Knowledge of oxygen saturation and the timing of nursing interventions were studied for their relationship to positive patient outcomes in a group of patients receiving intravenous conscious sedation during endoscopy. The convenience sample consisted of 38 patients receiving midazolam or a combination of midazolam/fentanyl during esophagogastroduodenoscopy or colonoscopy in a hospital-based endoscopy unit. Data collection included monitoring oxygen saturation levels, physiological parameters, and skin color. Baseline arterial oxygen saturation was obtained and monitored continuously throughout the procedure and during the recovery period. During the procedures, the nurse was aware of the oxygen saturation levels for half of the subjects. For the other subjects, the nurse was informed only when the oxygen saturation dropped below 85%. Data revealed a clinically significant relationship between knowledge of oxygen saturation and the timing of nursing interventions in effecting positive patient outcomes during endoscopic procedures. The results of this pilot study contributed to the development of standards of care for monitoring oxygen saturation in an endoscopy unit. The timeliness of nursing interventions was enhanced by the use of pulse oximetry, thereby producing positive patient outcomes and improving the quality of care for the endoscopic patient receiving conscious sedation.