Recovery of pulmonary functions, exercise capacity, and quality of life after pulmonary rehabilitation in survivors of ARDS due to severe influenza A (H1N1) pneumonitis

Background: Acute respiratory distress syndrome (ARDS) due to severe influenza A H1N1 pneumonitis would result in impaired pulmonary functions and health-related quality of life (HRQoL) after hospital discharge. Objectives: The recovery of pulmonary functions, exercise capacity, and HRQoL in the survivors of ARDS due to 2009 pandemic influenza A H1N1 pneumonitis (H1N1-ARDS) was evaluated in a tertiary teaching hospital in northern Taiwan between May 2010 and June 2011. Patients and Methods: Data of spirometry, total lung capacity (TLC), diffusing capacity of carbon monoxide (DL_CO), and 6-minute walk distance (6MWD) in the patients survived from H1N1-ARDS were collected 1, 3, and 6 months post-hospital discharge. HRQoL was evaluated with St. George respiratory questionnaire (SGRQ). Results: Nine survivors of H1N1-ARDS in the study period were included. All these patients received 2 months’ pulmonary rehabilitation program. Pulmonary functions and exercise capacity included TLC, forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), DL_CO, and 6MWD improved from 1 to 3 months post-hospital discharge. Only TLC had further significant improvement from 3 to 6 months. HRQoL represented as the total score of SGRQ had no significant improvement in the first 3 months but improved significantly from 3 to 6 months post-discharge. Conclusion: The impaired pulmonary functions and exercise capacity in the survivors of H1N1-ARDS improved soon at 3 months after hospital discharge. Their quality of life had keeping improved at 6 months even though there was no further improvement of their pulmonary functions and exercise capacity.