Validation of the AVAPS AE Algorithm in Chronic Obstructive Pulmonary Disease (COPD) Patients
Validation of the AVAPS AE Algorithm in Chronic Obstructive Pulmonary Disease (COPD) Patients
COPD continues to be a cause of major morbidity for patients. Those patients who also have
 respiratory failure and obstructive sleep apnoea are at higher risk of exacerbations and
 death and have worse health related quality of life than similar COPD patients without
 respiratory failure.

 Treatment options in this group of patients have been limited and data to support the use of
 machines to assist breathing (non-invasive ventilators) in stable patients are limited. A
 major limitation of these devices has been patient acceptance and achieving sufficient
 control of sleep breathing disturbance.

 Currently devices are set at a fixed pressure to support the breathing throughout the night.
 The new software within the trial device will aim to better match the support provided by the
 machine to that needed by the patient. It is hoped that this may offer enhanced comfort as
 well as superior control of respiratory failure.
Chronic Obstructive Pulmonary Disease (COPD) is a major cause of morbidity and mortality
 worldwide.

 Treatment options for COPD patients consist of medications, such as bronchodilators and
 anti-inflammatory drugs, pulmonary rehabilitation, long term oxygen therapy (LTOT), lung
 volume reduction surgery and lung transplantation. Studies have shown that bronchodilators
 and anti-inflammatory drugs show minor or no benefit on long term outcomes but rather are
 used mainly for symptomatic relief.1 Pulmonary rehabilitation has been demonstrated to
 improve functional status and symptoms but there is lacking evidence on long term outcomes of
 this therapy. 2 Lung volume reduction surgery and lung transplantation is only appropriate
 for a small number of patients; therefore, there is no demonstration of improved long-term
 survival rate.3, 4

 Of these available therapies, few have been shown to significantly improve long term patient
 outcomes. For the severe COPD patient, LTOT is the only treatment that demonstrated prolonged
 survival in controlled studies. 5, 6 But, despite the effectiveness of LTOT, COPD is still
 characterized by a high morbidity and mortality rate.

 Although the treatment of OSA with CPAP therapy has been associated with reduced hospital
 admissions and exacerbations there are possible adverse consequences on pulmonary mechanics
 due to exacerbating hyperinflation.

 Noninvasive positive pressure ventilation (NPPV) is one therapy that may prove beneficial to
 stable COPD patients. NPPV is the use of positive pressure ventilation administered via a
 nasal or full face mask (that covers both the nose and mouth). This type of ventilation has
 become a well established and increasingly used therapeutic option for patients with
 hypercapnic respiratory failure (HRF) due to COPD.7

 NPPV, used nocturnally, may improve nighttime hypoventilation that is common with COPD
 patients. An improvement in nocturnal hypoventilation would reset the respiratory center
 sensitivity for CO2.8 9 This would result in an improvement in daytime gas exchange and sleep
 quality. It is also known that hyperinflation in patients with COPD increases their work of
 breathing, thus fatiguing the respiratory muscles.10 It has been suggested that by applying
 nocturnal NPPV it would allow the respiratory muscles to rest, resulting in muscle function
 recovery, increased muscle strength, reduced tendency for fatigue and improvement in
 pulmonary function and gas exchange.11

 AVAPS AE AVAPS AE is a mode of therapy (Philips Respironics Inc, Monroeville, PA, USA) with
 potential advantages over the currently established modes of noninvasive positive pressure
 ventilation (CPAP and bilevel therapy). This mode of therapy incorporates AVAPS (automated
 adjustable IPAP setting to maintain target ventilation with a settable rate of change),
 AutoEPAP and Auto Back up Rate. In particular the automated EPAP algorithm will ensure
 optimal upper airway patency without exacerbating hyperinflation.

 In this study, we are evaluating the AVAPS AE mode as compared to the participant's current
 mode of ventilation. We believe that these automated parameters will allow better nocturnal
 ventilatory control to offset the differing elastic and resistive loads imposed by changes in
 body position during sleep. Furthermore, AVAPS AE will counter the changing ventilatory
 requirements due to alterations in lung volumes and airway resistance during different stages
 of sleep. In summary, the AVAPS AE mode will enable automatic adjustment in response to
 ventilatory changes throughout the night.

 Study Objective The objective of this study is to validate the performance of the AVAPS AE
 therapy in COPD-OSA overlap patients during nocturnal ventilation.
Inclusion Criteria:

 -  Age ≥ 21

 -  Diagnosis of COPD

 -  Currently using Bilevel device for COPD-OSA overlap syndrome

 -  Ability to provide consent

 -  Documentation of medical stability by PI

 Exclusion Criteria:

 -  Subjects, who are acutely ill, medically complicated or who are medically unstable.

 -  Subjects in whom PAP therapy is otherwise medically contraindicated.

 -  Subjects who have had surgery of the upper airway, nose, sinus, or middle ear within
 the previous 90 days.

 -  Subjects with untreated, non-OSA sleep disorders, including but not limited to;
 insomnia, periodic limb movement syndrome, or restless legs syndrome (PLMI > 10).