Study objective: To demonstrate the utility of pulse oxime

try in detecting clinically unapparent episodes of arterial desaturation in postoperative cardiac surgical patients and to evaluate the effect ofpulse oximetry on ordering arterial blood gas analyses. Design: Prospective, randomized, partially blinded enm parison. Setting: Cardiothoracic surgical intensive care unit. Patients: 35 patients following elective cardiac surgical procedures. interventions: All patients were monitored continuously with pulse oximetry throughout their ICU course. In group 1 patients, the Sp05 data were available at the bedside. In group 2 patients, the SpO, data were masked at the bedside and monitored at a remote location. Measurements and results: Utilization of pulse oximetry allowed a significant reduction in arterial blood gas utili zation in group 1 (group 1: 12.4±7.5 blood gas analyses per ICU admission vs group 2: 23.1±8.8; pO.0007) without adverse events. ClinicaHy unapparent desaturations were detected in 7 of 15 patients in group 2. Conclusions: Pulse oximetry improves patient safety tlu'ough the detection of clinically unapparent episodes of desaturation and can allow a reduction in the number of blood gas analyses utilized without adverse effects to the patient. This may allow a potential cost savings to the patient. (Cheat 1992; 102:1367-70)