Pulse Oximetry in Very Low Birth Weight Infants With Acute and Chronic Lung Disease

Abstract

With improved survival of very low birth weight infants, the incidence of bronchopulmonary dysplasia has significantly increased. Pulse oximetry appears to be an adequate alternative to transcutaneous Po₂, for continuous arterial oxygen saturation (Sao₂) monitoring in neonates; however, its usefulness has not been very well documented in very low birth weight infants. We studied 68 patients with birth weight < 1,250 g; 44 neonates had respiratory distress syndrome and 24 had bronchopulmonary dysplasia. Using a Nellcor N-100 pulse oximeter, we compared transcutaneous oxygen saturation with simultaneous arterial samples analyzed for Sao₂ (range 78% to 100%) using an IL 282 co-oximeter. Fetal hemoglobin was measured in 66 patients. We also evaluated the accuracy of transcutaneous Po₂ in reflecting arterial Po₂ in patients with bronchopulmonary dysplasia. Over a wide range of Po₂, Pco₂, pH, heart rate, BP, hematocrit, and fetal hemoglobin, linear regression analysis revealed a close correlation between pulse oximeter values and co-oximeter measured Sao₂ in patients with acute (r = .88, Y = 19.41 + 0.79X) and chronic (r = .90, Y = 9.72 + 0.92X) disease. Regression analysis of transcutaneous v arterial Po₂ in infants with bronchopulmonary dysplasia showed an r value of .78. In addition, in these patients with chronic disease, the mean difference between pulse oximeter Sao₂ and co-oximeter measured Sao₂ was 2.7 ± 1.9% (SD); whereas the mean difference between transcutaneous and arterial Po₂ was -14 ± 10.7 mm Hg.

Our findings indicate that pulse oximetry can be used reliably in very low birth weight infants with acute and chronic lung disease, for Sao₂ values greater than 78%. This technique is more advantageous than transcutaneous Po₂ in infants with bronchopulmonary dysplasia. Additional studies are needed to evaluate the performance of the pulse oximeter in tiny infants with Sao₂ values < 78%.