Pathophysiology of the adult respiratory distress syndrome. What have we learned from human studies?

A Fein, J P Wiener-Kronish, M Niederman, M A Matthay
Critical Care Clinics 1986, 2 (3): 429-53
Clinical studies of ARDS have been successful in determining the most common predisposing clinical disorders and the natural history of this syndrome. Sepsis, gastric aspiration, and major trauma are the most frequently associated high-risk factors. Overall mortality is in the range of 60% to 70%, but is even higher if ARDS is associated with sepsis, severe acidemia, or decreased renal function. It is evident that multisystem failure is responsible for death in many patients, as well as secondary pulmonary and extrapulmonary infections. Pathologic studies have provided descriptive information regarding the acute, subacute, and chronic phases of the syndrome, but little insight into the precise pathogenesis of the initial lung injury or the progressive fibrosing alveolitis and lung destruction that develops in some patients. There has been considerable circumstantial evidence from clinical studies implicating the neutrophil as a potentially important mediator of the early changes in lung endothelial and epithelial permeability. However, not all investigators have found the same alterations in neutrophil function in the circulation or in the lavage from the lungs of patients with ARDS. Also, the heterogeneous etiologies of ARDS make it difficult to be sure that there is a final common pathway for acute lung injury in all ARDS patients. In addition, there are a host of mediators, including products of complement activation and arachidonic acid metabolism, that may be important in amplifying the inflammatory response. Also, abnormalities of surfactant production and collagen turnover, as well as impaired host defenses in the lung, may contribute to the progressive respiratory failure that occurs in some ARDS patients, even though the acute, exudative phase of lung injury has resolved. Future human studies may provide useful information about the mechanisms of the acute lung injury through studies of circulating plasma markers, blood elements, and lavage fluids from high-risk patients. On the other hand, samples of cells and mediators from the airspaces with lavage still may not reflect the critical interactions of mediators and cells with the lung endothelium that lead to the protein-rich pulmonary edema that characterizes the first phase of ARDS. Thus, experimental studies must continue to study the details of the early phases of acute lung injury (see article by Flick, page 455). Finally, it is clear that treatment designed to reduce the severity and the incidence of ARDS must be started early, since the syndrome develops so rapidly in high-risk patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"