Background: Acute bronchiolitis is the most frequent lower respiratory tract infection in infants with a challenging prediction of its clinical course. Only small subsets of patients develop severe disease resulting in hospitalization despite having no identifiable clinical risk factors. There is still a debate as to the role of capnometry in assessing ventilation in children with acute respiratory distress, and bronchiolitis in particular.
Methods: This was a prospective, single blind cohort study. Children younger than 2 years presenting to the emergency department (ED) with bronchiolitis were included. Our primary outcome measures were the correlation between end tidal CO2 (EtCO2) and clinical decision of hospital admission and discharge and need for ICU. Our secondary outcome measure was the possible correlation of EtCO2upon arrival to the ED and clinical measures of bronchiolitis severity
Results: One hundred and fourteen children with clinical bronchiolitis were evaluated in our study. Their mean EtCO2 values upon arrival to the ED and discharge were 34.39±4.74 mmHg and 34.03±4.1 mmHg respectively. EtCO2 values upon admission or discharge were not found to be statistically different among patients who were hospitalized and among those who were discharged from the ED.
Among admitted patients, we found correlation between the capnometry readings at admission and the number of oxygen desaturation days (r=0.47, p=0.001) and with length of hospitalization (r=0.48, p<0.0001). Wang clinical score was found to predict nasogastric tube need, oxygen desaturation days, and length of hospitalization.
Conclusion: Capnometry readings upon arrival to the ED were correlated with the number of oxygen desaturation days and with length of hospitalization, and reflect some of the disease severity measures among hospitalized patients. EtCO2 values did not predict hospital admission or hospital discharge eligibility.
