OBJECTIVETo study the feasibility, efficiency and any benefits of recruitment maneuver (RM) in the facilitation of lung repair during recovery from ALI in acute lung injury (ALI) model of young piglets.

METHODSThe piglet model of ALI was established by an intravenous injection of lipopolysaccharide (LPS). Twelve ALI piglets were randomly divided into two groups: conventional ventilation (CON) and RM with low tidal volume. Arterial blood gas, dynamic lung compliance (Cdyn) and systematic hemodynamics were monitored during the treatment. TGF-β1 levels in bronchoalveolar lavage fluid (BALF) and plasma were measured. The mRNA expression of TGF-β1 in the lungs was assessed by real time PCR. Lung tissue was examined for morphological changes.

RESULTSNo significant difference was observed in cardiac output and peripheral vascular resistance (PVR) between the two groups. The extravascular lung water index (ELWI) from 6 hrs after ALI inducement and the pulmonary vascular permeability index (PVPI) 8 hrs after ALI inducement in the RM group decreased significantly compared with the CON group. Cdyn in the RM group increased quickly 1 hr after ALI inducement, and there was a significant difference between the two groups (P<0.05). P/F (ratio of PaO2 to FiO2) in the RM group was significantly higher than in the CON group from 2 hrs after ALI inducement (P<0.05). Alveolar-to-arterial oxygen difference in the RM group was obviously lower compared with the CON group from 2 hrs after ALI inducement (P<0.05). The levels of TGF-β1 in plasma and BALF and the mRNA expression of TGF-β1 in the lung tissue were lower than in the CON group. Volume density of alveolar aeration in the RM group was significantly higher than in the CON group, and the injury score in the RM group was lower (P<0.05).

CONCLUSIONSRM can improve gas exchange and Cdyn in the treatment of piglets with ALI. RM is a safe and effective approach to alveolar recruitment and can alleviate ventilation induced lung injury.