Pulse Oximetry: An Alternative Method for the Assessment of Oxygenation in Newborn Infants

Abstract

Continuous monitoring of oxygenation in sick newborns is vitally important. However, transcutaneous Po₂ measurements have a number of limiations. Therefore, we report the use of the pulse oximeter for arterial oxygen saturation (Sao₂) determination in 26 infants (birth weights 725 to 4,000 g, gestational ages 24 to 40 weeks, and postnatal ages one to 49 days). Fetal hemoglobin determinations were made on all infants and were repeated following transfusion. Sao₂, readings from the pulse oximeter were compared with the Sao₂ measured in vitro on simultaneously obtained arterial blood samples. The linear regression equation for 177 paired measurements was: y = 0.7x + 27.2; r = .9. However, the differences between measured Sao₂ and the pulse oximeter Sao₂ were significantly greater in samples with > 50% fetal hemoglobin when compared with samples with < 25% fetal hemoglobin (P < .001). The pulse oximeter was easy to use, recorded trends in oxygenation instantaneously, and was not associated with skin injury. We conclude that pulse oximetry is a reliable technique for the continuous, noninvasive monitoring of oxygenation in newborn infants.