[Treatment-Emergent Central Sleep Apnea - Detection and Treatment]

Treatment-Emergent Central Sleep Apnea - Detection and Treatment Abstract. In treatment-emergent central sleep apnea (TECSA), affected patients with obstructive sleep apnea newly develop central sleep apnea (AHI central ≥5/h) under therapy with positive pressure ventilation which cannot be explained by other causes. The pathophysiology of TECSA is incompletely understood. PaCO2 and the associated apnea threshold seem to play a central role. The incidence of TECSA varies (1.8-20%), and in about 2/3 of cases it is self-limiting in the course of the therapy. If persistence or new onset occurs later in the course of positive pressure therapy, a further evaluation (e.g., echocardiography, neurologic examination, medication history) is indicated. Effective treatment options include a change in ventilation therapy (adaptive servoventilation or bilevel ventilation with back-up frequency) or additional nocturnal oxygen supplementation; these options should be decided case by case.

Effect of Treatment of Central Sleep Apnea/Cheyne-Stokes Respiration on Left Ventricular Ejection Fraction in Heart Failure: A Network Meta-Analysis

STUDY OBJECTIVES

Patients who have experienced heart failure with central sleep apnea/Cheyne-Stokes respiration (CSA/CSR) have an impaired prognosis. Continuous positive airway pressure (CPAP) and adaptive servoventilation (ASV) as well as nocturnal oxygen (O₂) are proposed treatment modalities of CSA/CSR. The goal of the study is to assess whether and how different treatments of CSA/CSR affect cardiac function.

METHODS

Databases were searched up to December 2017 for randomized controlled trials (RCTs) comparing the effect of any combination of CPAP, ASV, O₂ or an inactive control on left ventricular ejection fraction (LVEF) in patients with heart failure and CSA/CSR. A systematic review and network meta-analysis using multivariate random-effects meta-regression were performed.

RESULTS

Twenty-four RCTs (1,289 patients) were included in the systematic review and data of 16 RCTs (951 patients; apnea-hypopnea-index 38 ± 3/h, LVEF 29 ± 3%) could be pooled in a network meta-analysis. Compared to an inactive control, both CPAP and ASV significantly improved LVEF by 4.4% (95% confidence interval 0.3-8.5%, P = 0.036) and 3.8% (95% confidence interval 0.6-7.0%, P = 0.025), respectively, whereas O₂ had no effect on LVEF (P = 0.35). There was no difference in treatment effects on LVEF between CPAP and ASV (P = 0.76). The treatment effect of positive pressure ventilation was larger when baseline LVEF was lower in systolic heart failure.

CONCLUSIONS

CPAP and ASV are effective in improving LVEF in patients with heart failure and CSA/CSR to a clinically relevant amount, whereas nocturnal O₂ is not. There is no difference between CPAP and ASV in the comparative beneficial effect on cardiac function.

Adherence to Positive Airway Therapy After Switching From CPAP to ASV: A Big Data Analysis

STUDY OBJECTIVES

There is a lack of data regarding adherence trajectories when switching from continuous positive airway pressure (CPAP) to adaptive servoventilation (ASV) in the context of persistent or treatment-emergent central sleep apnea (CSA). This study investigated 90-day adherence rates in patients with sleep apnea based on the type of positive airway pressure (PAP) device used and any switching of PAP modality over time.

METHODS

Telemonitoring data were obtained from a United States PAP database. Eligible patients were a 30% random sample who started PAP, plus all who started ASV, from January 1, 2015 to October 2, 2015. All received PAP and had at least one session with usage of 1 hour or more. Adherence and device usage were determined in three groups: started on CPAP and stayed on CPAP (CPAP only); started on ASV and stayed on ASV (ASV only); started on CPAP, switched to ASV (Switch). The United States Medicare definition of adherence was used.

RESULTS

The study included 198,890 patients; 189,724 (CPAP only), 8,957 (ASV only) and 209 (Switch). In the Switch group, average apnea-hypopnea index decreased significantly on ASV versus CPAP. At 90 days, adherence rates were 73.8% and 73.2% in the CPAP only and ASV only groups. In the Switch group, CPAP adherence was 62.7%, improving to 76.6% after the switch to ASV. Mean device usage at 90 days was 5.27, 5.31, and 5.73 h/d in the CPAP only, ASV only, and Switch groups, respectively.

CONCLUSIONS

Treatment-emergent or persistent CSA during CPAP reduced therapy adherence, but adherence improved early after switching from CPAP to ASV.

Opioids Cause Central and Complex Sleep Apnea in Humans and Reversal With Discontinuation: A Plea for Detoxification

ABSTRACT

Central sleep apnea (CSA) and continuous positive airway pressure (CPAP) emergent CSA are common in patients for whom opioids have been prescribed for chronic pain management. It is not known if opioids are the potential cause of CSA. We report the case of a patient who underwent multiple full nights of polysomnography testing while on opioids, off opioids, and with various positive airway pressure devices. While on opioids, the patient had severe CSA that persisted during both CPAP and bilevel titration but was eliminated with adaptive servoventilation therapy. Some time later, opioid use was discontinued by the patient. Repeat polysomnography showed resolution of the sleep-disordered breathing. Later-while the patient was still off opioids-she had gained weight and become symptomatic; polysomnography showed obstructive sleep apnea without CSA. This time, therapy with CPAP showed elimination of sleep apnea without emergent CSA. These data collectively indicate that opioids were the cause of CSA as well as emergent CSA.

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

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.

Adaptive servoventilation improves cardiac dysfunction and prognosis in heart failure patients with sleep-disordered breathing: a meta-analysis

BACKGROUND

Adaptive servoventilation (ASV) is a new therapeutic modality to treat sleep-disordered breathing (SDB) especially for central sleep apnoea associated with Cheyne-Stokes respiration, whereas the role of ASV in SDB patients with heart failure (HF) is controversial. The purpose of this study was to evaluate the effects of ASV on these patients through a meta-analysis of published data.

METHODS

A comprehensive literature search was performed to identify studies focused on ASV through databases, including PubMed, Medline, Embase, Cochrane Library and Web of science from 1950 to 2014. Parallel randomised controlled trials which compared ASV to other controls in HF and SDB patients with extractable data were meet our inclusion criteria. Random effects meta-analysis models were applied using RevMan 5.2.

RESULTS

Seven studies involving 301 patients were recruited in the meta-analysis. The weighted mean difference in apnoea hyponea index (-17.73 events/h, 95% CI, -21.85 to -2.94) and left ventricular ejection fraction (MD: 4.68, 95% CI, 2.74-6.63) both favored ASV compared to control conditions. The urinary noradrenaline level (MD: -32.18, 95%CI: -44.07 to -20.09) was decreased, while the exercise capacity measured by 6-min walk distance (MD: 41.26, 95% CI, 17.06-65.45) was improved after ASV treatment. Whereas neither left ventricular end-diastolic diameter (LVEDD) nor Epworth sleepiness-scale score (ESS) significantly changed after ASV therapy.

CONCLUSIONS

ASV is superior to other therapy, as it can result in good consequences for patients with SDB and improve their prognosis in cardiac function. Further studies will still be needed to assess the benefit of it.

Sleep-disordered Breathing in Heart Failure - Current State of the Art

Sleep-disordered breathing (SDB), either obstructive sleep apnoea (OSA) or central sleep apnoea (CSA)/Cheyne-Stokes respiration (CSR) and often a combination of the two, is highly prevalent in patients with heart failure (HF), is associated with reduced functional capacity and quality of life, and has a negative prognostic impact. European HF guidelines identify that sleep apnoea is of concern in patients with HF. Continuous positive airway pressure is the treatment of choice for OSA, and adaptive servoventilation (ASV) appears to be the most consistently effective therapy for CSA/CSR while also being able to treat concomitant obstructive events. There is a growing body of evidence that treating SDB in patients with HF, particularly using ASV for CSA/CSR, improves functional outcomes such as HF symptoms, cardiac function, cardiac disease markers, exercise tolerance and quality of life. However, conflicting results have been reported on 'hard' outcomes such as mortality and healthcare utilisation, and the influence of effectively treating SDB, including CSA/CSR, remains to be determined in randomised clinical trials. Two such trials (SERVE-HF and ADVENT-HF) in chronic stable HF and another in post-acute decompensated HF (CAT-HF) are currently underway.

Chiari 1 Malformation Presenting as Central Sleep Apnea during Pregnancy: A Case Report, Treatment Considerations, and Review of the Literature

Purpose: Chiari malformation (CM) type-1 frequently causes obstructive or central sleep-disordered breathing (SDB) in both adults and children, although SDB is relatively rare as a presenting manifestation in the absence of other neurological symptoms. The definitive treatment of symptomatic CM is surgical decompression. We report a case that is, to our knowledge, a novel manifestation of central sleep apnea (CSA) due to CM type-1 with severe exacerbation and initial clinical presentation during pregnancy.

Methods: Case report from tertiary care comprehensive sleep medicine center with literature review of SDB manifestations associated with CM type-1. PubMed search was conducted between January 1982 and October 2013.

Results: We report a 25-year-old woman with severe CSA initially presenting during her first pregnancy that eventually proved to be caused by CM type-1. The patient was successfully treated preoperatively by adaptive servoventilation (ASV), with effective resolution of SDB following surgical decompression, and without recurrence in a subsequent pregnancy. Our literature review found that 58% of CM patients with SDB had OSA alone, 28% had CSA alone, 8 (10%) had mixed OSA/CSA, and 6 (8%) had hypoventilation. Of CM patients presenting with SDB, 50% had OSA, 42% had CSA, 8% had mixed OSA/CSA, and 10.4% had hypoventilation. We speculate that CSA may develop in CM patients in whom brainstem compression results in excessive central chemoreflex sensitivity with consequent hypocapnic CSA.

Conclusion: Chiari malformation type-1 may present with a diversity of SDB manifestations, and timely recognition and surgical referral are necessary to prevent further neurological deficits. ASV therapy can effectively manage CSA caused by CM type-1, which may initially present during pregnancy.

A novel adaptive servoventilation (ASVAuto) for the treatment of central sleep apnea associated with chronic use of opioids

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.

The complex sleep apnea resolution study: a prospective randomized controlled trial of continuous positive airway pressure versus adaptive servoventilation therapy

INTRODUCTION

Prior studies show that adaptive servoventilation (ASV) is initially more effective than continuous positive airway pressure (CPAP) for patients with complex sleep apnea syndrome (CompSAS), but choosing therapies has been controversial because residual central breathing events may resolve over time in many patients receiving chronic CPAP therapy. We conducted a multicenter, randomized, prospective trial comparing clinical and polysomnographic outcomes over prolonged treatment of patients with CompSAS, with CPAP versus ASV.

METHODS

Qualifying participants meeting criteria for CompSAS were randomized to optimized CPAP or ASV treatment. Clinical and polysomnographic data were obtained at baseline and after 90 days of therapy.

RESULTS

We randomized 66 participants (33 to each treatment). At baseline, the diagnostic apnea-hypopnea index (AHI) was 37.7 ± 27.8 (central apnea index [CAI] = 3.2 ± 5.8) and best CPAP AHI was 37.0 ± 24.9 (CAI 29.7 ± 25.0). After second-night treatment titration, the AHI was 4.7 ± 8.1 (CAI = 1.1 ± 3.7) on ASV and 14.1 ± 20.7 (CAI = 8.8 ± 16.3) on CPAP (P ≤ 0.0003). At 90 days, the ASV versus CPAP AHI was 4.4 ± 9.6 versus 9.9 ± 11.1 (P = 0.0024) and CAI was 0.7 ± 3.4 versus 4.8 ± 6.4 (P < 0.0001), respectively. In the intention-to-treat analysis, success (AHI < 10) at 90 days of therapy was achieved in 89.7% versus 64.5% of participants treated with ASV and CPAP, respectively (P = 0.0214). Compliance and changes in Epworth Sleepiness Scale and Sleep Apnea Quality of Life Index were not significantly different between treatment groups.

CONCLUSION

Adaptive servoventilation (ASV) was more reliably effective than CPAP in relieving complex sleep apnea syndrome. While two thirds of participants experienced success with CPAP, approximately 90% experienced success with ASV. Because both methods produced similar symptomatic changes, it is unclear if this polysomnographic effectiveness may translate into other desired outcomes.

CLINICAL TRIALS

Clinicaltrials.Gov NCT00915499.

Bench test evaluation of adaptive servoventilation devices for sleep apnea treatment

RATIONALE

Adaptive servoventilation devices are marketed to overcome sleep disordered breathing with apneas and hypopneas of both central and obstructive mechanisms often experienced by patients with chronic heart failure. The clinical efficacy of these devices is still questioned.

STUDY OBJECTIVES

This study challenged the detection and treatment capabilities of the three commercially available adaptive servoventilation devices in response to sleep disordered breathing events reproduced on an innovative bench test.

METHODS

The bench test consisted of a computer-controlled piston and a Starling resistor. The three devices were subjected to a flow sequence composed of central and obstructive apneas and hypopneas including Cheyne-Stokes respiration derived from a patient. The responses of the devices were separately evaluated with the maximum and the clinical settings (titrated expiratory positive airway pressure), and the detected events were compared to the bench-scored values.

RESULTS

The three devices responded similarly to central events, by increasing pressure support to raise airflow. All central apneas were eliminated, whereas hypopneas remained. The three devices responded differently to the obstructive events with the maximum settings. These obstructive events could be normalized with clinical settings. The residual events of all the devices were scored lower than bench test values with the maximum settings, but were in agreement with the clinical settings. However, their mechanisms were misclassified.

CONCLUSION

The tested devices reacted as expected to the disordered breathing events, but not sufficiently to normalize the breathing flow. The device-scored results should be used with caution to judge efficacy, as their validity depends upon the initial settings.

Adaptive servoventilation (ASV) in patients with sleep disordered breathing associated with chronic opioid medications for non-malignant pain

BACKGROUND

Adaptive servoventilation (ASV) can be effective therapy for specific types of central apnea such as Cheyne-Stokes respiration (CSR). Patients treated chronically with opioids develop central apneas and ataxic breathing patterns (Biot's respiration), but therapy with CPAP is usually unsuccessful. There are no published studies of ASV in patients with sleep apnea complicated by chronic opioid therapy.

METHODS

Retrospective analysis of 22 consecutive patients referred for evaluation and treatment of sleep apnea who had been using opioid medications for at least 6 months, had an apnea-hypopnea index (AHI) > or = 20/h, and had been tested with ASV. Baseline polysomnography was compared with CPAP and ASV.

OUTCOME VARIABLES

AHI, central apnea index (CAI), obstructive apnea index (OAI), hypopnea index (HI), desaturation index, mean SpO2, lowest SpO2, time SpO2 < 90%, and degree of Biot's respiration.

RESULTS

Mean (SD) AHI measured 66.6/h (37.3) at baseline, 70.1/h (32.6) on CPAP, and 54.2/h (33.0) on ASV. With ASV, the mean OAI was significantly decreased to 2.4/h (p < 0.0001), and the mean HI increased significantly to 35.7/h (p < 0.0001). The decrease of CAI from 26.4/h to 15.6/h was not significant (p = 0.127). Biot's breathing persisted, and oxygenation parameters were unimproved with ASV.

CONCLUSIONS

Due to residual respiratory events and hypoxemia, ASV was considered insufficient therapy in these patients. Persistence of obstructive events could be due to suboptimal pressure settings (end expiratory and/or maximal inspiratory). Residual central events could be related to fundamental differences in the pathophysiology of CSR compared to opioid induced breathing disturbances.