Treatment with CPAP doesn’t appear to help with symptoms of dysfunctional breathing in adults with newly diagnosed obstructive sleep apnoea (OSA), Australian research shows.
In a prospective study at the Gold Coast University Hospital, almost half (47.6%) of 84 OSA patients referred for CPAP had dysfunctional breathing as indicated by a high Nijmegen questionnaire (NQ) score.
Patients who commenced CPAP were included in the treatment group and those who declined or delayed CPAP become the control group.
The study, published in the Internal Medicine Journal, found symptoms of excessive daytime sleepiness, as measured by the Epworth Sleepiness Score (ESS), significantly improved at follow-up in the CPAP group compared to controls.
And an average duration of CPAP use per night of 6.6 hours, suggested the therapy was administered effectively.
However there was no difference in the mean NQ scores between the two groups at follow-up.
Similarly, in a subgroup analysis of patients with confirmed dysfunctional breathing there was also no significant improvement in the CPAP group compared to the controls.
“Among patients who had [dysfunctional breathing] at baseline and were treated with CPAP, 5/19 (26%) experienced a clinically significant reduction in NQ compared to 1/21 in the control group,” the study authors said.
“The reason the NQ score did not improve with CPAP may be because the pathophysiology that drives dyspnoea in patients with OSA includes impaired respiratory mechanics and increased central respiratory drive which may not be addressed by CPAP during wakefulness.”
However some of the study limitations including patient self-selection and a relatively short follow-up of eight weeks in the treatment group may also be factors.
The study investigators concluded that while dysfunctional breathing may be common in OSA, CPAP did not appear to be helpful.
“Future research may need to explore non-CPAP therapies that may assist in the management of the dysfunctional breathing symptoms since such therapies, if combined with CPAP may ultimately improve the quality of life of a considerable proportion of patients with OSA.”
Lead author Dr Adrian Barnett, now at the Mater Hospital in Brisbane, told the limbic breathlessness was a common symptom reported by patients with OSA.
“I think it would have been tempting for doctors to say ‘let’s get you on CPAP treatment and see if your symptoms get better’ – alluding to both the breathlessness and the daytime tiredness – but it might be that the symptoms of breathlessness won’t improve.”
He said it was important to ensure there were no secondary causes for the breathlessness such as underlying cardiac conditions before referring patients to a physiotherapist for breathing retraining exercises.