Abstract: Objective  To evaluate the efficacy and safety of different degree of sedation in the treatment of patients with mechanical ventilation.  Methods  405 patients who received  mechanical ventilation over 48 hour from January 2014 to December 2016 in ICU of  the hospital  were enrolled. According to different methods of sedation， the patients were divided into intermittent sedation group (192 patients) and continuous sedation group (213 patients). The patients with continuous sedation were divided into light sedation group (SAS score 23) and deep sedation group (SAS score 45) according to the SAS scores. Each group was given fentanyl for analgesia and propofol or midazolam for sedation. Duration of mechanical ventilation， ICU hospitalization time， total hospitalization time， hospitalization fatality rate and incidence of complications and adverse events were recorded.Results  Compared with the continuous sedation group，the duration of mechanical ventilation  were significantly shorter than the intermittent sedation group(P<0.05). ICU hospitalization time， total hospitalization time， hospitalization fatality rate showed no significant differences between two groups(P>0.05). In the continuous sedation group， with continuous light sedation group compared to continuous deep sedation group， mechanical ventilation time， ICU hospitalization time  and total hospitalization time  were significantly longer and the incidence of VAP  was significantly higher in continuous deep sedation group (all P<0.05).Compared with the last light sedation group for deep sedation group，the mechanical ventilation time and ICU length of hospital stay， the total length of hospital stay and the incidence of VAP were significantly longer in the continuous light sedation group (all P<0.05).Hospital mortality， the incidence of delirium and accidental extubation of two groups had no statistical significance (P>0.05). Conclusion  Intermittent sedation and continuous sedation were feasible during mechanical ventilation， but the incidence of VAP was significantly reduced by continued shallow sedation， shortened mechanical ventilation and ICU hospitalization time.

Key words: respiration, artificial； , conscious sedation；deep , sedation；intensive care units