Journal of clinical monitoring
-
We evaluated the short-term variability of PaO2, PaCO2, pulse oximeter saturation (SpO2), and end-tidal PCO2 (PETCO2) in mechanically ventilated trauma patients. All patients were stable and undisturbed during the evaluation periods. Blood gases were obtained from an arterial catheter 4 times at 20-minute intervals. ⋯ The variability of PETCO2 was similar to the variability of PaCO2. However, the variability of PaO2 was considerably greater than that of SpO2, which was probably related to the shape of the oxyhemoglobin dissociation curve and the relatively high saturations of the patients in this study. Variability of blood gases, SpO2, and PETCO2 should be considered when these values are clinically interpreted.