Predictive value of dynamic monitoring of transcutaneous blood gas analysis and inflammatory indicators for bronchopulmonary dysplasia in neonatal respiratory distress syndrome

Objective To investigate the predictive value of dynamic monitoring of transcutaneous oxygen partial pressure p_tc(O₂), transcutaneous carbon dioxide partial pressure p_tc(CO₂), serum amyloid A (SAA), and interleukin-6 (IL-6) levels in predicting bronchopulmonary dysplasia (BPD) in neonates with neonatal respiratory distress syndrome (NRDS).

Methods A total of 240 NRDS patients were selected as the research subjects and divided into BPD group (108 cases) and non-BPD group (132 cases) based on whether BPD occurred. The levels of p_tc(O₂), p_tc(CO₂), SAA, and IL-6 were compared between the two groups on the 1st, 7th, and 14th day after birth. Spearman correlation analysis was used to explore the correlation between each indicator and the degree of illness. The relative risk (RR) and 95% confidence interval (CI) were used to evaluate the impact of each indicator on BPD in NRDS patients. Receiver operating characteristic (ROC) curves and decision curve analysis were used to evaluate the predictive efficacy and clinical net benefit of each indicator for BPD.

Results On the 1st day after birth, there were no statistically significant differences in p_tc(O₂), p_tc(CO₂), serum SAA, and IL-6 levels between the two groups (P>0.05). On the 7th and 14th day after birth, the p_tc(O₂) in the BPD group was lower than that in the non-BPD group, while the p_tc(CO₂) and serum SAA, IL-6 levels were higher than those in the non-BPD group (P < 0.05). Correlation analysis results showed that the degree of BPD in children was negatively correlated with p_tc(O₂) on the 7th day after birth (r=-0.724, P < 0.05), and positively correlated with p_tc(CO₂), SAA, and IL-6 on the 7th day after birth (r=0.635, 0.830, 0.715, P < 0.05). The degree of pulmonary dysfunction in children was negatively correlated with p_tc(O₂) on the 7th day after birth (r=-0.719, P < 0.05), and positively correlated with p_tc(CO₂), SAA, and IL-6 on the 7th day after birth (r=0.673, 0.756, 0.696, P < 0.05). On the 7th day after birth, the p_tc(O₂) of BPD patients was negatively correlated with SAA and IL-6 (r=-0.605, -0.623, P < 0.05), while p_tc(CO₂) was positively correlated with SAA and IL-6 (r=0.618, 0.650, P < 0.05). ROC curve showed that the combined prediction of p_tc(O₂), p_tc(CO₂), SAA, and IL-6 on the 7th day after birth for NRDS complicated with BPD was better than the individual prediction of the four indicators, with an area under the curve of 0.938 (95%CI, 0.899 to 0.965). The risk of BPD in high-expression of p_tc(CO₂), SAA, and IL-6 was 2.256, 1.668, and 1.667 times higher than that in low-expression, respectively. The risk of BPD in high-expression of p_tc(O₂) was 0.568 times higher than that in low-expression. The decision curve analysis showed that when the threshold value was within the range of 0.2 to 0.9, the combined model of p_tc(O₂), p_tc(CO₂), SAA, and IL-6 was superior to the individual prediction in predicting the net benefit rate of BPD in NRDS patients on the 7th day after birth.

Conclusion The severity of NRDS complicated with BPD is closely related to p_tc(O₂), p_tc(CO₂), SAA, and IL-6, and the combined detection of the four indicators can help improve the predictive efficacy and net benefit rate of NRDS complicated with BPD.