A meta analysis on the effect of different angle of bed elevation for patients with mechanical ventilation

Objective To evaluate the clinical effect of different angle of bed elevation for patients with mechanical ventilation. Methods CNKI, CBM, WanFang Data, Cochrane Library, PubMed, and Web of Science were searched for randomized controlled trials(RCTS) of bed head elevation for patients with mechanical ventilation.The citation tracking and manual retrieval was carried out and the retrieval date was as of June 2, 2016.The documents were screened by two reviewers according to the inclusion and exclusion standards.The quality of documents was strictly assessed and the data was extracted, stata SE12.0 software was used for the Meta analysis of the qualified studies. Results 961 records were obtained by searching, and 17 RCTs were included, among which there were 3 English literatures and 14 Chinese literature Meta analysis results showed that compared with a bed elevation of less than 30 degrees, a bed elevation of degree between 30 to 45 degrees can significantly reduce the incidence of ventilator-associated pneumonia (ventilator associated pneumonia, VAP)〔OR=0.33, 95%CI (0.27, 0.41)〕, and can shorten the duration of mechanical ventilation 〔SWD=-3.65, 95%CI(-4.90, -2.40)〕and ICU hospitalization time 〔SWD=-2.95, 95%CI(-4.05, -1.85)〕and can reduce the mortality〔OR=0.62, 95%CI(0.44, 0.87)〕. The sub-analysis results showed that compared with a bed elevation of 30 to 45 degrees, a bed elevation of 45 degrees semireclining position showed no obvious significance in improving patients' clinical outcomes, but can reduce the patients' comfort and increase the incidence of pressure ulcers. Conclusions 30 to 45 degrees semireclining position can not only reduce the incidence of VAP, but also shorten the mechanical ventilation time and ICU length of stay, meanwhile, it can reduce the mortality rate, hence it is recommended to promote clinical application. Key words: Bed elevation; Semireclining position; ICU; Mechanical ventilation; Meta analysis