Abstract: [Abstract]  Objective   To study the effect on intragastric pressure and digestive function by different mechanical ventilation modes and parameters. Method   The authors selected 40 inpatients from Janurary,2007 to June,2009 who suffered respiratory failure to carry out a prospective study. In different modes and parameters of mechanical ventilation, a multi-channel physiological signal recording device was used to monitor the patients with intra-trachea pressure(ITP), intra-gastric pressure(IGP) synchronously, as well as the emptying time of stomach, PH value and totle bile acid(TBA) concentration in gastric fluid. Result   First, no matter which type of ventilation mode or PEEP parameters was selected, as long as lower ITP, can reduce IGP. The highest IGP was found in CMV group(P<0.01) from the three various of ventilation mode(P<0.01), as well as in PEEP10 group from the three PEEP settings(P<0.01). Second, under mechanical ventilation support, when ITP increased, emptying time of stomach decreased (P<0.01), so as concentration of TBA (P<0.05). However, there was no significant change in PH of gastric fluid(P>0.05). Conclusion   Various mechanical ventilation modes and parameter settings induced different ITP, thereby affecting the IGP and gastric emptying. Maybe we can promote digestive function by choosing the appropriate mechanical ventilation mode and parameters.

Key words: Intra trachea pressure, intra-abdominal hypertension, Intragastric pressure