Respiratory Effort-related Arousals Research Articles

0736 POLYSOMNOGRAHIC FINDINGS IN FIVE PATIENTS WITH EXPLODING HEAD SYNDROME

Exploding Head Syndrome (EHS) attacks are characterized by perception of sudden loud banging noises, occasionally accompanied by the sensation of a flash of light. Although these attacks themselves are usually not painful, it is reported that EHS attacks may precede migraine as auras. EHS is classified as a type of parasomnia in the International Classification of Sleep Disorders (ICSD) 3rd edition and its pathophysiology is still unclear. We describe the polysomnography (PSG) characteristics of EHS patients with special emphasis on respiratory events that were followed by EHS attacks. The subjects were consecutive 20,926 patients who presented sleep and/or wake problems at our sleep center between April 1998 and March 2013. The diagnosis of EHS was based on ICSD-3 criteria. During PSG, we instructed them to ring a bell when they noticed an attack (heard a sound). We found 5 cases (0.17%) with EHS. The mean age (2 men and 3 women) was 64.8 ± 16.4 years. Three of them had otorhinolaryngologic diseases (sudden hearing loss, deflected nasal septum and sinusitis). All five subjects rang the bell for their attacks during PSG. The events occurred during stage N1 and N2. In 2 cases, respiratory events preceded the attacks. In 1 case, respiratory effort related arousal was followed by the attack. In the other 2 cases snoring preceded the attacks. One subject noticed the attack during stage W. Various respiratory events were related to the EHS attacks. A variety of ear dysfunctions or brainstem neural dysfunction during the transition from wakefulness to sleep has been reported as the pathophysiology of EHS. Our PSG findings suggest that checking otolaryngological status on subjects and respiratory events during sleep may be helpful in understanding its pathophysiology and in choosing therapeutic strategies. None.

Sleep Architecture Linked to Airway Obstruction and Intracranial Hypertension in Children with Syndromic Craniosynostosis.

Children with syndromic craniosynostosis often have obstructive sleep apnea and intracranial hypertension. The authors aimed to evaluate (1) sleep architecture, and determine whether this is influenced by the presence of obstructive sleep apnea and/or intracranial hypertension; and (2) the effect of treatment on sleep architecture. This study included patients with syndromic craniosynostosis treated at a national referral center, undergoing screening for obstructive sleep apnea and intracranial hypertension. Obstructive sleep apnea was identified by polysomnography, and categorized into no, mild, moderate, or severe. Intracranial hypertension was identified by the presence of papilledema on funduscopy, supplemented by optical coherence tomography and/or intracranial pressure monitoring. Regarding sleep architecture, sleep was divided into rapid eye movement or non-rapid eye movement sleep; respiratory effort-related arousals and sleep efficiency were scored. The authors included 39 patients (median age, 5.9 years): 19 with neither obstructive sleep apnea nor intracranial hypertension, 11 with obstructive sleep apnea (four moderate/severe), six with intracranial hypertension, and three with obstructive sleep apnea and intracranial hypertension. Patients with syndromic craniosynostosis, independent of the presence of mild obstructive sleep apnea and/or intracranial hypertension, have normal sleep architecture compared with age-matched controls. Patients with moderate/severe obstructive sleep apnea have a higher respiratory effort-related arousal index (p < 0.01), lower sleep efficiency (p = 0.01), and less rapid eye movement sleep (p = 0.04). An improvement in sleep architecture was observed following monobloc surgery (n = 5; rapid eye movement sleep, 5.3 percent; p = 0.04). Children with syndromic craniosynostosis have in principle normal sleep architecture. However, moderate/severe obstructive sleep apnea does lead to disturbed sleep architecture, which fits within a framework of a unifying theory for obstructive sleep apnea, intracranial hypertension, and sleep. Risk, II.

Update on Obstructive Sleep Apnea: Implications for Neuropsychiatry.

Update on Obstructive Sleep Apnea: Implications for Neuropsychiatry.

Quantitative assessment of the upper airway in infants and children with subglottic stenosis.

Determine whether quantitative geometric measures and a computational fluid dynamic (CFD) model derived from medical imaging of children with subglottic stenosis (SGS) can be effective diagnostic and treatment planning tools. Retrospective chart and imaging review in a tertiary care hospital. Computed tomography scans (n = 17) of children with SGS were analyzed by geometric and CFD methods. Polysomnograms (n = 15) were also analyzed. Radiographic data were age/weight flow normalized and were compared to an atlas created from radiographically normal airways. Five geometric, seven CFD, and five polysomnography measures were analyzed. Statistical analysis utilized a two-sample t test with Bonferroni correction and area under the curve analysis. Two geometric indices (the ratio of the subglottic to midtracheal airway, the percent relative reduction of the subglottic airway) and one CFD measure (the percent relative reduction of the hydraulic diameter of the subglottic airway) were significant for determining which children with SGS received surgical intervention. Optimal cutoffs for these values were determined. Polysomnography, the respiratory effort-related arousals index, was significant only prior to Bonferroni correction for determining which children received surgical intervention. Geometric and CFD variables were sensitive at determining which patients with SGS received surgical intervention. Discrete quantitative assessment of the pediatric airway was performed, yielding preliminary data regarding possible objective thresholds for surgical versus nonsurgical treatment of disease. This study is limited by its small, retrospective, single-institution nature. Further studies to validate these findings and possibly optimize treatment threshold recommendations are warranted. 4 Laryngoscope, 126:1225-1231, 2016.

A new approach in the diagnosis of upper airway resistance syndrome (UARS): PAP method.

Upper airway resistance syndrome (UARS) is characterized by repeated number of arousals at night, and excessive daytime sleepiness or somnolence (EDS). It is often missed in classical polysomnographic diagnostic approaches and misdiagnosed as simple snoring or idiopathic hypersomnia, thereby is often left untreated. We propose that positive airway pressure (PAP), which has shown to be effective against UARS, can be used as a diagnostic tool as well. The study designed to test whether patients with high titration pressures can be diagnosed for UARS, and whether this pressure can be used as the treatment pressure in UARS. This study is a retrospective cohort study. The patients with the following selection criteria: apnea hypopnea index (AHI) < 5, respiratory effort related arousal (RERA) index > 20, excessive daytime sleepiness or somnolence (EDS) without nocturnal oxygen desaturation levels were included to the study. After diagnostic polysomnography (PSG), PAP titrarion was applied to diagnose and treatment. Fourteen (%46.7) of the patients were male, 16 (%53.3) were female, with a mean age of 46.4 ± 9.9 and mean body mass index (BMI) of 26 ± 3.3. The patiens had a mean Epworth sleepiness scale 15.3 ± 3.9, mean AHI: 2.3 ± 1.4 and average RERA: 26.1 ± 4.9. The mean CPAP titration pressure was 7.1 ± 1.1 cmH2O. In the light of current findings, during PAP titration patients required high pressures is the evidence of increased upper airway resistance in UARS. Using the from therapy to diagnosis protocol, the PAP protocol determines the individual therapeutic pressures needed by patients. Following up the clinical outcomes of these patients under the PAP treatment, and including a larger cohort will contribute greatly to treating this syndrome, defined as one of the "unresolved problems in years".

Mild obstructive sleep apnea: beyond the AHI

A common conundrum faced by sleep medicine practitioners is how to manage the large group of patients with mild sleep apnea. Many patients are referred for sleep evaluation, with symptoms thought to be due to obstructive sleep apnea (OSA). Often polysomnography demonstrates only mild sleep apnea, and the clinician and patient are faced with the dilemma of whether to use continuous positive airway pressure (CPAP) therapy or an oral appliance. In making this important decision the clinician incorporates the commonly used definition of mild sleep apnea as an apnea-hypopnea index of between 5 and 14 apneas or hypopneas per hour of sleep. Moderate sleep apnea is defined as 15-29 events per hour, and severe is 30 and above events per hour. These arbitrary thresholds originated in the early 1980s when knowledge of this condition was in its infancy and little was known about the long term health effects. The definition was based on the finding of apneas, defined by the complete cessation of airflow for at least 10 seconds. The concept of hypopnea and respiratory-effort related arousal (RERA) came later and with frequently changing definitions that have been the subject of significant controversy throughout the last 30 years. Many sleep centers include these RERA’s in the definition of respiratory disturbance index, which is incorrectly used interchangeably with AHI. While the sleep literature has demonstrated the untoward effects of moderate to severe sleep apnea, there has been considerable debate about the clinical significance of mild sleep apnea, that is, an AHI between 5 and 15. The current paper by Quan, et al (1) is a significant contribution to the literature in sleep medicine addressing this important clinical question. This paper reports data drawn from the APPLES study, a large multi-center, well-conducted study designed to determine if CPAP therapy improves sleepiness, mood disorder, or cognitive function in patients with OSA, that has subsequently produced several important publications (2-6). As part of the study, extensive data was obtained on each of these neurocognitive parameters including the Epworth Sleepiness Scale, Stanford Sleepiness Scale, Hamilton Rating Scale for Depression, Profile of Mood States, and Sleep Apnea Quality of Life Index, all validated questionnaires used frequently in the sleep literature. In this part of the study, 199 patients with an AHI>5 but <15 were compared to 40 patients enrolled in the study, but with and AHI<5. The mean AHI was 10 per hour in the mild OSA group, and was 3 per hour in the non-OSA group. Size of the study was statistically large enough to determine significant differences. Remarkably, there

Heart rate variability is augmented in patients with positional obstructive sleep apnea, but only supine LF/HF index correlates with its severity.

Data on cardiac autonomic functioning, as expressed by heart rate variability (HRV), in patients with positional obstructive sleep apnea (p-OSA) disorder are lacking. The purpose of the study was to compare HRV indices between sleep segments derived from supine body position and another body position with and without apneic events, respectively. Our intention was to find some correlation between HRV indices and the pathophysiological characteristics of the corresponding temporal period. Nocturnal polysomnograms derived from twenty-seven patients (22 men) with documented positional apnea were retrospectively reviewed. Patients never treated for OSA and free from diseases/drugs altering HRV were examined. Data from total sleep studies were collected. Two N2 sleep segments, from supine body position with sleep-disordered breathing (SDB) and another body position without SDB were analyzed. Apneic events (namely, apneas, hypopneas, and respiratory effort-related arousals (RERAs)), arousals, number of desaturations, minimum pulse oximetry (SaO2min), time domain variables (average RR, SDNN, SDSD, RMSSD, pNN50, and HRV triangular index) and frequency domain variables (VLF, LF, HF, TP, LF/HF) were recorded for both temporal periods. With the exception of average RR and HF, all other variables were significantly higher in segments with SDB. Only LF/HF_supine ratio was positively correlated with the apneic_supine_index (t = 3.13, p < 0.01) and negatively correlated with SaO2min (t = -2.9, p < 0.01) and the desaturation_supine_index (t = -2.5, p = 0.02). Arousals were negatively correlated with SaO2min (t = -2.8, p < 0.01). SDB augments autonomic tone in patients with p-OSA, but only LF/HF correlates with its severity and might be used as a screening tool in the future. On the contrary, parasympathetic tone, as reflected by HF, remains constant in both periods.

Polysomnographic Investigation of Sleep and Respiratory Parameters in Women with Temporomandibular Pain Disorders

Temporomandibular pain disorders (TMD) and myofascial pain were linked to increased prevalence of insomnia and obstructive sleep apnea (OSA) on clinical grounds. However, the literature lacks an accurate polysomnographic (PSG) characterization of sleep abnormalities associated with TMD, given that prior studies included small or uncontrolled samples of TMD patients. The present investigation aims to objectively evaluate measures of sleep and respiratory disturbance in a large representative sample of TMD cases in comparison with matched controls. Sleep, respiration, and limb movements were measured using a 2-night attended PSG protocol in 170 women-124 TMD cases with myofascial pain and 46 demographically matched controls. The second night data were compared between the groups using ANCOVAs. In TMD cases, the relationship between pain ratings and sleep parameters was analyzed using multiple regressions. In comparison to healthy controls, TMD cased evidenced a significant increase in stage N1 sleep (12.2% ± 7.6% vs. 9.2% ± 5.0%, p = 0.03), which was only mild relative to normative values. TMD cases also demonstrated mild but significant elevations in arousals associated with all types of respiratory events (6.0/h ± 6.1 vs. 3.5/h ± 3.3 p = 0.02) and in respiratory effort related arousals (RERAs, 4.3/h ± 4.3 vs. 2.6/h ± 2.7, p = 0.02). Myofascial pain predicted a lower sleep efficiency (p = 0.01), more frequent awakenings (p = 0.04), and higher RERA index (p = 0.04) among TMD cases. Myofascial pain in TMD is associated with mild elevation in sleep fragmentation and increased frequency of RERA events. Further research is required to evaluate the clinical significance of these findings.

A pilot validation study for the NOX T3TM portable monitor for the detection of OSA

The aim of the current pilot study is to compare the diagnostic accuracy of the NOX T3(TM) (T3) portable sleep monitor (PM) to that of simultaneously recorded in-lab polysomnogram (PSG). A total of 40 participants were recruited following face-to-face evaluation at a sleep disorders clinic. Each participant wore both PSG and PM equipment simultaneously during their in-lab PSG. PSG records were manually scored using the American Academy of Sleep Medicine (AASM) criteria, and PM records were double-scored using the device's autoscore algorithm as well as manual scoring. The final sample consisted of 32 participants (56% male, 50% black) with a mean ESS, BMI, and apnea-hypopnea index (AHI) of 10.4, 32.8, and 16.3, respectively. Three participants (7.5%) were excluded for poor PM signal quality. Mean AHI derived from the T3's autoscore algorithm was similar to that from manual scoring (19.6 ± 18.9 vs. 18.6 ± 19.1, respectively). Autoscore-derived T3 AHI and PSG-derived AHI were strongly related (r = .93). The T3 (autoscored AHI) demonstrated a high degree of sensitivity for the presence of obstructive sleep apnea syndrome (OSA; 100%) and acceptable specificity for the exclusion of OSA using an AHI cutoff of ≥5 events/h (70%). The unit (autoscored) had a high degree of both sensitivity (92%) and specificity (85%) when the presence of OSA was defined more conservatively (AHI > 15 events/h). For OSA defined as an AHI of ≥5, the T3 (autoscored) correctly identified 88% of positive cases and 100% of negative cases. In this small, clinic-based sample, the T3 demonstrated very good measurement agreement compared to PSG and a high degree of sensitivity for detecting even mild OSA. False positives appeared to be due to respiratory effort-related arousals (RERAs) being autoscored as obstructive apneas and may be due to inherent discrepancy in flow measurement sensitivity between PSG and portable monitors.

Prevalence of the upper airway resistance syndrome in the general population

Background : Upper airway resistance syndrome (UARS) shares common clinical features with obstructive sleep apnea and hypopnea (OSAH). It is characterized by repetitive respiratory effort-related arousal (RERA), which may lead to daytime sleepiness and functional impairment. Little is known about the prevalence of UARS in the general population. Objectives : To determine the prevalence of UARS in the general population and to compare its characteristics to matched control subjects without UARS. 2020 subjects (50.0% women, 57.3 ± 10.7 years old, BMI 25.5 ± 4.3 kg/m 2 ) participating in an ongoing population-based sleep cohort study (HypnoLaus, Lausanne, Switzerland) underwent complete polysomnographic recordings at home. Respiratory events were scored according to the AASM Chicago criteria. UARS was present if the RERA index was ⩾5/h and accounted for more than 50% of the respiratory disturbance index (RDI), which is defined by the sum of the apnea–hypopnea index (AHI) and RERA index. Characteristics of each subject with confirmed UARS were compared with 5 age and sex matched control subjects with similar AHI but no RERA. The prevalence of UARS was 0.84% of this general population sample. Median AHI and RDI were respectively 4.4/h (IQ range 3.5–6.8/h) and 10.7/h (IQ range 9.1–15.6/h). Mean Epworth Sleepiness Score was 6.6 ± 3.2; male-to-female ratio was 0.7. There were no significant differences between UARS subjects and the control subjects regarding BMI (24.7 ± 3.1 vs. 24.0 ± 3.3, p = 0.46) and the Epworth Sleepiness Score (6.6 ± 3.2 vs. 7.4 ± 2.5, p = 0.15). Also, the same prevalence of hypertension (29.4 ± 47.0% vs. 25.9 ± 19.7%, p = 0.77), diabetes (5.9 ± 24.2% vs. 5.9 ± 11.8%, p = 1.0) and metabolic syndrome (29.4 ± 47.0% vs. 12.9 ± 12.1%, p = 0.16) were found in UARS and control subjects. In our middle-aged population-based cohort, the prevalence of UARS is lower than previously reported. There was no significant difference between UARS and control subjects in terms of BMI, daytime sleepiness, hypertension, diabetes and metabolic syndrome. Funding: Ligue pulmonaire vaudoise, Fondation Leenaards, Fond national Suisse and GSK.

Respiratory effort-related arousals contribute to sympathetic modulation of heart rate variability

Sympathetic activation induced by sleep-disordered breathing may contribute to cardiovascular morbidity. However, the apnea-hypopnea index (AHI) excludes respiratory effort-related arousals (RERAs) associated with inspiratory flow limitation without oxygen desaturation. We sought to determine whether RERAs are associated with sympathetic activation. Twenty-five adults (12 males, 13 females) with AHI < 10/h and RERA index >5/h were included in this study. Power spectral density analysis was performed on two non-contiguous 10-min segments containing inspiratory flow limitation and arrhythmia-free electrocardiogram during N2 sleep. One segment contained RERA; the other did not, NO-RERA. Spectral power was described in a low-frequency domain (LF; 0.04-0.15Hz), primarily sympathetic modulation, and a high frequency domain (HF; 0.15-0.4Hz), parasympathetic modulation. Analyses of LF and HF powers were made using normalized and absolute values. LF power was greater during RERA compared to NO-RERA (50.3 vs. 30.1%, p < 0.001) whereas HF power was greater during NO-RERA compared to RERA (69.9 vs. 49.7%, p < 0.001). The LF/HF ratio was greater during RERA than NO-RERA (1.01 vs. 0.43, p < 0.001). Gender differences emerged using absolute values of power: The percentage increase in LF power during RERA relative to NO-RERA was significantly greater for females than males, 247.6 vs. 31.9%, respectively (p < 0.02). RERAs are associated with a marked increase in cardiac sympathetic modulation, especially in females. Patients with a high RERA index, even in the setting of a low or normal AHI, may be exposed to elevated sympathetic tone during sleep.

Treatment of Obstructive Sleep Apnea with Positive Pressure Ventilation

Continuous positive airway pressure (CPAP) is the gold-standard treatment for moderate to severe obstructive sleep apnea (OSA). Before CPAP therapy, optimal pressure to relieve any airway obstructive events (apnea, hypopnea, respiratory effort-related arousals, and snoring) should be measured during the second polysomnography. The main benefits of CPAP use are 1) elimination of airway obstructions regardless of sleep stages and positions during sleep, 2) amelioration of daytime and nocturnal symptoms, 3) decreased incidence and progression of systemic co-morbidities such as cardiovascular diseases, and 4) decreas ed incidence of accident-related traumas and mortality related to somnolence caused by OSA. Although CPAP is the most reliable and effective treatment for OSA, lack of patient acceptance and compliance may limit the CPAP use. To solve these problems, it is very important to educate patients and manage complications associated with mask and pressure-related discomforts as early as possible.

Treatment of Central Sleep Apnea in US Veterans

There are no standard therapies for the management of central sleep apnea (CSA). Either positive pressure therapy (PAP) or supplemental oxygen (O(2)) may stabilize respiration in CSA by reducing ventilatory chemoresponsiveness. Additionally, increasing opioid use and the presence of comorbid conditions in US veterans necessitates investigations into alternative titration protocols to treat CSA. The goal was to report on the effectiveness of titration with PAP, used alone or in conjunction with O(2), for the management of CSA associated with varying comorbidities and opioid use. This was a retrospective chart review over 3 years, performed at a VA sleep disorders center. The effects of CPAP, CPAP+O(2), and BPAP+O(2), used in a step-wise titration protocol, on consecutive patients diagnosed with CSA were studied. CSA was diagnosed in 162 patients. The protocol was effective in eliminating CSA (CAI ≤ 5/h) in 84% of patients. CPAP was effective in 48%, while CPAP+O(2) combination was effective in an additional 25%, and BPAP+O(2) in 11%. The remaining 16% were non-responders. Forty-seven patients (29%) were on prescribed opioid therapy for chronic pain, in whom CPAP, CPAP+O(2), or BPAP+O(2) eliminated CSA in 54%, 28%, and 10% cases, respectively. CPAP, CPAP+O(2), and BPAP+O(2) each produced significant declines in the AHI, CAI, and arousal index, and an increase in the SpO(2). The data demonstrate that using a titration protocol with CPAP and then PAP with O(2) effectively eliminates CSA in individuals with underlying comorbid conditions and prescription opioid use. Comparative studies with other therapeutic modalities are required.

Multimodality Therapy for Sleep Apnea Syndromes

Multimodality Therapy for Sleep Apnea Syndromes

Rules for Scoring Respiratory Events in Sleep: Update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events

Rules for Scoring Respiratory Events in Sleep: Update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events

Esophageal Pressures, Polysomnography, and Neurobehavioral Outcomes of Adenotonsillectomy in Children

Esophageal pressure monitoring during polysomnography in children offers a gold-standard, “preferred” assessment for work of breathing, but is not commonly used in part because prospective data on incremental clinical utility are scarce. We compared a standard pediatric apnea/hypopnea index to quantitative esophageal pressures as predictors of apnea-related neurobehavioral morbidity and treatment response. Eighty-one children aged 7.8 ± 2.8 (SD) years, including 44 boys, had traditional laboratory-based pediatric polysomnography, esophageal pressure monitoring, multiple sleep latency tests, psychiatric evaluations, parental behavior rating scales, and cognitive testing, all just before clinically indicated adenotonsillectomy, and again 7.2 ± 0.8 months later. Esophageal pressures were used, along with nasal pressure monitoring and oronasal thermocouples, not only to identify respiratory events but also more quantitatively to determine the most negative esophageal pressure recorded and the percentage of sleep time spent with pressures lower than -10 cm H(2)O. Both sleep-disordered breathing and neurobehavioral measures improved after surgery. At baseline, one or both quantitative esophageal pressure measures predicted a disruptive behavior disorder (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-defined attention-deficit/hyperactivity disorder, conduct disorder, or oppositional defiant disorder) and more sleepiness and their future improvement after adenotonsillectomy (each P < .05). The pediatric apnea/hypopnea index did not predict these morbidities or treatment outcomes (each P > .10). The addition of respiratory effort-related arousals to the apnea/hypopnea index did not improve its predictive value. Neither the preoperative apnea/hypopnea index nor esophageal pressures predicted baseline hyperactive behavior, cognitive performance, or their improvement after surgery. Quantitative esophageal pressure monitoring may add predictive value for some, if not all, neurobehavioral outcomes of sleep-disordered breathing.

The Emergence of Central Sleep Apnea after Surgical Relief of Nasal Obstruction in Obstructive Sleep Apnea

By the current definition, complex sleep apnea (CompSA) refers to the emergence of central sleep apnea (CSA) during the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). However, new-onset CSA has been described with use of other treatments for OSA, including tracheostomy, maxillofacial surgery, and mandibular advancement device. We present a patient with CSA beginning after endoscopic sinus and nasal surgery for nasal obstruction in the setting of mild OSA. This case highlights the importance of non-PAP mechanisms in the pathogenesis of CompSA.

Class II correction improves nocturnal breathing in adolescents

To examine modifications in sleep pattern and in craniofacial morphology of adolescents with mandibular retrognathism. Sixteen subjects at maximum pubertal growth (12.6 years [±11.5 months]) were selected and treated for 12 months with maxillary expansion and mandibular advancement with a Herbst appliance. Cephalometric radiography and magnetic resonance imaging were obtained prior to and after treatment and were compared using the paired Student's t-test or the nonparametric Wilcoxon rank-sum test. Four polysomnographic recordings were obtained with pressurized nasal cannulae and were analyzed by analysis of variance. The length of the mandible was increased, while the antero-posterior position of the maxilla remained stable. The posterior airway space was increased, the length of the tongue was preserved, and the hyoid bone was moved to a more anterior position. After Herbst treatment, sleep efficiency, sleep latency, rapid eye movement (REM) sleep latency, and percentage of REM sleep remained stable. We did observe a reduction (P < .05) in the relative proportions of stage 1 and stage 3-4 (from 4.30 ± 1.99 to 2.61 ± 1.83 for stage 1 and from 25.78 ± 7.00 to 19.17 ± 7.58 for stages 3-4) as well as an increase (P < .01) in the percentage of stage 2 after treatment (49.03 ± 6.25 to 56.90 ± 6.22). There was a reduction (P < .05) in the number of respiratory effort-related arousals (7.06 ± 5.37 to 1.31 ± 1.45 per hour of sleep) due to an increase (P < .01) in airway volume. In the short term, the increase in airway space improved nocturnal breathing associated with the correction of mandibular retrognathism.

Outcome of Continuous Positive Airway Pressure Treatment with Suboptimal Pressure in Obstructive Sleep Apnea

Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnea (OSA) and is highly effective particularly in moderate-to-severe OSA, defined as an apnea-hypopnea index (AHI) exceeding 15/h.1,2 CPAP functions as a “pneumatic splint” by delivering an intraluminal pressure, thereby preventing the upper airway from collapsing during sleep in OSA.3 Following diagnostic polysomnography (PSG), patients who meet the diagnostic criteria for OSA and is regarded as candidates for CPAP and undergo CPAP titration in the sleep laboratory. Although the optimal end point of titration has not been scientifically determined, most laboratories titrate to eliminate obstructive apnea, hypopnea, snoring, oxygen desaturation, and respiratory effort-related arousals.4 The target AHI with CPAP treatment is usually between 5 and 10/h.5 However, during positive pressure titration, it may be difficult to determine the optimal pressure in some patients. If the pressure is too low, it fails to eliminate obstructive apnea adequately, and if the pressure is too high, it could interfere the sleep itself. In addition, “CPAP-related central sleep apnea (CSA)” could appear during CPAP titration.4 Due to these reasons, some patients inevitably undergo CPAP treatment with suboptimal pressure. To date, the efficacy of CPAP treatment with suboptimal pressure in OSA remains controversial. In this study, we aimed to evaluate the treatment outcome of CPAP with suboptimal pressure in OSA.

UARS presenting with the symptoms of anxiety and depression

Abstract Upper airway resistance syndrome (UARS) is a condition where the apnea-hypopnea index is less than 5 and respiratory-effort related arousal index is more than 10. The clinical presentation of UARS may be the same as obstructive sleep apnea-hypopnea syndrome (OSAS); it sometimes shows up with symptoms hardly suggestive of a sleep-disordered breathing. A 17 year-old male patient had applied to a local psychiatry clinic and complained of chronic fatigue, insomnia, behavioral and academic problems and was treated for anxiety and depression. After a period of unresponsive treatment, he was sent to a sleep center for evaluation of insomnia, which turned out to be a fragmented, unrefreshing sleep episode. Polysomnographical evaluation revealed that he had UARS without OSAS. His complaints decreased dramatically after he received CPAP treatment. This case shows that UARS should be considered in young patients with functional somatic syndromes even if the clinical presentation does not apparently imply the condition.