Astral VAPS AutoEPAP Clinical Trial


Patients with chronic respiratory failure such as those associated with Chronic Obstructive Pulmonary Disease (COPD), Obesity Hypoventilation Syndrome (OHS), Obstructive Sleep Apnea (OSA) or Neuromuscular Disease (NMD) are increasingly managed with domiciliary non-invasive positive pressure ventilation (NIPPV). The aim of this study is to now compare the Automatic Expiratory Positive Airway Pressure (AutoEPAP) algorithm with a fixed manual EPAP in iVAPS mode on an Astral mixed mode ventilator. It is proposed that the automatic settings of AutoEPAP will be as effective at managing respiratory failure and upper airway obstruction (UAO) as manual EPAP on the Astral device. Specifically demonstrating that the AutoEPAP function is as effective at treating UAO as manual EPAP.

Full Title of Study: “The Evaluation of the Astral VAPS AutoEPAP Treatment Algorithm”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Crossover Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Participant)
  • Study Primary Completion Date: March 1, 2017


  • Device: Astral
    • Astral ventilator

Arms, Groups and Cohorts

  • Experimental: iVAPS with AutoEPAP
    • This is a crossover study. During overnight PSG, Astral device will be set using iVAPS with AutoEPAP on the first night, and on iVAPS with manual EPAP on the second night.
  • Active Comparator: iVAPS with manual EPAP
    • This is a crossover study. During overnight PSG, Astral device will be set using iVAPS with manual EPAP on the first night, and on iVAPS with AutoEPAP on the second night.

Clinical Trial Outcome Measures

Primary Measures

  • Oxygen Desaturation Index 4% (ODI4%)
    • Time Frame: Overnight, up to 8 hrs on nights 1 and 2
    • Mean paired difference AutoEPAP-manual EPAP: Comparison of Oxygen Desaturation Index 4% (ODI4%) values between groups by using mean ODI4% (#events/hour). A cross-over analysis was generated to investigate the influence of a possible period effect on the primary endpoint, paired change in ODI4% between Auto and manual EPAP

Secondary Measures

  • Sleep Efficiency (%)
    • Time Frame: Overnight, up to 8 hrs on nights 1 and 2
    • To assess sleep efficacy between groups by using rapid eye movement sleep (REM) (% of total sleep time)
  • Apnea Hypopnea Index (AHI)
    • Time Frame: Overnight, up 8 hrs on night 1 and 2
    • To assess sleep-breathing parameters between groups using mean AHI (#events/hour)
  • Nadir Arterial Oxygen Saturation (SpO2)
    • Time Frame: Overnight, up 8 hrs on night 1 and 2
    • To assess Sleep-breathing parameters between groups using mean SpO2 (%)
  • Arterial Carbon Dioxide (PCO2)
    • Time Frame: Overnight, up 8 hrs on night 1 and 2
    • To assess Sleep-breathing parameters between groups using mean PCO2 (mmHg)

Participating in This Clinical Trial

Inclusion criteria for the study are:

1. Participant has ability to provide written informed consent

2. Participants aged ≥18 years old

3. Participant has documented respiratory failure (e.g. sleep hypoventilation with historical PtCO2 increase ≥ 10mmHg) and/or daytime hypercapnia (>45 mmHg)

4. Participant is currently using non-invasive positive pressure ventilation in ST or VAPS mode for ≥ 3 months

5. Participants with a previously documented AHI ≥ 5/hr

6. Participants with a recently (≤ 12 months ago) reviewed EPAP setting

Exclusion criteria for the study are:

1. Participants are not compliant on NIPPV (e.g. < 4 hr/night)

2. Participants who are pregnant

3. Participants on oxygen therapy ≥5 L/min

4. Participants with an invasive interface (e.g. tracheostomy)

5. Participants who have had an acute exacerbation within the last 3 months that resulted in a hospitalisation

6. Participants who are acutely ill, medically complicated or who are medically unstable

7. Participants in whom NIPPV therapy is otherwise medically contraindicated

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

9. Participants with untreated, non-OSA sleep disorders, including but not limited to; insomnia, periodic limb movement syndrome, or restless legs syndrome.

10. Participants who have the following pre-existing conditions: severe bullous lung disease, recurrent pneumothorax or pneumomediastinum, cerebrospinal fluid leak, recent cranial surgery or trauma.

11. Participant does not comprehend English

12. Participant is unable or unwilling to provide written informed consent

13. Participant is physically and/or mentally unable to comply with the protocol

14. Participant is not suitable to participate in the trial for any other reason in the opinion of the investigator

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • ResMed
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Lisa Wolfe, MD, Principal Investigator, Northwestern Medical Center


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Masa JF, Celli BR, Riesco JA, Hernández M, Sánchez De Cos J, Disdier C. The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation. Chest. 2001 Apr;119(4):1102-7.

Remmers JE, deGroot WJ, Sauerland EK, Anch AM. Pathogenesis of upper airway occlusion during sleep. J Appl Physiol Respir Environ Exerc Physiol. 1978 Jun;44(6):931-8.

Ward S, Chatwin M, Heather S, Simonds AK. Randomised controlled trial of non-invasive ventilation (NIV) for nocturnal hypoventilation in neuromuscular and chest wall disease patients with daytime normocapnia. Thorax. 2005 Dec;60(12):1019-24.

Laghi F, Tobin MJ. Disorders of the respiratory muscles. Am J Respir Crit Care Med. 2003 Jul 1;168(1):10-48. Review.

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