View source for Comparison of AutoASV and Bilevel ST Therapy

==Introduction and Purpose==
This study compares the use of AutoASV (adaptive servo-ventilation) therapy against ST (bilevel spontaneous/timed) in a blind trial with a cohort of patients using Opioid therapy and exhibiting symptoms of central apnea.  There are very few studies that actually compare ASV with ST head-to-head, and it is important to demonstrate that ST is not intended, nor effective in the treatment of central and complex apnea <ref>https://www.resmed.com/us/dam/documents/products/titration/s9-vpap-tx/user-guide/1013904_Sleep_Lab_Titration_Guide_amer_eng.pdf</ref>.  While the cohort in this study is associated with central apnea associated with chronic opioid use, we believe the results are applicable to CSA in general including neurological, PAP therapy onset CSA and idiopathic cases.  

A very high visitation rate by CSA patients prescribed the use of bilevel and Bilevel ST machines indicates that ST continues to be prescribed to central apnea patients.  We repeatedly see very poor results and patients experiencing high levels of apnea and discomfort when prescribed ST therapy rather than ASV. None of the major manufacturers of respiratory assist devices recommend the use of bilevel ST for the treatment of ST, and yet we see this egregious practice repeated time after time. This article is suggested as a means of quantitatively demonstrating the significant difference in efficacy for ASV vs ST in the hopes we can spare a few patients the pain and frustration of having to endure the wrong therapy. Please use the linked study and provide it to your doctor if they prescribe ST for a central apnea problem, and ask them for any study which demonstrates that the efficacy of ST is efficacious in the treatment of CSA, and particularly to show where ST has ever proven superior to ASV in the treatment of central or complex sleep disordered breathing.  Although this study dates to 2014, we are unaware of any study that recommends ST as superior to ASV in any medical study.  Based on our observations of repeated failure to achieve efficacy, the use of ST to treat central and complex sleep apnea should be discontinued.

==A novel adaptive servoventilation (ASVAuto) for the treatment of central sleep apnea associated with chronic use of opioids==
[https://pubmed.ncbi.nlm.nih.gov/25126031/ |Michelle Cao, Chia-Yu Cardell, Leslee Willes, June Mendoza, Adam Benjafield, Clete Kushida]

===Abstract===
'''Study objectives:''' To compare the efficacy and patient comfort of a new mode of minute ventilation-targeted adaptive servoventilation (ASVAuto) with auto-titrating expiratory positive airway pressure (EPAP) versus bilevel with back-up respiratory rate (bilevel-ST) in patients with central sleep apnea (CSA) associated with chronic use of opioid medications.

'''Methods:''' Prospective, randomized, crossover polysomnography (PSG) study. Eighteen consecutive patients (age ≥ 18 years) who had been receiving opioid therapy (≥ 6 months), and had sleep disordered breathing with CSA (central apnea index [CAI] ≥ 5) diagnosed during an overnight sleep study or positive airway pressure (PAP) titration were enrolled to undergo 2 PSG studies-one with ASVAuto and one with bilevel-ST. Patients completed 2 questionnaires after each PSG; Morning After Patient Satisfaction Questionnaire and PAP Comfort Questionnaire.

'''Results:''' Patients had a mean age of 52.9 ± 15.3 years. PSG prior to randomization showed an apnea hypopnea index (AHI) of 50.3 ± 22.2 and CAI of 13.0 ± 18.7. Titration with ASVAuto versus bilevel-ST showed that there were significant differences with respect to AHI and CAI. The AHI and CAI were significantly lower on ASVAuto than bilevel-ST (2.5 ± 3.5 versus 16.3 ± 20.9 [p = 0.0005], and 0.4 ± 0.8 versus 9.4 ± 18.8 [p = 0.0002], respectively). Respiratory parameters were normalized in 83.3% of patients on ASVAuto versus 33.3% on bilevel-ST. Patients felt more awake and alert on ASVAuto than bilevel-ST based on scores from Morning After Patient Satisfaction Questionnaire (p = 0.0337).

'''Conclusions:''' The ASVAuto was significantly more effective than bilevel-ST for the treatment of CSA associated with chronic opioid use.

[[file:ASVauto vs BiPAP ST.png]]