reduced lung function and psychological impacts such as PTSD.

Review Questions

• What are the key criteria for diagnosing acute respiratory distress syndrome according to the Berlin Definition?
  • The Berlin Definition outlines specific criteria for diagnosing acute respiratory distress syndrome (ARDS), which include the timing of onset (within one week of a known clinical insult), bilateral opacities on chest imaging consistent with pulmonary edema, and a need to exclude other causes of respiratory failure. The degree of hypoxemia is also categorized into mild, moderate, or severe based on the ratio of arterial oxygen to fractional inspired oxygen (PaO2/FiO2). These criteria help clinicians accurately identify ARDS and differentiate it from other respiratory conditions.
• How does the pathophysiology of acute respiratory distress syndrome lead to impaired gas exchange?
  • In acute respiratory distress syndrome (ARDS), widespread inflammation in the lungs leads to increased permeability of the alveolar-capillary membrane. This results in pulmonary edema and impaired surfactant production, causing alveolar collapse. Consequently, areas of the lung fill with fluid instead of air, preventing effective gas exchange. The combination of decreased lung compliance and intrapulmonary shunting further exacerbates hypoxemia, making it difficult for patients to maintain adequate oxygen levels in their blood.
• Evaluate the long-term implications for patients who survive acute respiratory distress syndrome and how these may affect their quality of life.
  • Patients who survive acute respiratory distress syndrome (ARDS) may face several long-term implications that can significantly affect their quality of life. Common outcomes include persistent pulmonary function impairment due to scarring or fibrosis in the lungs, which can lead to chronic shortness of breath and reduced exercise capacity. Additionally, many survivors experience psychological effects such as post-traumatic stress disorder (PTSD), anxiety, and depression stemming from their critical illness experience. Addressing these long-term effects is essential for improving overall patient well-being and rehabilitation post-ARDS.

Related terms

Pulmonary Edema: A condition characterized by excess fluid in the lungs, which can lead to impaired gas exchange and is often associated with ARDS.

Ventilator Support: A medical intervention that provides mechanical assistance with breathing for patients with severe respiratory distress, often necessary in cases of ARDS.

Intrapulmonary Shunting: A phenomenon where blood bypasses the alveoli without participating in gas exchange, commonly seen in patients with ARDS.