Clinical presentation, treatment, and outcomes
In Toddlers and preschoolers, the frequency of peribronchial thickening and interstitial opacities was higher than in the other age groups. Regarding to clinical findings, patients that presented with fever for more than 3 days did not have a predominant radiological pattern. When comparing the group with SARS-CoV-2 alone to the group with codetection, there was a significant difference in the frequency of peribronchial thickening and interstitial opacities (56% versus 79%, respectively p= 0.002). On the other hand, virus-virus isolation showed a higher frequency of peribronchial thickening and interstitial opacities compared to virus-bacteria isolation. Furthermore, there was not difference in consolidation pattern between different isolation groups (p >0.9). (Table 3)
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When treatment was assessed, it was observed that among the 126 patients who received antibiotic therapy, only 8.1% exhibited a consolidation pattern, which was significantly higher than the frequency observed in the group that did not receive antibiotics (1.9%) (P=0.02). Antibiotic treatment was given to eleven of the sixteen patients (69%) that had a consolidation pattern. Conversely, there was no significant difference in the radiograph findings between patients who received corticosteroids and those who did not.
Out of 267 patients on oxygen therapy, 25% had normal chest x-rays, compared to 45% of the 125 patients who did not receive oxygen therapy. The requirement of oxygen was not associated with a different pattern in the chest x-ray. However, patients presenting with respiratory failure had higher (32%) of alveolar opacities in comparison to patients that did not present respiratory failure.
Location of radiological findings did not have a variation in frequency among different outcomes assessed. Nevertheless, difusse distribution had a higher frequency in patients with ventilatory failure (37%). Patients admitted to PICU had lower percentage of normal radiological results compared to those in standard care. From the ones that had abnormal radiological findings, peribronchial thickening was the most common pattern. There was not a significant difference of radiological pattern in relation to the duration of stay in the PICU as well as in standard care.
Mortality was observed in 11 patients, with alveolar opacities being the most common finding at 45%, followed by peribronchial thickening at 36%. Meanwhile, among the group of patients who survived, predominant pattern was peribronchial thickening followed by normal pattern was found in 32%.
DISCUSSIONTo our knowledge, compared to other studies conducted in Colombia regarding this topic, this study involves a greater number of patients. Our findings shed light on key aspects related to patient demographics and clinical features, as well as the interobserver agreement among radiologists in interpreting the radiographs. In contrast to previous studies, different populations reported average ages ranging from 5 to 7 years (27)(28). We found that the median age of our patients was 2 years old. However, our clinical characteristics, including main symptoms, microorganism codetection, hospitalization days, and admission to pediatric intensive care units (PICU), were in line with other studies conducted in Colombia and internationally
Regarding the interobserver agreement, we found a moderate kappa coefficient for alveolar opacities. Previous studies have indicated that interobserver variability may be influenced by the level of expertise, lack of precise definitions for findings other than consolidation, and occasionally the quality of the image . Interestingly, we observed that the quality of the image did not significantly impact kappa’s value in our study, which is an essential consideration for future interpretations.
Alveolar opacities emerged as the category with the best interobserver concordance in our study. This finding contrasts with the study developed by Ugas-Charcape et al., where peribronchial thickening showed the highest interobserver agreement
In our cohort, we also identified peribronchial thickening as the most common radiological finding, in line with previous studies . Interestingly, we did not observe a significant association between oxygen requirement and specific radiological findings, which contrasts with the study by Mania et al., where interstitial and/or ground-glass opacities were more frequent in patients receiving oxygen therapy . This can be explained by considering that, in the aforementioned study, the average age is higher than that of this group, this difference in age could account for the observed radiological findings lacking specificity. Presumably, older children may exhibit patterns akin to those established as typical in adults, such as ground glass opacities.
Regarding the location of radiological findings, we did not find significant variation among assessed outcomes. However, central distribution was more frequent in patients with ventilatory failure. A descriptive study by Oterino Serrano et al. in 2020, evaluating chest tomography and X-ray findings, reported that unfavorable outcomes were more common with extensive involvement, characterized by peribronchial thickening, ground-glass opacities, and bilateral or diffuse consolidation . While our study did not provide a specific definition for unfavorable outcomes, it is important to consider these radiological patterns in the context of clinical assessment.
In our cohort, peribronchial thickening was the most common radiological pattern and was associated with admission to PICU, antibiotic prescription, isolated viral or bacterial detection, and a fever lasting more than three days. Although this finding is nonspecific, fever has consistently been reported as the most frequently observed symptom in different studies .
A noteworthy finding in our cohort of patients who died was the higher occurrence of alveolar opacities as the main pattern on their chest x-rays. While there is limited literature that directly relates these variables, a retrospective cohort study with 110 patients MIS-C described diffuse bilateral coalescent opacities observed in three patients admitted to the intensive care unit with severe respiratory distress, with one of these patients deteriorating on the fourth day of admission to the PICU. A similar pattern has been studied in adults, where it has been associated with mortality.Although the presence of this pattern does not necessarily imply a different treatment approach from the clinical indications, it may work as an alert to closely and strictly monitor the patient.