Description
Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) are defined as:
- Bilateral pulmonary infiltrates on chest x-ray
- Pulmonary Capillary Wedge Pressure < 18 mmHg (2.4 kPa)
- PaO2/FiO2* <300 mmHg (40 kPa) = ALI
- PaO2/FiO2 <200 mmHg (26.7 kPa)= ARDS
There are two forms of ALI. Primary ALI is caused by a direct injury to the lung (e.g., pneumonia). Secondary ALI is caused by an indirect insult (e.g., pancreatitis). There are two stages – the acute phase characterized by disruption of the alveolar-capillary interface, leakage of protein rich fluid into the interstitium and alveolar space, and extensive release of cytokines and migration of neutrophils. A later reparative phase is characterized by fibroproliferation and organization of lung tissue.
The patient has low lung volumes, atelectasis, loss of compliance, ventilation-perfusion mismatch (increased deadspace), and right to left shunt.
Clinical features are – severe dyspnea, tachypnea, and resistant hypoxemia.
Read more about this topic: Acute Lung Injury
Famous quotes containing the word description:
“Whose are the truly labored sentences? From the weak and flimsy periods of the politician and literary man, we are glad to turn even to the description of work, the simple record of the month’s labor in the farmer’s almanac, to restore our tone and spirits.”
—Henry David Thoreau (1817–1862)
“Everything to which we concede existence is a posit from the standpoint of a description of the theory-building process, and simultaneously real from the standpoint of the theory that is being built. Nor let us look down on the standpoint of the theory as make-believe; for we can never do better than occupy the standpoint of some theory or other, the best we can muster at the time.”
—Willard Van Orman Quine (b. 1908)
“God damnit, why must all those journalists be such sticklers for detail? Why, they’d hold you to an accurate description of the first time you ever made love, expecting you to remember the color of the room and the shape of the windows.”
—Lyndon Baines Johnson (1908–1973)