Background: Intelligent volume-assured pressure support (iVAPS) is a new noninvasive ventilation (NIV) mode that can automatically adjust pressure support to deliver effective ventilation. Our aim was to compare treatment efficacy and level of satisfaction between auto-titrating expiratory positive airway pressure (auto-EPAP) and fixed expiratory positive airway pressure (fixed-EPAP) during iVAPS treatment in stable hypercapnic chronic obstructive pulmonary disease (COPD) patients.
Material and methods: In this prospective single-blinded, randomized study, 50 patients with chronic stable hypercapnia (COPD) who met the study criteria were randomized into a group I treated with auto-EPAP and a group II who received fixed-EPAP during iVAPS treatment for 5 consecutive days. The patients' characteristics, arterial blood gases, and lung function test were recorded. Numeric rating scale (NRS), dyspnea and comfort scale were obtained. The study subjects were evaluated and followed up after initiating therapy for 5 consecutive days. Outcome measures were recorded at baseline (T0) and after three (T1) and five (T2) days of each consecutive period All parameters were collected and statistically analyzed.
Result: No significant differences were found regarding age, sex, or BMI between the both groups. It was noted that daytime PaCO2 decreased significantly over the follow-up period in the group I patients treated with auto-EPAP as compared with fixed-EPAP. Regarding the patient comfort and dyspnea during iVAPS treatment, dyspnea sensation was significantly lower with auto-EPAP 7.9 ± 1.8 (T0) vs 3.5 ± 1.1 (T2), p = 0.001 and fixed-EPAP 7.7 ± 1.9 (T0) vs 3.4 ± 1.6 (T2), p = 0.001, but no significance was reached between the both groups. However, auto-EPAP demonstrated significant improvement in comfort when compared with fixed-EPAP modality. However, the overall satisfaction of the patients receiving auto-EPAP modality was significantly increased. Mean tidal volume tended to be higher in auto-EPAP 698 ± 213 mL compared with 628 ± 178 mL in fixed-EPAP (p = 0.001). The air leak was significantly lower in auto-adjusting mode (2.5 ± 1.3 vs 3.7 ± 2.2 L/ min) in fixed-EPAP modality.
Conclusion: Auto-titrating NIV mode may provide additional benefit in decreasing PaCO2 more efficiently and improve patient comfort and satisfaction.
Keywords: hypercapnic respiratory failure; noninvasive ventilation.