Complex Sleep Apnea Research Articles

Randomized Controlled Trial of Noninvasive Positive Pressure Ventilation (NPPV) Versus Servoventilation in Patients with CPAP-Induced Central Sleep Apnea (Complex Sleep Apnea)

To compare the treatment effect of noninvasive positive pressure ventilation (NPPV) and anticyclic servoventilation in patients with continuous positive airway pressure (CPAP)-induced central sleep apnea (complex sleep apnea). Randomized controlled trial. Sleep center. Thirty patients who developed complex sleep apnea syndrome (CompSAS) during CPAP treatment. NPPV or servoventilation. Patients were randomized to NPPV or servo-ventilation. Full polysomnography (PSG) was performed after 6 weeks. On CPAP prior to randomization, patients in the NPPV and servoventilator arm had comparable apnea-hypopnea indices (AHI, 28.6 ± 6.5 versus 27.7 ± 9.7 events/h (mean ± standard deviation [SD])), apnea indices (AI,19 ± 5.6 versus 21.1 ± 8.6 events/h), central apnea indices (CAI, 16.7 ± 5.4 versus 18.2 ± 7.1 events/h), oxygen desaturation indices (ODI,17.5 ± 13.1 versus 24.3 ± 11.9 events/h). During initial titration NPPV and servoventilation significantly improved the AHI (9.1 ± 4.3 versus 9 ± 6.4 events/h), AI (2 ± 3.1 versus 3.5 ± 4.5 events/h) CAI (2 ± 3.1 versus 2.5 ± 3.9 events/h) and ODI (10.1 ± 4.5 versus 8.9 ± 8.4 events/h) when compared to CPAP treatment (all P < 0.05). After 6 weeks we observed the following differences: AHI (16.5 ± 8 versus 7.4 ± 4.2 events/h, P = 0.027), AI (10.4 ± 5.9 versus 1.7 ± 1.9 events/h, P = 0.001), CAI (10.2 ± 5.1 versus 1.5 ± 1.7 events/h, P < 0.0001)) and ODI (21.1 ± 9.2 versus 4.8 ± 3.4 events/h, P < 0.0001) for NPPV and servoventilation, respectively. Other sleep parameters were unaffected by any form of treatment. After 6 weeks, servoventilation treated respiratory events more effectively than NPPV in patients with complex sleep apnea syndrome.

Occurrence of complex sleep apnea during continuous positive airway pressure therapy

To explore the occurrence of complex sleep apnea syndrome in patients with obstructive sleep apnea during continuous positive airway pressure titration and evaluate their polysomnographic characteristics. A total of 420 patients with obstructive sleep apnea were recruited to undergo an overnight continuous positive airway pressure titration at the Sleep Medicine Center, West China Hospital from January 2010 to December 2012. Their polysomnographic records of respiratory events, oxygen desaturation events and sleep stages were retrospectively reviewed. The incidence of complex sleep apnea syndrome was 7.9% (33/420) and central apnea index (9.0 ± 5.1) /h.No significant differences existed in age, gender, body mass index and titration pressure of continuous positive airway pressure between two groups. Compared with those with non-complex sleep apnea, complex sleep apnea patients had significant increases in apnea/hypopnea index (12.8/h vs 3.6/h, P < 0.05) and oxygen desaturation index (10.3/h vs 3.8/h, P < 0.05) which mainly happened in non-rapid eye movement stage. They also showed decreases in total sleep time ((365 ± 96) vs (402 ± 77) min), rapid eye movement stage (16% ± 8% vs 20% ± 10%) , increases in non-rapid eye movement stage 1 (24% ± 17% vs 15% ± 13%), wakefulness after sleep onset ((108 ± 93) vs (79 ± 61) min) and brief arousal index ((28 ± 15) vs (20 ± 12)/h). And the differences were statistically significant (all P < 0.05). Complex sleep apnea syndrome is common among Chinese patients with obstructive sleep apnea. Compared with those with non-complex sleep apnea, complex sleep apnea patients have reduced sleep time and worse sleep quality during continuous positive airway pressure therapy.

Complex sleep apnea syndrome

Complex sleep apnea syndrome (CompSAS) is a distinct form of sleep-disordered breathing characterized as central sleep apnea (CSA), and presents in obstructive sleep apnea (OSA) patients during initial treatment with a continuous positive airway pressure (CPAP) device. The mechanisms of why CompSAS occurs are not well understood, though we have a high loop gain theory that may help to explain it. It is still controversial regarding the prevalence and the clinical significance of CompSAS. Patients with CompSAS have clinical features similar to OSA, but they do exhibit breathing patterns like CSA. In most CompSAS cases, CSA events during initial CPAP titration are transient and they may disappear after continued CPAP use for 4~8 weeks or even longer. However, the poor initial experience of CompSAS patients with CPAP may not be avoided, and nonadherence with continued therapy may often result. Treatment options like adaptive servo-ventilation are available now that may rapidly resolve the disorder and relieve the symptoms of this disease with the potential of increasing early adherence to therapy. But these approaches are associated with more expensive and complicated devices. In this review, the definition, potential plausible mechanisms, clinical characteristics, and treatment approaches of CompSAS will be summarized.

Central sleep apnea and complex sleep apnea in patients with epilepsy

We sought to examine the prevalence of central sleep apnea (CSA) and complex sleep apnea (CompSA) in patients with epilepsy and to examine their clinical profile, with respect to epilepsy type, etiology, medication use, and EEG abnormalities. We undertook a retrospective analysis of 719 consecutive patients with epilepsy who underwent polysomnography (PSG) at our institution between 2004 and 2011. Of the 458 patients with complete data, we excluded 42 patients with congestive heart failure or left ventricular ejection fraction <40 %. Comparison of clinical and PSG variables between the three groups were conducted with Fisher exact test and analysis of variance. Out of 416 patients tested, 315 (75 %) had obstructive sleep apnea (OSA), 16 (3.7 %) had CSA, 33 (7.9 %) had CompSA. There were more males in the CSA and CompSA groups than in the OSA group (81.2, 81.8, and 59.6 %, respectively, p=0.04). Focal seizures were more prevalent in patients with CSA than in patients OSA or CompSA (62.5, 265, and 21.1 %, respectively, p=0.02). About 11 % of epilepsy patients have sleep-breathing disorders with central apneas, which is not higher than that in a general population. These data should be expanded with future research investigating the role of interictal, ictal, and postictal central apneas in epileptogenesis and epilepsy.

Clinical heterogeneity of patients with complex sleep apnea syndrome

BackgroundThe definition of complex sleep apnea (CompSAS) encompasses patients with obstructive sleep apnea (OSA) who develop central apnea activity upon restitution of airway patency. Presence of arterial hypertension (HTN), coronary artery disease (CAD) and heart failure (HF) have been proposed as risk factors for CompSAS among OSA patients. Using our database of patients with CompSAS, we examined the prevalence of these risk factors and defined other clinical characteristics of patients with CompSAS.MethodsThrough retrospective search of the database, we examined the medical and clinical characteristics of consecutive patients diagnosed with CompSAS between 11/1/2006 and 6/30/2011 at NorthShore University HealthSystem.ResultsOne hundred and fifty patients with CompSAS were identified. Among patients included in the study, 97 (64.7 %) had at least one risk factor for CompSAS, while 53 (35.3 %) did not have any of them. Prevalence of low left ventricular ejection fraction and hypocapnia were low. Therapeutic interventions consisted of several positive airway pressure therapies, mainly adaptive servo ventilation. A hundred and ten patients (73.3 %) complied with recommended therapy and improved clinically.ConclusionsAlthough most patients with CompSAS have cardiac comorbidities, about one third of patients do not have any risk factors of CompSAS prior to sleep testing. Further research on factors involved in development of CompSAS will allow for better tailoring of therapy to pathophysiology involved in an individual case.

Adaptive Servo-Ventilation Therapy in a Case Series of Patients with Co-morbid Insomnia and Sleep Apnea

Adaptive Servo-Ventilation Therapy in a Case Series of Patients with Co-morbid Insomnia and Sleep Apnea Study objectives: The study measured the effects and use of adaptive servo-ventilation (ASV) therapy among insomnia patients with co-morbid sleep-disordered breathing (complex insomnia) who failed standard positive airway pressure (PAP) therapy. Methods: A chart review was conducted on 56 consecutive patients with complex insomnia and self-reported anxiety or psychiatric distress to compare outcomes from their use of standard PAP therapy with their use of ASV. Measurements included polysomnographic changes in breathing events, sleep stages, sleep continuity markers, and adherence data downloads. Results: On standard PAP titrations, expiratory pressure intolerance and central apneas were highly prevalent, yielding a diagnosis of or subthreshold criteria for complex sleep apnea, after which patients received ASV therapy. Compared to standard PAP, ASV significantly improved objective breathing event indices. ASV also was associated with increased sleep efficiency, REM% sleep, and REM sleep consolidation as well as decreased awakenings, arousals, and time awake during the night. Among 39 of 43 current ASV users, adherence was significantly greater for nightly use and hours per night compared to prior use of standard PAP. Conclusions: Fifty-six complex insomnia patients failed standard PAP therapy and developed complex sleep apnea. ASV therapy was associated with improved sleep quality and increased device usage in this select sample.

Chronic opioid use: a risk factor for central sleep apnoea and successful therapy with adaptive pressure support servo-ventilation

Sleep apnoea is a global health problem with significant morbidity. Obesity is a well-known risk factor for this condition, however chronic intake of opioids as a risk factor for central sleep apnoea is under-recognised. We report a case of a 47-year-old man who developed significant sleep-disordered breathing secondary to opioid use for chronic pain. A sleep study demonstrated a picture of complex sleep apnoea with a prominent central sleep apnoea component. He had no significant improvement with conventional continuous positive airway pressure therapy. However, adaptive servo-ventilation had a dramatic effect on his symptoms and compliance. This case highlights the significant risk of central sleep apnoea with opioid use and illustrates the importance of adaptive servo-ventilation in the management of sleep-disordered breathing secondary to impaired central respiratory drive.

Complex sleep apnea syndrome in stroke patients

Fig. 1. A profile of Tiberius Claudius Germanicus appears on the obverse of this silver denarius struck during the Imperial Roman Era (ca. first century CE; photo provided courtesy of A Pangerl of www.romancoins.info). To the Editor We would like to thank Dr. Sacchetti and co-workers for their interest in our article [1]. Sacchetti et al. raise the question whether a stroke may transform, in selected patients, an obstructive sleep apnea syndrome (OSAHS) into a complex-sleep apnea syndrome (Comp-SAS) and postulate that the appearance of central respiratory events may represent a stable consequence of stroke, and may complicate the treatment approach to sleep apnea. This hypothesis is supported by their preliminary data showing mixed (obstructive and central) apneas four months after the stroke. This high prevalence of central and mixed respiratory events in stable phase after stroke is higher than that found in other studies, about the time course of sleep breathing disorders and central periodic breathing in stroke patients [2,3]. These data also contradict in part the attenuation of central respiratory events within week or a few months after the stroke described by the same authors or in OSAHS patients with CompSAS [4]. In OSAHS patients some predictive factors for appearance of CompSAS during CPAP treatment have been proposed [5], which include atrial fibrillation, use of opioids, sleep disruption and features of initial sleep apnea syndrome (in term of severity of obstructive apneas and presence of relevant mixed/central events). The last two factors are probably strictly related to the fluctuations of ventilatory control system and CO2 levels, that we documented in our paper [1], as well as, the fluctuations of arousal system in NREM sleep that have been described as possible distinctive patterns of some patients with OSAHS [6]. Finally, in our opinion, the question is to clarify if these or other factors can tell us whether initial ‘‘complex’’ cases of OSAHS are more prone to develop a clear CompSAS after a stroke and, whether as suggestedbySacchetti andco-workers, tomerge this ‘‘pre-stroke’’ profile of sleep disordered breathing with ‘‘post-stroke’’ features. Thismay enable us to findout possible factors able to distinguish patientswith a transient CompSAS frompatientswith a persistent one.

Analysis of cardiopulmonary coupling to assess adaptive servo-ventilation success in complex sleep apnea management

Adaptive servo-ventilation (ASV) is used to treat complex sleep apnea syndrome (CompSAS), but with variable success. Factors influencing success are poorly understood. ASV devices determine their output based upon characteristics of a given breath and on proprietary algorithms that assume a periodic breathing pattern. Periodic breathing patterns produce elevated narrow band low-frequency cardiopulmonary coupling (eNB-LFC). Therefore, we hypothesized that ASV success would correlate with elevated proportions of periodic breathing as marked by eNB-LFC on cardiopulmonary coupling (CPC) analysis. This was a retrospective study of 106 consecutive patients presenting to an academic tertiary care sleep center with CompSAS between July 2008 and July 2009 who underwent ASV titration with polysomnographic signals amenable to CPC analysis. The study included 89 males (84 %) and 17 females (16 %), with mean age of 63.3 years. Median diagnostic apnea-hypopnea index (AHI) was 38 (21, 56)/h, and on continuous positive airway pressure (CPAP), the median residual AHI (CompSAS) was 36.5 (23, 58)/h, with central apneas occurring on average 22.5 (13, 39)/h. ASV brought AHI to 11.0 ± 13.0, with success in 81.1 % of patients, as defined by an AHI of <10/h. NB-LFC was elevated (>0) in 45.3 %; however, the percentage of eNB-LFC did not correlate with ASV treatment success (p = 0.518). No clinical factors were found to be associated with ASV success. ASV was successful in 81 % of patients with CompSAS. However, eNB-LFC calculated from CPC, a marker for periodic breathing, did not correlate with ASV success and therefore may not be a useful tool to predict ASV success.

Multimodality Therapy for Sleep Apnea Syndromes

Multimodality Therapy for Sleep Apnea Syndromes

Adaptive servoventilation in patients with central or complex sleep apnea related to chronic opioid use and congestive heart failure.

Adaptive servoventilation (ASV) is often used to treat central sleep apnea (CSA) and complex sleep apnea syndrome (CompSAS). Both CompSAS and CSA may occur in the setting of CHF and with the use of chronic opioids. We hypothesized that ASV would be less successful in treatment of CSA and CompSAS secondary to opioid use than in CHF patients. Consecutive patients were studied between January and December 2009 who underwent ASV titration for CSA or CompSAS due to CHF (defined as EF < 45%, or > 50% with evidence for diastolic dysfunction on echocardiogram) and chronic opioid users (defined by the use of opioids > 6 months). Study included one hundred and eight patients with 77 males (71.3%) and 31 females (28.7%). Subjects had severe sleep apnea at baseline (AHI 45.6 ± 27.4) and inadequate control of sleep disordered breathing on CPAP (AHI 50.0 ± 32.2, CAI 36.6 ± 32). No significant differences were found between the groups in overall ASV success, defined as AHI < 10/h (p = 0.236). ASV was successful in 28 (59.6%) of those in the opioid group, compared to 43 (70.5%) of those in the CHF group. When ASV success was defined as AHI < 5/h at optimum EEP, there was again no significant difference between the groups (p-value = 0.812). Logistic regression showed unit increases in BMI, unit increases in HCO(3), and presence of CSR were each associated with decreased likelihood of ASV success. We did not find a statistically significant difference in the effectiveness of ASV between CHF patients and chronic opioid users, with the overall success rate approaching 70%, as defined by an AHI < 10/h. A commentary on this article appears in this issue on page 577.

Treatment of Complex Sleep Apnea Syndrome

Complex sleep apnea syndrome (CompSAS) describes the coexistence or appearance and persistence of central apneas or hypopneas in patients with obstructive sleep apnea upon successful restoration of airway patency. We review data on treatment of CompSAS with CPAP, bilevel positive airway pressure, and adaptive servoventilation and discuss evidence for the addition of medications (analgesics, hypnotics, acetazolamide) and gases (oxygen, CO2) to positive airway pressure therapy. Future research should focus on defining outcomes in patients with CompSAS and allow for more accurate tailoring of therapy to the pathophysiology present in the individual patient.

The Emergence of Central Sleep Apnea after Surgical Relief of Nasal Obstruction in Obstructive Sleep Apnea

By the current definition, complex sleep apnea (CompSA) refers to the emergence of central sleep apnea (CSA) during the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). However, new-onset CSA has been described with use of other treatments for OSA, including tracheostomy, maxillofacial surgery, and mandibular advancement device. We present a patient with CSA beginning after endoscopic sinus and nasal surgery for nasal obstruction in the setting of mild OSA. This case highlights the importance of non-PAP mechanisms in the pathogenesis of CompSA.

Assessment of Therapeutic Options for Mild Obstructive Sleep Apnea Using Cardiopulmonary Coupling Measures

To examine the efficacy of various therapeutic modalities for mild obstructive sleep apnea using cardiopulmonary coupling variables of sleep quality. A 67-year-old Caucasian subject's sleep was recorded at home for 10 nights using a type 3 sleep recording device that measured ECG and body position, followed by generation of the cardiopulmonary sleep spectrogram. Three baseline nights, one night with a sleep jacket containing 3 tennis balls to restrict sleep in the supine position, 2 nights with oxygen only delivered via a nasal cannula at a flow rate of 2 L/minute, 2 nights with a mandible advancing appliance (MAA) only, and 2 nights using oxygen at 2 L/minute with the MAA were compared. Baseline sleep quality estimated using the ratio of high-frequency and low-frequency coupling (1.03) was below the expected normal adult values ranging from 1.67-4.0. The sleep quality ratio was significantly higher (2.08) using the MAA alone compared to baseline, sleep position restriction (1.61), oxygen therapy (0.81), and the combination of MAA with oxygen (1.66). Sleep quality measured objectively using cardiopulmonary coupling variables differentiated the efficacy of therapeutic options for mild obstructive sleep apnea. Such an approach may have practical utility.

Driving On “Auto”: Hands-On is More Effective Than Hands-Free

Driving On “Auto”: Hands-On is More Effective Than Hands-Free

Trials of Bilevel Positive Airway Pressure—Spontaneous in Patients with Complex Sleep Apnoea

Introduction: Patients with complex sleep apnoea (CompSAS) have obstructive sleep apnoea and experience persistent central apnoeas when exposed to positive airway pressure. Elevated loop gain is one of the postulated mechanisms of CompSAS. We speculated that bilevel positive airway pressure—spontaneous (BPAP-S), by producing relative hyperventilation, may more readily produce CompSAS activity than continuous positive airway pressure (CPAP). If found to do so, a trial of BPAP-S might be a simple way of identifying patients with elevated loop gain who are at risk for CompSAS. Materials and methods: Thirty-nine patients with complex sleep apnoea were included in the study. Segments of NREM sleep on CPAP and BPAP-S matched for body position and expiratory airway pressure (“comparison pressure”) were retrospectively analysed. Correlations between clinical and demographic variables and polysomnographic response to CPAP and BPAP-S were sought. Results: There was no difference in any of the polysomnographic indices on CPAP and BPAP-S. In 19 patients the use of CPAP was associated with lower AHI at the comparison pressure; in 20 patients the opposite was true. No clinical variables correlated to the differential response to CPAP vs. BPAP-S. Conclusions: BPAP-S was not more effective than CPAP in stimulating complex sleep apnoea activity.

A prospective polysomnographic study on the evolution of complex sleep apnoea

A prospective polysomnographic study on the evolution of complex sleep apnoea

Sleep

See related article, pp 791–796 Much work has focused on the link between sleep apnea and hypertension, and the evidence that suggests an underlying association between these 2 conditions is persuasive. Sleep apnea syndromes encompass 3 related disorders, obstructive sleep apnea, central sleep apnea, and mixed (or complex) sleep apnea. Obstructive sleep apnea is common, readily diagnosed, and more often than not treatable. Obtaining a thorough sleep history from a patient for symptoms of obstructive sleep apnea, including snoring, witnessed apnea, irregular breathing during sleep, restless sleeping often with choking or gasping arousals, excessive sleepiness, frequent traffic accidents, and declines in cognitive function is now viewed as standard practice. However, obstructive sleep apnea is but one of a number of sleep-related disturbances with the potential for short and more long-term effects on blood pressure (BP).1,2 In that regard, emerging evidence suggests a link between restless legs syndrome (RLS)/periodic limb movements in sleep (PLMS) and hypertension.3–6 RLS is a neurological disorder characterized by pulsating, tugging, creeping, or other unpleasant sensory feelings in the legs and an uncontrollable and sometimes overwhelming urge to shift leg position. In a typical patient, symptoms occur primarily at night as a person might otherwise be relaxing or when one is resting. Symptoms can be present throughout the day, and severity can accentuate during the nighttime hours with leg movement oftentimes relieving the discomfort. The sensations range in severity from simple discomfort to a painful irritation with the integrity of sleep regularly being disrupted. Periodic limb movement disorder …

Continuous positive airway pressure intolerance associated with elevated nasal resistance is possible mechanism of complex sleep apnea syndrome

Complex sleep apnea syndrome (CompSAS) is diagnosed after an elimination of obstructive events with continuous positive airway pressure (CPAP), when a central apnea index ≥5/h or Cheyne-Stokes respiration pattern emerges in patients with obstructive sleep apnea syndrome (OSAS). However, the pathophysiology of CompSAS remains controversial. Of the 281 patients with suspected OSAS, all of whom underwent polysomnography conducted at Nagoya University Hospital, we enrolled 52 patients with apnea-hypopnea index ≥15/h (age 51.4 ± 13.3 years). The polysomnographic findings, left ventricular ejection fraction (LVEF), and nasal resistance were compared between the CompSAS patients and OSAS patients. Forty-three patients were diagnosed with OSAS and nine patients with central sleep apnea syndrome by natural sleep PSG. Furthermore, 43 OSAS patients were classified into the OSAS patients (OSAS group, n = 38) and the CompSAS patients (CompSAS group, n = 5) by the night on CPAP PSG. The nasal resistance was significantly higher in CompSAS group than in OSAS group (0.30 ± 0.10 vs. 0.19 ± 0.07 Pa/cm(3)/s, P = 0.004). The arousal index, percentage of stage 1 sleep, and oxygen desaturation index were significantly decreased, and the percentage of stage REM sleep was significantly increased in the OSAS group with the initial CPAP treatment, but not in the CompSAS group. In addition, the patients with CompSAS showed normal LVEF. CPAP intolerance secondary to an elevated nasal resistance might relate to frequent arousals, which could presumably contribute to an increase in central sleep apnea. Further evaluation in a large study is needed to clarify the mechanism of CompSAS.

Comparison of two servo ventilator devices in the treatment of complex sleep apnea

Objective Servo ventilation (SV) devices generate positive airway pressure with a variable pressure support that changes in response to a patient’s own respiratory output. Two currently available SV devices—VPAP-AdaptSV® and BIPAP-AutoSV®—have been used in treatment of complex sleep apnea (CompSAS), but no side-by-side comparisons are available. Methods Data of 76 consecutive patients with complex sleep apnea, who were prescribed a VPAP-AdaptSV® or BIPAP-AutoSV® in a non-randomized parallel design, were retrospectively analyzed. Patients underwent a diagnostic polysomnogram followed by a continuous positive airway pressure (CPAP) titration and a SV titration study. Objective compliance with the device was assessed at the first visit at 4–6 weeks of its use. Results Thirty-five patients received a VPAP-AdaptSV® device, while 41 patients were treated with BIPAP-AutoSV®. Patients treated with BIPAP-AutoSV® had a significantly higher apnea–hypopnea index during their CPAP titration study than patients treated with VPAP-AdaptSV® [49/h (28–60) vs. 35/h (19.5–49.5), median (interquartile range), p < 0.001]. On follow-up, 56 patients (73.7%) were using their device. Mean nightly use was 5.0 h (2.8–6.4) for VPAP-AdaptSV® group and 6.0 h (3.5–7.2) for BIPAP-AutoSV® group ( p = 0.081); an improvement in Epworth Sleepiness Scale score was higher in the BIPAP-AutoSV® group than in the VPAP-AdaptSV® group [4 (1–9) vs. 2.5 (0–5), p = 0.02]. Conclusion Our retrospective data indicate that the two servo-ventilation devices are comparable means of controlling complex sleep apnea, and the compliance with them is high.