CPAP versus Bilivel: Long term treatment in Obesity Hypoventilation Syndrome

Introduction: Obesity hypoventilation syndrome (OHS) is defined as a combination of obesity (BMI ⩾30 kg·m−2) and daytime hypercapnia (PaCO2 ⩾45 mmHg). Nocturnal ventilation is usually use to treat the OHS but to date it still unclear if is better use CPAP or Bilevel. Aim: Compare the long-term (3-year) results obtained through ventilatory therapy with Bilevel or CPAP in terms of reduction of PaCO2, improvement of PaO2 and daytime sleepiness. Methods: 26 OHS (Age 54±11.8; BMI 47.16±7.1, PaCO2 52.45±5.2) were followed for 3 years after diagnosis and initiation of night-time ventilatory therapy. All subjects were first titrated with CPAP, if the results were not satisfactory (in term of reduction of AHI or T90) or the patients did not tolerate CPAP they were then treated with Bilevel, thus 16 patient received Bilevel and 10 CPAP. Once a year for three consecutive years have undergone pneumological examination, blood gas analysis, weight control and sleepiness. Results: In both groups a significant reduction in PaCO2 values was obtained (Bilevel 52.4±5.1 vs 44.5±2.9, p Conclusions: CPAP or Bilevel ventilation ensures improved gas exchange and daytime sleepiness in OHS patients, however a higher percentage of patients need Bilevel and they achieve better results in terms of PaCO2 reduction.