Emergency Medical Services Resolution of Hypoxemia

About this Research Project

Authors: Ryba, C¹, ²; Wilson, SM³; Brook, M⁴,⁵,⁶; Baker, GL³; Green, A⁷; Page, D⁸; Aufderheide TP⁹

¹Department of Emergency Medicine, University of Utah Health, Salt Lake City, Utah; ²Salt Lake City Fire Department, Salt Lake City, Utah; ³Department of Emergency Healthcare, Dumke College of Health Professions, Weber State University, Ogden, UT; ⁴Gouverneur Rescue, Gouverneur, NY; ⁵University of Vermont Health Network, Elizabethtown Community Hospital, Elizabethtown, NY; ⁶Department of Emergency Medicine- EMS Education, SUNY Upstate Medical University, Syracuse NY; ⁷Clinical & Research Services, ImageTrend Inc., USA; National EMS Quality Alliance, USA.; ⁸Allina Health EMS, Minneapolis, MN; ⁹Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI

Background

We evaluated emergency medical services (EMS) resolution of hypoxemia.

Methods

A retrospective review of the national ImageTrend Collaborate database from January 1, 2022, to December 31, 2022. Inclusion criteria: 911 EMS patients transported to an emergency department (ED), adults (≥ 18 years old), a primary or secondary impression of Respiratory Distress, an initial SPO2≤89%, and at least 2 documented SPO2 values. Cardiac arrest prior to EMS arrival was excluded. The first and last SPO2 values were compared to determine the resolution of hypoxemia, based on the Airway Measure Guidelines by the National Association of EMS State Officials, defined as an SPO2 ≥ 90%.

Results

Out of 5,095,330 adult patients, 71,792 met inclusion criteria; median age was 71.0 (Interquartile Range:61,80) years; 36,600(51.0%) were female; race distribution was Black: 9,890(13.8%), Hispanic/Latino: 2,860(4.0%), White: 43,161(60.1%), Other: 2,740(3.8%), and Missing Data: 13,141(18.3%). Successful resolution of hypoxemia occurred in 55,133(76.8%) and did not resolve in 16,659(23.2%). Overall, 826(1.2%) patients had subsequent cardiac arrest; 260/826 (31.5%) had resolution, and 566/826 (68.5%)had no resolution of hypoxemia, p<0.0000001. Of 150/826(18.2%) cardiac arrest patients who died in the field or ED, 30/150(20.0%) had resolution and 120/150(80%) no resolution of hypoxemia, p<0.0000001; Odds of death in the field or ED after cardiac arrest with unsuccessful resolution of hypoxemia was OR:15.74, CI: 9.06,28.24.

Conclusion

EMS treatment of hypoxemia did not achieve guideline standards for resolution in 23.2% of cases. Unsuccessful EMS resolution of hypoxemia was significantly associated with a higher proportion of subsequent cardiac arrest and odds of death in the field or ED.