A total of 100 newborns (51 male / 49 female; 12 twins) were enrolled in the study,
86 delivered by elective CS and 14 delivered by emergency CS.
7 infants were admitted to the NICU in the first hours of life for respiratory distress and treated with nCPAP for at least 24 hours.
The mean time point of the first clinical and echographic evaluation (T0) was 14,4 ± 0,2 minutes (range: 6 - 28 minutes).
Gestational age was between 33w+6d and 41w+4d (mean GA 38w+2d ± 1w+6d): 86 infants were full-term (GA ≥ 37 weeks) and 14 infants were late preterm (GA ≥ 33w+6d and ≤ 36w+6d).
85 infants had a birth weight >2500 gr and 15 infants <2500 gr; 20 were classified as having IUGR (birth weight <10°perc for gestational age).
16% of pregnancies were complicated by gestational diabetes,
but none of the children born to diabetic mothers was admitted to the NICU.
Demographic characteristics and clinical features of the study population are summarized in tables 1 and 2.
Among the demographic characteristics only BW was significantly related to the admission to the NICU (p:0,001); GA,
type of CS and presence of gestational diabetes were not significantly associated to hospitalization.
At T0 22 infants (22%) showed clinical signs of respiratory distress,
18 were treated with free-flow O2 in the incubator and,
among these,
5 infants were hospitalized for worsening of the respiratory status.
Other 2 neonates,
without significant symptoms at T0,
developed respiratory distress later and were admitted to the NICU.
We found significant correlation between admission to the NICU and Sat-O2 at T0 (p:0,002),
and presence of clinical signs of distress at T0 (p:0,005).
LUS evaluation:
Results of the LUS assessment are summarized in table 3.
At T0 patients were classified as follows: 5 Profile A,
6 Profile B,
62 Profile C,
10 Profile D and 17 Profile E.
All infants classified as Profile A were admitted to the NICU and treated with nCPAP for at least 24 hours; only one patient with Profile B and one with Profile C were hospitalized.
We found a significant association between admission to the NICU and the LUS score at T0 (p: 0,002).
Subsequently the significant variables in the univariate analysis were put in the multivariate analysis,
excluding BW that is influenced by the presence of late preterm infants.
We found that a LUS score ≥ 2,5 (Profiles A and B) was the only variable significantly associated with the admission to the NICU,
with a sensitivity of 85,7% and specificity of 94,6%; the corresponding PPV and NPV were 54,5% and 98,9%.
Since all false positives were Profiles B,
we recalculated sensitivity and specificity considering as true positives only infants with Profile A,
that showed a sensitivity and specificity respectively of 100% and 71,4% in predicting admission to the NICU for respiratory distress,
with corresponding PPV and NPV respectively of 100% and 97,8%; thus Profile A at T0 is strongly associated with hospitalization.