Higher Levels of Spontaneous Breathing Induce Lung Recruitment and Reduce Global Stress/Strain in Experimental Lung Injury

• DOI: 10.1097/aln.0000000000000124
• Publication Date: 2014-01-09T11:05:21Z
• Authors: Andreas Güldner; Anja Braune; Nadja Carvalho; Alessandro Beda; Stefan Zeidler; Bärbel Wiedemann; Gerd Wunderlich; Michael Andreeff; Christopher Uhlig; Peter M. Spieth; Thea Koch; Paolo Pelosi; Jörg Kotzerke; Marcelo Gama de A...
• Keywords: Positive airway pressure

Spontaneous breathing (SB) in the early phase of acute respiratory distress syndrome is controversial. Biphasic positive airway pressure/airway pressure release ventilation (BIPAP/APRV) commonly used, but level SB necessary to maximize potential beneficial effects unknown.Experimental was induced by saline lung lavage anesthetized and mechanically ventilated pigs (n = 12). By using a Latin square crossover design, animals were with BIPAP/APRV at four different levels total minute (60 min each): (1) 0% (BIPAP/APRV0%); (2) greater than 0 30% (BIPAP/APRV>0-30%); (3) 30 60% (BIPAP/APRV>30-60%); (4) (BIPAP/APRV>60%). Gas exchange, hemodynamics, variables measured. Lung aeration assessed high-resolution computed tomography. The distribution perfusion marked Ga-labeled microspheres evaluated positron emission tomography.The authors found that higher during improved oxygenation; decreased mean transpulmonary (stress) despite increased inspiratory effort; reduced nonaerated tissue, minimal changes perfusion, resulting low aeration/perfusion zones; global strain (mean ± SD) (BIPAP/APRV0%: 1.39 0.08; BIPAP/APRV0-30%: 1.33 0.03; BIPAP/APRV30-60%: 1.27 0.06; BIPAP/APRV>60%: 1.25 0.04, P < 0.05 all vs. BIPAP/APRV0%, BIPAP/APRV>60% BIPAP/APRV0-30%).In model experimental pigs, currently recommended for clinical practice, is, 10 30%, improve oxygenation increasing dependent zones without relevant redistribution perfusion. In presence recruitment, reduce stress an increase effort.