LUS findings
Details about LUS features in acutely ill children are described in Table 4. Table 4 shows, in particular the differences, of the ultrasound features among acutely ill children , healthy infants and children with bronchiolitis.
Short vertical artifacts were found in 100% of patients with bronchiolitis and are present in 21.3% of healthy infants. According to the data published by our study on the analysis of the ultrasound pattern of healthy infants, short vertical artifacts are present during the first 3 months of life in all lung regions and with the passing of the months their presence decreases.2 In contrast, in our study population (acutely ill children ), no patient presented short vertical artifacts, thus with a significant statistical difference (p <0.001) compared to bronchiolitis and healthy patients.
Long vertical artifacts are present in 100% of acutely ill children with a statistically significant difference (p <0.001), particularly compared to healthy patients.
But what is more important, regarding long vertical artifacts, for the qualitative and / or semi quantitative analysis of sonographic interstitial syndrome7,8,10,25 are the differences - in the three groups of patients - of the characteristics and distribution of long vertical artifacts in the different lung fields.
In particular
- 100% of acutely ill patients have multiple long vertical artifacts with a significant difference (p <0.001), particularly compared to healthy patients who have single long vertical artifacts in 70.6% of cases.
- Multiple vertical artifacts are 91.3% non-confluent inacutely ill children with a statistically significant difference (p <0.001) compared to the other two groups.
- We found that in acutely ill children , the distribution of long vertical artifacts occurs both ”without spared areas” (52.17% of cases) and ”with spread areas” (47.83%). On the contrary, in 61% of healthy patients and in 100% of patients with bronchiolitis, they distribute “with spared areas” in a less homogenous and more densely-packed way. Therefore, also for this ultrasound results, we found statistically significant differences (p <0.001).
- Another important result concerns the different distributions of long vertical artifacts in the different lung fields explored, which is statistically significant (p <0.001) in the three groups of patients: in acutely ill children , we found a distribution predominantly in the basal fields (86.96 %) and also multiple long vertical artifacts are always bilaterally distributed (100%); on the contrary, in 69.7% of healthy patients, unilateral distribution prevails with diffusion in all fields explored (87.89% of cases); as well as in patients with bronchiolitis in 100% of cases we find long vertical artifacts widespread in all fields explored with a predominantly unilateral (37.74%) or bilateral distribution with a prevalent diffusion in the right and / or left lung (39.62%).
We analyzed the presence and distribution of anechoic pleural effusion : it was found only in acutely ill children and in particular in 73.91% of patients with a bilateral distribution in 41.19% of cases.
No acutely ill patients enrolled had supleural consolidations or pleural line irregularities . A minority of acutely ill patients (26.09%) had a globally regular pleural line with sporadic areas of irregularity. Even in healthy newborns, no subpleural consolidations and irregularities of the pleura line were found in any patient, on the contrary in patients with bronchiolitis subpleural consolidations and irregularities of the pleural line were found in 100% of patients.
Table 5 shows the differences in ultrasound results in the two groups ofacutely ill children with pro-BNP level lower and higher than 1000 pg / ml. For many of the ultrasound findings, there are no statistically significant differences in the two groups. We found a significant difference (p <0.001) in the distribution of long vertical artifacts “with or without spared areas”. In particular, we reconsidered that 100% of acutely ill patients with pro-BNP <1000 pg / ml present a destruction of long vertical artifacts “with spared areas”. Most children with pro-BNP <1000 belong to the group of acutely ill children with systemic inflammatory disease/sepsis in the absence of organic and / or functional damages in the myocardium (Table 1 and Table 2). In 85.71% of cases of the children belonging to the group with pro-BNP> 1000 pg / ml (most of these belong to the heart disease group with or without systemic inflammation/sepsis as shown in Table 1 and Table 2) vertical artifacts are distributed homogeneously ”without spared areas ” (as from early cardiogenic edema).
Table 6 shows the differences of the ultrasound features in the three diagnostic categories of acutely ill children .