Discussion
We modified the LUS scanning method and developed a simplified assessing system(based on ”high-risk” image patterns) to predict respiratory support need for the first time. As far as we know, this system is practical and useful in obstetrics and gynaecology hospital that need to identify infants with potential lung diseases in several hours right after birth. It can help physicians to pick up these potential patients before their respiratory symptoms deteriorated and chest X-ray applied so that physicians can implement NICU cares earlier.
Findings and interpretation: This study has two clinically relevant findings. (1) There are four ”low-risk” patterns and two ”high-risk” patterns can be found in late-preterm or term infants right after birth. Even if two of ”low-risk” patterns, ”moderate discrete B-line” pattern and ”abundant discrete B-line”, was reported to be pathological in previous studies27-28, our study shows they can be seen as strong evidence of healthy infants right after birth. This ddiscrepancy may be because these two patterns are only the result of the delay of lung fluid clearance. This delay make a small amount of alveoli uninflated and full of fluid29-31but not enough to cause TTN. (2) Two ”high-risk” patterns have high predictive reliability for respiratory support need. These two patterns are also regarded as evidence of other diseases, such RDS15, MAS8 and pneumonia32. This concordence indicated that our findings of ”high-risk” patterns are high likely to be a early stage of RDS or MAS, especially when infants just have mild respiratory symptoms.
Because of the total ten scanning regions, the number of regions with ”high-risk” reversely relate to those with ”low-risk” patterns. Thus ROC of ”low-risk” patterns can support the predictive reliability of ”high-risk” patterns.