BACKGROUND Numerous studies have demonstrated the need for increased inspired oxygen with endotracheal suctioning to prevent hypoxemia; however, increased arterial pressure has been reported as a consequence of lung hyperinflation/inflation used to deliver hyperoxygenation. OBJECTIVES To compare insufflation during endotracheal suctioning with a standard procedure of hyperoxygenation using a ventilator on arterial pressure, pulmonary artery pressure, heart rate, arterial oxygen saturation, and blood gases in intubated, mechanically ventilated coronary artery bypass graft patients. METHODS A within-subjects, repeated-measures design was used to measure arterial pressure (systolic, diastolic, and mean), pulmonary artery pressure (systolic, diastolic, and mean), airway pressure, heart rate and rhythm, arterial oxygen tension, arterial carbon dioxide tension, pH, and arterial oxygen saturation during an oxygen insufflation protocol and a hyperoxygenation protocol via the ventilator. RESULTS Using analysis of variance for repeated measures, statistically significant time effects were found for all variables. Statistically significant differences between protocols over time were found for arterial pressure, arterial oxygen tension, and arterial oxygen saturation. CONCLUSIONS Oxygen insufflation resulted in less increase in arterial pressure than did the hyperoxygenation protocol. The hyperoxygenation protocol resulted in hyperoxia. Based on this study, oxygen insufflation is a safe alternative for providing oxygen during endotracheal suctioning.