PREVALENCE OF BREATHING PATTERN DISORDER IN PATIENTS WITH ASTHMA

Hyperventilation is the most common breathing pattern disorder. Several studies indicate that hyperventilation is common in asthmatic patients. There has been no study on prevalence of hyperventilation syndrome in Iran so far. This study aimed to evaluate the prevalence of hyperventilation syndrome in asthmatic patients. This cross-sectional study was conducted on 100 patients with mild to moderate asthma in Imam Khomeini Hospital of Ahvaz between November 2013 and June 2014. In this study, Nijmegen questionnaire and Capnograph device for measuring the pressure of end tidal carbon dioxide was used for diagnosis of hyperventilation syndrome. Data management and analysis was performed using SPSS software. P <0.05 was considered for significant level. The subjects’ mean age were 40.90±11.04 and duration of asthma ranged from one month to 40 years. 54% of subjects had a mean pressure of end tidal carbon dioxide below 32 mmHg. 47% of participants had a scores greater than 17 on the Nijmegen questionnaire. Average of Nijmegen score and end tidal carbon dioxide pressure was 17.90±7.60 and 31.1±4.9mmHg, respectively. This study showed that the prevalence of hyperventilation syndrome in asthmatic patients is 47%. This high prevalence indicates importance of therapeutic intervention related with abnormal breathing patterns in asthmatic patients.