296ASSESSMENT OF HIGH-INTENSITY NONINVASIVE VENTILATION IN COPD PATIENTS WITH STABLE HYPERCAPNIC SYMPTOMS: A RANDOMIZED CONTROLLED TRIALChronic obstructive pulmonary disease (COPD) with stable hypercapnic symptoms often requires treatment with high-intensity noninvasive ventilation (NIV). This study aimed to assess the adherence and physiological outcomes associated with high-intensity NIV in COPD patients with persistent nocturnal hypoventilation and hypercapnic symptoms. Methods: Randomized controlled trials (RCTs) were conducted involving COPD patients with daytime PaCO2 ? 0.7 kPa and persistent nocturnal hypoventilation. Patients were randomly assigned to receive either high-intensity NIV with highpressure conditions or high-intensity NIV with low-pressure conditions (high-pressure group). The primary outcome was ventilator usage at night. Secondary endpoints included symptom severity and physiological parameters. Results: 24 patients were enrolled, with 14 completing the 12-week trial protocol. The mean age of participants was 70 years, with a mean FEV1/FVC ratio of 50% and a mean FEV1 of 32%. Baseline measurements showed a mean PaCO2 of 7.6 x 2.7 kPa and a mean PaO2 of 6.3 x 2.4 kPa. There was no significant difference in ventilator usage between the high-intensity and highpressure groups (four minutes difference; 95% CI 45 to 53; P = 0.9). However, the low-pressure group exhibited significantly fewer symptoms compared to the high-pressure group. Secondary endpoints did not show significant differences between the groups. Conclusion: Adding a high backup rate to noninvasive high-pressure ventilation did not result in additional benefits in COPD patients with stable hypercapnic symptoms. High-pressure noninvasive ventilation remains crucial for managing increasingly severe hypercapnic respiratory failure in these patientsDr. Priya Smriti Soy@gmail.comResearch1122021 COPD, Noninvasive ventilation, Hypercapnic symptoms, Randomized controlled trial, Respiratory failureDr. Priya Smriti SoyAssociate Professor, Department of Physiology, Gouri Devi Institute of Medical Sciences & Hospital, Durgapur, West Bengal