With s-Cath, samples were collected by physicians and trained ICU nurses; the procedure was rapid and no complications occurred. This result indicates an advantage of the s-Cath selleck chemicals llc procedure because collection can be performed shortly after intubation and at the onset of ALI or hydrostatic oedema. Another advantage is that fluid is suctioned undiluted without saline, and, therefore, the measurement of protein or potential mediators of lung injury can be made without dilution. For this reason, the protein concentration ratio of the oedema fluid:plasma was calculated in our different groups using samples obtained by the s-Cath. The main disadvantage of the s-Cath oedema fluid sampling method is that it seldom yields lung oedema fluid after the first 24 hours of intubation.

Therefore, this sampling technique is preferred for studying lung fluid at the onset of lung injury shortly after endotracheal intubation.In the patient population in this study, the mean value of the oedema fluid protein/plasma ratio in patients with primary ALI/ARDS was significantly lower compared with the value in the group of patients with a secondary form of ALI/ARDS. We speculate that during secondary ARDS, there is a more severe capillary leak that may flood the alveoli [19], possibly explaining the higher protein concentration ratio in the early disease phase of indirect ALI/ARDS while the early direct insult of the alveoli in pneumonia-associated ALI/ARDS may exude less protein resulting in a lower oedema fluid/plasma ratio.Our results did not show a good agreement between the s-Cath and mini-BAL sampling techniques.

Using protein content and PMN percentage as efficacy parameters, we found, in applying Bland-Altman plots, a significant bias with wide limits of agreement between Carfilzomib the two methods. When the protein concentration in the lung was high, the s-Cath method is a better method for estimating protein concentration (Figure (Figure4);4); in contrast, as inflammation increases, both methods provide similar estimates of the percentage of neutrophils in the air spaces of the lung (Figure (Figure5).5). The analysis of our plots indicates that, compared with the results for mini-BAL, the protein content was significantly higher in the same patient when measured by s-Cath. In other words, the s-Cath sampling technique ‘detected more’ protein content, meaning that this method could be more sensitive than mini-BAL itself for this purpose. These results suggest that the s-Cath and mini-BAL procedures cannot be used interchangeably for studying lung fluid composition during lung injury and that collection of lung oedema fluid should be performed with the same method.Interestingly, our results show an increased absolute PMN count recorded in patients with ACLE.