(1394) Reducing Hyperoxemia in Mechanically Ventilated ED Patients: A Before-and-After Study

Introduction: Hyperoxemia has been associated with worse outcomes in critically ill patients, even when the duration of exposure is brief. In the ED, initial fraction of inspired oxygen (FIO2) is often set to 100% leading to high risk for hyperoxemia. This study aimed to create a simple guideline for ED providers and nurses to safety titrate ventilator FIO2 to reduce exposure to hyperoxemia.

Methods: This quality improvement (QI) project and before-and-after study was conducted in the ED of an urban academic medical center and Level 1 trauma center. All adult patients receiving mechanical ventilation in the ED with ABG measured were included. The intervention comprised of a clinical guideline and educational program targeting ED physicians and nursing staff. The guideline, which included an algorithm for nurses and physicians to adjust FIO2 based on SpO2 and PaO2 was emailed, posted to the institution’s online clinical algorithms page, and attached to ED ventilators. The education program included emails and brief ( < 5min) presentations at ED morning huddle 2-3x/week for 4 weeks. Data were collected over a 15-month period with 6 months pre-intervention (03/15/2023-09/15/2023) and 6-months post-intervention (12/15/2023-06/15/2024) with a 3-month washout period. The primary outcome measure was incidence of severe hyperoxemia (PaO2>300 mmHg) during ED stay and 6 hours after hospital admission. The safety outcome was incidence of hypoxemia (PaO2 < 55 mmHg). Data were extracted from the electronic health record.

Results: 1586 patients were included in the study, with 890 in the pre-intervention group and 696 in the post-intervention group. The incidence of severe hyperoxemia decreased significantly from 42.1% in the pre-intervention group to 34.8% in the post-intervention group (p=0.003). The incidence of hypoxemia increased from 6.6% to 10.5% (p=0.006).

Conclusions: Severe hyperoxemia is common, affecting over a third of mechanically ventilated patients in the ED. A QI and educational initiative reduced exposure to severe hyperoxemia, but was associated with an increase in hypoxemia. Time of year of data collection and seasonal respiratory illness may be a significant confounder. Future work will focus on sustainability of the intervention, further investigation of safety, and linking with clinical outcomes.