Bratislava Medical Journal Vol.115, No.11, p.704-707, 2014

Objective: The aim of study was to find predictive factors for treatment failure of the continuous positive airway pressure (CPAP).
Background: Sleep apnea syndrome (SAS) affects 4–8 % of the general population. Despite good adherence, CPAP is ineffective in about 13 % of patients. In those patients, a higher level of treatment by bilevel positive airway pressure (BiPAP) has to be used.

Methods: Totally, 983 patients with moderate to severe SAS (AHI ≥ 15, apnea/hypopnea index) were treated with CPAP during 2005–2010 in a tertiary hospital. 506 patients fulfilled the inclusion criteria.

In all patients, sleep monitoring was performed and AHI, the presence of hyposaturation T90 (oxygen saturation less than 90 %) and ODI (oxygen distress index) were recorded and a comparison was made between CPAP-effective and CPAP-failure treatment groups.
Results: Of all the variables evaluated, only T90 significantly predicted the failure of CPAP treatment. A T90 value above 43.5 % predicted CPAP failure in 94.5 % of patients regardless of age.
Conclusions: The value of T90 enables the determination of patients who will not benefit from CPAP treatment and BiPAP should be used as a treatment of the first choice (Tab. 2, Fig. 1, Ref. 31).