Galectin-3 is a biomarker for fibrotic activity. In the course of invasive ventilation, fibrotic changes in the lungs may occur. The study aims to investigate whether the level of galectin-3 levels correlates with clinical weaning parameters.

Galectin-3 (Gal-3) is a protein with an important role in cell-cell adhesion, cell-matrix interactions, macrophage activation, angiogenesis, metastasis and apoptosis. Galectin-3 is expressed in the nucleus, cytoplasm, mitochondrion, cell surface, and extracellular space.It is involved in different biological processes: cell adhesion, cell activation and chemoattraction, cell growth and differentiation, cell cycle, and apoptosis. Several studies revealed the function of galectin-3 in cancer, inflammation and (lung) fibrosis, heart disease, and stroke. Expression of galectin-3 is associated with heart failure, including myofibroblast proliferation, fibrogenesis, tissue repair, inflammation, and ventricular remodeling. A correlation between galectin-3 expression levels and various types of fibrosis has been found. Galectin-3 is upregulated in idiopathic pulmonary fibrosis.

Mechanical ventilation can cause lung damage, or worsen it if already present. This phenomenon is called ventilation-induced lung damage. Main mechanisms are high tidal volumes causing overexpansion of the lungs (volutrauma), high airway pressure (barotrauma) and cyclical collapse and reopening of atelectatic alveolar regions (atelectrauma) leading to a pulmonary inflammatory reaction called "bio-trauma".

To evaluate the (potential) lung injury serum levels of galectin-3 are measured on admission to our hospital. During respiratory weaning invasiveness of ventilation will be reduced. Data relating biomarkers especially galectin3 during/after successful respiratory weaning are missing.

This is why follow up measurements of galectin-3 will be done and correlated with ventilation parameters/duration/ success of respiratory weaning.

Prior studies evaluated the role of proGRP and CA 15-3 in patients with lung fibrosis. As a part of the study galectin-3 serum levels will be correlated with serum levels of proGRP and CA 15-3.

In summary the aim of this study is to evaluate the diagnostic value of galectin-3 in respiratory weaning.

Inclusion Criteria:

• written informed consent
• mechanical ventilation

Exclusion Criteria:

• history of pulmonary disease
• left ventricular ejection fraction<45%
• missing declaration of consent

Patients with mechanical ventilation who are admitted to our hospital for respiratory weaning.