[The reliability of pulse oximetry monitoring of arterial oxygen saturation in centrally intubated and hypothermic patients].

The present study tests the effectiveness of pulse oximetric measurement in attaining reliable saturation values even in patients with hypothermia and centralization. 20 patients who had all required endoprosthetic surgery of the lower extremities were included in the study. During the process of removing 98 samples for arterial blood-gas analysis, pulse oximetric saturation, heart rate (pulse oximeter and ECG), rectal temperature, peripheral temperature at the back of the fingers, arterial pressure (catheter) and central venous pressure were registered. The results can be summarized as follows: 1. Acute changes in arterial saturation can be very quickly recognized with the help of pulse oximetry. 2. The reliability of pulse oximetric measurement is, in the area examined, dependent neither on the peripheral nor the rectal temperature, nor on the temperature difference between the core and surface temperature of the body, and, therefore not dependent on the degree of centralization. 3. In the area examined, the reliability of pulse oximetric measurement is influenced neither by blood pressure fluctuations nor by intravascular hypo- or hypervolemia. 4. There is merely a sharp increase in the Pulsoximeter when the temperature decreases. The Pulsoximeter still indicates the correct saturation as long as the peripheral pulse rate corresponds to the heart rate on the ECG Monitor.