Auto-adjusting Positive Airway Pressure Research Articles

Accuracy of positive airway pressure titration through telemonitoring of auto-adjusting positive airway pressure device connected to a pulse oximetry in patients with obstructive sleep apnea.

In COVID-19 era, all forms of access of patients to the sleep units should be reduced as much as possible when implementing telemedicine. In the field of obstructive sleep apnea (OSA) therapy with positive airway pressure (PAP) devices, telemedicine includes the use of built-in software (BIS) and storage of PAPs and remote-controlled data (BISrc data) that are processed and transmitted daily to sleep units. We compared two methods of evaluating the final residual severity of OSA patients in home PAP titration: BISrc data versus nocturnal portable multichannel monitoring (PM) data in PAP (reference method) and to verify whether the efficacy PAP therapy guided by BISrc data was clinically adequate. We conducted a real-life prospective study in newly diagnosed patients with OSA. Patients used an auto-adjusting positive airway pressure (AirSense 10 ResMed) with a pulse oximeter that allows daily transfer of BISrc data (apnea hypopnea index [AHI] and SaO2 ) and remote changes in ventilator setting. Once the PAP titration was completed, the pressure value or ranges were kept constant for 3 days and home PM was repeated. There were 41 patients with moderate to severe OSA who completed the study. When considering AHI only, the diagnostic accuracy of BISrc on the third day was equal to 97.5%; when considering AHI > 10/h, ODI > 10/h, and SaO2 < 90%, the diagnostic accuracy slightly decreased to 90.2%. In clinical practice, the two measurement methods are equivalent. The use of BISrc data for home titration would reduce the access to sleep units. We urge that widespread use of BISrc be promoted in the current practice of management of OSA.

0444 Racial Differences in Positive Airway Pressure Requirements Amongst Obstructive Sleep Apnea Patients (The RACE-PAP Study)

Abstract Introduction Prior studies of patients with obstructive sleep apnea (OSA) show racial differences in clinical presentation. When compared with White patients, Black patients present with more severe OSA and greater sleepiness. Racial differences in upper airway collapsibility could explain these differences. Here, we investigated whether mean positive airway pressure (PAP) levels, a clinically accessible measure of upper airway collapsibility, differed by race in a cohort of patients adherent to PAP. Methods We conducted a retrospective analysis of White and Black adults with OSA who were prescribed auto-adjusting PAP (aPAP) therapy at a single academic center between January 2018 and January 2020. The analysis included adherent patients (usage on &amp;gt;70% of nights for ≥4 hours per night) with well-controlled OSA (defined as ≥50% reduction in apnea-hypopnea index [AHI] on aPAP and residual AHI&amp;lt; 10). Mean PAP level was compared between White and Black patients using linear regression controlled for age, gender, body mass index (BMI), AHI, O2 nadir, and mask type (full face, nasal, or unknown). Results Overall, 148 Black (56% women) and 230 White (36% women) patients were included. On average, Black patients were younger (50.7±14.6 vs. 53.8±12.7 years; p=0.037) with higher BMI (40.4±9.5 vs. 34.9±7.6 kg/m2; p&amp;lt; 0.0001). Black patients had less severe OSA on average, but this difference was not statistically significant (AHI of 33.9±25.5 vs 38.6±24.9 events/hour; p=0.077). After adjusting for covariates, Black patients had a 0.62 cm H2O (95% CI: 0.21 to 1.03) higher mean PAP level than White patients (p=0.003). There was a larger racial difference in mean PAP level among men (0.76 [0.16, 1.35] cm H2O; p=0.013) compared to a non-significant difference among women (0.34 [-0.23, 0.91] cm H2O; p=0.242). While statistically significant, differences were &amp;lt; 1 cm H2O and, thus, not clinically meaningful. Conclusion Black patients with OSA had a statistically significant but clinically insignificant difference in mean PAP level when compared with White patients. There was evidence of stronger differences in men than women. Further studies are needed to explore other potential mechanisms, including craniofacial anatomy, which may underlie racial differences in OSA presentation and outcomes. Support (if any) National Institutes of Health R01 1R01HL144859 (PIs: Schwartz, Dedhia)

Exploding Head Syndrome Associated With Severe Obstructive Sleep Apnea

Exploding head syndrome (EHS) is characterized by a sudden loud noise or sense of explosion in the head at the wake-sleep transition or upon waking during the night. In many cases, its symptoms tend to disappear spontaneously without requiring treatment. Some studies have suggested an association between EHS and obstructive sleep apnea. Here I present an elderly man having an intermittent sense of lightning with a little sound in his head during sleep. Polysomnographic evaluation revealed hypopnea preceding his habitual symptom. EHS symptoms decreased by positional therapy with weight reduction. They nearly disappeared after auto-adjusting positive airway pressure therapy.

Continuous Positive Airway Pressure-Mandibular Advancement Device Combination Therapy for Moderate-to-Severe Obstructive Sleep Apnea: A Preliminary Study.

The purpose of this pilot study was to determine whether compliance to auto-adjusting positive airway pressure (APAP) improves with the addition of a mandibular advancement device (MAD). Secondary outcome measures included were APAP pressure, subjective daytime sleepiness, apnea-hypopnea index (AHI), and mask leaks. Participants included were diagnosed with moderate-to-severe obstructive sleep apnea (OSA) and became noncompliant to prescribed APAP. Thirteen participants with a mean age of 61.6 years were recruited for this study. All participants were given a MAD to use with their APAP. Parameters measured included APAP pressure, AHI, mask leak reported via ResMed AirViewTM software, and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]). A paired two-sample for mean t-test was performed to determine significance. The mean difference of pre- and postintervention APAP compliance was 23.1%, which was statistically significant (p = 0.015). The mean APAP air pressures were unchanged. The difference between pre- and postintervention mean ESS scores was 1.4 and was statistically significant (p = 0.027). The mean difference between pre- and postintervention AHI values and mask leak showed no significant difference. This study showed that combination of APAP-MAD therapy, for patients with moderate-to-severe OSA who were noncompliant to APAP use, significantly increased compliance with APAP therapy, and significantly decreased the daytime sleepiness of participants.

Sleep health service in China during the coronavirus disease outbreak.

Citation:Zhang XL, Xiao Y. Sleep health service in China during the COVID-19 outbreak. J Clin Sleep Med. 2020;16(7):1221–1222.

Practical and rapidly-implemented parameters for assessing APAP titration failure.

This study aimed to show the predictive value of simple polysomnographic parameters including latency of deep sleep (nREM3), latency of rapid eye movement sleep (REM), and minimum oxygen saturation (SpO2) for predicting failure of autoadjusting positive airway pressure (APAP) titration. Out of 1470 patients with moderate to severe obstructive sleep apnea syndrome (OSAS) who underwent APAP titration between July 1, 2016, and December 31, 2017, 22 patients with titration failure were enrolled in the study. The demographic and polysomnographic characteristics of this group were compared with 44 patients with an adequate APAP titration who were matched with the titration failure group by age, sex, and OSAS severity. The periods between the start of sleep and the start of REM and nREM3 stages were noted as REM latency and nREM3 latency, respectively. The between group differences in the parameters including nREM3 latency, REM latency, and minimum SpO2 during the titration test were statistically significant (p = 0.004, p = 0.008, p <0.001 respectively). Possible threshold values to predict failure of APAP titration were found as 40 min and 135 min for nREM3 and REM latencies, respectively. The best threshold for minimum SpO2 was 86% with an 86.4% of sensitivity. Despite the high negative predictive values (81% for nREM3 latency, 75% for REM latency), the sensitivities (63.6% for nREM3 latency, 54.5% for REM latency) of the prior parameters in determining titration failure were relatively low. The minimum SpO2 < 86% can be used as a readily available indicator of APAP titration failure. nREM3 and REM latencies may be regarded as supplementary indicators in detecting the patients who may need an advanced PAP device.

Improvements in quality of life in female obstructive sleep apnea patients using a gender specific positive airway pressure device

Study Objectives: Females with obstructive sleep apnea (OSA) have more flow limitation, lower apnea-hypopnea index (AHI), shorter apneas, and less severe oxygen desaturations than males. A female-specific auto-adjusting continuous positive airway pressure (fAPAP) algorithm has been developed to target these characteristics. This study investigated the effects of fAPAP therapy on quality of life (QoL) in women with OSA. Methods: Female patients with AHI ≥ 15/h were eligible. Participants underwent polygraphy or polysomnography. The primary endpoint was change from baseline in Functional Outcomes of Sleep Questionnaire (FOSQ) score after 3 months’ fAPAP (AutoSet for Her, ResMed). Secondary endpoints included other sleep-related and QoL questionnaires. Results: A total of 122 patients were enrolled in the study (age 53.7 ± 9.5 years, body mass index 32.8 ± 6.2 kg/m2, apnea-hypopnea index [AHI] 39.0 ± 18.2/h); 111/122 completed the study. There was a significant improvement (p<0.0001) in FOSQ score from baseline (15.0 ± 3.3) to 3 months (16.9 ± 3.2). Significant improvements were also seen in the Patient Health Questionnaire-9 score (12.3 ± 6.0 vs. 7.2 ± 5.4), Epworth Sleepiness Scale score (10.8 ± 4.9 vs. 7.3 ± 4.7), EuroQol (EQ)-5D Index score (0.636 ± 0.248 vs. 0.763 ± 0.210), EQ-5D visual analogue scale score (54.4 ± 21.7 vs. 64.5 ± 21.5) (all p<0.0001), and Changes in Sexual Functioning Questionnaire score (38.7 ± 9.5 vs. 42.4 ± 8.5; p=0.001). In patients with PSG data, fAPAP improved other respiratory parameters (AHI, oxygen desaturation index, oxygen saturation; all p<0.0001), and increased time spent in rapid eye movement (REM) sleep (39.7 ± 24.0 vs. 48.1 ± 24.5 min; p=0.022). Average daily fAPAP usage was 4.8 ± 2.0 h/night. Conclusion: Usage of fAPAP significantly improved QoL and increased REM sleep, with good treatment compliance.

Employer-mandated obstructive sleep apnea treatment and healthcare cost savings among truckers.

To evaluate the effect of an employer-mandated obstructive sleep apnea (OSA) diagnosis and treatment program on non-OSA-program trucker medical insurance claim costs. Retrospective cohort analysis; cohorts constructed by matching (randomly, with replacement) Screen-positive Controls (drivers with insurance screened as likely to have OSA, but not yet diagnosed) with Diagnosed drivers (n = 1,516; cases = 1,224, OSA Negatives = 292), on two factors affecting exposure to medical claims: experience level at hire and weeks of job tenure at the Diagnosed driver's polysomnogram (PSG) date (the "matching date"). All cases received auto-adjusting positive airway pressure (APAP) treatment and were grouped by objective treatment adherence data: any "Positive Adherence" (n = 932) versus "No Adherence" (n = 292). Bootstrap resampling produced a difference-in-differences estimate of aggregate non-OSA-program medical insurance claim cost savings for 100 Diagnosed drivers as compared to 100 Screen-positive Controls before and after the PSG/matching date, over an 18-month period. A two-part multivariate statistical model was used to set exposures and demographics/anthropometrics equal across sub-groups, and to generate a difference-in-differences comparison across periods that identified the effect of OSA treatment on per-member per-month (PMPM) costs of an individual driver, separately from cost differences associated with adherence choice. Eighteen-month non-OSA-program medical claim costs savings from diagnosing (and treating as required) 100 Screen-positive Controls: $153,042 (95% CI: -$5,352, $330,525). Model-estimated effect of treatment on those adhering to APAP: -$441 PMPM (95% CI: -$861, -$21). Results suggest a carrier-based mandatory OSA program generates substantial savings in non-OSA-program medical insurance claim costs.

0535 Improvements in Quality of Life in Female Obstructive Sleep Apnea Patients using a Gender Specific Auto-adjusting Positive Airway Pressure Device

0535 Improvements in Quality of Life in Female Obstructive Sleep Apnea Patients using a Gender Specific Auto-adjusting Positive Airway Pressure Device

Reduction in sympathetic tone in patients with obstructive sleep apnoea: is fixed CPAP more effective than APAP? A randomised, parallel trial protocol

IntroductionObstructive sleep apnoea (OSA) is a prevalent disease associated with cardiovascular events. Hypertension is one of the major intermediary mechanisms leading to long-term cardiovascular adverse events. Intermittent hypoxia and hypercapnia...

Treatment of Adult Obstructive Sleep Apnea With Positive Airway Pressure: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment.

The purpose of this systematic review is to provide supporting evidence for the clinical practice guideline for the treatment of obstructive sleep apnea (OSA) in adults using positive airway pressure (PAP). The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of PAP with no treatment as well as studies that compared different PAP modalities. Meta-analyses were performed to determine the clinical significance of using PAP in several modalities (ie, continuous PAP, auto-adjusting PAP, and bilevel PAP), to treat OSA in adults. In addition, meta-analyses were performed to determine the clinical significance of using an in-laboratory versus ambulatory strategy for the initiation of PAP, educational and behavioral interventions, telemonitoring, humidification, different mask interfaces, and flexible or modified pressure profile PAP in conjunction with PAP to treat OSA in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations. The literature search resulted in 336 studies that met inclusion criteria; 184 studies provided data suitable for meta-analyses. The data demonstrated that PAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. In addition, the initiation of PAP in the home demonstrated equivalent effects on patient outcomes when compared to an in-laboratory titration approach. The data also demonstrated that the use of auto-adjusting or bilevel PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP. Furthermore, data demonstrated a clinically significant improvement in PAP adherence with the use of educational, behavioral, troubleshooting, and telemonitoring interventions. Systematic reviews for specific PAP delivery method were also performed and suggested that nasal interfaces compared to oronasal interfaces have improved adherence and slightly greater reductions in OSA severity, heated humidification compared to no humidification reduces some continuous PAP-related side effects, and pressure profile PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP.

Obstructive sleep apnoea in patients with fibrotic diffuse parenchymal lung disease-characterization and treatment compliance assessment.

IntroductionRecent studies have reported a high prevalence of obstructive sleep apnoea (OSA) among patients with diffuse parenchymal lung disease (DPLD), mainly idiopathic pulmonary fibrosis (IPF). Effective OSA treatment appears to have a positive impact on morbidity and mortality in these patients. However, poor compliance to positive airway pressure (PAP) treatment in fibrotic DPLD patients has been reported. The aims of our study were to characterize patients with fibrotic DPLD and OSA and to assess their compliance to PAP treatment.MethodsForty-nine patients with fibrotic DPLD underwent level III polysomnography. Auto-adjusting PAP (APAP) treatment was proposed for those patients with moderate-to-severe OSA and those with mild OSA with daytime sleepiness and/or cardiovascular disease. The APAP treatment compliance was assessed after 1 month of therapy.ResultsThe distribution of the 49 fibrotic DPLD patients included was as follows: 21 with chronic hypersensitivity pneumonitis, 12 with IPF, 10 with connective-tissue associated DPLD, 4 with stage IV sarcoidosis, 1 with idiopathic pleuropulmonary fibroelastosis, and 1 with DPLD-associated vasculitis. Thirty-four (69.4%) of the patients presented with OSA; 22 had mild OSA, and 12 had moderate-to-severe OSA. APAP treatment was prescribed in 17 of the patients. After 1 month of therapy, all patients used APAP more than 70% of the nights for more than 4 h per night.ConclusionWe found a high prevalence of OSA among all of the patients with fibrotic DPLD (not only IPF). Despite certain difficulties, it was possible to achieve good APAP compliance in these patients.

Verifying the Relative Efficacy between Continuous Positive Airway Pressure Therapy and Its Alternatives for Obstructive Sleep Apnea: A Network Meta-analysis.

Obstructive sleep apnea (OSA) is a common breathing disorder, and continuous positive airway pressure (CPAP) therapy together with its alternatives has been developed to treat this disease. This network meta-analysis (NMA) was aimed to compare the efficacy of treatments for OSA. Cochrane Library, MEDLINE, and Embase were searched for eligible studies. A conventional and NMA was carried out to compare all therapies. Sleeping characteristics, including Apnea–Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), arterial oxygen saturation, and arousal index (AI), and changes of blood pressure were selected as outcomes. A total of 84 studies were finally included after rigorous screenings. For the primary outcomes of AHI and ESS, the value of auto-adjusting positive airway pressure (APAP), CPAP, and oral appliance (OA) all showed statistically reduction compared with inactive control (IC). Similar observation was obtained in AI, with treatments of the three active interventions. A lower effect of IC in SaO2 was exhibited when compared with APAP, CPAP, and OA. Similar statistically significant results were presented in 24 h systolic blood pressure and 24 h DBP when comparing with CPAP. Our NMA identified CPAP as the most efficacious treatment for OSA patients after the evaluation of sleeping characteristics and blood pressures. In addition, more clinical trials are needed for further investigation due to the existence of inconsistency observed in this study.

Nonadherence with Employer-Mandated Sleep Apnea Treatment and Increased Risk of Serious Truck Crashes.

To evaluate the effect of an employer-mandated obstructive sleep apnea (OSA) program on the risk of serious preventable truck crashes. Data are from the first large-scale, employer-mandated program to screen, diagnose, and monitor OSA treatment adherence in the US trucking industry. A retrospective analysis of cohorts was constructed: polysomnogram-diagnosed drivers (OSA positive n = 1,613, OSA negative n = 403) were matched to control drivers unlikely to have OSA (n = 2,016) on two factors affecting crash risk, experience-at-hire and length of job tenure; tenure was matched on the date of each diagnosed driver's polysomnogram. Auto-adjusting positive airway pressure (APAP) treatment was provided to all cases (i.e. OSA positive drivers); treatment adherence was objectively monitored. Cases were grouped by treatment adherence: "Full Adherence" (n = 682), "Partial Adherence" (n = 571), or "No Adherence" (n = 360). Preventable Department-of-Transportation-reportable crashes/100,000 miles were compared across study subgroups. Robustness was assessed. After the matching date, "No Adherence" cases had a preventable Department of Transportation-reportable crash rate that was fivefold greater (incidence rate ratio = 4.97, 95% confidence interval: 2.09, 10.63) than that of matched controls (0.070 versus 0.014 per 100,000 miles). The crash rate of "Full Adherence" cases was statistically similar to controls (incidence rate ratio = 1.02, 95% confidence interval: 0.48, 2.04; 0.014 per 100,000 miles). Nontreatment-adherent OSA-positive drivers had a fivefold greater risk of serious preventable crashes, but were discharged or quit rapidly, being retained only one-third as long as other subjects. Thus, the mandated program removed risky nontreatment-adherent drivers and retained adherent drivers at the study firm. Current regulations allow nonadherent OSA cases to drive at another firm by keeping their diagnosis private. A commentary on this article appears in this issue on page 961.

Validation of the S9 AutoSet APAP device for the apnea-hypopnea index detection in OSA patients

Introduction: Auto-adjusting positive airway pressure (APAP) is an accepted treatment for obstructive sleep apnea (OSA). Reporting of apnea-hypopnea index (AHI) from APAP devices might be useful for determining therapy compliance and monitoring therapy efficiency as well as the presence of residual sleep apnea. The detection algorithm of the S9 AutoSet APAP device (ResMed, Sydney, Australia) is able to discern between central and obstructive events.

Advanced Positive Airway Pressure Modalities

Auto-adjusting positive airway pressure (PAP) devices are increasingly becoming the first line treatment for obstructive sleep apnea (OSA). More complex sleep- disordered breathing such as Cheyne-Stokes respirations and central sleep apnea related to heart failure as well as complex sleep-disordered breathing related to chronic hypoventilation syndromes may require the use of advanced positive airway pressure modalities such as automated servo ventilation (ASV) and volume targeted pressure limited ventilation. Identifying patients with complex sleep-disordered breathing that will benefit from treatment with advanced modalities re- mains an area of active investigation. A recent and surprising development found ASV to be associated with an increased risk of sudden cardiac death when used to treat central sleep apnea in patients with symptomatic systolic heart failure and an ejection fraction less than 45 %. The optimal treatment of central sleep apnea in heart failure and the role of ASV are currently in question. The following chapter is intended to provide the clinician with a description of newer PAP modal- ities; a review of evidence supported indications for use as well as provide a framework for managing patients with ad- vanced positive airway pressure therapy.

Lipid profile after long-term APAP in OSA patients.

This study aimed to explore the impact of an 8-year therapy with autoadjusting positive airway pressure (APAP) on fasting lipid level in a sample of Portuguese moderate/severe obstructive sleep apnea (OSA) patients. Besides contributing to the comprehension of the complex relationship between dyslipidemia and OSA, it provided new data regarding the effectiveness of a long term APAP treatment. Thirty-nine male patients with moderate to severe OSA were included in the study. APAP was prescribed to all patients. Fifteen patients were under lipid-lowering medication throughout the study, and another 15 patients never used lipid-lowering medication at any time during the study. Fasting morning venous blood samples were collected at three time points (baseline 6months and 8years) and lipids were estimated. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) 21.0 software. After 8years of APAP treatment, patients presented a similar body mass index but a significantly less severe daytime sleepiness. Patients on lipid-lowering medication exhibited a higher reduction in total cholesterol than those naïf from that medication, but the reduction was not statistically significant after adjusting for medication and APAP adherence. Long-term APAP treatment improves OSA but does not seem to contribute to changes in fasting lipids.

Auto-adjusting positive airway pressure treatment for sleep apnea diagnosed by home sleep testing.

Compare auto-adjusting positive airway pressure (APAP) treatment with positive airway pressure (PAP) titration by polysomnography (PSG) followed by CPAP treatment in patients diagnosed with obstructive sleep apnea (OSA) by home sleep apnea testing (HSAT). Prospective randomized treatment study. Tertiary Veterans Administration Medical Center. 156 patients diagnosed with OSA by HSAT (apneahypopnea index [AHI] ≥ 10/h) suitable for APAP treatment. APAP arm: Treatment with an APAP device, CPAP arm: PSG PAP titration followed by CPAP treatment. Mean PAP adherence, Epworth sleepiness scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ). The mean (± SD) age, BMI, and diagnostic AHI (APAP: 28.6 ± 18.5, CPAP: 28.3 ± 16.0/h, p = NS) did not differ between the study arms. After 6 weeks of treatment, 84.6% of 78 patients started on APAP and 84.3% of 70 patients started on CPAP (8 declined treatment after the titration) were using PAP, p = NS. The 90% APAP and level of CPAP were similar (10.8 ± 3.1, 11.7 ± 2.5 cm H2O, p = 0.07). The average nightly PAP use did not differ (APAP: 4.45 ± 2.3, CPAP: 4.0 ± 2.3 h, p = NS). The improvements in the ESS (APAP: -4.2 ± 4.7, CPAP: -3.7 ± 4.8, p = NS) and in the FOSQ (APAP: 2.6 ± 3.5, CPAP: 2.2 ± 3.7, p = NS) were not different. Following diagnosis of OSA by HSAT, treatment with APAP results in equivalent PAP adherence and improvement in sleepiness compared to a PSG titration and CPAP treatment. A commentary on this article appears in this issue on page 1277.

Poor versus good sleepers in patients under treatment for sleep-related breathing disorders: better is not good enough

Dear editor Recently we published a retrospective study in this journal which reported the significant relationship between nocturnal awakening, respectively high arousal index, and fatigue in 410 patients with sleep disorders admitted to our sleep laboratory.1 In this study we noticed that Pittsburgh Sleep Quality Index (PSQI) mean values2 were lower in patients who have been treated for sleep-related breathing disorders (SRBD) compared with either treatment-naive SRBD patients, or with patients with periodic limb movement disorder (PLMD), restless legs syndrome (RLS), or insomnia. However, this study was not focused on PSQI values and we did not classify the patients into good and poor sleepers according to the established PSQI cut-off (less than or equal to versus greater than five). The PSQI was initially developed to screen impaired subjective sleep quality in patients with insomnia and depression, but today it is widely used in sleep medicine in general. We now report the results of a classification of our patients into good and poor sleepers according to their PSQI values, using the PSQI-cut-off of ≤ or >5 that we performed subsequent to our original study. To our knowledge, there have been to date only a few studies in this issue that have investigated the use of PSQI in obstructive sleep apnea (OSA) patients. These studies had inconsistent findings and small sample sizes. Macey et al3 did not find a significant relationship between the apnea-hypopnea-index per hour of sleep (AHI) and PSQI values in 49 untreated OSA patients. Chihara et al4 reported a significant improvement of PSQI values after auto-adjusting positive airway pressure (APAP) with flexible positive airway pressure (C-Flex) (n=29), but not with APAP alone (n=28) or APAP in combination with fixed inspiration/expiration pressure difference (A-Flex) (n=28). Mermigkis et al5 found no significant improvement of PSQI values before and after continuous positive airway pressure (CPAP) in a small sample of 12 patients.

Sleep differences in auto-adjustable CPAP devices and manual standard CPAP titration in a sleep laboratory

Continuous positive airway pressure (CPAP) and auto-adjusting positive airway pressure (APAP) devices are the mainstay of treatment for moderate to severe obstructive sleep apnea (OSA). The normalizing of sleep architecture may be one of the consequences of the treatment and may be related to treatment compliance and the relief of sleepiness. Determination the positive pressure required by a patient may be determined by standard CPAP (s-CPAP) or APAP, but there isn’t a universally accepted method to determine the optimal positive pressure value. Knowledge of the night sleep architecture in unselected OSAs patients by using s-CPAP or APAP devices during the determination the positive pressure by means of a full polysomnography (PSG) in the sleep lab attended by a sleep technician. 107 OSAS patients were one night full PSG controlees to titrated CPAP pressure, 63 of them (41 males and 22 females) by using APAP device and 44 patients (32 males and 12 females) by using s-CPAP. All patients were previously treated almost three months before (the pressure was calculated with a prediction formula). The groups were not different in their respective ages or BMIs. The PSG did not show differences in both groups in Total sleep time, sleep efficiency, sleep stage N1 or R, but the proportion of stage N3 was higher ( p = 0.035) and stage N2 was lower ( p = 0.022) in the APAP group. Other variables, such as taking hypnotics, CPAP tolerance, improving clinical manifestation with CPAP use, Epworth sleepiness scale, sleep position and previous randomized pressure did not show significant differences between groups. This is especially interesting taking into account that the APAP group had slept more hours the previous night. The mean CPAP pressure of the APAP group was higher (10.553 ± 1.78) than that of the s-CPAP group (9.250 ± 1.69) p = 0.000. The sleep structure was better on the APAP adjusted group than on the s-CPAP group, despite its mean CPAP pressure being higher. Only a minority of studies found in the bibliography are in agreement with this last observation. Both findings cannot be explained, but they could be a consequence of the slower increase of pressure in s-CPAP than in APAP. Therefore, it can be concluded that the use of APAP devices could be considered a good method for the adjustment of pressure levels and for normalizing sleep structure.