Objective: This study used near-infrared spectroscopy (NIRS) to detect the pulmonary regional oxygen saturation (rSO2) of premature infants. The oxygenation state of the lung tissue was also evaluated, which provided preliminary evidence regarding the application of NIRS in oxygen therapy for premature infants.Methods: NIRS was used to measure the pulmonary rSO2 of 26 premature infants (gestational age <32 weeks). The correlations between pulmonary rSO2 and the arterial partial pressure of oxygen (PaO2), arterial oxygen saturation (SaO2), and pulse oxygen saturation (SpO2) were analyzed. The diagnostic value of NIRS was evaluated via both Pearson's correlation and receiver operating characteristic (ROC) curve analyses.Results: Pulmonary rSO2 was positively correlated with both PO2 and SaO2; the linear correlation coefficients (r) were 0.544 (p = .004) and 0.515 (p = .007), respectively. No significant correlation was found between rSO2 and SpO2 (p = .098). SpO2 was positively correlated with PO2 (r = 0.402, p = .042) and SaO2 (r = 0.625, p = .001). NIRS could be used to predict hypoxemia (area under the curve [AUC] = 0.843; Youden's index =0.654) when the pulmonary rSO2 was 62.39%, the sensitivity was 88.9%, and the specificity was 23.5% (p = .005) as well as predict hyperoxemia (AUC = 0.775; Youden's index = 0.65) when the pulmonary rSO2 was 61.99%, the sensitivity was 100%, and the specificity was 35% (p = .045). SpO2 predicted hypoxemia (AUC = 0.784, p = .019) but not hyperoxemia (AUC = 0.7, p = .144).Conclusion: NIRS objectively reflects the changes in oxygenation in the lung tissue. This study provides evidence for the clinical application of NIRS.
Keywords: Blood gas analysis; near-infrared spectroscopy; premature infants; pulmonary regional oxygen saturation.