[The specific features of respiratory support in patients with obstructive sleep apnoea syndrome concurrent with chronic obstructive pulmonary disease (crossing-syndrome)].

Aim: To determine the specific features of respiratory support in patients with obstructive sleep apnoea syndrome (OSAS) concurrent with chronic obstructive pulmonary disease (COPD).

Subjects And Methods: Thirty-six patients with OSAS concurrent with COPD were examined. External respiration function, apnoea/hypopnoea index, and arterial gas composition were determined in all the patients. The efficiency of continuous positive airway pressure (CPAP) therapy was evaluated in all the patients with the crossing-syndrome (CS).

Results: The prevalence of CS among the patients with OSAS was 18.8%. The CS patients' need for bilevel positive airway pressure (BiPAP) therapy was 27.8%. These patients and those treated with CPAP had at baseline a daytime hypercapnia level of 50.7 +/- 1.8 and 42.0 +/- 1.2 mm Hg (p = 0.005) and a nocturnal blood oxygen saturation level of 83.6 +/- 1.3 and 88.8 +/- 0.9% (p = 0.004), respectively. BiPAP therapy resulted in a 1.8-fold reduction in the desaturation index than did CPAP therapy.

Conclusion: On choosing a respiratory support method in patients with OSAS, one should assess the presence of chronic lower airway obstruction, the degree and type of chronic respiratory failure, and the presence and magnitude of clinical, functional, and laboratory signs of alveolar hypoventilation. Bilevel lung ventilation is more effective in patients who have CS, daytime hypercapnia, and nocturnal hypoxemia uncorrected by CPAP therapy and who need high therapeutic pressure.