Use of a pulse oximeter in an adult emergency department: impact on the number of arterial blood gas analyses ordered.

STUDY OBJECTIVES To assess the impact of pulse oximetry (SpO2) on the indications and the number of arterial blood gas (ABG) levels ordered in an adult emergency department (ED). DESIGN A prospective study during a 2-month period in 1993 with a pulse oximeter available and a comparison with the same period in 1992 without the oximeter. SETTING An adult medical ED of a university hospital in France. PATIENTS All patients who underwent ABG or SpO2 measurements. INTERVENTIONS During the prospective study, residents ordered ABG or SpO2 measurements at their discretion. The reasons for their ordering were reviewed by two independent experts who determined whether their choice was justified. The data were compared with those for 184 consecutive patients who had ABG measurements in 1992. MEASUREMENTS AND RESULTS The study included 152 patients. SpO2 alone was used in 33 patients; ABG levels were measured in 119 patients. The use of SpO2 did not result in the ordering of fewer useful ABG determinations. One hundred and five (88%) ABG measurements were justified. There were fewer unjustified ABG determinations in 1993 when the pulse oximeter was available than in 1992 when it was not (14 of 119 vs 54 of 184; p<0.001) mainly because fewer ABG determinations were ordered for miscellaneous nonrespiratory indications (13 of 119 vs 43 of 184; p<0.01). CONCLUSION The availability of a pulse oximeter did not affect the ordering of useful ABG measurements but allowed a significant reduction of unjustified ABG measurements. Substantial cost savings could be achieved by using SpO2 in an ED.