No abstract

SUMMAR Y The decrease in genioglossus (GG) muscle activity during sleep, especially rapid eye movement (REM) or paradoxical sleep, can lead to airway occlusion and obstructive sleep apnoea (OSA). The hypoglossal nucleus innervating the GG muscle is under the control of serotonergic, noradrenergic and histaminergic neurons that cease firing during paradoxical sleep. The objectives of this study were to determine the effect on GG muscle activity during different wake-sleep states of the microdialysis application of serotonin, histamine (HA) or noradrenaline (NE) to the hypoglossal nucleus in freely moving cats. Six adult cats were implanted with electroencephalogram, electrooculogram and neck electromyogram electrodes to record wake-sleep states and with GG muscle and diaphragm electrodes to record respiratory muscle activity. Microdialysis probes were inserted into the hypoglossal nucleus for monoamine application. Changes in GG muscle activity were assessed by power spectrum analysis. In the baseline conditions, tonic GG muscle activity decreased progressively and significantly from wakefulness to slow-wave sleep and even further during slow-wave sleep with ponto-geniculo-occipital waves and paradoxical sleep. Application of serotonin or HA significantly increased GG muscle activity during the wake-sleep states when compared with controls. By contrast, NE had no excitatory effect. Our results indicate that both serotonin and HA have a potent excitatory action on GG muscle activity, suggesting multiple aminergic control of upper airway muscle activity during the wake-sleep cycle. These data might help in the development of pharmacological approaches for the treatment of OSA.k e y w o r d s genioglossus, histamine, hypoglossus, noradrenaline, obstructive sleep apnoea, serotonin, sleep INTRODUCTIONThe activity of the genioglossus (GG) muscle, innervated by the hypoglossal (XII) motor nucleus (HMN), contributes to the maintenance of upper airway patency (Ryan and Bradley, 2005;White, 2006). During sleep, especially rapid eye movement (REM) or paradoxical sleep (PS), GG muscle activity decreases in animals (Horner et al., 2002;Megirian et al., 1985) and humans (Katz and White, 2004;Sauerland and Harper, 1976). In individuals with an anatomically small pharyngeal airway, this decrease in GG muscle activity can lead to airway occlusion (Remmers et al., 1978), i.e. obstructive sleep apnoea (OSA), a sleep disorder affecting up to 4% of adults (Young et al., 1993). The mechanisms responsible for this selective obstruction of the upper airway during PS remain unclear and pharmacological therapies have not Correspondence: Pierre-Charles Neuzeret, INSERM U628, Physiologie Inte´gre´e du Syste`me dÕEveil,

By mimicking human pathogenic sleep conditions, we have developed a new reversible animal model of OSA.

BackgroundNon-invasive ventilation (NIV) has been shown to improve survival and quality of life in COPD patients with chronic hypercapnic respiratory failure. However, the proportion of COPD patients with chronic hypercapnia is not yet known and clinical data enabling better identification of patients are scarce. The HOmeVent registry was initiated to determine the prevalence of chronic hypercapnia in COPD in an outpatient setting and to evaluate the predictors of hypercapnia.MethodsHOmeVent is a multicenter, prospective, observational, non-interventional patient registry that includes COPD patients in GOLD stage 3 or 4. Eligible patients were identified and enrolled in an outpatient setting during routine clinic visits. Assessments included blood gas analyses, pulmonary function testing and quality of life assessment.ResultsTen outpatient clinics in Germany enrolled 231 COPD patients in the registry (135 in GOLD stage 3 (58%) and 96 in GOLD stage 4 (42%)). Arterial carbon dioxide pressure (PaCO2) was ≥45 mmHg in 58 patients (25%); of these, 20 (9%) had PaCO2 ≥50 mmHg. The prevalence of hypercapnia at both cut-off values was numerically higher for patients in GOLD stage 4 versus 3. An increased body mass index, a decreased forced vital capacity and an increased bicarbonate level were significant independent predictors of hypercapnia. The proportion of patients who received NIV was 6% overall and 22% of those with hypercapnia.ConclusionA relevant proportion of COPD patients in GOLD stage 3 and 4 exhibits chronic hypercapnia and might, therefore, be candidates for long-term domiciliary NIV treatment.

Introduction: Patient interface is important for the success of continuous positive airway pressure (CPAP), but few trials have examined the influence of mask choice on CPAP adherence. Objectives: To compare the impact of different nasal masks on CPAP in patients with newly-diagnosed obstructive sleep apnea (OSA). Methods: OSA patients were randomized in a 2:3 ratio to receive CPAP via different first-line nasal masks:. Mask acceptance, CPAP compliance and Home Care Provider (HCP) interventions were compared between groups after 3 months of CPAP therapy using modified intent-to-treat (mITT; after exclusion of patients with mouth leaks during CPAP initiation) and on-treatment (OT; CPAP adherent) analyses. Results: Of 285 randomized patients, 90 requiring a full-face mask were excluded, leaving 195 and 151 in the mITT and OT analyses, respectively. Mask acceptance rate was higher in the MFX versus control group (mITT: 79% vs 68%, P 5 0.067; OT: 90% vs 76%, P 5 0.022). CPAP compliance was higher (5.9 6 1.8 vs 5.1 6 1.6 h/night, P 5 0.011) and nasal mask issue-related HCP visits lower (3% vs 17%, P 5 0.006) in the MFX group. Nasal mask failures due to mask discomfort (5% vs 1%) or unintentional leakage (5% vs 0%) were higher in control vs MFX group. Mask acceptance was significantly associated with fewer mask leaks (P 5 0.002) and higher pressure therapy (P 5 0.042). Conclusions: This study highlights differences between nasal masks for CPAP delivery and shows that initial mask selection can influence adherence and healthcare utilization during CPAP.Please cite this paper as: Neuzeret P-C and Morin L. Impact of different nasal masks on CPAP therapy for obstructive sleep apnea: a randomized comparative trial. Clin Respir J 2017; 11: 990-998.

No abstract

No abstract

No abstract