Failure of Lung Repair Following Acute Lung Injury: Clinical Classification of Acute Lung Injury (2)
In addition to the pulmonary abnormalities, signs of systemic illness may be present, including fever, decreased systemic vascular resistance, increased cardiac output, and hypermetabolism. This constellation of findings, referred to as the “sepsis syndrome,” may or may not be associated with an identified source of infection. When a source of infection can be identified early in the course of ARDS, this source is frequently intra-abdominal. The source of sepsis syndrome occurring late in the clinical course of lung injury remains unclear in many cases. Although bacterial pneumonia accounts for some of these cases, the inability to clearly diagnose a lung infection in these patients is common. Buy Asthma Inhalers Online
The hypothesis that noninfec-tious mediators of sepsis syndrome and multiple organ failure such as interleukin 1 and tumor necrosis factor (TNF) are being produced and released into the circulation by the injured lungs is an active area of investigation. For example, TNF concentrations are elevated in the plasma of patients with sepsis and high concentrations of TNF have been detected in the lower respiratory tract of patients with ALI. These observations suggest a possible pathogenic role for local pulmonary TNF production in the sepsis syndrome characteristic of ALI.