Pulse Oximetry as a Fifth Vital Sign in Emergency Geriatric Assessment

Abstract. Objective: To determine the utility of pulse oximetry as a routine fifth vital sign in emergency geriatric assessment.
Methods: Prospective study using pulse oximetry to measure O₂ saturation in geriatric patients presenting to ED triage. Saturation values were disclosed to clinicians only after they had completed medical evaluations and were ready to release or admit each patient. The authors measured changes in medical management and diagnoses initiated after the disclosure of pulse oximetry values. The study included 1,963 consecutive adults aged ≤ 65 years presenting to triage at a university ED. Measurements included changes in select diagnostic tests: chest radiography, complete blood count (CBC), spirometry, arterial blood gases (ABGs), pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, β-agonists, and supplemental O₂; and hospital admission and final diagnoses that occurred after complete ED evaluation when physicians were informed of triage pulse oximetry values.
Results: 397 (20.2%) geriatric patients had triage pulse oximetry values <95%. Physicians ordered repeat oximetry for 51 patients, additional chest radiography for 23, CBC for 16, ABGs for 15, spirometry for 5, and ventilation-perfusion scans for none. Physicians ordered 49 new therapies for 44 patients, including antibiotics for 14, supplemental O₂ for 29, and 3-agonists for 6. Nine patients initially scheduled for ED release were subsequently admitted to the hospital. Physicians changed or added diagnoses for 27 patients.
Conclusions: Using pulse oximetry as a routine fifth vital sign resulted in important changes in the diagnoses and treatments of a small proportion of emergency geriatric patients.