title: Derivation of recruitment function from the pressure-volume curve in an acute lung injury model.
abstract: Lung volume changes involve the recruitment of collapsed alveoli and the expansion of already opened alveoli. This study aimed to determine the alveolar recruitment function by using a mathematical model from a pressure-volume curve (P-V curve). We assumed a lung model as VL=R(P)V0f(P), where R recruitment function is the fraction of recruited alveoli, V0 is the resting lung volume at FRC of a fully recruited lung, and f(P) corresponds to the normalized compliance function of the lungs open to ventilation. Seven white rabbits were subjected to saline-lavage lung injury, and P-V curves were calculated using the slow inflation technique. We obtained the P-R curve from the P-V curve, and two curves were differently shaped after lung injury. We concluded that the recruitment function was obtained from the P-V curve and that the P-R curve estimated the recruitment and derecruitment status.
authors.affiliation: Department of Rehabilitation, Kameda Medical Center, 929 Higashi, Kamogawa, Chiba, 2968602, Japan. Electronic address: yoshiuzawa@yahoo.co.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uzawa
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 1138655, Japan. Electronic address: mohtsuji-tky@umin.ac.jp.
authors.forename: Mikiya
authors.initials: M
authors.lastname: Otsuji
authors.affiliation: Department of Anesthesiology & Critical Care Medicine, Tokyo Medical & Dental University, 1-1-45 Yushima, Bunkyo-ku, Tokyo 1138519, Japan. Electronic address: nakazawa.mane@tmd.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakazawa
authors.affiliation: Department of Anesthesiology & Critical Care Medicine, Tokyo Medical & Dental University, 1-1-45 Yushima, Bunkyo-ku, Tokyo 1138519, Japan. Electronic address: cnmgfw@hotmail.co.jp.
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.affiliation: Department of anesthesiology, The Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 1138655, Japan. Electronic address: YAMADAY-ANE@h.u-tokyo.ac.jp.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D055371:Acute Lung Injury / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D008170:Lung Compliance / Q000502:physiology; D008176:Lung Volume Measurements; D008962:Models, Theoretical; D011175:Positive-Pressure Respiration / Q000379:methods; D011650:Pulmonary Alveoli / Q000503:physiopathology*; D011817:Rabbits; D015656:Respiratory Mechanics / Q000502:physiology
keywords: ARDS; Alveolar recruitment; Pressure–volume curve