Evaluation of airway inflammation in mechanically ventilated patients using cell count and protein concentration

Mechanically ventilated (MV) patients may present airway inflammation and elevated secretion production. However, it is unknown whether cell and/or protein counts in bronchial samples may be useful to evaluate their clinical condition. Our aim was to standardize sampling and propose a new mechanical mucus dissolution in Tracheal-Bronchial secretions. In all patients, bronchial lining fluid aspiration (BLF), Bronchoalveolar lavage (BAL) and Bronchial Washings (BW40, BW5) were performed, while visible bronchial secretions were obtained via bronchoscopy (VBS) and blinded, via a common catheter for tracheobronchial aspiration (AC). Mucus was mechanically or DTT dissolved and cell number was count. Protein, albumin and TNF-α levels were measured, in mucus dissolved samples from control and MV patients. Cell number and protein levels were elevated in mucus dissolved compared to non-dissolved, or DTT dissolved. Cell number and TNF-α levels were elevated in MV patients compared to controls, while protein levels were lower in MV patients. Differences in cell and protein levels were observed in samples acquired using different sampling technics. Therefore, mechanical mucus dissolution provides a proper sample for evaluation, and the sampling technic used can influence the sample's characteristics.