Pulse oximetry used for documenting oxygen saturation and right-to-left shunting immediately after birth.

The objective of this study was to investigate the clinical applicability of pulse oximetry to measure haemoglobin oxygen saturation and heart rate in the first 20 min of life and to analyse the effect of pre- or post-ductal (hand, respectively, foot) fixation of sensors on oxygen saturation. Measurements were carried out on 53 newborn infants selected at random after delivery by caesarean section. Signal detection occurred significantly faster from the hand (50% after 1.3 min, 90% after 4 min) than from the foot (50% after 3.1 min, 90% after 9 min). Both fixation sites showed equally great sensitivity to motion. The heart rates from pulse oximetry recordings were up to 30% lower than those from ECG recordings. Saturation values from the hand were nearly always higher than those from the foot (median difference in the 5th min was 10%; between the 5th and 10th min it was 7%; no significant difference occurred after the 17th min). We conclude that pulse oximetry can be used for documenting oxygenation and right-to-left shunting in newborn infants during the first minutes of life in spite of limitations due to incomplete pulse wave detection and artifacts.

[Reliability and limitations of pulse oximetry in corrective cyanotic heart surgery]. / Anwendbarketi und Grenzen der Pulsoximetrie bei Korrektur zyanotischer Herzvitien.

The aim of this study was to evaluate the agreement between arterial and pulse oximeter saturation values, especially under hypoxemic conditions, and to test the applicability of the method under routine anesthesia conditions. We studied 13 patients (12 children, 1 adult) with congenital cyanotic heart defects; 12 had a surgical correction during nonpulsatile cardiopulmonary bypass and 1 had a palliative operation. Arterial and pulse oximeter measurements were simultaneously taken and compared during induction of anesthesia, surgery, and in some cases during the postoperative period. Pulse oximeter saturation values were recorded by an Ohmeda Biox 3700 pulse oximeter, and the corresponding arterial saturations determined with a CO Oximeter (OSM2 Hemoximeter, Radiometer). The values lay in the range of 43%-100% arterial oxygen saturation. The results were evaluated while taking into account the steady state and non-steady state situations (i.e., when there were rapidly changing pulse oximetric saturation readings and difficulties in coordinating the comparative arterial measurements time-wise), as well as the equipment's internal characterization of the signal quality (High Quality Signal (HQS)/Low Quality Signal (LQS]. The correlation analysis for all comparative measurements, under both steady state and non-steady state conditions, gave a result of r = 0.927. When the comparison was restricted to the measurements in the steady state conditions, r = 0.935 resulted. The pulse oximetry saturation values had a tendency to lie below the corresponding arterial values. The fact that the pulse oximetry values were designated with HQS or LQS was no indication of a better or worse correlation with the arterial value.(ABSTRACT TRUNCATED AT 250 WORDS)