Comment

Active ulcer bleeding can usually be stopped by therapeutic endoscopy but 15–20% of patients rebleed, usually within the first 24 hours. The rebleeding rate is similar for all endoscopic haemostatic modalities1 and combinations of endoscopic treatments are little better than single modalities.2 Patients who rebleed have a high risk of dying. Rebleeding occurs as the blood clot which is formed over the arterial defect within the ulcer base is either dislodged or dissolves. It is clear that blood clot stability is dependent on intragastric pH and below 5, clot lysis occurs due to the combined effects of trypsin and acid.3 A pH greater than 6 is necessary for optimum platelet aggregation. Thus powerful acid suppressing drugs by stabilising the arterial plug have the potential to reduce rebleeding rates and thereby improve prognosis.

In 1992 Daneshmend and colleagues4 reported an extremely large randomised trial in which patients presenting acutely with gastrointestinal bleeding were administered intravenous boluses of omeprazole or placebo. The major end points of rebleeding and mortality were similar in both groups. This influential study persuaded the gastrointestinal community that omeprazole should not be used indiscriminately in all patients presenting with upper gastrointestinal bleeding. This conclusion is undoubtedly correct but it may not follow that acid suppressing drugs have no role in subgroups of patients. Eighty per cent of patients who present with acute gastrointestinal bleeding have an excellent prognosis without any type of intervention while at the other end of the spectrum a minority of patients will inevitably do badly because of massive bleeding or are unlikely to respond …