High-frequency oscillatory ventilation reduces lung inflammation: a large-animal 24-h model of respiratory distress

• Published in: Intensive care medicine Vol. 33; no. 8; pp. 1423 - 1433
• Main Authors: Muellenbach, Ralf M., Kredel, Markus, Said, Harun M., Klosterhalfen, Bernd, Zollhoefer, Bernd, Wunder, Christian, Redel, Andreas, Schmidt, Michael, Roewer, Norbert, Brederlau, Jörg
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.08.2007; Berlin Springer Nature B.V
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Chronic obstructive pulmonary disease, asthma; Disease Models, Animal; DNA Primers; Emergency and intensive respiratory care; Experiments; Female; Gases; Germany; Hemodynamics; High-Frequency Ventilation; Intensive care medicine; Medical sciences; Pilot projects; Pneumology; Pneumonia - prevention & control; Prospective Studies; Pulmonary arteries; Pulmonary Gas Exchange - physiology; Random Allocation; Respiratory distress syndrome; Respiratory Distress Syndrome, Adult - physiopathology; Reverse Transcriptase Polymerase Chain Reaction; Swine; Veins & arteries; Ventilators; Germany; United States > US; Animal model; Intensive care; Animal models; High-frequency ventilation, Intermittent positive-pressure ventilation, Acute respiratory distress syndrome; Positive pressure; Respiratory disease; Intermittent; Respiratory distress; Inflammation; Inflammation, Messenger RNA; High frequency ventilation; Resuscitation
• ISSN: 0342-4642; 1432-1238
• DOI: 10.1007/s00134-007-0708-x

High-frequency oscillatory ventilation (HFOV) may reduce ventilator-induced lung injury in experimental neonatal respiratory distress. However, these data permit no conclusions for large animals or adult patients with acute respiratory distress syndrome (ARDS), because in neonates higher frequencies and lower amplitudes can be used, resulting in lower tidal volumes (VT) and airway pressures. The aim of this study was to compare gas exchange, lung histopathology and inflammatory cytokine expression during lung-protective pressure-controlled ventilation (PCV) and HFOV in a long-term large-animal model of ARDS. Prospective, randomized, controlled pilot study. University animal laboratory. Sixteen female pigs (55.3 +/- 3.9 kg). After induction of ARDS by repeated lavage, the animals were randomly assigned to PCV (VT = 6 ml/kg) and HFOV (6 Hz). After lung injury, a standardised lung recruitment was performed in both groups, and ventilation was continued for 24 h. After lung recruitment sustained improvements in the oxygenation index were observed in both groups. The mean airway pressure (mPaw) was significantly lower in the HFOV group during the experiment (p < 0.01). Histologically, lung inflammation was significantly ameliorated in the HFOV group (p < 0.05). The messenger RNA expression of IL-1-beta in lung tissue was significantly lower in the HFOV-treated animals (p < 0.01). These data suggest that HFOV compared with conventional lung-protective ventilation can reduce lung inflammation in a large-animal 24-h model of ARDS. Furthermore, it was shown that lung recruitment leads to sustained improvements in gas exchange with a significantly lower mPaw when HFOV is used.