Study population
Two hundred and thirteen patients whit SARS-CoV2 infectionwere enrolledbetween 15st November 2020 and 30st June 2021. One hundred and ten (51.6%) patients were male witha median age of 2 years and 5 months (IQR 4mm- 11 yyand4 mm). Eighty-seven (40.9%) children had less than 1 years of age, of whom 63 (29.6%) had less than 6 months of age. At medical history 160 (75.1%) children presented fever at home, 67 (31.5%)had respiratory symptoms, 75 (35.2%) reported a reductionoffood intake and 106 (49.8%) indicated anepidemiological link. Fifteen (7%) children had chest pain, 8 (3.7%) had anosmia and 6 (2.8%) had ageusia. At clinical evaluation the mean oxygen saturation was 98.4 % (± 2.0) in room air, 16 (7.5%) presented respiratory distressand16 (7.5%) had whistles/wheezingat the auscultation of the thorax. One hundred and forty-eight (69.4%) children were admitted in hospital, of whom 9 (6.1%) in pediatric intensive care unit.Thirteen (6.1%) children needed oxygen therapy during the hospitalization. At LUS examination the median score was of 2 (IQR 0- 5.5). In particular the most encountered ultrasound pathological features are the irregularity of pleural line (33,3%) and the B lines (46.5%). Table 1 summarizes demographic, clinical and LUS findings of children with COVID‐19.
Dividing the sample into 2 age groups, greater or less than one years old, we got 2 groups of 87 and 126 children. In Table 2, the demographic, clinical and LUS findings of the two groups are summarized and compared
From a clinical viewpoint, younger children presented a higher rate of reduction of food intake (80.4% vs 16.7%; p = 0.001) and a higher rate offever (83.9%vs 68.3%; p = 0.009)compared with older patients. We also observed in children whit less of 1 year of age a higher level of oxygen saturationduring the evaluation (99 (± 1.6)vs 98.1 (± 2.1); p= 0.001) and a lowerneed foroxygen therapy during the hospitalization (0 vs 10.3%; p= 0.002)than inolder patients.
Considering LUS pathological features, we observed that the occurrence of the irregular pleural line and the presence of B-lines were seen more frequently in younger children (43% vs 60.71%; p = 0.035 and 53.2% vs 36.8%; p = 0.013 respectively). Moreover, the presence of sub-pleural consolidation and pleural effusion were significantly more common in children whit greater of 1 year of age (21.4% vs5.7%; p= 0.001 and 19.8% vs 6.9%; p= 0.006).
No other significant differenceswere evidencedbetween these two groups.
We found an inverse correlation between the LUS score and the oxygen saturation during the clinical evaluation (r = −0.16; p = 0.019).
We also divided the enrolled children in two sample on the basis of the need for oxygen therapy during hospitalization. We summarized in Table 3 the demographic, clinical and LUS findings of the two groups.
We found that the 13 children who needed oxygen therapy were significantly older (13 yy 9 mm (11 yy 7 mm- 16 yy 6 mm) vs 1 yy 6 mm (4 mm- 9 yy 8 mm); p= 0.001) and reported more frequently chest pain ( 30.8% vs 5.5%; p= 0.008) than the other group.
Moreover, childrenwho had needed oxygen therapy presented,during the clinical assessment, a lower oxygen saturation (94.3 (± 3.2) vs98.7 (± 1.5); p= 0.023) and a more frequent hospitalization in intensive care unit (30% vs 6.1%; p= 0.017).
Among LUS pathological features, irregular pleural line, sub-pleural consolidation and pleural effusion were significantly greater in who had needed oxygen therapy (69.2% vs 31%; p = 0.007;46.2% vs13%; p = 0.006 and 53.8%vs 12%; p = 0.001, respectively). Finally, the LUS scores were significantly higher in who had needed oxygen therapy (8 (3 - 19) vs 2 (0 - 4); p= 0.001, Figure 1).
We also divided our cohorts in children younger than 5 years, 5-11 years and older than 12 years of age (which reflects the different age groups that have had access to vaccination).
We found that with increasing age decreased the oxygen saturation value found at the time of LUS (p= 0.002) so older patients were those who most frequently needed oxygen therapy (p= 0.001) and hospitalization in intensive care unit (p = 0.001). At LUS older patients had more irregular pleural line and B-Lines than younger children (p = 0.001 and p=0034,respectively). In Table 4, the demographic, clinical and LUS findings of the three groups are summarized.