Background: During an asthma exacerbation, pulmonary function test parameters (PFTs) return to their baseline values within a few weeks. Factors affecting the recovery of PFTs other than the severity of exacerbation are not well known.
Objective: The primary aim of the study was to determine the risk factors for recovery of PFTs > 7 days after a moderate to severe asthma exacerbation in children.
Methods: Children who had moderate to severe asthma exacerbation performed serial prebronchodilator PFTs on days 1, 3, 7 of the exacerbation and then once weekly until their PFTs reached a plateau. All children received systemic corticosteroid for 3 days and inhaled salbutamol as long as they needed.
Results: Fifty-seven children were recruited. When all PFTs were considered, 42% and 74% of children recovered within 7 and 14 days, respectively. The last recovered PFT parameter was FEF25-75 . Allergic rhinitis (AR) (P = 0.016), persistent AR (P = 0.005), and severe asthma exacerbation (P = 0.009) were significantly higher in children whose PFTs recover >7 days; only severe asthma exacerbation was different for recovery >14 days (P = 0.048). Logistic regression analysis revealed that AR and severe asthma exacerbation increase the recovery of PFTs > 7 days by 4.3 (95% CI: 1.29-14.67) and 8.1 (95% CI: 1.51-44.43), respectively.
Conclusions: Recovery of PFTs during a moderate/severe asthma exacerbation may take up to 4 weeks. Apart from severity of the exacerbation, AR is a significant factor affecting the recovery time of PFTs and therefore may impact asthma management. This issue reinforces the combined treatment of AR and asthma.
Keywords: allergic rhinitis; asthma; children; exacerbation; pulmonary function tests.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.