Hospital-wide Incidence, Clinical Characteristics and Outcomes of ARDS

The Acute Respiratory Distress Syndrome (ARDS) impacts one of every four patients requiring mechanical ventilation for respiratory support and carries a mortality rate of 40%. To diagnose ARDS, doctors currently use the Berlin definition, that requires chest radiographs and analysis of oxygenation in the blood (arterial blood gas). These tests are not available in areas of the world with constrained resources and may be unnecessarily invasive. A modification of the Berlin definition, using ultrasound and pulse oximetry (a small device that measures oxygen level non-invasively by clipping to the body, typically a finger), has been recently developed and tested in Kigali, Rwanda. This study will try to confirm the validity of the Kigali modification initially in Boston and Toronto and subsequently in other hospitals worldwide. If confirmed, this new definition could allow for faster recognition and potentially improved treatment of patients with ARDS and facilitate studies worldwide. The purposes of this study are: 1. To describe clinical characteristics and outcomes of patients diagnosed with ARDS according to the Berlin and Kigali definitions; 2. To determine how well chest radiograph and ultrasound of the chest are able to define ARDS, in comparison to chest computer tomography (CT).