Acute respiratory distress syndrome: Clinical

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Acute respiratory distress syndrome: Clinical

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A 62-year-old man presents to the emergency department after being pulled out of a frozen lake. The family reports the patient was fishing when he suddenly fell through the ice; he was extricated 10 minutes later. The patient has a past medical history of heart failure with preserved ejection fraction and hypertension. His temperature is 34°C (93.2°F), pulse is 45/min, respirations are 22/min, blood pressure is 110/94 mmHg, and oxygen saturation is 85% on room air. Physical examination shows a male patient who is shivering, appears pale, and is cool to the touch. The patient can speak one- to two-word sentences at a time, but his history is limited by a persistent non-productive cough and altered mental status. The patient is subsequently intubated for airway protection and admitted to the intensive care unit on mechanical ventilation. A chest x-ray and laboratory results are demonstrated below:  

Reproduced from: Wikipedia
Laboratory value  Result 
Blood Gases, Serum 
pH  7.49 
 PCO2  24 mmHg 
 PO2  53 mm Hg 
 Cardiac Enzymes, Serum 
 Brain Natriuretic Peptide (BNP)  <100 ng/dL (N = <100) 
 Troponin  <.03 ng/dL 
Which of the following is a recommended treatment strategy for the management of this patient’s condition?


Content Reviewers


Acute respiratory distress syndrome, or ARDS is a condition where there’s inflammation throughout the lungs leading to pulmonary edema.

The main site of injury in ARDS is the alveolar-capillary membrane.

Now, any damage to the alveolar epithelium or the capillary endothelium increases the permeability of the alveolar-capillary membrane, causing fluid to move into the alveoli.

Oxygen and carbon dioxide have to travel across this fluid, so it acts as a barrier against normal gas exchange.

The fluid also dilutes out the surfactant molecules coating the alveoli, and as a result the alveoli are less able to remain open and compliant, so they become stiff.

If the injury continues, the alveoli eventually collapse.

Now, the pulmonary edema from ARDS causes the same problems as pulmonary edema from congestive heart failure, but because the triggering events are different, the term non-cardiogenic pulmonary edema is often used for ARDS.

Now, ARDS is not a primary lung disease, rather it arises as a complication of a systemic injury that causes widespread inflammation which results in damage to the alveolar-capillary membranes within the lung.

The most common underlying systemic cause of ARDS is sepsis, which causes systemic inflammation in response to an infection.

But other insults include trauma, severe burns, near-drowning, disseminated intravascular coagulation or DIC, acute pancreatitis, massive blood transfusions, aspiration of gastric contents, and toxic smoke inhalation.


Acute respiratory distress syndrome (ARDS) is a potentially life-threatening condition that occurs when the lungs are unable to provide sufficient oxygen to the bloodstream. Symptoms of ARDS can include rapid breathing, shortness of breath, chest pain, and extreme fatigue. ARDS is most often caused by another underlying condition, such as pneumonia, sepsis, or trauma.


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