The nurse is caring for a client with acute respiratory distress syndrome (ARDS) secondary to a chest injury. The client has crackles in the bilateral posterior lung fields, tachycardia, delayed capillary refill, decreased urine output, and the following arterial blood gas (ABG) results: pH 7.56, PaO2 51, PaCo2 58, HCO3 24, SaO2 76%. Which is the healthcare team's priority?