Commonly employed medications used in critically ill patients requiring life support include proton pump inhibitors (PPIs). These medications are thought to prevent gastrointestinal (GI) bleeding from stress-induced ulceration. Despite their widespread use, they do hold some risks which include infection in the form of pneumonia and diarrheal illnesses such as Clostridioides difficile infection (C. difficile). Emerging high-quality studies suggest PPI usage does not influence susceptibility to COVID-19 infection, however some studies suggest PPI use leads to poor outcomes in this population, including prolonged time on life-support and death. While we can appreciate the negative effects of PPI may be magnified in the sickest of patients, namely hospitalized patients with COVID-19, the beneficial or potentially harmful role they play in this population remains unclear. We aim to build a clinical profile to further describe critically ill patients with COVID-19 in Ontario using the infrastructure of an ongoing multicenter clinical trial of acid suppression. We will identify characteristics that predict poor outcomes among sick COVID patients, examining the impact of PPIs on this population.