Subjective sleep quality during average volume assured pressure support (AVAPS) ventilation in patients with hypercapnic COPD: A physiological pilot study

Non-invasive Positive Pressure Ventilation (NPPV) is an advanced treatment (1) aimed to improve both physiological (2-4) and clinical outcomes (5-7), including sleep (8-10), during the long-term management of patients with Chronic Respiratory Failure (CRF) due to severe hypercapnic Chronic Obstructive Pulmonary Disease (COPD). Several studies evaluating the nocturnal application of mask ventilation in stable COPD patients (11-13) have shown a limited effectiveness of pressure based modes of NPPV in this patient group. However, further studies have shown that compliance to ventilation may influence the long-term efficacy of this treatment as patients who are compliant with NPPV are able to maintain arterial blood gase (ABG) improvements over 6-months when compared with those who discontinued this therapy (14).A new NPPV modality, called Average Volume Assured Pressure Support (AVAPS), combines both the pressure and volume characteristics of ventilation and, accordingly, delivers a range of inspiratory pressures to guarantee a pre-fixed inspiratory tidal volume. This hybrid mode of ventilation has been studied in intubated patients with acute respiratory failure (15) and in patients with chronic hypoventilation linked to obesity (16,17) and other conditions (16). Under these circumstances AVAPS is able to induce high pulmonary volumes and reduce muscle workload, thus providing physiological benefits and comfort similar to those achieved by pressure support (PS) modes. However, positive effects on sleep quality have not yet been confirmed.This pilot evaluated short-term compliance, night-time efficacy and physiological responses to Average Volume Assured Pressure Support (AVAPS) ventilation in patients with stable hypercapnic COPD.