الفهرس 
Biochemical Assay for Biomarkers in Acute Lung InjuryOnly 14 pages are availabe for public view
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Abstract
ARDS is a clinical devastating syndrome that affects both medical and surgical patients. Despite great advances in understanding the pathogenesis of disease mortality rate is still high. Even survivors of ARDS usually experience long ICU stay, hospital stay and several co-morbidities. Moreover survivors require prolonged rehabilitation time till full recovery.
AECC defined ALI/ARDS as an acute condition characterized by bilateral pulmonary infiltrates and severe hypoxemia in the absence of evidence for cardiogenic pulmonary edema. Cardiogenic pulmonary edema must be excluded either by clinical criteria or by a pulmonary capillary wedge pressure (PCWP) lower than 18 mm Hg. Recently with Berlin Definition defined as an acute, diffuse, inflammatory lung injury that leads to increased pulmonary vascular permeability, increased lung weight, and a loss of aerated tissue.
Many causes have been identified but the four most frequent causes include: Sepsis (Most common cause), Aspiration, Pneumonia andSevere Trauma.
Recent studies reported much lower incidences of 1.5 to 8.3 per 100,000 and ~200,000 cases per year in the US alone. The prognosis of acute respiratory distress syndrome (ARDS) has improved over the last 20 years. 60% to 70% of patients survive. Patients with poor prognostic factors include those older than 65 years and those with sepsis as the underlying cause. The adverse effect of age may be related to underlying health status. The severity of hypoxemia at the time of diagnosis does not correlate well with survival rates
Mortality rates of acute lung injury also vary greatly depending on the age of the patient and presence of non-pulmonary organ dysfunctions. Advanced age, shock, and hepatic failure are most predictive of death whereas young trauma patients have the best outcomes.
An ideal clinically suitable biomarker should fulfill the following requirements: add independent information about the risk or prognosis, account for a large proportion of the risk associated with a given disease or condition, be reproducible (as determined by the low coefficient of variation), be sensitive, specific and should present with a high predictive value, be of easy safe and cheap determination, should be proven treatment to modify the biomarker, should be consistent across genders and ethnic groups.
Currently, biomarkers in ALI have role in pathophysiologic mechanisms involved in acute lung injury and its subsequent repair although they have been shown to have prognostic value as well.
There are both proinflammatory and anti-inflammatory mediators and therefore it maybe more the balance of these mediators and their biological inhibitors in the surrounding milieu that regulate much of the development of lung injury and repair which may have implications for their use as biomarkers in isolation or in combination.
The combination of clinical predictors and elevated levels of two to three plasma biomarkers may prove useful to predict prognosis in patients with ALI, as well as to select patients for clinical trials of new therapeutic modalities.
Biomarkers in ALI have a great importance in the whole spectrum of the disease through understanding the pathogenesis, support diagnosis, predicting prognosis and development of new therapeutic agents.