Fig 1.
Representative respiratory tracings.
Representative respiratory tracings of airway pressure(Paw), esophageal pressure (Pes), intragastric pressure (Pgas),transpumonary pressure (PL),Airflow、abdominal muscles surface electromyography (EMGab)and diaphragmatic esophageal surface electromyography (EMGdi) in BIPAPSB,BIPAPAP group in representative animals. BIPAPSB = biphasic positive airway pressure with SB; BIPAPAP = biphasic positive airway pressure with abdominal muscles paralysis.
Fig 2.
Time course of the dead space volume to tidal volume (VD/VT) ratio in experimental groups (n = 6 per group). BIPAPSB = biphasic positive airway pressure with SB; BIPAPAP = biphasic positive airway pressure with abdominal muscles paralysis; SB = spontaneous breathing; *P < 0.05, vs. other groups.
Fig 3.
Time course of the end- expiratory lung volume (EELV) in experimental groups (n = 6 per group). BIPAPSB = biphasic positive airway pressure with SB; BIPAPAP = biphasic positive airway pressure with abdominal muscles paralysis; SB = spontaneous breathing; *P < 0.05, vs. other groups.
Table 1.
Respiratory Measurements.
Fig 4.
The Levels of IL-6 and IL-8 in plasma and the mRNA expression levels in the lung tissue.
The Levels of interleukin (IL)-6 and IL-8 in plasma (*P < 0.05 vs. other groups) and the messenger RNA (mRNA) expression levels of IL-6 and IL-8 in the lung tissue after 8h mechanical ventilation (*P < 0.05 vs. control group; #P < 0.05 vs. BIPAPAP group;). BIPAPSB = biphasic positive airway pressure with SB, n = 6; BIPAPAP = biphasic positive airway pressure with abdominal muscles paralysis, n = 6; SB = spontaneous breathing; NS = no significantly difference;
Fig 5.
Histopathological examination.
Representative appearances and photomicrographs of hematoxylineosin–stained lung sections (magnification ×200) from control group (A, n = 6), BIPAPSB = biphasic positive airway pressure with SB (B, n = 6), and BIPAPAP = biphasic positive airway pressure with abdominal muscles paralysis (C, n = 6).The control group had minimal alveolar congestion, and inflammatory cell infiltration. The BIPAPAP group showed mild thickening of the alveolar walls, alveolar congestion, and hemorrhage. In the BIPAPSB group, inflammatory cell infiltration, thickening of the alveolar walls, alveolar congestion, and more prominent hemorrhagic areas were observed.
Table 2.
Histological subscores in experimental groups.