Nocturnal continuous positive airway pressure in severe non-apneic asthma. A pilot study.

INTRODUCTION: It has been demonstrated that brief periods of nocturnal continuous positive airway pressure (nCPAP) reduce airway reactivity in animal models and in patients with asthma. The effects of nCPAP in severe uncontrolled non-apneic asthmatic patients are not well known. AIM: In this open pilot study, we aimed to assess the effect nCPAP on peak flow (PEF) variability and asthma control in this type of patients.
METHODS: CPAP was applied to 10 patients with severe long-standing asthma without obstructive sleep apnea for seven consecutive nights. CPAP was titrated in auto setting and applied to the patients. Daily PEF, was measured from 2 weeks before the intervention to 2 weeks after the end of nCPAP treatment. PEF amplitude and PEF morning dip (MD) over 24-h periods averaged over 1 week were calculated as indexes of PEF variability. Asthma control test (ACT) and European quality of life (EuroQol) questionnaire were measured at baseline and after 1 month, and at baseline and at the end of CPAP period, respectively.
RESULTS: The PEF amplitude significantly decreased both during CPAP period and in the first week after nCPAP discontinuation as compared with the baseline (19.8 ± 7.5%, 23.9 ± 9.1% and 28.9 ± 11.5%, respectively, always P < 0.05). PEF MD significantly decreased during nCPAP in comparison with the baseline (P < 0.001). The ACT and EuroQol significantly improved after nCPAP in comparison with the basal value.
CONCLUSIONS: In this preliminary report, brief period of nCPAP reduces PEF variability and improves control in severe non-apneic asthma at a short-term evaluation. Further studies with longer-term evaluation and larger number of patients are warranted.