Pulse oximetry in comparison to arterial blood oxygen saturation in children with bronchial asthma coming to the emergency room

Background Bronchial asthma is currently defined as a chronic inflammatory disorder of the airways. Hypoxia is a universal finding in acute exacerbations of asthma. However, respiratory failure with PaO2 below 60 mmHg or PaCO2 above 45 mmHg occurs in no more than one-third of patients. Pulse oximetry allows noninvasive measurement of arterial oxygen saturation (SpO2), without the risks associated with arterial puncture.Aim The aim of this study was to evaluate pulse oximetry as a valid tool to predict respiratory failure in children with acute severe attack of bronchial asthma as compared with the standard arterial blood gas (ABG) analysis.Patients and methods The study was carried out on 50 children, 30 of them were patients with acute bronchial asthma and 20 of them were healthy controls. All patients and controls were subjected to the following: Full history taking, clinical examination such as pulse oximetry and investigations which included chest radiography, echocardiography, and ABG analysis.Results There was no significant difference between asthmatic and control groups regarding age, sex, weight, and height. We found that respiratory rate and heart rate was higher in asthmatic patients than controls. We demonstrated a negative correlation between PaCo2 and SPO2 and between PaO2 and PaCO2, and a positive correlation between SaO2 and SPO2 and between PaO2 and SPO2. Oxygen saturation measured by pulse oximetry (SpO2) was greater than oxygen saturation measured by the ABG analyzer, but this difference was not statistically significant.Conclusion Arterial oxygen saturation measured by pulse oximetry can be used as a tool to diagnose respiratory failure in an emergency setting where ABG facility in not available.