TY - JOUR
T1 - Recruitment and derecruitment during acute respiratory failure
T2 - An experimental study
AU - Pelosi, P.
AU - Goldner, M.
AU - McKibben, A.
AU - Adams, A.
AU - Eccher, G.
AU - Caironi, P.
AU - Losappio, S.
AU - Gattinoni, L.
AU - Marini, J. J.
PY - 2001/7/1
Y1 - 2001/7/1
N2 - We aimed to elucidate the relationships between pleural (Ppl), esophageal (Pes), and superimposed gravitational pressures in acute lung injury, and to understand the mechanisms of recruitment and derecruitment. In six dogs with oleic acid respiratory failure, we measured Pes and Ppl in the uppermost, middle, and most dependent lung regions. Each dog was studied at positive end-expiratory pressure (PEEP) of 5 and 15 cm H2O and three levels of tidal volume (VT; low, medium, and high). For each PEEP-VT combination, we obtained a computed tomographic (CT) scan at end-inspiration and end-expiration. The variations of Ppl and Pes pressures were correlated (r = 0.86 ± 0.07, p < 0.0001), as was the vertical gradient of transpulmonary (PL) and superimposed pressure (r = 0.92, p < 0.0001). Recruitment proceeded continuously along the entire volume-pressure curve. Estimated threshold opening pressures were normally distributed (mode = 20 to 25 cm H2O). The amount of end-expiratory collapse at the same PEEP and PL was significantly lower when ventilation was performed at high VT. End-inspiratory and end-expiratory collapse were highly correlated (r = 0.86, p < 0.0001), suggesting that as more tissue is recruited at end-inspiration, more remains recruited at end-expiration. When superimposed pressure exceeded applied airway pressure (Paw), collapse significantly increased.
AB - We aimed to elucidate the relationships between pleural (Ppl), esophageal (Pes), and superimposed gravitational pressures in acute lung injury, and to understand the mechanisms of recruitment and derecruitment. In six dogs with oleic acid respiratory failure, we measured Pes and Ppl in the uppermost, middle, and most dependent lung regions. Each dog was studied at positive end-expiratory pressure (PEEP) of 5 and 15 cm H2O and three levels of tidal volume (VT; low, medium, and high). For each PEEP-VT combination, we obtained a computed tomographic (CT) scan at end-inspiration and end-expiration. The variations of Ppl and Pes pressures were correlated (r = 0.86 ± 0.07, p < 0.0001), as was the vertical gradient of transpulmonary (PL) and superimposed pressure (r = 0.92, p < 0.0001). Recruitment proceeded continuously along the entire volume-pressure curve. Estimated threshold opening pressures were normally distributed (mode = 20 to 25 cm H2O). The amount of end-expiratory collapse at the same PEEP and PL was significantly lower when ventilation was performed at high VT. End-inspiratory and end-expiratory collapse were highly correlated (r = 0.86, p < 0.0001), suggesting that as more tissue is recruited at end-inspiration, more remains recruited at end-expiration. When superimposed pressure exceeded applied airway pressure (Paw), collapse significantly increased.
KW - ALI/ARDS
KW - Computed tomography
KW - Mechanical ventilation
KW - Oleic acid
KW - Volume pressure curve
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U2 - 10.1164/ajrccm.164.1.2007010
DO - 10.1164/ajrccm.164.1.2007010
M3 - Article
C2 - 11435250
AN - SCOPUS:0035402479
SN - 1073-449X
VL - 164
SP - 122
EP - 130
JO - American journal of respiratory and critical care medicine
JF - American journal of respiratory and critical care medicine
IS - 1
ER -