Multi-center safety and efficacy study of a negative-pressure intraoral device in obstructive sleep apnea.

BACKGROUND: Intraoral devices, with or without negative oral pressure, can stabilize the oropharynx and reduce obstructive sleep apneas. We tested the hypothesis that treatment with the iNAP® Sleep Therapy System, which applies negative oral pressure through an intra-oral appliance, would reduce the severity of obstructive sleep apnea in a multi-center, prospective, first-night-randomized-order cross-over study. METHODS/PATIENTS: 130 patients fulfilled the entry criteria (age <75, AHI 15-55, BMI <33), and 63 entered the primary endpoint cohort (Total Sleep Time ≥4 h/night on the baseline polysomnogram and an oral negative vacuum time maintained by iNAP® ≥ 4 h/night and total sleep time ≥4 h/night during the first treatment study). 54 patients completed a second treatment sleep study at least 28 days after the first sleep study. RESULTS: Among the primary endpoint cohort (n = 63, age = 53.2 ± 11.3, BMI = 27.1 ± 2.8), 33 patients (52 %; 95 % confidence interval = 40%-64 %, p < 0.001) responded to iNAP treatment according to the Sher criteria (>50 % reduction in AHI and an AHI ≤20 events/hr). The average oxy-hemoglobin saturation increased by 1-2%, and the average percent oxygen desaturation decreased (was less severe) by 1 % while using the iNAP device. The incidence of adverse events, all self-limited, was low. The reduction in the apnea-hypopnea index was durable over the 28-day study. Patients used iNAP on average 5.6 h per night during the study period. CONCLUSION: The iNAP® Sleep Therapy System achieved a durable benefit in more than half the patients with moderate to severe obstructive sleep apnea and may be considered in patients who object to or failed continuous positive airway pressure. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02698059.

Hypoglossal nerve stimulation for obstructive sleep apnea: updated position paper of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery.

Since the first statement of the German Society of Oto-Rhino-Laryngology, hypoglossal nerve stimulation (HNS) is meanwhile an established treatment option for obstructive sleep apnea (OSA). There are three HNS systems available in Germany which differ in their technical details of the underlying comparable basic principle. For the unilateral HNS with respiratory sensing, several comparative studies, high-volume register analysis and long-term reports exist. The continuous HNS without respiratory sensing does not require a sleep endoscopy for indication. For the bilateral continuous HNS as the single partially implantable device, a feasibility study exists. For indication, the assessment of positive airway pressure failure by sleep medicine is crucial, and the decision for HNS should be made in discussion of other treatment options for at least moderate OSA. The implantation center holds primarily responsibility among the interdisciplinary sleep team and is primary contact for the patient in problems. This depicts why structural processes are required to secure outcome quality and minimize the complications. The aftercare of HNS patients can be provided interdisciplinary and by different medical institutions, whereat, minimal reporting standards to document outcome and usage are recommended.

Die Stimulation des Nervus hypoglossus in der Behandlung der obstruktiven Schlafapnoe ­ Aktualisiertes Positionspapier der Arbeitsgemeinschaft Schlafmedizin der DGHNO-KHC.

Hypoglossal nerve stimulation for obstructive sleep apnea - Updated position paper of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. Since the first statement of the German Society of Oto-Rhino-Laryngology, hypoglossal nerve stimulation (HNS) is meanwhile an established treatment option for obstructive sleep apnea (OSA). There are three HNS systems available in Germany which differ in their technical details of the underlying comparable basic principle. For the unilateral HNS with respiratory sensing, several comparative studies, high-volume register analysis and long-term reports exist. The continuous HNS without respiratory sensing does not require a sleep endoscopy for indication. For the bilateral continuous HNS as the single partially implantable device, a feasibility study exists. For indication, the assessment of positive airway pressure failure by sleep medicine is crucial, and the decision for HNS should be made in discussion of other treatment options for at least moderate OSA. The implantation center holds primarily responsibility among the interdisciplinary sleep team and is primary contact for the patient in problems. This depicts why structural processes are required to secure outcome quality and minimize complications. The aftercare of HNS patients can be provided interdisciplinary and by different medical institutions whereat minimal reporting standards to document outcome and usage are recommended.

Treatment of Cheyne-Stokes respiration with adaptive servoventilation-analysis of patients with regard to therapy restriction.

PURPOSE: The SERVE-HF study revealed no benefit of adaptive servoventilation (ASV) versus guideline-based medical treatment in patients with symptomatic heart failure, an ejection fraction (EF) ≤45% and a predominance of central events (apnoea-hypopnea Index [AHI] > 15/h). Because both all-cause and cardiovascular mortality were higher in the ASV group, an EF ≤ 45% in combination with AHI 15/h, central apnoea-hyponoea index [CAHI/AHI] > 50% and central apnoea index [CAI] > 10/h were subsequently listed as contraindications for ASV. The intention of our study was to analyse the clinical relevance of this limitation. METHODS: Data were analysed retrospectively for patients treated with ASV who received follow-up echocardiography to identify contraindications for ASV. RESULTS: Echocardiography was conducted in 23 patients. The echocardiogram was normal in 10 cases, a left ventricular hypertrophy with normal EF was found in 8 patients, there was an EF 45-50% in 2 cases and a valvular aortic stenosis (grade II) with normal EF was found in 1 case. EF <45% was present in just 2 cases, and only 1 of these patients also had more than 50% central events in the diagnostic night. CONCLUSION: The population typically treated with ASV is entirely different from the study population in SERVE-HF, as nearly half of the patients treated with ASV showed a normal echocardiogram. Thus, the modified indication for ASV has little impact on the majority of treated patients. The current pathomechanistic hypothesis of central apnoea must be reviewed.

[Sleep in the intensive care unit]. / Schlaf auf der Intensivstation.

Many patients are treated in intensive care units daily, often over a long period of time. Sleep plays a role that should not be underestimated for these patients. Sleep disorders are a relevant problem for intensive care patients and lead to a higher prevalence of delirium in these patients and thus to a longer length of stay in the intensive care unit and to a higher mortality. This article tries to show the causes of sleep disorders in intensive care medicine and possible strategies for avoiding sleep disorders in intensive care patients.

Effects of continuous positive airway pressure therapy on daytime and nighttime arterial blood pressure in patients with severe obstructive sleep apnea and endothelial dysfunction.

PURPOSE: A nocturnal non-dipping or rise in blood pressure (BP) is associated with poor cardiovascular outcome. This study aimed to test whether continuous positive airway pressure (CPAP) therapy can reduce nocturnal BP and normalize the 24-h BP profile in patients with severe obstructive sleep apnea (OSA) and erectile dysfunction as a surrogate for endothelial dysfunction (ED). PATIENTS AND METHODS: Eighteen consecutive patients with OSA and ED on stable antihypertensive medication (age 55.8 ± 9.5 years, body mass index 35.5 ± 3.8 kg/m2, apnea-hypopnoea index 66.1 ± 27.4/h) were treated with CPAP for 6 months (average daily use 5.8 ± 2.3 h). Twenty-four hour BP recordings were performed using a portable monitoring device. Rising was defined as an increase, whereas non-dipping was defined as a fall in nocturnal BP of less than 10% compared to daytime values. Serum noradrenaline levels as markers of sympathetic activity were measured at baseline and at 6 month follow up. RESULTS: Compared to baseline, nocturnal systolic and diastolic BP were significantly reduced after CPAP therapy (128.5 ± 14 to 122.9 ± 11 mmHg, p = 0.036; 76.2 ± 9 to 70.5 ± 5 mmHg, p = 0.007). The frequency of non-dipping and rising nocturnal systolic BP, as well as mean nocturnal heart rate, was reduced after CPAP treatment (73 to 27%, p = 0.039; 20 to 7%, p = 0.625; from 81.5 ± 10 to 74.8 ± 8 beats per minute p = 0.043). Serum levels of noradrenaline were significantly lower after CPAP therapy (398 ± 195 ng/l vs. 303 ± 135 ng/l, p = 0.032). CONCLUSION: In patients with severe OSA and clinically apparent ED, CPAP therapy was associated with a decrease in nocturnal BP and serum noradrenaline levels, as well as a normalization of the 24-h BP profile.

Obesity hypoventilation syndrome treated with non-invasive ventilation: Is a switch to CPAP therapy feasible?

BACKGROUND AND OBJECTIVE: Obesity hypoventilation syndrome (OHS) can be treated with either continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) therapy; the device choice has important economic and operational implications. METHODS: This multicentre interventional trial investigated the safety and short-term efficacy of switching stable OHS patients who were on successful NIV therapy for ≥3 months to CPAP therapy. Patients underwent an autotitrating CPAP night under polysomnography (PSG); if the ensuing parameters were acceptable, they were sent home on a fixed CPAP for a 4-6-week period. It was hypothesized that blood gas analysis, PSG parameters and lung function tests would remain unchanged. RESULTS: A total of 42 OHS patients were recruited, of whom 37 patients were switched to CPAP therapy. All patients had a history of severe obstructive sleep apnoea syndrome; chronic obstructive pulmonary disease (COPD) (Global Initiative for Obstructive Lung Disease (GOLD) I/II) was present in 52%. Regarding the primary outcome, 30 of 42 patients (71%, 95% CI: 55-84%) maintained daytime partial pressure of carbon dioxide (PaCO2 ) levels ≤45 mm Hg after the home CPAP period. There was no further impairment in quality of life, sleep parameters or lung function. Interestingly, 24 patients (65%) preferred CPAP as their long-term therapy, despite the high pressure levels used (mean: 13.8 ± 1.8 mbar). After the CPAP period, 7 of 37 patients were categorized as CPAP failure, albeit only due to mild hypercapnia (mean: 47.9 ± 2.7 mm Hg). CONCLUSION: It is feasible to switch most stable OHS patients from NIV to CPAP therapy, a step that could significantly reduce health-related costs. The auto-adjusted CPAP device, used in combination with the analysis of the PSG and capnometry, is a valid titration method in OHS patients.

CPAP therapy improves erectile function in patients with severe obstructive sleep apnea.

OBJECTIVES: Erectile dysfunction (ED) is highly prevalent in obstructive sleep apnea (OSA), however, the effect of continuous positive airway pressure (CPAP) therapy on erectile function has not yet been thoroughly investigated in these patients. METHODS: Ninety-four men with severe OSA (ie, with an apnea-hypopnea-index ≥ 30/h of sleep) were prospectively evaluated for the presence and severity of ED before and after 6-12 months of CPAP therapy. The abbreviated version of the International Index of Erectile Function, (the IIEF-5) was used to rate erectile function. Furthermore, all study participants responded to standard questionnaires of daytime sleepiness (Epworth Sleepiness Scale), quality of life (WHO Wellbeing 5 questionnaire) and depression (Major Depression Inventory). RESULTS: ED as defined by an IIEF-5 score of ≤21 was present in 64 patients (68.1%). CPAP treatment significantly improved erectile function in those patients suffering from moderate and severe ED. Additionally, a trend for a correlation between the improvement of erectile function under CPAP and the hours of its use was observed. Finally, this effect was associated with larger improvements of quality of life in affected patients. CONCLUSIONS: ED is very frequent in men with severe OSA and can at least partly be reversed by long-term CPAP therapy in most seriously affected patients. The beneficial effect on erectile function may depend on CPAP compliance and is accompanied by improvements of quality of life. Randomized controlled trials are needed to confirm these findings.

Effects of respiratory muscle training (RMT) in patients with mild to moderate obstructive sleep apnea (OSA).

PURPOSE: Different forms of training focusing on the muscles of the upper airways showed limited effects on obstructive sleep apnea (OSA) and/or snoring. We investigated the effect of generalized respiratory muscle training (RMT) in lean patients with mild to moderate OSA. METHODS: Nine male subjects (52.0 ± 10.8 years, BMI 29.1 ± 2.1 kg/m2) with obstructive sleep apnea (apnea-hypopnea index (AHI) 9-29) participated in an open, single-arm pilot study. After a 1-week build-up phase, patients underwent 4 weeks of normocapnic hyperpnea RMT five times a week for 30 min each. The initial and final measurements comprised polysomnography, pulmonary function tests, Epworth sleepiness scale (ESS), and SF-36 questionnaire (quality of life (QoL) self-assessment). The investigational site was a university-affiliated hospital for pulmonary diseases and sleep medicine, Solingen/Germany. RESULTS: Patients trained effectively, seen by a significant (p < 0.01) increase of breathing frequency (23.3 ± 1.5 /min vs. 30.6 ± 2.9 /min) and minute volume (81.2 ± 13.7 L vs. 109.1 ± 21.9 L). AHI, snoring and ESS remained unchanged after training. QoL as measured by SF-36 significantly (p < 0.05) improved after the training in the subscales "bodily pain" (79 ± 21 vs. 90 ± 12) and "change of health" (3.1 ± 0.3 vs. 2.4 ± 0.5). CONCLUSIONS: There is no evidence that AHI, pulmonary function or daytime sleepiness are affected by 5 weeks of RMT. Nevertheless, there is an improvement of parameters of quality of life. TRIAL REGISTRATION: ClinicalTrials.gov , register no. NCT 00936286.

Effect of a Heated Breathing Tube on Efficacy, Adherence and Side Effects during Continuous Positive Airway Pressure Therapy in Obstructive Sleep Apnea.

BACKGROUND: Heated breathing tubes were developed to improve heated humidification in continuous positive airway pressure (CPAP) therapy of patients with obstructive sleep apnea syndrome (OSAS). OBJECTIVES: We wanted to investigate the influence of a heated breathing tube on patients' satisfaction with the treatment, the rate of side effects and the adherence to treatment. METHODS: Eighty-eight patients with primarily diagnosed OSAS were treated in a randomized, controlled, single-blind trial for 12 months either with a CPAP system plus conventional heated humidifier or with a CPAP system plus heated humidifier and an integrated heated breathing tube. RESULTS: Both systems improved the respiratory disturbances and the quality of sleep in a similar manner. The difference in the overall satisfaction with the treatment (subscale 3 of the visual analogue scale) between the two treatment groups was not statistically significant (mean difference -14.1, 95% CI -28.7 to 0.6; p = 0.059). The rate of side effects and the quality of life did not differ significantly between the two groups. The patients with the heated breathing tube used the treatment on average 1 h longer, but this was not statistically significant (4.96 ± 1.95 vs. 3.90 ± 2.54 h/night; p = 0.06). CONCLUSIONS: Controlled heated breathing tube humidification as compared to conventional heated humidification improves neither the adherence to treatment, nor the rate of side effects, nor the quality of life in nonselected OSAS patients.

Anticyclic modulated ventilation versus continuous positive airway pressure in patients with coexisting obstructive sleep apnea and Cheyne-Stokes respiration: a randomized crossover trial.

BACKGROUND: Although coexisting obstructive sleep apnea (OSA) and Cheyne-Stokes respiration (CSR) occur frequently in patients with heart diseases, optimal treatment remains unclear. Positive airway pressure (PAP) effectively treats OSA and adaptive servo-ventilation (ASV) has been shown to improve CSR. We compared a new treatment algorithm combining automatic continuous positive airway pressure (APAP) and ASV (anticyclic modulated ventilation, ACMV) versus continuous positive airway pressure (CPAP). METHODS: Thirty-nine patients (35 male, four female; aged 65.5±9.7 years; body mass index, 31.0±5.9 kg/m2) with underlying heart disease and coexisting OSA and CSR were enrolled. After diagnostic polysomnography (PSG) and CPAP titration, patients were randomized either to CPAP or to ACMV for four weeks of treatment in a crossover design. RESULTS: Total apnea-hypopnea index (AHI) was 49.0±18.8/h at baseline, 12.3±14.6/h with CPAP (P<0.001 vs baseline), and 3.7±5.6/h with ACMV (P<0.001 vs. baseline and vs. CPAP). Obstructive AHI was 20.7±14.4/h at baseline, 5.1±9.3/h with CPAP (P<0.001 vs. baseline), and 0.4±0.4/h with ACMV (P<0.001 vs. baseline and vs. CPAP). Central AHI was 28.3±13.4/h at baseline, 7.2±9.7/h with CPAP (P<0.001 vs baseline) and 3.3±5.4/h with ACMV (P<0.001 vs. baseline and vs. CPAP). Ejection fraction was increased significantly (from 38.6±15.6 to 44.4±12.2%) only with ACMV. Subjective sleepiness significantly improved only with CPAP whereas objective sleep quality and treatment adherence were not different between both treatment modalities. CONCLUSION: ACMV is an effective treatment option in patients with coexisting OSA and CSR. It is superior to CPAP in reducing total AHI as well as obstructive and central AHI.

Long-term auto-servoventilation or constant positive pressure in heart failure and coexisting central with obstructive sleep apnea.

BACKGROUND: The coexistence of obstructive sleep apnea (OSA) and central sleep apnea (CSA) and Cheyne-Stokes respiration (CSR) is common in patients with heart failure (HF). While CPAP improves CSA/CSR by about 50%, maximal suppression is crucial in improving clinical outcomes. Auto-servoventilation (ASV) effectively suppresses CSA/CSR in HF, but few trials have been performed in patients with coexisting OSA and CSA/CSR. Our objective was to evaluate a randomized, controlled trial to compare the efficacy of ASV and CPAP in reducing breathing disturbances and improving cardiac parameters in patients with HF and coexisting sleep-disordered breathing. METHODS: Both modes were delivered using the BiPAP autoSV (Philips Respironics) over a 12-month period. Seventy patients (63 men, 66.3 ± 9.1 y, BMI 31.3 ± 6.0 kg/m(2)) had coexisting OSA and CSA/CSR, arterial hypertension, coronary heart disease, or cardiomyopathy and clinical signs of heart failure New York Heart Association classes II-III. Polysomnography, brain natriuretic peptide (BNP), spiroergometry, and echocardiography were performed at baseline and after 3 and 12 months of treatment. RESULTS: Both modes of therapy significantly improved respiratory disturbances, oxygen desaturations, and arousals over the study period. ASV reduced the central apnea hypopnea index (baseline CPAP, 21.8 ± 11.7; ASV, 23.1 ± 13.2; 12 months CPAP, 10.7 ± 8.7; ASV, 6.1 ± 7.8, P < .05) and BNP levels (baseline CPAP, 686.7 ± 978.7 ng/mL; ASV, 537.3 ± 891.8; 12 months CPAP, 847.3 ± 1848.1; ASV, 230.4 ± 297.4; P < .05) significantly more effectively as compared with CPAP. There were no relevant differences in exercise performance and echocardiographic parameters between the groups. CONCLUSIONS: ASV improved CSA/CSR and BNP over a 12-month period more effectively than CPAP.

Long-term therapy with continuous positive airway pressure in obstructive sleep apnea: adherence, side effects and predictors of withdrawal - a 'real-life' study.

BACKGROUND: Long-term adherence to positive airway pressure (PAP) treatment is essential in patients with obstructive sleep apnea syndrome (OSAS). OBJECTIVES: The aim of the present study was to analyze treatment adherence under real-life conditions and factors associated with discontinuation of PAP therapy. METHODS: Patients newly diagnosed with OSAS and started on PAP therapy were contacted by telephone after a minimum of 1 year. Side effects, quality of life, subjective treatment adherence and Epworth Sleepiness Scale (ESS) scores were assessed. Objective treatment adherence was calculated by reading the built-in run time counter of the PAP device. Anthropometric parameters, level of education, apnea-hypopnea index (AHI), ESS score and the type of PAP therapy prescribed at the time of the first stay in the sleep lab were collected retrospectively. RESULTS: Median follow-up was 13 months (range 7-18 months). Of 303 patients (69 female, 234 male) available for this study, 191 patients (63%) still used the PAP device regularly ('users'), while 83 (27.4%) had definitively discontinued PAP treatment ('nonusers'). In the nonusers group, 29 patients (34.9%) discontinued PAP treatment within the first 3 months. In the users group, subjective PAP usage was 6.6 ± 1.5 h/night and objective adherence was 4.7 ± 2.3 h/night. Objective nightly use of PAP treatment correlated significantly with baseline AHI (r = 0.13, p = 0.041) but not with sex, age, body mass index, ESS score or education level. Patients with a low AHI and ESS score and patients without a coexisting medical condition or with more than two comorbidities tended to discontinue PAP therapy more frequently. CONCLUSIONS: PAP treatment adherence has to be optimized in OSAS patients. When initiating PAP therapy, clinicians have to focus on those patients at risk for discontinuing treatment. Education sessions and closer follow-up are possible strategies to improve treatment adherence and to avoid treatment discontinuation.

Evaluation of a system for transcutaneous long-term capnometry.

BACKGROUND: The measurement of CO(2) partial pressure (PCO(2)) is of great importance. Former systems of transcutaneous capnometry combining the measurement of oxygen partial pressure (PO(2)) and PCO(2) had their limitations due to skin irritations caused by the heating-up of the sensor and a short application time of 4 h. OBJECTIVES: To evaluate for the first time combined monitoring of transcutaneous PCO(2) (tcPCO(2)) and oxygen saturation applying a lower temperature (sensor temperature 42 degrees C) and a new sensor technology in healthy individuals during sleep. METHODS: Twenty-nine healthy individuals [12 males, age 35.2 +/- 17.0 years, body height: 170.2 +/- 12.0 cm (mean +/- SD), weight: 76.3 +/- 15.8 kg, body mass index 26.5 +/- 5.4] were monitored for more than 6 h at night with the TOSCA 500 instrument (Radiometer, Basel, Switzerland). tcPCO(2) was continuously monitored and its correlation with selective measured capillary PCO(2) values (PcapCO(2)) was monitored at 0.00 and 4.00 h. RESULTS: At 0.00 h, PcapCO(2) was 37.1 +/- 5.1 mm Hg and tcPCO(2) was 43.4 +/- 6.6 mm Hg (p < 0.001). At 4.00 h, PcapCO(2) was 37.0 +/- 5.6 mm Hg and tcPCO(2) was 43.5 +/- 5.4 mm Hg (p < 0.001). PcapCO(2) and tcPCO(2) were positively and significantly correlated (0.00 h: r = 0.5, p < 0.02 and 4.00 h: r = 0.72 and p < 0.001) at both time points. In the course of the night, there was no significant drift in the tcPCO(2) values. CONCLUSION: The investigated system enables stable measurement of tcPCO(2) without relevant drift in healthy individuals and does not require recalibration. tcPCO(2) is highly suitable as a measure of PcapCO(2) because the two parameters are highly correlated and there is no inconvenience to the patient.

Esophageal pressure method and impulse oscillometry to assess mechanical properties of the respiratory system in healthy men.

BACKGROUND: Lung elasticity can be assessed by pulmonary compliance using the esophageal pressure method, but this technique is invasive and time-consuming. Impulse oscillometry has been established as a non-invasive method to describe mechanical properties of the respiratory system and preliminary data suggest that it may be used as a marker of lung elasticity. Therefore we compared impulse oscillometry and pulmonary compliance in healthy subjects. MATERIAL/METHODS: In 31 healthy male volunteers aged 20 to 25 years we performed pulmonary function tests including spirometry, bodyplethysmography and pulmonary compliance by the esophageal pressure method. Impulse oscillometry (IOS) was used to determine capacitance (X 5 Hz) and resistance (R 5 Hz and R 20 Hz). RESULTS: Mean dynamic pulmonary compliance was 2.53+/-0.58 l/kPa and mean static pulmonary compliance was 2.82+/-0.85 l/kPa. R 5 Hz and R 20 Hz were between 0.14 and 0.49 kPa/(l/s), while mean X 5 Hz was -0.08+/-0.02 kPa/(l/s). There was demonstrated a highly significant correlation between impulse oscillometric capacitance X 5 Hz and pulmonary compliance parameters. CONCLUSIONS: The results of the present study suggest that impulse oscillometry may be used as an alternative for the invasive esophageal pressure method in determining pulmonary elasticity.

Combined adaptive servo-ventilation and automatic positive airway pressure (anticyclic modulated ventilation) in co-existing obstructive and central sleep apnea syndrome and periodic breathing.

BACKGROUND: The co-existence of obstructive and central sleep apnea/hypopnea syndrome (OSAS) and periodic breathing is common in patients with and without underlying heart diseases. While automatic continuous positive airway pressure (APAP) has proven to effectively treat OSAS, the adaptive servo-ventilation (ASV) sufficiently improves periodic breathing. This is the first trial on a device which combines both treatment modes. METHODS: Pilot study on a two-week treatment in patients with co-existing obstructive and central and periodic breathing disturbances during sleep. Twelve consecutive patients (9 male, 3 female, age 56.9+/-10.6 years, BMI 32.4+/-5.5 kg/m(2)) were treated with a new algorithm which combines APAP and ASV (also called anticyclic modulated ventilation (ACMV), SOMNOventCR, Weinmann, Hamburg, Germany). Seven suffered from arterial hypertension, coronary heart disease and mitral regurgitation, none from congestive heart failure. RESULTS: The total apnea-hypopnea index (AHI) improved from 43.8+/-24.0/h to 2.1+/-2.4 (p<0.01), the obstructive AHI from 12.8+/-14.3/h to 0.3+/-0.6/h (p<0.01) and the central AHI from 31.0+/-17.5/h to 1.7+/-2.0/h (p<0.01). Moreover, there was a significant improvement in the total number of arousals, respiratory induced arousals, oxygen saturation and sleep profile. CONCLUSION: The algorithm combining automatic continuous positive airway pressure (CPAP) and ASV normalizes all types of co-existing obstructive and central apnea/hypopnea and periodic breathing.

Comparison of manual titration and automatic titration based on forced oscillation technique, flow and snoring in obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) treatment in obstructive sleep apnea syndrome (OSAS) requires pressure titration usually performed during attended in-hospital polysomnography. This manual titration procedure is not well standardized. The aim of the study was to ascertain whether a new automatic titration device is as effective as standard manual titration in determining constant CPAP pressure. METHODS: We included 38 patients with a newly diagnosed OSAS. Participants were randomly assigned to attended in-laboratory manual titration and automatic titration in two consecutive nights. Fixed CPAP pressure was set at the optimal pressure determined during the second night. The follow-up period was 6 weeks. Main outcomes were apnea/hypopnea index (AHI) and Epworth sleepiness scale (ESS). RESULTS: AHI (manual: baseline 40.5+/-21.5/h vs. treatment 6.4+/-3.3/h (p<0.001); automatic: 53.3+/-28.1/h vs. 7.8+/-3.3/h (p<0.001)) and ESS (manual: 11.3+/-4.7 vs. 8.8+/-5.1 (ns); automatic: 11.5+/-5.6 vs. 7.0+/-3.8 (p<0.05)) showed a similar improvement in both groups. Pressure recommendation by the device and the technician, although not statistically different (8.7+/-2.9 vs. 9.0+/-3.3 mbar), corresponded only in 50% of the patients. CONCLUSIONS: Automatic titration effectively predicts constant CPAP pressure for long-term treatment when performed during an attended polysomnography. Careful evaluation of raw data and polysomnography recording is mandatory before choosing a fixed CPAP pressure after automatic titration.

Adaptive servo-ventilation in patients with coexisting obstructive sleep apnoea/hypopnoea and Cheyne-Stokes respiration.

OBJECTIVE: The coexistence of obstructive (OSAS) and central sleep apnoea (CSA) and Cheyne-Stokes respiration (CSR) is common in patients with and without underlying heart diseases. CPAP has been shown to improve CSA/CSR by about 50%, but recent data suggest maximal suppression of CSA is important in improving clinical outcomes in heart failure patients. Adaptive servo-ventilation (ASV) effectively suppresses CSA/CSR in heart failure, but only few trials have considered patients with coexisting OSAS and CSA/CSR. METHODS: Prospective, observational pilot study to evaluate the efficacy of a new ASV device, the BiPAP AutoSV, in 10 male consecutive patients with coexisting OSAS and CSA/CSR with and without heart failure over eight weeks. Six had stable heart failure. MEASUREMENTS AND RESULTS: The total AHI improved from 48.9+/-20.6/h to 8.7+/-7.4, the obstructive AHI from 15.8+/-16.2/h to 2.6+/-2.5/h and the central AHI from 33.1+/-10.8/h to 6.1+/-5.9/h (all p<0.01). Furthermore, there was a significant improvement in sleep profile and respiratory related arousals. The six patients with cardiovascular disease, including three with congestive heart failure, showed similar improvements in all parameters. CONCLUSIONS: BiPAP AutoSV was effective in reducing all types of respiratory disturbances in coexisting OSAS and CSA/CSR with and without heart failure. Further studies comparing the long-term clinical efficacy of this device against CPAP are warranted.

Comparison of automatic and continuous positive airway pressure in a night-by-night analysis: a randomized, crossover study.

BACKGROUND: Long-term compliance is suboptimal in the treatment of the obstructive sleep apnea syndrome (OSAS). OBJECTIVES: We compared the efficacy of and the adherence to automatic continuous positive airway pressure (APAP) and constant continuous positive airway pressure (CPAP) based on a night-by-night analysis. METHODS: We performed a randomized, single-blind crossover study in 20 patients with moderate-to-severe OSAS. After diagnostic polysomnography and manual titration, patients were treated for 8 weeks with both constant CPAP and APAP in random order. Compliance and leakage were analyzed night by night using the software LOGSoft of the Magellan iPAP device. RESULTS: The reduction in the apnea/hypopnea index (baseline 32.9 +/- 19.1/h, CPAP 4.6 +/- 2.9/h, APAP 5.6 +/- 3.6/h; p < 0.001 compared to baseline) and the Epworth Sleepiness Scale (baseline 10.3 +/- 5.7, CPAP 6.6 +/- 4.8, APAP 4.9 +/- 4.6; p < 0.001 compared to baseline) did not significantly differ between the treatment modes. Leakage time and compliance per night were not statistically different (leakage CPAP 31 +/- 57 min, APAP 25 +/- 49 min; compliance CPAP 383 +/- 116 min, APAP 382 +/- 107 min). There was no correlation between leakage and compliance. Thirteen patients (65%) preferred APAP at the end of the study. CONCLUSIONS: Treatment efficacy and adherence are similar with CPAP and APAP. There is a trend towards lower leakage with APAP therapy. Patients prefer the automatic mode to fixed pressure.