Continuous oxygen saturation monitoring during cardiac catheterization in adults.

Arterial hypoxemia may contribute to morbidity during cardiac catheterization. Therefore, we measured arterial hemoglobin oxygen saturation (SaO2) continuously using pulse oximetry in 29 patients (age range, 21 to 83 years) undergoing cardiac catheterization. Baseline SaO2 was 96 +/- 0.4 percent. All patients had a decrease in SaO2 at some time during the procedure. Eleven patients (38 percent) had episodes of arterial hypoxemia, defined as a decrease in SaO2 below 90 percent. In these 11 patients, the mean number of episodes of hypoxemia was 16 +/- 7, and the mean duration of each episode was 53 +/- 25 seconds. Multiple stepwise regression analysis showed that the minimum SaO2 during catheterization for any patient was significantly associated with the baseline SaO2, duration of the procedure, and end-diastolic volume (EDV) as described by the following regression equation: minimum SaO2 = 46.8 - 0.0580 (duration of procedure in minutes) + 0.5362 (baseline SaO2) - 0.0159 (EDV). Based on our finding of arterial hypoxemia in greater than one third of our patients, we would consider continuous SaO2 monitoring or supplemental oxygen during cardiac catheterization, especially for those patients with poor ventricular function or low resting SaO2 or those expected to have long procedures.