Pulmonary aspiration only increases the risk of right-sided pneumonia in children: comparison of salivagrams and chest radiographs.

PURPOSE: A salivagram is often used to detect pulmonary aspiration, whereas chest radiography is often used to diagnose pneumonia. This study analysed the relationship between pulmonary aspiration and aspiration pneumonia in children, and the differences between lungs.

PATIENTS AND METHODS: The salivagram and chest radiography results of 696 children (466 boys and 230 girls; aged 1-54 months; mean age, 4.7 months; median age, 3 months) diagnosed with respiratory tract infections between December 2013 and June 2017 were retrospectively analysed. Patients were classified as positive or negative on the basis of their salivagram results, and the radiography positivity rates were analysed.

RESULTS: Among all paediatric patients, 197 were salivagram positive and 499 were salivagram negative. The positivity rate was 28.3% (197/696); the positivity rate of the right side was 98.0% (193/197). The radiography positivity rates of the right side in the positive group, negative group and the total sample were 84.3% (166/197), 69.5% (347/499) and 73.7% (513/696), respectively. The radiography positivity rates of the left side were 69.5% (137/197), 68.5% (342/499) and 68.8% (479/696), respectively. Inter-group comparisons of the radiography positivity rates of the right side showed significant differences between the positive group and the total sample, as well as between the positive and negative groups (P=0.001 and 0.000, respectively). There were no significant differences in the radiography positivity rates of the left side (P=0.846 and 0.796, respectively). The radiography positivity rate of the right side in the positive group was 14.8% higher than that in the negative group.

CONCLUSION: Pulmonary aspiration tends to occur in the right side and only increases the risk of right-sided pneumonia.