Showing papers by "Michael A. Matthay published in 1984"

Elevated concentrations of leukotriene D4 in pulmonary edema fluid of patients with the adult respiratory distress syndrome

Abstract: The possible contribution of metabolites of arachidonic acid to the increased permeability of the alveolar-capillary barrier in the adult respiratory distress syndrome was examined by quantifying the pulmonary edema fluid concentrations of lipoxygenase and cyclooxygenase products. The concentration of leukotriene D4 in pulmonary edema fluid of 10 patients with the adult respiratory distress syndrome (18.5±6.8 pmol/ml; mean±SD), assessed by specific radioimmunoassay after isolation of the mediator, was significantly higher (P<0.001) than that of five patients with cardiogenic pulmonary edema (4.4±1.1 pmol/ml). The concentrations of leukotrienes B4 and C4, prostaglandin E2, and thromboxane B2 in edema fluid were not significantly different in the adult respiratory distress syndrome patients than in the other subjects with pulmonary edema. The edema fluid concentration of leukotriene D4 correlated with the ratio of edema fluid to plasma concentrations of albumin (r=0.64). Leukotriene D4 thus may contribute to the permeability defect which allows an accumulation of proteinrich alveolar fluid in the adult respiratory distress syndrome.

Biologically active products of complement and acute lung injury in patients with the sepsis syndrome.

Abstract: To determine if biologically active products of complement appear during sepsis and to establish the relationship of these components to the respiratory and hemodynamic complications of sepsis, we measured C5a des Arg and C3a des Arg (radioimmunoassay), neutrophil chemotaxis, and neutrophil-aggregating activity in plasma obtained from 40 patients at the time sepsis was suspected clinically. Levels of C3a des Arg and C5a des Arg were elevated in 35 and 38 patients, respectively, and in all 25 with positive blood cultures. Highest C5a des Arg levels occurred in patients with hypotension (less than 90 mmHg) and/or acidemia. The C5a des Arg concentrations were significantly higher in patients with than in those without neutrophil-chemotactic activity. Neutrophil-aggregating activity was less sensitive an index of complement activation, as it was positive in only 8 patients and correlated poorly with C5a des Arg and C3a des Arg values. Using a composite scoring system to quantify sepsis-related pulmonary abnormalities, we found that neither biologic nor immunologic assays of complement activation products correlated with the initial severity nor predicted the development or worsening of associated acute lung injury.

Neurogenic pulmonary edema.

Abstract: A variety of central nervous system (CNS) insults may be complicated by the acute development of pulmonary edema. This occurrence has been termed neurogenic pulmonary edema (NPE), and experimental models have clearly shown that CNS insults may cause pulmonary edema. Unfortunately, the pathophysiologic aspects of this response are not clearly understood. Basing an approach to the development of pulmonary edema on Starling's equation leads to the conclusion that NPE is caused by changes in pulmonary endothelial permeability and/or microvascular pressures. It was previously suggested (the "blast theory") that CNS insults caused acute systemic arterial and pulmonary venous spasm and increased venous return, which would result in a severe pulmonary vascular hydrostatic insult and a secondary permeability defect. Although such hydrostatic derangements may explain certain cases of NPE, recent clinical and experimental studies have indicated that CNS disorders may cause a permeability defect without a vascular insult. The mediating factor for a permeability defect is not clear. The implications of these findings are that NPE may be caused by either permeability abnormalities or hydrostatic insults, may present clinically in a variety of ways, and may require different approaches to treatment. Our understanding of the CNS sites that might mediate NPE is not sophisticated enough, at present, to define the neural mechanisms involved in the pathogenesis of NPE.