Current oxygen management in mechanically ventilated patients: A prospective observational cohort study

Purpose: Oxygen (O-2) is the most common therapy in mechanically ventilated patients, but targets and dose are poorly understood. We aimed to describe current O-2 administration and titration in such patients in an academic intensive care unit. Materials and Methods: In consecutive ventilated (> 48 hours) patients we prospectively obtained fraction of inspired O-2 (FIO2), pulse oximetry O-2 saturation (SpO(2)) and arterial O-2 tension (PaO2) every 6 hours. We calculated the amount of excess O-2 delivery and the intensivists' response to hyperoxemia (SpO(2) > 98%). Results: During 358 mechanical ventilation days in 51 critically ill patients, median calculated excess O-2 delivery was 3472 L per patient. Patients spent most of their time with their SpO(2) > 98% (59% [29-83]) and PaO2 between 80 and 120 mm Hg (59% [38-72]). In addition, 50% of all observations showed hyperoxemia and 4% severe hyperoxemia (PaO2 > 202.5 mm Hg). Moreover, 71% of the calculated total excess 263,841 L of O-2 was delivered when the FIO2 was 0.3 to 0.5. When hyperoxemia occurred with an FIO2 between 0.3 and 0.4, for 88% of episodes, no FIO2 adjustments were made. Conclusions: Excess O-2 delivery and liberal O-2 therapy were common in mechanically ventilated patients. Current O-2 therapy practice may be suboptimal and further investigations are warranted. (C) 2013 Elsevier Inc. All rights reserved.