The emergence of central sleep apnea after surgical relief of nasal obstruction in obstructive sleep apnea

The prevalence of treatment-emergent central sleep apnea with mandibular advancement device therapy

STUDY OBJECTIVES

Treatment-emergent central sleep apnea (TECSA) describes the appearance or persistence of central sleep apnea while undergoing treatment for obstructive sleep apnea. TECSA is well studied in continuous positive airway pressure therapy with an estimated prevalence of 8%. Based on a few case reports, mandibular advancement devices (MAD) may also provoke TECSA. This study aims to gain insight into the prevalence of TECSA with MAD therapy.

METHODS

This retrospective study includes a total of 129 patients with moderate to severe obstructive sleep apnea who were treated with a custom-made titratable MAD. Baseline and follow-up sleep studies were compared to identify patients with TECSA. Since different diagnostic criteria to define TECSA are used in literature, prevalence was calculated according to three definitions (TECSA-1, -2, and -3). Demographics, MAD treatment variables, and findings of the diagnostic polysomnography were compared between TECSA and non-TECSA patients to identify possible predictors.

RESULTS

Depending on the definition used, TECSA was found in 3.1%-7.8% of patients undergoing MAD therapy. TECSA patients had a higher apnea index (9.2 vs 2.0 events/h, P = .042), central apnea-hypopnea index (4.1 vs 0.2 events/h, P = .045) and oxygen desaturation index (23.9 vs 16.3 events/h, P = .018) at baseline compared to non-TECSA patients. No differences were found in demographics and treatment variables.

CONCLUSIONS

These findings demonstrate that TECSA also occurs in patients starting MAD treatment. Patients with TECSA had a higher apnea index, central apnea-hypopnea index, and oxygen desaturation index at baseline compared to non-TECSA patients.

CITATION

Hellemans S, Van de Perck E, Braem MJ, Verbraecken J, Dieltjens M, Vanderveken OM. The prevalence of treatment-emergent central sleep apnea with mandibular advancement device therapy. J Clin Sleep Med. 2023;19(12):2035-2041.

Practice recommendations for the role of physiotherapy in the management of sleep disorders: the 2022 Brazilian Sleep Association Guidelines

This clinical guideline supported by the Brazilian Sleep Association comprises a brief history of the development of Brazilian sleep physiotherapy, outlines the role of the physiotherapist as part of a sleep health team, and describes the clinical guidelines in respect of the management of some sleep disorders by the physiotherapist (including sleep breathing disorders, i.e., obstructive sleep apnea, central sleep apnea, upper airway resistance syndrome, hypoventilation syndromes and overlap syndrome, and pediatric sleep breathing disorders; sleep bruxism; circadian rhythms disturbances; insomnia; and Willis-Ekbom disease/periodic limb movement disorder. This clinical practice guideline reflects the state of the art at the time of publication and will be reviewed and updated as new information becomes available.

Central and mixed sleep apnea related to patients treated with maxillomandibular advancement for obstructive sleep apnea: A retrospective cohort study

The aim of this study was to evaluate the clinical efficacy of maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) patients with a percentage of central and mixed apnea index in the total apnea-hypopnea index (CMAI%) ≧25%. Patients treated with MMA for OSA were retrospectively evaluated for baseline and postoperative patient data and polysomnographic results. The pre- and postoperative obstructive, central and mixed apnea parameters were compared. Of the included 78 patients, 21 patients (27%) presented with CMAI% ≧25% (median CMAI%, 49.1%; 35.9-63.8) prior to MMA. In 67% of these cases, MMA resulted in CMAI% <25 (median CMAI%, 6.1%; 2.1-8.9) and significantly improved the apnea-hypopnea index (AHI) (p < 0.001), the lowest oxyhemoglobin saturation (p < 0.001), central and mixed apnea index (p < 0.001), percentage of central and mixed apneas of total AHI (p = 0.004), central apnea index (p < 0.001), and mixed apnea index (p < 0.001). CMAI% ≧25% emerged in 25% of patients after MMA (median CMAI%, 49.1%; 35.9-63.8). Within the undeniable limitations of the study, it seems that the presence of CMAI% ≧25% should not be regarded as a contraindication for MMA in OSA patients.

Evaluation of the Impact of Body Position on Primary Central Sleep Apnea Syndrome

OBJECTIVE

To evaluate the impact of the body position on primary central sleep apnea syndrome.

METHODS

Fifty-five subjects diagnosed with central sleep apnea (CSA) through polysomnographic examinations were prospectively enrolled in the study. All patients underwent cardiologic and neurologic examinations. Primary positional central sleep apnea (PCSA) was determined when the supine Apnea-Hypopnea Index (AHI) was greater than two times the non-supine AHI. The primary PCSA and non-PCSA groups were compared in terms of demographic characteristics, sleep parameters, and treatment approaches.

RESULTS

Overall, 39 subjects diagnosed with primary CSA were included in the study; 61.5% of the subjects had primary PCSA. There were no differences between the primary PCSA and non-PCSA groups regarding age, sex, body mass index (BMI), co-morbidities, and history of septoplasty. In terms of polysomnography parameters, AHI (P=.001), oxygen desaturation index (P=.002), the time spent under 88% saturation during sleep (P=.003), number of obstructive apnea (P=.011), mixed apnea (P=.009), and central apnea (P=.007) was lower in the primary PCSA group than in the non-PCSA group. Twenty-nine percent of the patients in the primary PCSA group were recommended position treatment and 71% were recommended positive airway pressure (PAP) therapy; all patients in the non-PCSA group were recommended PAP therapy.

CONCLUSIONS

Our results demonstrated that the rate of primary PCSA was high (61.5%) and primary PCSA was associated with milder disease severity compared with non-PCSA. The classification of patients with primary CSA regarding positional dependency may be helpful in terms of developing clinical approaches and treatment recommendations.

Treatment-emergent central sleep apnea associated with non-positive airway pressure therapies in obstructive sleep apnea patients: A systematic review

This systematic review summarizes the prevalence of treatment-emergent central sleep apnea (TECSA) occurring with therapies other than positive airway pressure (PAP) for the management of obstructive sleep apnea (OSA). We describe its natural course as well as the proposed underlying pathophysiological mechanisms and the clinical management of affected patients. A systematic search of PubMed, Embase, Web of science, and the Cochrane Library was performed until June 2020. Eighteen studies (n = 284 patients) were included. TECSA was observed in 31 patients with the use of four different medical devices (mandibular advancement device, hypoglossal nerve stimulation, tongue stabilizing device and nasal expiratory PAP) and after three different types of surgical treatments (tracheostomy, maxillofacial surgery and oro-nasal surgery). Due to the paucity of data available, it was not possible to establish a clear prevalence rate of TECSA for each alternative treatment. After the initiation of non-PAP treatments, a systematic reassessment of the treatment efficacy with follow-up sleep studies will be helpful to identify TECSA. A spontaneous resolution over time was described as well as a persistence of TECSA. In this case, treatment should focus on patients' specific underlying pathophysiology. Overall, the limited current literature suggests that this phenomenon is rare (<4%).

Treatment-emergent central sleep apnea: a unique sleep-disordered breathing

Treatment-emergent central sleep apnea (TECSA) is a specific form of sleep-disordered breathing, characterized by the emergence or persistence of central apneas during treatment for obstructive sleep apnea. The purpose of this review was to summarize the definition, epidemiology, potential mechanisms, clinical characteristics, and treatment of TECSA. We searched for relevant articles up to January 31, 2020, in the PubMed database. The prevalence of TECSA varied widely in different studies. The potential mechanisms leading to TECSA included ventilatory control instability, low arousal threshold, activation of lung stretch receptors, and prolonged circulation time. TECSA may be a self-limited disorder in some patients and could be resolved spontaneously over time with ongoing treatment of continuous positive airway pressure (CPAP). However, central apneas persist even with the regular CPAP therapy in some patients, and new treatment approaches such as adaptive servo-ventilation may be necessary. We concluded that several questions regarding TECSA remain, despite the findings of many studies, and it is necessary to carry out large surveys with basic scientific design and clinical trials for TECSA to clarify these irregularities. Further, it will be vital to evaluate the baseline demographic and polysomnographic data of TECSA patients more carefully and comprehensively.

Evaluation of the Impact of Body Position on Primary Central Sleep Apnea Syndrome

OBJECTIVE

To evaluate the impact of the body position on primary central sleep apnea syndrome.

METHODS

Fifty-five subjects diagnosed with central sleep apnea (CSA) through polysomnographic examinations were prospectively enrolled in the study. All patients underwent cardiologic and neurologic examinations. Primary positional central sleep apnea (PCSA) was determined when the supine Apnea-Hypopnea Index (AHI) was greater than two times the non-supine AHI. The primary PCSA and non-PCSA groups were compared in terms of demographic characteristics, sleep parameters, and treatment approaches.

RESULTS

Overall, 39 subjects diagnosed with primary CSA were included in the study; 61.5% of the subjects had primary PCSA. There were no differences between the primary PCSA and non-PCSA groups regarding age, sex, body mass index (BMI), co-morbidities, and history of septoplasty. In terms of polysomnography parameters, AHI (P=.001), oxygen desaturation index (P=.002), the time spent under 88% saturation during sleep (P=.003), number of obstructive apnea (P=.011), mixed apnea (P=.009), and central apnea (P=.007) was lower in the primary PCSA group than in the non-PCSA group. Twenty-nine percent of the patients in the primary PCSA group were recommended position treatment and 71% were recommended positive airway pressure (PAP) therapy; all patients in the non-PCSA group were recommended PAP therapy.

CONCLUSIONS

Our results demonstrated that the rate of primary PCSA was high (61.5%) and primary PCSA was associated with milder disease severity compared with non-PCSA. The classification of patients with primary CSA regarding positional dependency may be helpful in terms of developing clinical approaches and treatment recommendations.

Sleep Apnea Treatment Considerations in Patients with Comorbidities

A wide range of sleep, psychiatric, and medical comorbidities can present with obstructive sleep apnea (OSA), complicating treatment because of intolerance or low adherence to traditional modalities of therapy. Providers must have heightened awareness of how these comorbidities can affect their patients' OSA and work together as a team to optimize health and well-being in this complex population.

Emergence of Central Sleep Apnea Events After Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea

PURPOSE

Central sleep apnea (CSA) can develop after the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). No studies have identified whether treatment of OSA with maxillomandibular advancement surgery (MMA) can result in CSA. The purpose of our study was to determine the incidence and clinical significance of CSA emerging after MMA surgery to treat OSA.

PATIENTS AND METHODS

A retrospective review was conducted of all patients who had undergone MMA surgery for OSA at the Department of Oral and Maxillofacial Surgery at the QEII Health Sciences Centre (Halifax, NS, Canada) from 1996 through 2016. All patients with preoperative level 1 polysomnography and follow-up level 1 study results available at least 6 months postoperatively were included the present study. The pre- and postoperative central apnea index (CAI) results were compared.

RESULTS

A total of 113 patients (84 men and 29 women) with an average age of 44.0 years were included in the present study. In 35 patients (31.0%), the emergence of CSA events were recorded on postoperative polysomnograms. Only 2 of the 113 patients experienced the emergence of clinically significant postoperative CSA (CAI >5). In our patient cohort, gender (P = .085), patient age (P = .238), and preoperative (P = .716) and postoperative (P = .209) Apnea-Hypopnea Index (AHI) results correlated with the postoperative development of CSA events after MMA surgery. The mean AHI values had decreased from 41.4 to 8.7 in all patients treated with MMA in our study.

CONCLUSIONS

The emergence of CSA events occurred in 31% of patients after OSA treatment with MMA surgery. The rate of clinically significant CSA events emerging after MMA surgery in our study was 1.8%. These findings help to support the use of MMA surgery for OSA as a reasonable treatment alternative for patients unable to tolerate CPAP.

Persistent High Residual AHI After CPAP Use

ABSTRACT

Treatment-emergent central sleep apnea has recently been noted after various treatment modalities for obstructive sleep apnea. It often remits spontaneously or can be treated with continuous positive airway pressure. However, we encountered a pediatric patient with obstructive sleep apnea who presented with severe complications, including growth failure, attention-deficit hyperactivity disorder, poor school performance, daytime sleepiness, and urinary difficulty that required permanent cystostomy. His obstructive sleep apnea resolved after adenotonsillectomy. However, treatment-emergent central sleep apnea developed after adenotonsillectomy and was further aggravated after continuous positive airway pressure and bilevel positive airway pressure without a backup respiratory rate use. After bilevel positive airway pressure with a backup respiratory rate treatment for 3 months initially, all his symptoms improved, except growth failure. Later, after adaptive servoventilation was used for 10 months, the patient's growth began to improve.

A systematic review on prevalence and risk factors associated with treatment- emergent central sleep apnea

INTRODUCTION:

Treatment-emergent central sleep apnea (TECSA) is the appearance of central apneas and hypopneas after significant resolution of the obstructive events has been attained using positive airway pressure (PAP) therapy. The aim of the study was to determine the prevalence of TECSA and to understand what factors are associated with its development.

METHODS:

PubMed, MEDLINE, Scopus, Web of Science and Cochran Library databases were searched with Mesh headings to locate studies linking TECSA and obstructive sleep apnea (OSA).

RESULTS:

Nine studies were identified that reported the prevalence of TECSA ranging from 5.0% to 20.3%. Prevalence of TECSA for studies using only full night titration was between 5.0% and 12.1% where as it was between 6.5% and 20.3% for studies using split-night polysomnogram. The mean effective continuous PAP (CPAP) setting varied between 7.5 cm and 15.2 cm of water for patients in TECSA group and between 7.4 cm and 13.6 cm of water for the group without TECSA.

CONCLUSIONS:

The aggregate point prevalence of TECSA is about 8% with the estimated range varying from 5% to 20% in patients with untreated OSA. The prevalence tends to be higher for split-night studies compared to full night titration studies. TECSA can occur at any CPAP setting although extremely high CPAP settings could increase the likelihood. Male gender, higher baseline apnea-hypopnea index, and central apnea index at the time of diagnostic study could be associated with the development of TECSA at a subsequent titration study.

Complex sleep apnea associated with use of nasal expiratory positive airway (nEPAP) device

Complex sleep apnea syndrome (CompSAS) is characterized by predominant obstructive sleep disordered breathing with evolution of central disordered breathing following exposure to nasal continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea (OSA) patients. We report a case of CompSAS associated with use of a nasal expiratory positive airway (nEPAP, Provent) device. We therefore recommend obtaining objective sleep data to confirm treatment effectiveness of the nEPAP device for OSA prior to long-term prescription. Further research is warranted to understand the underlying pathophysiological mechanisms and risk factors associated with CompSAS.

Complex sleep apnea

OPINION STATEMENT

Complex sleep apnea currently refers to the emergence and persistence of central apneas and hypopneas following the application of positive airway pressure therapy in patients with obstructive sleep apnea. However, this narrow definition is an "outcome" and does not capture the spectrum of pathological activation of the respiratory chemoreflex in sleep apnea. The International Classification of Sleep Disorders - 3rd edition recognizes the phenomenon of Treatment-Related Central Sleep Apnea, but the phenotype is usually evident prior to onset of therapy. The key polysomnographic characteristics of chemoreflex modulated and mediated sleep apnea are nonrapid eye movement (NREM) dominance of respiratory events, short (<30 seconds) or long (>60 seconds) cycle time with a self-similar metronomic timing, and spontaneous improvement during rapid eye movement (REM) sleep. Thus, the majority of chemoreflex effects go unrecognized due to the bias toward obstructive sleep apnea's current scoring criteria. Any treatment of apparently obstructive sleep apnea, including surgery and oral appliances, can expose chemoreflex-driven instabilities. As both sleep fragmentation and a narrow CO2 reserve or increased loop gain drive the disease, sedatives (to induce longer periods of stable NREM sleep and reduce the destabilizing effects of arousals in NREM sleep) and CO2-based stabilization approaches are logical. Adaptive ventilation reduces mean hyperventilation yet can induce ventilator-patient desynchrony, while enhanced expiratory rebreathing space (EERS, dead space during positive pressure therapy) and CO2 manipulation directly stabilize respiratory control by moving CO2 above the apnea threshold. Carbonic anhydrase inhibition can provide further adjunctive benefits. Novel pharmacological approaches may target mediators of carotid body hypoxic sensitization, such as the balance between gas neurotransmitters. In complex apnea patients, single mode therapy is unlikely to be successful, and the power of multi-modality therapy should be harnessed for optimal outcomes.

Randomized controlled trial of noninvasive positive pressure ventilation (NPPV) versus servoventilation in patients with CPAP-induced central sleep apnea (complex sleep apnea)

STUDY OBJECTIVES

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).

DESIGN

Randomized controlled trial.

SETTING

Sleep center.

PATIENTS

Thirty patients who developed complex sleep apnea syndrome (CompSAS) during CPAP treatment.

INTERVENTIONS

NPPV or servoventilation.

MEASUREMENTS AND RESULTS

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.

CONCLUSIONS

After 6 weeks, servoventilation treated respiratory events more effectively than NPPV in patients with complex sleep apnea syndrome.

Clinical heterogeneity of patients with complex sleep apnea syndrome

Background

The 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.

Methods

Through 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.

Results

One 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.

Conclusions

Although 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.

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.