Summary. Cerebral stroke – is one of the leading causes of morbidity and mortality, the frequency of which is constantly increasing and is about 1 million people per year in Europe; and from 13 to 35% of these patients die within the first 30 days of treatment, and 20-40% of patients who survived, are dependent on the external physical assistance and only about 10% return to a full-quality life. A significant part of patients with ischemic stroke has obstructive sleep breathing disorders, which are often the cause of the stroke development and significantly complicate its course, primarily due to the impaired airway patency, numerous episodes of apnea/hypopnea and hypoxemia, hypercapnia, etc. A comprehensive study of the frequency of the obstructive sleep apnea syndrome development and its degree of severity, its inherent ventilation and oxygenation disorders against the background of standard treatment and in combination with noninvasive respiratory support in patients with ischemic stroke, can play an important positive role on the way to the improvement of the results of treatment and rehabilitation. Objective. To study changes in ventilation and oxygenation in patients in the acute period of ischemic stroke, depending on the method of intensive therapy. Methods. Ischemic patients were performed a questionnaire survey and screening monitoring to find sleep breathing disorders («SomnoChek micro», Weinman, Germany), based on the results of which there were formed two groups: traditional stroke treatment and in combination with auto-CPAP support, which was performed with the help of «ResMed Air Sence-i» (Australia). To control the effectiveness of respiratory support, «SomnoChek micro» (Weinman, Germany) and «Masimo SafetyNet» (Masimo, USA) were used, the obtained somnological indices were processed statistically. Results. The frequency of detection of obstructive sleep apnea syndrome in patients with ischemic stroke in the acute period is 44%. The initial values of the apnea/hypopnea index (AHI) did not statistically significantly differ from each other and were 51.38±20.31/hour in the patients of the experimental group, and 51.21±20.27/hour in patients of the control group. During the 7th day, the AHI values in patients of the experimental group, whose traditional treatment of ischemic stroke was supplemented with sessions of CPAP-therapy at night, statistically significantly decreased at 89.2% compared to the initial data and were 5.54±1.98/hour, which are normal values and indicate the rapid and high efficiency of CPAP-support and its good tolerability by patients. In patients of the control group receiving only traditional treatment, the AHI values remained high, within pathological values and were 46.73±20.21/hour. When comparing reliable AHI intervals in observation groups, their 8.4-fold difference was determined. Against the background of CPAP-therapy, during the 7th day of observation, a statistically significant decrease in hypercapnia was determined in the patients of the experimental group, namely a decrease in the average PnCO2 at 23% compared to the initial level up to the limit of 37.57±1.04 mm Hg. Against the background of the use of CPAPtherapy in patients of the experimental group during the 7th day of observation, there was found a decrease (p<0.001) of snoring at 92.1% (12.6-fold), compared to the initial level up to the limit of 2.43±2.22%, which indicates a stable restoration and maintenance of free patency of the upper respiratory tract under the influence of CPAP-support. Conclusion. Manifestations of obstructive sleep apnea syndrome in patients with ischemic stroke in the acute period were found in 88 people (44%), of which 68% had a moderate and severe form of nocturnal breathing disorders that required respiratory correction. Standardized medicinal therapy and early rehabilitation of patients with ischemic stroke does not affect the course and severity of the accompanying syndrome of obstructive sleep apnea and needs to be supplemented with methods of non-invasive respiratory support. In patients with ischemic stroke against the background of auto CPAP-therapy, positive dynamics was recorded in terms of correction of obstructive sleep apnea syndrome: a steady tendency or normalization of somnologic indices, ventilation, oxygenation, cessation of snoring. A clinical problem remains the low patients’ adherence to the use of CPAP-support and its tolerability, despite the absolute indications for its use.