Comparison of systemic cytokine levels in patients with acute respiratory distress syndrome, severe pneumonia, and controls

Procalcitonin versus interleukin-6 levels in bronchoalveolar lavage fluids of trauma victims with severe lung contusion

OBJECTIVE

To examine whether measurement of procalcitonin (PCT) in comparison with interleukin-6 is a reliable marker to score the extent of lung contusion in bronchoalveolar lavage (BAL) fluids in polytrauma patients.

DESIGN

Prospective, nonrandomized, observational study.

SETTING

Twelve-bed intensive care unit in a 1,100-bed primary care university hospital.

PATIENTS

Fourteen trauma victims presenting with severe lung contusion and acute lung injury or acute respiratory distress syndrome were enrolled in the study.

INTERVENTIONS

Bronchoscopy with collection of lavage fluid and serum blood samples. Samples were obtained on days 1 and 2 after severe chest trauma, and lung contusion was assessed by computed tomography scan.

MEASUREMENTS AND MAIN RESULTS

PCT was detectable in BAL fluids of all 14 patients. A significant correlation for PCT serum and BAL levels was found on day 2 (p =.0063). For PCT, no significant correlations (Spearman rank) were found to the lung injury score (p =.93), the abbreviated injury scale-lung (p =.33), or the sepsis-related organ failure assessment score-lung (p =.38). Also, for interleukin-6 there was no significant correlation to the lung injury score (p =.62), abbreviated injury scale-lung (p =.45), or the sepsis-related organ failure assessment score-lung (p =.54).

CONCLUSIONS

PCT and interleukin-6 BAL levels cannot be considered as reliable parameters to assess the extent of lung contusion.

Acute lung injury: cellular mechanisms and derangements

The clinical course of acute lung injury (ALI) is a complex and variable process accompanied by severe lung dysfunction, which persists for a long period of time with variable recovery of pulmonary function. The extent and severity of the lung disease associated with ALI varies with those patients having the most severe manifestations of lung disease being grouped as acute respiratory distress syndrome (ARDS). The pathological injury associated with this disease process, termed diffuse alveolar damage (DAD), has three overlapping phases (exudative, proliferative and fibrotic) which are the consequences of severe injury to the alveolar-capillary unit. There is no uniformity to the progression and length of each stage. This review explores those cellular mechanisms and derangements involved in the progression of ARDS. Those areas that demonstrate the major advances within the field are highlighted because of the diverse and vast nature of the cellular components involved in the process of ALI. We are beginning to identify those processes that contribute to the cellular derangements which are the hallmark of ALI. By expanding our understanding of those factors, we should in the future be able to construct therapeutic interventions that address the aetiology of ALI.