IMPACT OF PORTABLE PULSE OXIMETRY ON ARTERIAL BLOOD-GAS TEST ORDERING IN AN URBAN EMERGENCY DEPARTMENT

Study objective: To determine the impact of portable pulse oximetry on physician use of arterial blood gas tests (ABGs) in an urban emergency department. Design: Prospective, controlled clinical trial. Setting: The ED of the Regional Medical Center at Memphis, a publicly subsidized, 450-bed, acute care hospital staffed by residents and faculty of the University of Tennessee, Memphis. Type of participants: Rotating housestaff treating adult ED patients with a wide variety of medical and surgical problems. Intervention: Introduction of a portable pulse oximeter for noninvasive measurement of blood oxygenation. Measurements: Rates of ABG test ordering, housestaff reason(s) for ordering an ABG, and the incidence of adverse clinical outcomes before and after introduction of portable pulse oximetry. Main results: A total of 20,120 patient visits occurred during the four-month study. Before oximeter introduction, emergency physicians ordered 699 ABGs, 63% of which were indicated by explicit criteria. After oximeter introduction, 440 ABGs were ordered (a 37% decrease). Almost all of this decrease was due to fewer ABGs ordered to assess oxygenation (260 before vs 75 after; chi-2, P < .001). These reductions were not explained by differences in total patient visits or case mix. Physicians decreased ordering of indicated ABGs by almost as great an extent as they reduced ordering of unindicated tests, suggesting they did not consistently distinguish between the two. However, decreased testing did not result in any serious adverse outcomes, defined as unanticipated respiratory or cardiac arrest in the ED, unanticipated arrest on the floor within 24 hours of admission, or death within two days of hospital discharge. Conclusion: Portable pulse oximetry can provide a simple, noninvasive way to determine oxygen saturation in the ED. Routine use of portable pulse oximetry may substantially reduce rates of ABG testing and associated patient charges without adversely affecting the quality of emergency care. [Kellerman AL, Cofer CA, Joseph S, Hackman BB: Impact of portable pulse oximetry on arterial blood gas test ordering in an urban emergency department. Ann Emerg Med February 1991;20:130-134.]