Residual Apnea-hypopnea Index Research Articles

0522 A RANDOMIZED-CONTROL TRIAL OF ADHERENCE AND ACCEPTANCE OF A TELEMEDICINE MONITORING SYSTEM FOR OSA PATIENTS TREATED WITH CPAP

Adherence to CPAP treatment in OSA patients is still not optimal and is still a clinical problem. New telemedicine monitoring systems can improve adherence, but this has not been clearly demonstrated yet. Primary outcome of this study was to assess PAP adherence (hours of use per night and percentage of days of use) after 1, 3 and 6 months in telemicine patients compared to standard care patients. Secondary outcome measures were subjective sleep quality and patient’s satisfaction randomized controlled trial that compared standard care CPAP treatment versus CPAP treatment by a telemedicine monitoring system (EncoreAnywhere, Philips Respironics). 30 patients (mean age 53.3 ± 9.5 yrs) with moderate to severe OSA (mean apnea hypopnea index (AHI) 45.3 ± 21) that had PAP prescribed, were randomized to either standard care (SC) or to telemedicine (TM), an autotitrating PAP machine that transmitted data (adherence, leaks, residual AHI) daily to a website that could be reviewed by clinical staff. If problems were identified from information from the website, the patient were contacted by telephone as necessary according to set criteria. 16 patients were randomized to TM and 14 to SC. After 1 month, mean PAP adherence was significantly greater in the TM arm (379 min per day) versus the SC arm (324 min per day; mean difference = 55 min, p<.05). Percentage of days of use for more than 4 hrs at 1 month was 89.7% in the TM arm and 60.8 % in the standard arm (p < .05), 92% vs 74.8% at 3 months and 93.3% vs 73.4% at 6 months. Significant independent predictors of adherence was the use of TM (p<.001). On average, we calculated a reduction of the number of visits per patients in the TM arm compared with the SC arm (5 vs 9, p<.05). Patients satisfaction was significantly superior in the telemedicine group (p<.05). PAP adherence and satisfaction can be improved with the use of a web-based telemedicine system implemented at the initiation of treatment and used for long-term monitoring of compliance. This research was supported by Philips Respironics Italy.

0521 IMPACT OF MASK TYPE ON CONTINUOUS POSITIVE AIRWAY PRESSURE EFFICACY AND COMPLIANCE: A META-ANALYSIS

Continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA). The impact of the mask type on the efficacy and acceptance of CPAP is inconclusive. The present study aimed to compare the effects and compliance of oronasal and nasal mask by the meta-analysis of the existing trials. Studies were retrieved from PubMed, EMBASE, and CENTRAL up to August 2016. The literature was reviewed by two independent authors. The mean difference of residual apnea-hypopnea index (AHI), therapeutic pressure, usage hour, and preference between oronasal and nasal mask was quantified. The pooled effect was analyzed with random-effect generic inverse variance and the heterogeneity was assessed with I2. From 6070 articles, 13 studies comprising 4000 subjects were included for the meta-analysis. The number of recruited subjects was different and the recruited trials were heterogeneous for all four outcomes. The 寫Newcastle-Ottawa scale showed that two studies (120 subjects) enrolling participants inadequately response to oronasal CPAP were biased. Compared to nasal masks, the oronasal masks had higher residual AHI for 5.5/hour (95% CI 2.3–8.8, p<0.001, I2 94%, 676 subjects), higher therapeutic pressure for 1 cmH2O (0–2.1, p=0.05, I2 76%, 534 subjects), and shorter usage per night for 0.8 hour (-1.06 - -0.54, p<0.001, I2 25%, 1364 subjects), and less preferred (odds ratio 0.05, 95% CI 0–0.6, p=0.02, 153 subjects). The subgroup analysis of 11 unbiased trials (3880 subjects) gave the same results for all four outcomes. Subgroup analysis of 5 randomized control trials (RCT) (176 subjects) had similar results except that therapeutic pressure was similar between two masks (p=0.97). The present studies showed that oronasal masks were associated with higher residual AHI, higher therapeutic pressure, shorter usage, and less preference compared to nasal masks. This study was supported by National Taiwan University (NTU) Hospital (105-S2998), Ministry of Science and Technology (103-2314-B-002-139-MY3), and NTU (NTU-ERP-105R8951-1).

Validation of the System One RemStar Auto A-Flex for Obstructive Sleep Apnea Treatment and Detection of Residual Apnea-Hypopnea Index: A European Randomized Trial

Autotitrating continuous positive airway pressure (CPAP) devices adjust pressure in response to changes in airflow and are an alternative to attended in-laboratory titration polysomnography (PSG) to determine optimal pressure levels. The aim of this study was to compare the performance of the System One RemStar Auto A-Flex (Philips Respironics, Murrysville, PA, USA) automatically adjusted positive airway pressure (APAP) mode to manually titrated, fixed pressure CPAP and to validate the device's breathing event detection capabilities against attended in-laboratory PSG. Sixty-one patients investigated in five centers for moderate to severe obstructive sleep apnea between May 2012 and June 2013 were invited to participate. Participants underwent two full-night attended polysomnograms in random order with manually titrated, fixed pressure CPAP versus APAP. Fifty-three participants with a mean apnea-hypopnea index (AHI) of 45.9 ± 23 completed two sleep studies and were included in the analysis. There were significant but not clinically relevant differences between APAP and CPAP respectively: Apnea index [1.0 (2.8 ± 0.8), median (mean ± standard deviation)] versus [1.8 (5.3 ± 11.5)], p = 0.004; percentage of N1 sleep [12.3 (15.9 ± 0.5)] versus [14.3 (18.9 ± 12.7)], p = 0.028. AHI values differed between PSG [2.8 (5.5. ± 9.3)] and device [3.7 (6.0 ± 8.6)], p = 0.003). Regarding residual events detection, intraclass correlation coefficients for AHI were strong (0.956, p < 0.001) and the area under the curve was 0.988 (AHI cut-off value of 10). The new APAP modality was effective and residual apnea-hypopnea indices calculated by the device strongly correlated to those assessed by PSG. A commentary on this article appears in this issue on page 167.

Optimal level of continuous positive airway pressure: Auto-CPAP titration versus predictive formulas

Continuous positive airway pressure (CPAP) is the most effective treatment of obstructive sleep apnea hypopnea syndrome (OSAHS). The therapeutic level of CPAP is achieved by manual titration or an auto CPAP device, but an alternative way involves the use of mathematical equations.Aim of the work: to compare between CPAP pressure obtained by autoCPAP titration and that calculated from five different mathematical formulas. MethodsWe enrolled 30 patients with OSAHS. In addition to standard examination, anthropometric measurements and investigations, all patients underwent an over-night polysomnography (PSG) AutoCPAP (level II) to diagnose OSAHS. Manual scoring of polysomnographic data was performed according to criteria established by the American Academy of Sleep Medicine in 2012. All patients used AutoCPAP with pressure ranging from 4 to 20cm H2O. Information recorded was downloaded and the following data were retrieved: 1) P90% (90th percentile pressure delivered by the autoCPAP device and eliminated snoring, flow limitation and apnea), this pressure was chosen as the therapeutic pressure, 2) peak pressure level, 3) mean pressure level, 4) the estimated residual apnea hypopnea index (AHI), 5) P90%/mean pressure level ratio, which is an index of pressure variability, was calculated. Five predictive formulas were retrieved from published literature and calculated for all patients. ResultsThe mean±SD of AHI was 47.94±27.21events/h. OSAHS was mild in 5 patients (16.67%), moderate in seven patients (23.33%), and severe in 18 patients (60%). AutoCPAP P90% was 10.59±2.66cm H2O and showed significantly direct correlation with each of Epworth sleepiness scale (p=0.000), BMI (p=0.001), neck circumference (p=0.002), neck to height ratio (p=0.000), and AHI (p=0.000). Also it was found to show statistically significant inverse correlation with each of minimal (p=0.000), and average minimal oxygen saturation (p=0.032). The pressure calculated by Hoffstein et al. equation was significantly lower than autoCPAP P90%. There was no significant difference with pressure calculated by the other four formulas and P90%. The following model of predictive equation was derived from the studied sample: Predicted therapeutic pressure=4.740+68.575 X (N/H) – 0.153 X (Minimal SpO2). ConclusionsPredictive formulas might be useful as an alternative to autoCPAP. The model of predictive formula derived from the present small sample of Egyptian patients with OSAHS should be validated on a larger sample size.

Oronasal mask may compromise the efficacy of continuous positive airway pressure on OSA treatment: is there evidence for avoiding the oronasal route?

Continuous positive airway pressure (CPAP) delivered by nasal mask is the gold standard treatment for obstructive sleep apnea (OSA). However, oral and oronasal masks are also available. We considered experimental evidence and reviewed clinical trials that evaluated the impact of oral and oronasal mask on OSA treatment. One recent study in 18 OSA patients that slept with a customized oronasal mask with two sealed compartments showed that the change of CPAP flow from nasal to oronasal and oral caused upper airway obstruction because of posterior displacement of the tongue demonstrated by nasoendoscopy. Oral masks use a mouthpiece that may stabilize the jaw and the tongue and have shown to be effective. However, oral masks are not widely used in clinical practice. Four out of five observational studies and all five reviewed randomized studies showed a worse performance of oronasal when compared with nasal masks. Oronasal masks were associated with higher residual apnea-hypopnea index, lower adherence, more leaks, and less satisfaction than nasal mask in the majority of the studies. Nasal CPAP must be the first choice to treat OSA. Patients on oronasal mask should be carefully followed. VIDEO ABSTRACT.

Gel pillow designed specifically for obstructive sleep apnea treatment with continuous positive airway pressure

ABSTRACTObjective:To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. Methods:Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with an appropriate CPAP mask and were instructed to use CPAP for 15 nights. They were instructed to sleep with their own pillow (the control pillow) from nights 1 to 5 and with either a foam pillow or a gel pillow, both of which had side cutouts, for 5 consecutive nights each, in random order. After night 15, auto-CPAP machine data were downloaded and patients rated their satisfaction with each pillow on a visual analog scale. Results:Twenty-two patients completed the protocol. The pressures administered, residual apnea-hypopnea index, air leaks, and mean duration of CPAP use did not differ among the periods during which each pillow was used. Patients were significantly more satisfied with the gel pillow than with the control pillow and the foam pillow (p = 0.022 and p = 0.004, respectively), their level of satisfaction with the gel pillow correlating significantly with excessive daytime sleepiness (r2 = 0.19; p = 0.0443). Conclusions:Among obstructive sleep apnea patients treated with nasal CPAP, the use of a gel pillow with side cutouts appears to have no impact on treatment effectiveness. Nevertheless, such patients seem to prefer a gel pillow over other types of pillows.

Oronasal Masks Require a Higher Pressure than Nasal and Nasal Pillow Masks for the Treatment of Obstructive Sleep Apnea.

Oronasal masks are frequently used for continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea (OSA). The aim of this study was to (1) determine if CPAP requirements are higher for oronasal masks compared to nasal mask interfaces and (2) assess whether polysomnography and patient characteristics differed among mask preference groups. Retrospective analysis of all CPAP implementation polysomnograms between July 2013 and June 2014. Prescribed CPAP level, polysomnography results and patient data were compared according to mask type (n = 358). Oronasal masks were used in 46%, nasal masks in 35% and nasal pillow masks in 19%. There was no difference according to mask type for baseline apnea-hypopnea index (AHI), body mass index (BMI), waist or neck circumference. CPAP level was higher for oronasal masks, 12 (10-15.5) cm H2O compared to nasal pillow masks, 11 (8-12.5) cm H2O and nasal masks, 10 (8-12) cm H2O, p < 0.0001 (Median [interquartile range]). Oronasal mask type, AHI, age, and BMI were independent predictors of a higher CPAP pressure (p < 0.0005, adjusted R(2) = 0.26.). For patients with CPAP ≥ 15 cm H2O, there was an odds ratio of 4.5 (95% CI 2.5-8.0) for having an oronasal compared to a nasal or nasal pillow mask. Residual median AHI was higher for oronasal masks (11.3 events/h) than for nasal masks (6.4 events/h) and nasal pillows (6.7 events/h), p < 0.001. Compared to nasal mask types, oronasal masks are associated with higher CPAP pressures (particularly pressures ≥ 15 cm H2O) and a higher residual AHI. Further evaluation with a randomized control trial is required to definitively establish the effect of mask type on pressure requirements. A commentary on this article appears in this issue on page 1209.

Novel Approach to Simulate Sleep Apnea Patients for Evaluating Positive Pressure Therapy Devices.

Bench testing is a useful method to characterize the response of different automatic positive airway pressure (APAP) devices under well-controlled conditions. However, previous models did not consider the diversity of obstructive sleep apnea (OSA) patients’ characteristics and phenotypes. The objective of this proof-of-concept study was to design a new bench test for realistically simulating an OSA patient’s night, and to implement a one-night example of a typical female phenotype for comparing responses to several currently-available APAP devices. We developed a novel approach aimed at replicating a typical night of sleep which includes different disturbed breathing events, disease severities, sleep/wake phases, body postures and respiratory artefacts. The simulated female OSA patient example that we implemented included periods of wake, light sleep and deep sleep with positional changes and was connected to ten different APAP devices. Flow and pressure readings were recorded; each device was tested twice. The new approach for simulating female OSA patients effectively combined a wide variety of disturbed breathing patterns to mimic the response of a predefined patient type. There were marked differences in response between devices; only three were able to overcome flow limitation to normalize breathing, and only five devices were associated with a residual apnea-hypopnea index of <5/h. In conclusion, bench tests can be designed to simulate specific patient characteristics, and typical stages of sleep, body position, and wake. Each APAP device behaved differently when exposed to this controlled model of a female OSA patient, and should lead to further understanding of OSA treatment.

C-reactive Protein as a Potential Biomarker of Residual Obstructive Sleep Apnea Following Adenotonsillectomy in Children.

Adenotonsillectomy (AT) is first-line treatment for pediatric obstructive sleep apnea (OSA), with most children having improvements in polysomnography (PSG). However, many children have residual OSA following AT as determined through PSG. Identification of a biomarker of residual disease would be clinically meaningful to detect children at risk. We hypothesize serum high-sensitivity C-reactive protein (hsCRP), an inflammatory biomarker, is predictive of residual OSA following AT. PSG was performed both preoperatively and postoperatively on children undergoing AT for the diagnosis of OSA. HsCRP serum concentrations were determined in all children pre-AT, and in most children post-AT. Resolution of OSA after AT was defined by a post-AT apnea-hypopnea index (AHI) < 1.5/h total sleep time (TST). Residual OSA was defined as a post-AT AHI > 5/h TST, which is considered clinically significant. AT significantly improved the AHI from 15.9 ± 16.4 to 4.1 ± 5.3/h TST in 182 children (P < 0.001). Of 182 children, residual OSA (post-AT AHI > 5) was seen in 46 children (25%). Among children who had hsCRP levels measured pre- and post-AT (n = 155), mean hsCRP levels pre-AT were 0.98 ± 1.91 mg/L and were significantly reduced post-AT (0.63 ± 2.24 mg/dL; P = 0.011). Stratification into post-AT AHI groups corresponding to < 1.5/h TST, 1.5/h TST < AHI < 5/h TST, and AHI > 5/h TST revealed post-AT hsCRP levels of 0.09 ± 0.12, 0.57 ± 2.28, and 1.49 ± 3.34 mg/L with statistical significance emerging comparing residual AHI > 5/h TST compared to post-AT AHI < 1.5/h TST (P = 0.006). Hierarchical multivariate modeling confirmed that pre-AT AHI and post-AT hsCRP levels were most significantly associated with residual OSA. Even though AT improves OSA in most children, residual OSA is frequent. Assessment of post-AT hsCRP levels emerges as a potentially useful biomarker predicting residual OSA.

Maxillomandibular Advancement for Treatment of Obstructive Sleep Apnea

Maxillomandibular advancement (MMA) is an invasive yet effective surgical option for obstructive sleep apnea (OSA) that achieves enlargement of the upper airway by physically expanding the facial skeletal framework. To identify criteria associated with surgical outcomes of MMA using aggregated individual patient data from multiple studies. The Cochrane Library, Scopus, Web of Science, and MEDLINE from June 1, 2014, to March 16, 2015, using the Medical Subject Heading keywords maxillomandibular advancement, orthognathic surgery, maxillary osteotomy, mandibular advancement, sleep apnea, surgical, surgery, sleep apnea syndrome, and obstructive sleep apnea. Inclusion criteria consisted of studies in all languages of (1) adult patients who underwent MMA as treatment for OSA; (2) report of preoperative and postoperative quantitative outcomes for the apnea-hypopnea index (AHI) and/or respiratory disturbance index (RDI); and (3) report of individual patient data. Studies of patients who underwent adjunctive procedures at the time of MMA (including tonsillectomy, uvulopalatopharyngoplasty, and partial glossectomy) were excluded. Three coauthors systematically reviewed the articles and updated the review through March 16, 2015. The PRISMA statement was followed. Data were pooled using a random-effects model and analyzed from July 1, 2014, to September 23, 2015. The primary outcomes were changes in the AHI and RDI after MMA for each patient. Secondary outcomes included surgical success, defined as the percentage of patients with more than 50% reduction of the AHI to fewer than 20 events/h, and OSA cure, defined as a post-MMA AHI of fewer than 5 events/h. Forty-five studies with individual data from 518 unique patients/interventions were included. Among patients for whom data were available, 197 of 268 (73.5%) had undergone prior surgery for OSA. Mean (SD) postoperative changes in the AHI and RDI after MMA were -47.8 (25.0) and -44.4 (33.0), respectively; mean (SE) reductions of AHI and RDI outcomes were 80.1% (1.8%) and 64.6% (4.0%), respectively; and 512 of 518 patients (98.8%) showed improvement. Significant improvements were also seen in the mean (SD) postoperative oxygen saturation nadir (70.1% [15.6%] to 87.0% [5.2%]; P < .001) and Epworth Sleepiness Scale score (13.5 [5.2] to 3.2 [3.2]; P < .001). Rates of surgical success and cure were 389 (85.5%) and 175 (38.5%), respectively, among 455 patients with AHI data and 44 (64.7%) and 13 (19.1%), respectively, among 68 patients with RDI data. Preoperative AHI of fewer than 60 events/h was the factor most strongly associated with the highest incidence of surgical cure. Nevertheless, patients with a preoperative AHI of more than 60 events/h experienced large and substantial net improvements despite modest surgical cure rates. Maxillomandibular advancement is an effective treatment for OSA. Most patients with high residual AHI and RDI after other unsuccessful surgical procedures for OSA are likely to benefit from MMA.

Effectiveness of oral pressure therapy in obstructive sleep apnea: a systematic analysis.

Oral pressure therapy (OPT) has emerged as a novel technique to treat obstructive sleep apnea (OSA) in the past few years. Given this is a relatively new treatment approach, currently, little is known with respect to its clinical utility. The aim of this review was to explore the success rate of OPT when used to treat OSA. PubMed, MEDLINE, Scopus, Web of Science, and the Cochrane Library databases were searched for pertinent studies. The OPT treatment success rates varied widely between 25 and 79% depending on the residual apnea-hypopnea index (AHI) cut off defined for treatment success. When using standard definitions (at least 50% reduction from the baseline AHI and the post-OPT treatment residual AHI less than or equal to 10), the success rate of OPT treatment varied between 25 and 37%. Although there was a significant reduction in AHI with OPT, the baseline AHI was not suppressed in majority of patients to the extent to call these patients as optimally treated. Successful treatment with OPT did not correlate with severity of OSA; however, patients with retro-palatal collapse responded better to treatment. Further research is needed to identify OSA patients who would benefit with this treatment modality.

Clinical Use of Loop Gain Measures to Determine Continuous Positive Airway Pressure Efficacy in Patients with Complex Sleep Apnea. A Pilot Study.

Measures of unstable ventilatory control (loop gain) can be obtained directly from the periodic breathing duty ratio on polysomnography in patients with Cheyne-Stokes respiration/central sleep apnea and can predict the efficacy of continuous positive airway pressure (CPAP) therapy. In this pilot study, we aimed to determine if this measure could also be applied to patients with complex sleep apnea (predominant obstructive sleep apnea, with worsening or emergent central apneas on CPAP). We hypothesized that loop gain was higher in patients whose central events persisted 1 month later despite CPAP treatment versus those whose events resolved over time. We calculated the duty ratio of the periodic central apneas remaining on the CPAP titration (or second half of the split night) while patients were on optimal CPAP with the airway open (obstructive apnea index < 1/h). Loop gain was calculated by the formula: LG = 2π/[(2πDR - sin(2πDR)]. Patients were followed on CPAP for 1 month. Post-treatment apnea-hypopnea index and compliance data were recorded from smart cards. Thirty-two patients with complex sleep apnea were identified, and 17 patients had full data sets. Eight patients continued to have a total of more than five events per hour (11.8 ± 0.5/h) (nonresponders). The remaining nine patients had an apnea-hypopnea index less than 5/h (2.2 ± 0.4/h) (responders). Loop gain was higher in the nonresponders versus responders (2.0 ± 0.1 vs. 1.7 ± 0.2, P = 0.026). Loop gain and the residual apnea-hypopnea index 1 month after CPAP were associated (r = 0.48, P = 0.02). CPAP compliance was similar between groups. In this pilot study, loop gain was higher for patients with complex sleep apnea in whom central apneas persisted after 1 month of CPAP therapy (nonresponders). Loop gain measurement may enable an a priori determination of those who need alternative modes of positive airway pressure.

Response to Braghiroli et al., regarding our study “Accuracy of a novel auto-CPAP device to evaluate the residual apnea-hypopnea index in patients with obstructive sleep apnea”

Response to Braghiroli et al., regarding our study “Accuracy of a novel auto-CPAP device to evaluate the residual apnea-hypopnea index in patients with obstructive sleep apnea”

Continuous Positive Airway Pressure Treatment Increases Serum Vitamin D Levels in Male Patients with Obstructive Sleep Apnea.

Recent studies report a link between obstructive sleep apnea (OSA) syndrome, low vitamin D levels, and high parathyroid hormone (PTH) concentrations. The aim of the current study is to evaluate the effect of 7-night continuous positive airway pressure (CPAP) therapy on serum vitamin D, PTH, and calcium levels in patients with severe OSA syndrome. Patients with severe OSA were enrolled into the study and compared to control subjects. Patients with OSA underwent CPAP therapy for 7 nights and were consequently divided into responders (OSA-R, mean residual AHI < 5/h) and nonresponders (OSA-nR, mean residual AHI > 5/h). Serum vitamin D, PTH, and calcium levels were measured at baseline in patients with severe OSA (apnea-hypopnea index > 30/h) and control subjects. Patients with OSA underwent a final morning blood sample after 7-night CPAP therapy. We enrolled 90 patients with OSA into the study (65 OSA-R and 25 OSA-nR) compared to 32 control subjects. At baseline, lower vitamin D and higher PTH levels were detected in the OSA group compared to controls. After 7-night CPAP therapy, male OSA-R patients showed a significant increase in vitamin D levels. Conversely, female OSA-R patients did not show the same increase in vitamin D levels. It was also observed that OSA-nR subjects did not show modifications of serum markers after nCPAP-therapy. The study demonstrates that short-term nCPAP treatment is able to promote the recovery of vitamin D homeostasis in male patients with OSA. The mediation of sexual hormones in regulating vitamin D is a possible explanation of the lack of recovery of vitamin D homeostasis in female patients with OSA as it often affects postmenopausal women.

Oscillating Positive Airway Pressure Versus CPAP for the Treatment of Obstructive Sleep Apnea.

Although continuous positive airway pressure (CPAP) is the most effective therapy for obstructive sleep apnea (OSA), it is not always well tolerated by the patients. Previous physiological studies showed that pressure oscillations applied to the pharynx could activate upper airway muscles, but it is not clear whether these pressure oscillations could be tolerated during sleep in OSA patients. The aim of this study was to assess the tolerance of oscillating positive airway pressure (O-PAP) (a CPAP device delivering high-frequency pressure oscillations to the upper airway) compared to CPAP. Fourteen OSA patients currently on CPAP [age 59.9 ± 10.1 years old, BMI 34.8 ± 7.2 kg/m2, initial apnea–hypopnea index (AHI): 58.7 ± 25.2 events/h] used O-PAP or CPAP on two consecutive nights under polysomnography, in a single-blind randomized crossover design to assess sleep quality. A subtherapeutic pressure (70% of the optimal titrated pressure) was applied in both conditions and the residual AHI with each technique was also compared. There was no difference in measured or perceived sleep quality between the two treatment modalities (sleep efficiency 90.0% versus 88.1%, p = 0.54). Despite the small sample, we also found a trend toward a decrease in residual respiratory events with O-PAP compared to CPAP (median AHI 14.3 versus 20.5/h, p = 0.194). The good tolerance of O-PAP and the positive trend toward a reduction in residual AHI should stimulate further research on the effects of O-PAP in OSA patients.

Comorbidity modulates non invasive ventilation-induced changes in breath print of obstructive sleep apnea syndrome patients.

In obstructive sleep apnea syndrome (OSAS), exhaled volatile organic compounds (VOCs) change after long-term continuous positive airway pressure (CPAP). The objective of the study was to verify whether changes in VOCs pattern are detectable after the first night of CPAP and to identify correlates, if any, of these changes. Fifty OSAS patients underwent a multidimensional assessment and breath print (BP) analysis through 28 sensors e-nose at baseline and after the first night of CPAP. Boxplots of individual BP evolution after CPAP and groups were compared by ANOVA and Fisher's exact t. Partial least square discriminant analysis (PLS-DA), with leave-one-out as cross-validation was used to calculate to which extent basal BP could predicts changes in apnea-hypopnea index (AHI). CPAP was effective in all the patients (delta AHI 35.8 events/h; residual AHI 6.0 events/h). BP dramatically changed after a single-night CPAP and changes conformed to two well-distinguished patterns: pattern C (n = 29), characterized by consonant boxplots, and pattern D (n = 21), with variably discordant boxplots. The average number of comorbid diseases (1.55 [standard deviation, SD 1.0] in group C, 3.14 [SD 1.8] in group D, p < 0.001) and the prevalence of selected comorbidity (diabetes mellitus, metabolic syndrome, and chronic heart failure), were the only features distinguishing groups. We found that BP change after a single night of CPAP largely depends upon comorbidity. Comorbidity likely contributes to phenotypic variability in OSAS population. BP might qualify as a surrogate index of the response to and, later, compliance with CPAP.

Apnea burden: efficacy versus effectiveness in patients using positive airway pressure

BackgroundModern continuous positive airway pressure (PAP) machines track hours of use and residual respiratory events while on treatment. A substantial portion of sleep apnea patients are partially compliant, emphasizing the need to distinguish between PAP efficacy and PAP effectiveness in chronic management of patients with sleep apnea. MethodsWe used a combination of three data sources to estimate the sleep apnea burden in a convenience cohort of PAP users from our clinics that were compliant based on Medicare criteria: self-reported habitual total sleep time, and PAP usage times with residual apnea–hypopnea index (AHI) from compliance downloads. ResultsAssuming that the off-PAP time consists of baseline AHI severity, an estimated apnea burden was calculated to estimate PAP effectiveness. Whereas 70% of patients in our cohort showed machine AHI values <5/h, the apnea burden calculations revealed that only one-third of patients are predicted to have an effective AHI <5. ConclusionEstimating PAP effectiveness through the concept of apnea burden has implications for clinical care as well as research trials.

Oronasal masks require higher levels of positive airway pressure than nasal masks to treat obstructive sleep apnea

The purpose of this study was to compare the therapeutic pressure determined by an automated CPAP device (AutoCPAP) during the titration period, between nasal and oronasal mask and the residual apnea-hypopnea index (AHI) on a subsequent poligraphy performed with the established therapeutic CPAP. As a retrospective study, 109 subjects with moderate and severe obstructive sleep apnea-hypopnea (apnea-hypopnea index≥15 events/h) were studied. CPAP titration was performed using an auto-titrating device. There was significant difference in the mean pressure delivered with autoCPAP between the group of patients using the nasal mask (mean 10.0 cmH2O±2.0 SD) and the group which used the oronasal mask (mean 11.2 cmH2O±2.1) (p<0.05). Residual apneas were lower when using a nasal mask: average AHI of 2.6±2.5 compared to 4.5±4.0 using an oronasal mask (p<0.05). On multivariate analysis, the only independent predictor of the level of therapeutic pressure of CPAP was the type of mask used (r=0.245, p 0.008). Therapeutic CPAP level for OSAH is higher when administered via oronasal mask, leaving more residual events. These findings suggest that nasal mask should be the first choice for OSAH treatment.

Does Patient’s Initial Evaluation Predict a Change in Optimal Pressure on CPAP Retitration?

Introduction: Only vindication of a nasal continuous positive airway pressure (CPAP) retitration procedure will be an actual change in the optimal CPAP pressure after that test. The purpose of this study was to identify any items in patient characteristics, clinical features, baseline PSG and initial CPAP titration as predictors of change in optimal pressure on CPAP retitration. Methods: 46 patients with obstructive sleep apnea (OSA) were divided in two groups: Group I (optimal pressure was changed on CPAP retitration): N = 30, M 22 and F 8, age 31-72, BMI 26-50 Kg/m2, neck size 15 – 20", tonsillectomy in 8, narrow oropharynx in 15, uvuvlopalatopharyngoplasty (UP3) in 2, abnormal chin in 3, deviated nasal septum (DNS) and prior nose surgery in 1 each, initial CPAP pressure 6-19 cm, sleep efficiency 65%-98%, REM latency 0-304 minutes and residual apnea hypopnea index (AHI) 0-23/hour. Group II (optimal pressure unchanged after CPAP retitration): N = 16, M 11 and 5 F, age 32-69, BMI 23-62 Kg/m2, neck size 14.5-20", tonsillectomy in 6, narrow oropharynx in 5, abnormal chin in 4, corrective nasal surgery in 2, DNS in 1, initial CPAP pressure 8-13 cm of H2O, sleep efficiency 69%-95%, REM latency 0-270 minutes and residual AHI 0-19/hour. The statistical analyses were performed using two-tailed Fisher’s t test and unpaired t test. A p value of tency, residual AHI and initial CPAP pressure) did not differ significantly between the 2 groups (p = 0.09-0.99). Conclusion: Patient characteristics, clinical features or variables on baseline PSG and initial CPAP titration do not predict a change in optimal pressure on CPAP retitration. The results suggest that 1) Significant weight change; 2) Patient’s subjective feeling of pressure being too high or insufficient; 3) Residual or recurrent daytime sleepiness uncorrected by interface readjustments; 4) Post-op

Evaluation of adenotonsillectomy outcome for obstructive sleep apnea syndrome in children, by pre and postoperative polysomnography

We evaluated, using objective data from pre- and postoperative polysomnography (PSG) data, the outcome of adenotonsillectomy for obstructive sleep apnea syndrome (OSAS) in children in our sleep unit. Retrospectively study was conducted including 55 healthy children (3–12 years of age) with OSAS, diagnosed on the basis of polysomnography as having an apnea hypopnea index (AHI) of 3 or greater, who underwent adenotonsillectomy between January 2010 and January 2013. Postoperative polysomnography was performed at least 3 months after surgery. Scores from pre- and postoperative polysomnography were compared using statistical analysis software. For all children, the preoperative AHI value was higher than the postoperative value. The mean preoperative AHI was 22.8 with 58.1% (32) with severe OSAS (AHI > 10). The mean postoperative AHI was 2.9. Pathological residual apnea/hypopnea index (defined in this study as residual AHI > 3), was found in 34.5% (19). 68.4% of these children, with pathological residual index, had preoperative severe OSAS. 6 children (31.6%), with preoperative AHI 3–10, had pathological residual apnea/hypopnea index postoperatively. Adenotonsillectomy improves respiratory parameters, measured by polysomnography, in the majority of children but does not resolve OSAS in all children of this group of patients. High preoperative AHI is associated with persistence of pathological residual apnea/hypopnea index after adenotonsillectomy. Sleep Unit – HUMValdecilla.