Lung Function of Children Following an Intensive Care Unit Admission for Asthma

To determine the lung function of children admitted to the intensive care unit (ICU) for a severe asthma exacerbation in the medium- to long-term following hospital discharge. We performed a retrospective chart review of children ≥6 years of age admitted to the ICU for a severe asthma exacerbation at a tertiary care center from January 1, 2000, to December 31, 2013. Lung function was ascertained during outpatient follow-up visits at 3-12 months and 12-24 months postdischarge. A total of 72 subjects met the inclusion criteria. Subjects were predominantly boys (56.9%) and had a mean (standard deviation [SD]) age at admission of 10.3 years (3.4 years). The median (interquartile range) length of stay in the ICU was 1 day (1-3 days). Thirty-eight and 28 subjects performed pulmonary function tests with acceptable technique at the 3-12 months and 12-24 months postdischarge visits, respectively. At 3-12 months, the mean (SD) predicted forced expiratory volume in 1 s (FEV₁) and forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75) percent were 95.9 (16.7) and 76.7 (25.8), respectively, and 97.4 (17.6) and 70.5 (24.9), respectively, at 12-24 months. FEV₁/forced vital capacity (FEV₁/FVC) was 81.7 (8.3) at 3-12 months and 79.3 (7.7) at 12-24 months. A paired t-test on 20 subjects who performed acceptable spirometry at both visits showed a significant intraindividual decrease in FEV₁ (P = 0.008), FEF_25-75 (P = 0.02), and FEV₁/FVC (P = 0.01) between the 2 time points. Although prospective studies are required to confirm our findings, our study suggests that children admitted to the ICU for severe asthma exacerbations may be at risk for declining pulmonary function in the medium- to long-term postdischarge.