Regional lung tissue changes with mechanical ventilation and fluid load. (1st May 2015)

• Record Type: Journal Article
• Authors: Marcozzi, Cristiana; Moriondo, Andrea; Solari, Eleonora; Reguzzoni, Marcella; Severgnini, Paolo; Protasoni, Marina; Passi, Alberto; Pelosi, Paolo; Negrini, Daniela
• Is Part Of: Experimental lung research. Volume 41:Number 4(2015:Apr.)
• Page Start: 228
• Page End: 240
• Publication Date: 2015-05-01
• Subjects: Lungs -- Periodicals; Lungs -- Diseases -- Periodicals; Lung Diseases; Lung -- physiology; Respiratory System; 616.24
• Languages: English
• ISSNs: 0190-2148

Abstract

<abstract> <title>ABSTRACT</title> <p> <italic>Purpose:</italic> To investigate the regional gravity-dependent impact of mechanical ventilation and fluid overload on lung extracellular matrix (ECM) in healthy lungs. <italic>Materials and Methods:</italic> The glycosaminoglycans (GAGs) composition of the ventral and dorsal lung parenchyma was determined in anesthetized supine healthy rats mechanically ventilated for 4 hours in air: (a) at low (∼7.5 mL/kg) or high (∼ 23 mL /kg) tidal volume (<italic>V</italic>_T) and 0 cmH₂O positive end-expiratory pressure (PEEP); (b) at low or high <italic>V</italic>_T at 5 cmH₂O PEEP and (c) with or without 7 mL /(kg·h) intravenous saline infusion. <italic>Results:</italic> Mechanical ventilation degraded lung ECM, with alveolar septa thinning and structural GAGs disorganization. Low <italic>V</italic>_T ventilation was associated with significant tissue structure changes in both ventral and dorsal lung regions, while high <italic>V</italic>_T mainly affected the dependent ones. PEEP decreased ECM injury mainly in the ventral lung regions, although it did not prevent matrix fragmentation and washout at high <italic>V</italic>_T. Intravascular fluid load increased lung damage prevalently in the ventral lung regions. <italic>Conclusion:</italic> Mechanical ventilation and fluid load may cause additive injuries in healthy lungs, mainly in ventral regions.</p> </abstract>