[Bronchial hyperreactivity and nCPAP therapy]

In patients with obstructive sleep apnoea (OSA) nCPAP may irritate the mucous membranes of the upper airways. We investigated in this study whether nCPAP can induce bronchial hyperreactivity (BHR). Forty-one patients (33 men, mean age 52.6 years) were treated with nCPAP due to OSA. All of them were tested for BHR with histamine ("pari-provo-Test") before and six weeks after initiation of the nCPAP therapy. Thirty-five of the patients showed BHR neither before nor after the beginning of CPAP. Six patients developed a BHR of moderate degree (PD20: 50-100 micrograms) during the study; four of these six patients were not symptomatic. The two other patients complained about more colds than usual or about noctumal cough. Both of them received inhaled steroids and a moistening system. Nobody of the enrolled patients was obliged to finish CPAP therapy due to BHR. Four patients had already a BHR before nCPAP therapy began. Most of the patients did not acquire a BHR during the first 6 weeks after nCPAP therapy had started. A BHR bronchial may develop, but in the majority it remains without clinical relevance. In patients with a BHR and OSA, the benefits of nCPAP therapy excel the potential adverse effects.