Objective To evaluate the relationship between the pH value change of gastric fluid and the prognosis in critical patients and to provide the principle for early intervention measurements.Methods The gastric fluid was got through gastric tube,the change of pH value was dynamically measured by using the pH test value paper in 120 critical patients who were randomly selected.Results (1) Between the survivor group and the death group,the value of gastric fluid pH and other indictors had significant differen...