THE USE OF PULSE OXIMETRY IN THE PREVENTION OF HYPEROXAEMIA IN PRETERM INFANTS

When deciding an appropriate upper limit for pulse oxygen saturation ( SpO(2)) in preterm infants the usefuleness of current data is limited by the fact that previous studies have examined a population of more m ature infants and children or have applied various exclusion criteria which produce results unrepresentative of clinical practice. We tested the hypothesis of previous workers that maintaining the SpO(2) below 98% would ensure an arterial oxygen tension (PaO2) less than 12 kPa. A total of 477 simultaneous measurements of PaO2 and SpO(2) were made u sing Ohmeda Biox oximeters on 43 infants who were less than 33 weeks g estation and receiving supplementary oxygen. Of 435 measurements perfo rmed when the SpO(2) was 97% or less, 26 (6%) had a PaO2 greater than 12kPa. Further examination of the data showed that of 108 estimations performed when the SpO(2) was less than 94%, none had a PaO2 greater t han 12kPa. Conclusion When using Ohmeda Biox pulse oximeters an upper limit of 97% for SaO(2) is not effective in preventing hyperoxaemia; h owever, a limit of 93% is likely to maintain the PaO2 below 12kPa.