6OJIAKO K, SHINGALA H, SCHORR C, et al. Famotidine ver- sus pantoprazole for preventing bleeding in the upper gastrointesti- nal tract of critically ill patients receiving mechanical ventilation [J].Am J Crit Care,2008,17(2) : 142 -147.
7HIGGINS JPT, GREEN S. Assessing risk of bias in included studies : cochrane handbook for systematic reviews of interventions 5.1.0. [EB/OL]. (2011 -03) [2012 -09 -06]. http:// www. cochrane-handbook org html.