Objective: Relatively little is known about the use of pulse oximetry in the prehospital setting. The purpose of this study was to determine how emergency medical technicians (EMTs) use pulse oximetry information to influence their decisions regarding the involvement of advanced life support (ALS) personnel in a two-tiered emergency medical services (EMS) system.
Methods: EMTs were trained and authorized to use pulse oximetry in predefined clinical situations. The EMTs completed a questionnaire describing the influence of the oximetry information on their decision making regarding the involvement of ALS units.
Results: The EMTs reported an influence on their decisions whether to involve ALS care in 35 (12%) of 302 cases. The addition of the pulse oximetry information caused the EMTs to request ALS dispatch in 11 cases, to cancel a previously dispatched ALS response in eight cases, and not to request an ALS response from the scene when they otherwise would have requested it in 16 cases.
Conclusion: Prehospital pulse oximetry has a measurable influence on EMT decisions concerning ALS involvement in a two-tiered EMS system. It improves system efficiency by helping to match patients to an appropriate level of care.