This chapter deals with protecting ICU patients from their own gastric secretions. The group at greatest risk (over 20-fold) are the mechanically ventilated patients, followed by those with coagulopathy and shock. Broadly, the options include antacids (old-school), sucralfate (also outdated), H2-receptor antagonists and PPIs. Of these, the PPIs appear to have the greatest effect, but the NNT is 37 when comapred to the H2As. Considering the cost of ranitidine is just 1 US cent per tablet, the extra expense is difficult to justify.