Retrospective, nonrandomized controlled study on autoadjusting, dual-pressure positive airway pressure therapy for a consecutive series of complex insomnia disorder patients

Abstract

Purpose: Emerging evidence shows that positive airway pressure (PAP) treatment of obstructive sleep apnea (OSA) and upper airway resistance syndrome (UARS) in chronic insomnia patients (proposed "complex insomnia" disorder) leads to substantial decreases in insomnia severity. Although continuous PAP (CPAP) is the pressure mode most widely researched, intolerance to fixed pressurized air is rarely investigated or described in comorbidity patients. This retrospective study examined dual pressure, autoadjusting PAP modes in chronic, complex insomnia disorder patients.

Patients and methods: Chronic insomnia disorder patients (mean [SD] insomnia severity index [ISI] =19.11 [3.34]) objectively diagnosed with OSA or UARS and using either autobilevel PAP device or adaptive servoventilation (ASV) device after failing CPAP therapy (frequently due to intolerance to pressurized air, poor outcomes, or emergence of CSA) were divided into PAP users (≥20 h/wk) and partial users (<20 h/wk) for comparison. Subjective and objective baseline and follow-up measures were analyzed.

Results: Of the 302 complex insomnia patients, PAP users (n=246) averaged 6.10 (1.78) nightly hours and 42.71 (12.48) weekly hours and partial users (n=56) averaged 1.67 (0.76) nightly hours and 11.70 (5.31) weekly hours. For mean (SD) decreases in total ISI scores, a significant (group × time) interaction was observed (F[1,300]=13.566; P<0.0001) with PAP users (-7.59 [5.92]; d=1.63) showing superior results to partial users (-4.34 [6.13]; d=0.81). Anecdotally, patients reported better tolerability with advanced PAP compared to previous experience with CPAP. Both adaptive servoventilation and autobilevel PAP showed similar ISI score improvement without statistical differences between devices. Total weekly hours of PAP use correlated inversely with change in insomnia symptoms (r=-0.256, P<0.01).

Conclusion: Insomnia severity significantly decreased in patients using autoadjusting PAP devices, but the study design restricts interpretation to an association. Future research must elucidate the interaction between insomnia and OSA/UARS as well as the adverse influence of pressure intolerance on PAP adaptation in complex insomnia patients. Randomized controlled studies must determine whether advanced PAP modes provide benefits over standard CPAP modes in these comorbidity patients.

Keywords: CPAP failure; adaptive servoventilation; autobilevel; insomnia; obstructive sleep apnea; upper airway resistance syndrome.

Figure 1

Flowchart of inclusion criteria and group definition. Notes: Data presented as mean (SD). ^aPrescription given after a full night ASV or ABPAP titration PSG or split-therapy PSG where traditional PAP was failed early in the study allowing for subsequent titration with advanced PAP device. ^bFollow-up included appointments during which patients completed outcome questionnaires: ISI and ESS. ^cCurrent PAP use defined by Objective Data Download or Subjective report. ^dPAP users: PAP use ≥20 h/wk. ^ePartial users: PAP use <20 h/wk. Abbreviations: ABPAP, autobilevel positive airway pressure; ASV, adaptive servoventilation; ESS, Epworth Sleepiness Scale; h, hours; ISI, insomnia severity index; N, nights; PAP, positive airway pressure; PSG, polysomnography; Rx, prescription; SDB, sleep disordered breathing; wk, week.

Figure 2

Timing of subjective and objective PAP mode failure.^a Notes: (A) Reasons for PAP failure following prescription from MSAS or other sleep laboratories. (B) Reasons for PAP failure during PSG desensitization. (C) Reasons for PAP failure during technologist-attended titration PSG. Total number of reasons for failure at each time point exceeds sample size (n) due to multiple reasons for failure. Single-item reasons for failure in graphs (B) and (C) exceed sample size (n) due to failure on multiple modes of PAP (CPAP, BPAP, and ABPAP). ^aSubjective and objective reasons for PAP failure: emerging CSA: objective central-like pauses on airflow curve; pressure >15: optimal pressures >15 cmH₂O; aborted use: very limited or no use at home; subjective EPI: subjective intolerance to pressurized air (difficulty exhaling against PAP pressure); poor outcomes: persistently elevated ISI, fatigue, or daytime symptoms despite PAP therapy use; variable pressures: technologist observed need for variable pressures due to body position or sleep stage; residual SDB: persistent CSA, OSA, or UARS evident on data download or despite increases in PAP pressure; objective EPI: objective EPI on airflow waveform; and complex SA: presence of ≥5.0 central events/h (CAI) comprising >50% of AHI events. ^bPrescribed device: patients who were prescribed a device and demonstrated subjective and objective PAP failure at home. ^cPresleep/desensitization: PAP failure occurred either during a prestudy pressure desensitization the night of a titration or during daytime nap study used to gradually introduce PAP therapy to apprehensive patients (PAP-NAP). ^dTitration: PAP failure occurred during a technologist-attended titration PSG in the sleep laboratory. Abbreviations: ABPAP, autobilevel positive airway pressure; AHI, apnea–hypopnea index; BPAP, Bilevel PAP; CAI, Central Apnea Index; CPAP, continuous positive airway pressure; CSA, central sleep apnea; EPI, expiratory pressure intolerance; MSAS, Maimonides Sleep Arts & Sciences; OSA, obstructive sleep apnea; PAP, positive airway pressure; PSG, polysomnography; SA, sleep apnea; SDB, sleep disordered breathing; UARS, upper airway resistance syndrome.

Figure 3

Subjective symptoms for psychophysiological conditions and poor sleep hygiene reported at intake.^a Notes: ^aItems extracted from Intake Questionnaires. *Data from TMB-10, a questionnaire assessing time-monitoring behavior as it pertains to an individual’s insomnia. Abbreviations: EtOH, alcohol; THC, marijuana TMB-10, Time Monitoring Behavior questionnaire.

Figure 4

Within-group comparison of mean (SD) intake vs follow-up ISI values for (A) Total sample (n=302), (B) ASV sample (n=199), and (C) ABPAP sample (n=103). Abbreviations: ABPAP, autobilevel positive airway pressure; ASV, adaptive servoventilation; ISI, insomnia severity index; PAP, positive airway pressure.

Figure 5

Within-group comparison of mean intake vs follow-up values^a for 299^b patients on the following 3 ISI questions: SOI, SMI, and EMA. Notes: (A) PAP users (n=243) vs partial users (n=56). (B) ASV users (n=154) vs ASV partial users (n=43). (C) ABPAP users (n=89) vs ABPAP partial users (n=13). ^aCohen’s d reported above each follow-up average. ^bIndividual ISI responses were unavailable for 3 subjects. *P=0.001. Abbreviations: ABPAP, autobilevel positive airway pressure; ASV, adaptive servoventilation; EMA, early morning awakenings; ISI, insomnia severity index; PAP, positive airway pressure; SMI, sleep maintenance insomnia; SOI, sleep onset insomnia.