Bilevel positive airway pressure for obstructive sleep apnea

Obstructive sleep apnoea-hypopnoea syndrome: state of the art

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is an extremely common sleep-related breathing disorder (SRBD) characterised by complete or partial collapse of the upper airways. These nocturnal phenomena cause high-frequency hypoxemic desaturations (or intermittent hypoxia, IH) during sleep and alterations in gas exchange. The result of IH is the development or worsening of cerebro-cardio-vascular, metabolic and other diseases, which cause a high risk of death. Hence, OSAHS is a multifactorial disease affecting several organs and systems and presenting with various clinical manifestations involving different medical branches. Although it has been estimated that about one billion individuals worldwide are affected by OSAHS, this SRBD remains underestimated also due to misinformation regarding both patients and physicians. Therefore, this review aims to provide information on the main symptoms and risk factors for the detection of individuals at risk of OSAHS, as well as to present the diagnostic investigations to be performed and the different therapeutic approaches. The scientific evidence reported suggest that OSAHS is an extremely common and complex disorder that has a large impact on the health and quality of life of individuals, as well as on healthcare expenditure. Moreover, given its multifactorial nature, the design and implementation of diagnostic and therapeutic programmes through a multidisciplinary approach are necessary for a tailor-made therapy for each patient.

Treatment of Obstructive Sleep Apnea: Choosing the Best Positive Airway Pressure Device

Positive airway pressure (PAP) remains primary therapy for most patients with obstructive sleep apnea (OSA). CPAP, APAP, and BPAP are all reasonable therapies that can be used for patients with uncomplicated OSA across the spectrum of disease severity. BPAP should be considered for patients who are nonadherent to CPAP or APAP therapy because of pressure intolerance. Several additional factors should be considered when choosing the type of PAP device for a given patient, including associated symptoms and comorbid medical problems, cost, access to online data management and patient portals, and the portability for the device for patients who travel frequently.

Treatment of Obstructive Sleep Apnea: Choosing the Best Positive Airway Pressure Device

Positive airway pressure (PAP) remains primary therapy for most patients with obstructive sleep apnea (OSA). CPAP, APAP, and BPAP are all reasonable therapies that can be used for patients with uncomplicated OSA across the spectrum of disease severity. BPAP should be considered for patients who are nonadherent to CPAP or APAP therapy because of pressure intolerance. Several additional factors should be considered when choosing the type of PAP device for a given patient, including associated symptoms and comorbid medical problems, cost, access to online data management and patient portals, and the portability for the device for patients who travel frequently.

Auto-trilevel versus bilevel positive airway pressure ventilation for hypercapnic overlap syndrome patients

PURPOSE

Although bilevel positive airway pressure (Bilevel PAP) therapy is usually used for overlap syndrome (OS), there is still a portion of OS patients in whom Bilevel PAP therapy could not simultaneously eliminate residual apnea events and hypercapnia. The current study was expected to explore whether auto-trilevel positive airway pressure (auto-trilevel PAP) therapy with auto-adjusting end expiratory positive airway pressure (EEPAP) can serve as a better alternative for these patients.

METHODS

From January of 2014 to June of 2016, 32 hypercapnic OS patients with stable chronic obstructive pulmonary diseases (COPD) and moderate-to-severe obstructive sleep apnea syndrome (OSAS) were recruited. Three variable modes of positive airway pressure (PAP) from the ventilator (Prisma25ST, Weinmann Inc., Germany) were applicated for 8 h per night. We performed the design of each mode at each night with an interval of two nights with no PAP treatment as a washout period among different modes. In Bilevel-1 mode (Bilevel-1), the expiratory positive airway pressure (EPAP) delivered from Bilevel PAP was always set as the lowest PAP for abolishment of snoring. For each patient, the inspiratory positive airway pressure (IPAP) was constantly set the same as the minimal pressure for keeping end-tidal CO₂ (ETCO₂) ≤45 mmHg for all three modes. However, the EPAP issued by Bilevel PAP in Bilevel-2 mode (Bilevel-2) was kept 3 cmH₂O higher than that in Bilevel-1. In auto-trilevel mode (auto-trilevel) with auto-trilevel PAP, the initial part of EPAP was fixed at the same PAP as that in Bilevel-1 while the EEPAP was automatically regulated to rise at a range of ≤4 cmH₂O based on nasal airflow wave changes. Comparisons were made for parameters before and during or following treatment as well as among different PAP therapy modes. The following parameters were compared such as nocturnal apnea hypopnea index (AHI), minimal SpO₂ (minSpO₂), arousal index, sleep structure and efficiency, morning PaCO₂, and daytime Epworth Sleepiness Scale (ESS).

RESULTS

Compared with the parameters before PAP therapies, during each mode of PAP treatment, significant reduction was detected in nocturnal AHI, arousal index, morning PaCO₂, and daytime ESS while significant elevation was revealed in nocturnal minSpO₂ and sleep efficiency (all P < 0.01). Comparison among three PAP modes indicated that under the same IPAP, the auto-trilevel PAP mode could result in the lowest arousal index, daytime ESS, and the highest sleep efficiency. Compared with Bilevel-1, it was detected that (a) AHI was lower but minSpO₂ was higher in both Bilevel-2 and auto-trilevel (all P < 0.05) and (b) morning PaCO₂ showed no statistical difference from that in auto-trilevel but displayed higher in Bilevel-2 (P < 0.05). Compared with Bilevel-2, in auto-trilevel, both AHI and minSpO₂ showed no obvious changes (all P > 0.05) except with a lower morning PaCO₂ (P < 0.05).

CONCLUSION

Auto-trilevel PAP therapy was superior over conventional Bilevel PAP therapy for hypercapnic OS patients with their OSAS moderate to severe, since auto-trilevel PAP was more efficacious in synchronous elimination of residual obstructive apnea events and CO₂ retention as well as in obtaining a better sleep quality and milder daytime drowsiness.

Combined surgical treatment for severe sleep apnoea, to improve BiPAP compliance

Positive airway pressure (PAP) devices are used in the treatment of obstructive sleep apnoea syndrome (OSAS). In cases of PAP failure, many different surgical methods can be used for the treatment. The authors present an unusual case of a patient with Bi-level PAP (BiPAP)-intolerant severe OSAS who was treated with combined surgical methods. A 55-year-old man was treated with BiPAP due to OSAS; he was admitted to the clinic with nose stuffiness, respiratory distress and BiPAP adherence with tolerance and compliance problems. Septal deviation, concha hypertrophy, lateral pharyngeal band hypertrophy and Thornwaldt cyst were determined in the examination. Combined surgical methods were administered. The patient's apnoea hypopnoea index (AHI) was 72.8 in diagnostic polysomnography. Preoperative AHI was 7.3 and postoperative AHI was 2.3 while using BiPAP and, after the surgery, the BiPAP intolerance was eliminated. The authors suggest that a combination of different surgical methods would be an adjuvant treatment to increase BiPAP compliance.

Obstructive sleep apnoea syndrome and its management

Obstructive sleep apnoea (OSA) is a common disorder characterized by repetitive episodes of nocturnal breathing cessation due to upper airway collapse. OSA causes severe symptoms, such as excessive daytime somnolence, and is associated with a significant cardiovascular morbidity and mortality. Different treatment options are now available for an effective management of this disease. After more than three decades from its first use, continuous positive airway pressure (CPAP) is still recognized as the gold standard treatment. Nasal CPAP (nCPAP) is highly effective in controlling symptoms, improving quality of life and reducing the clinical sequelae of sleep apnoea. Other positive airway pressure modalities are available for patients intolerant to CPAP or requiring high levels of positive pressure. Mandibular advancement devices, particularly if custom made, are effective in mild to moderate OSA and provide a viable alternative for patients intolerant to CPAP therapy. The role of surgery remains controversial. Uvulopalatopharyngoplasty is a well established procedure and can be considered when treatment with CPAP has failed, whereas maxillar-mandibular surgery can be suggested to patients with a craniofacial malformation. A number of minimally invasive procedures to treat snoring are currently under evaluation. Weight loss improves symptoms and morbidity in all patients with obesity and bariatric surgery is an option in severe obesity. A multidisciplinary approach is necessary for an accurate management of the disease.