Which of the following findings is virtually always seen in a patient with ARDS ?
A. A small localized mass on chest x-rayB. Reduced lung compliance
C. Normal oxygenation with impaired minute ventilation
D. Increased arterial Pco2
The answer is B
Adult respiratory distress syndrome
(ARDS, "wet lung") begins with a disruption of capillary integrity,
which leads to extravasation of fluid, fibrin, and protein into the alveoli. As
a result, the lungs become wet and stiff (i.e., noncompliant). This condition
is characterized by severe hypoxia caused by extreme ventilation-perfusion
(V/Q) imbalance and shunting of blood in the fluid-filled areas of the lung.
Clinical features include progressive tachypnea; patchy, diffuse, fluffy
infiltrates on chest x-ray; increased minute ventilation; and decreased lung
volumes. There usually is an absence of specific physical findings.
