Proton Pump Inhibitors vs. Histamine-2 REceptor Blockers for Ulcer Prophylaxis Therapy in the Intensive Care Unit

INTERVENTION: Study treatment is open label Proton Pump Inhibitors (PPIs) vs. Histamine‐2 Receptor Blockers (H2RBs) as the default routine therapy for ulcer prophylaxis. Each study ICU will use PPIs or H2RBs as routine therapy for a period of six months. At the end of this six month period, the ICU will then swap to the opposite routine ulcer prophylaxis strategy which will then be used for the next six months. The specific PPI or H2RB, dose, mode of administration and duration of study treatment will be the individual ICU clinician’s decision or until the patient is discharged from ICU (whichever is shorter). The PPI and H2RBs will be given as per routine medication (usually by the ICU nurse). Study treatment will only be administered in situations where the treating clinician believes ulcer prophylaxis is in the patient’s best interests and, irrespective of the treatment assigned to the ICU, either a PPI or an H2RB can be used for an individual patient, if the treating clinician believes that a particular treatment is indicated. Intervention adherence will not be checked for individual patients; however once a month, at a set time, stress ulcer prophylaxis use will be recorded for all mechanically ventilated patients. CONDITION: Critical illness Mechanical ventilation Ulcer prophylaxis PRIMARY OUTCOME: In‐hospital mortality SECONDARY OUTCOME: Clostridium difficile infection rates. ; Clostridium difficile infections are defined as toxin‐positive or culture‐positive stool samples collected during an ICU admission (excluding any patients who had positive tests from specimens collected prior to ICU admission). Hospital length of stay, which will be obtained from the ANZICS APD. Hours of mechanical ventilation (where available) ICU length of stay, which will be obtained from the ANZICS APD. Upper gastrointestinal bleeding (new clinically significant upper GI bleeding developing as a complication in ICU). ; Clinically significant upper GI bleeding is defined as: overt GI bleeding (eg. haematemesis, malaena or frank blood in the nasogastric tube or upper GI endoscopy) ; AND 1 or more of the following features within 24 hours of GI bleeding: 1) spontaneous drop of systolic, mean arterial pressure or diastolic blood pressure of 20 mmHg or more, 2) start of vasopressor or a 20% increase in vasopressor dose 3) decrease in haemoglobin of at least 20 g/L or 4) transfusion of 2 units of packed red blood cells or more). ; INCLUSION CRITERIA: All patients aged 18 years or older who are mechanically ventilated within 24 hours of ICU admission.