Accuracy of pulse oximetry in preterm and term infants is insufficient to determine arterial oxygen saturation and tension.

AIM

Oxygen saturation is frequently monitored with pulse oximetry to assess vital signs in critically ill patients. Optimally, pulse oximetry closely tracks arterial oxygen tension (PaO ), which provides guidance in oxygen titration. We investigated whether monitoring peripheral oxygen saturation (SpO ) could accurately guide oxygen titration in newborn infants.

METHODS

Twenty seven thousand two hundred thirty seven SpO readings were retrospectively paired with arterial oxygen saturation (SaO ) and PaO results from blood gas analyses performed in infants with arterial catheters in place.

RESULTS

SpO overestimated SaO readings by 2.9 ± 5.8%. When pulse oximetry readings were within the defined oxygen saturation target range, 7809 (20.9%) SaO values were below and 2830 (7.6%) exceeded the target range. In 57% of patients, PaO levels < 6 kPa was diagnosed while SpO readings were > 90%. PaO  > 11 kPa was recorded in 19% of cases, when SpO readings were < 95%. Infants treated with supplemental oxygen showed a threefold increased risk of hypoxaemia compared to infants breathing room air. Sensitivity and specificity for detecting upper and lower target range limits were fair to good. For SpO values below 91%, ISO quality criteria were no longer fulfilled.

CONCLUSIONS

Based on arterial blood gas analyses as reference, pulse oximetry readings did not fulfil the performance requirements for titrating oxygen in neonatal patients.