Obstructive sleep apnea in developmental age. A narrative review.

Sleep is a physiological function that undergoes, at different stages of life, to considerable variations in neurophysiological and behavioral functions. The developmental age is a period characterized by a continuous process of physical and neuropsychological changes and synaptic remodeling processes that are the neurophysiological basis of brain plasticity, typical of this developmental phase, occurring mainly during sleep. In the description of obstructive sleep apnea (OSA) in children, two main points should be highlighted: its variability in different age groups, and its specificity compared with OSA in adults. The definition and criteria used for the diagnosis of OSA in adults are not applicable to OSA in developmental age. Although the adenotonsillar hypertrophy is the most common risk factor for pediatric OSA, obesity is becoming an increasingly prevalent risk factor, mostly in early childhood (6-9 years) and adolescence. OSA has been shown to affect cognitive function in children and adults. However, OSA impact on cognitive function in children is more severe since acting on the plastic brain structures can change the neuro-psychic development, learning skills, and social interactions. There is a clear difference in the definition of pathology between developmental age and adulthood according to the instrumental parameters: an AHI ≥ 5, which represents, in the pediatric age, the cut-off for a therapeutic pathway necessary to avoid a long-term effect on the child, instead, it represents in adulthood, the lower limit value for the definition of disease. This is a narrative review concerning obstructive sleep apnea in developmental age.Conclusions: OSA is a common disorder in children and those at risk must be identified, studied, and treated promptly because untreated OSA can be responsible for cardiovascular, metabolic, and neurocognitive morbidities and may induce, sometimes, non-reversible deficits given his insistence on a period of physical and neuro-psychic development.What is Known:•This is a review concerning Obstructive Sleep Apnea in developmental age•Clinical manifestation, diagnostic and therapeutic criteria of sleep apnea in developmental ageWhat is New:•This is a "narrative" review•This narrative review describes sleep apnea comparing and analyzing the different ages of life.

Sleep Breathing Disorders in the COVID-19 Era: Italian Thoracic Society Organizational Models for a Correct Approach to Diagnosis and Treatment.

The attenuation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, at least in Italy, allows a gradual resumption of diagnostic and therapeutic activities for sleep respiratory disorders. The knowledge on this new disorder is growing fast, but our experience is still limited and when a physician cannot rely on evidence-based medicine, the experience of his peers can support the decision-making and operational process of reopening sleep laboratories. The aim of this paper is to focus on the safety of patients and operators accessing hospitals and the practice of diagnosing and treating sleep-related respiratory disorders. The whole process requires a careful plan, starting with a triage preceding the access to the facility, to minimize the risk of infection. Preparation of the medical record can be performed through standard questionnaires administered over the phone or by e-mail, including an assessment of the COVID-19 risk. The home sleep test should include single-patient sensors or easy-to-sanitize material. The use of nasal cannulas is discouraged in view of the risk of the virus colonizing the internal reading chamber, since no filter has been tested and certified to be used extensively for coronavirus due to its small size. The adaptation to positive airway pressure (PAP) treatment can also be performed mainly using telemedicine procedures. In the adaptation session, the mask should be new or correctly sanitized and the PAP device, without a humidifier, should be protected by an antibacterial/antiviral filter, then sanitized and reassigned after at least 4 days since SARS-CoV-2 was detected on some surfaces up to 72 h after. Identification of pressure should preferably be performed by telemedicine. The patient should be informed of the risk of spreading the disease in the family environment through droplets and how to reduce this risk. The follow-up phase can again be performed mainly by telemedicine both for problem solving and the collection of data. Public access to hospital should be minimized and granted to patients only. Constant monitoring of institutional communications will help in implementing the necessary recommendations.

OSA and CPAP therapy: effect of gender, somnolence, and treatment adherence on health-related quality of life.

BACKGROUND: Obstructive sleep apnea (OSA) often has a significant impact on health-related quality of life (HRQoL) with social and psychological implications. For most OSA patients, a reduction in their HRQoL is due to symptoms such as poor sleep quality, excessive daytime somnolence, and fatigue with differences between gender. PURPOSE: This study explores the CPAP treatment effect on self-perceived HRQoL related to gender, somnolence, and CPAP adherence. METHODS: Out of 1082 consecutive Italian outpatients, 125 (82 M) (60.3 ± 9.6 years) completed the prospective observational study and were evaluated at the first visit (T0), and the follow-up visit (T1). Two self-reported HRQoL questionnaires were administered: six subscales Psychological General Well-Being Index (PGWBI) and 12-Item Short-Form Health Survey (SF-12). RESULTS: Scores of PGWBI and SF-12 MCS improved from T0 to T1. Patients with CPAP use ≥ 4 h/night showed a significant improvement in all dimensions evaluated, except for SF-12 PCS. At T1, participants with ESS > 10 improved in all scores, except SF-12 PCS. Gender comparison shows better-perceived HRQoL in males at first visit and CPAP follow-up visit. Variation of PGWBI was significantly correlated with CPAP use, ESS at T0 and T1 (p < 0.0001; r2 = 0.26). CONCLUSIONS: This study provides evidence on the effectiveness of CPAP treatment on perceived HRQoL. Participants with greater adherence to therapy, greater sleepiness, and greater improvement of daytime sleepiness with CPAP therapy, reported a higher quality of life improvement. Gender comparison shows better-perceived HRQoL in males at first visit and CPAP follow-up, despite a more considerable improvement in females.

Relaxin in Obstructive Sleep Apnea: Relationship with Blood Pressure and Inflammatory Mediators.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with nocturnal intermittent hypoxia, which may be responsible for increased circulating levels of vascular endothelial growth factor (VEGF) and inflammatory mediators, such as metalloproteinases (MMPs), and which contributes to the pathogenesis of systemic hypertension. Why some OSA patients remain normotensive is poorly understood. Relaxin-2, a pregnancy hormone, may sometimes circulate in men and could increase in hypoxic conditions. It exerts a vasodilatory activity and can modulate the release of molecules, such as MMPs and VEGF. OBJECTIVES: The objective of this study was to explore if circulating relaxin-2 in male OSA subjects may be related to OSA severity, to circulating levels of MMPs, of their inhibitors (tissue inhibitors of metalloproteinases; TIMPs), and of VEGF, and if it may protect from hypertension. PATIENTS AND METHODS: Fifty untreated male subjects with suspected OSA were recruited. After nocturnal polysomnography, a morning venous blood sample was withdrawn. Then, 24-hour ambulatory blood pressure (BP) monitoring was performed. RESULTS: The respiratory disturbance index in the sample was 30.4 [interquartile range (IQR) 15.6-55.2]. Relaxin-2 was detectable in 20 subjects. These subjects did not differ in OSA severity or diurnal and nocturnal BP from subjects with undetectable relaxin-2, but they showed lower TIMP-1 (126.8 ± 29.1 vs. 156.9 ± 41.7 pg/ml, respectively; p = 0.007) and a marginally higher MMP-9/TIMP-1 molar ratio [0.58 (IQR 0.23-1.35) vs. 0.25 (IQR 0.15-0.56); p = 0.052]. CONCLUSIONS: Relaxin-2 in male subjects was not related to OSA severity, but it was associated with lower TIMP-1. As it was often undetectable, even when BP values were normal, it is unlikely that it plays a role as a major factor protecting from hypertension in OSA.

Heart rate variability during sleep at high altitude: effect of periodic breathing.

BACKGROUND: Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. PURPOSE: The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization, i.e., two different levels of hypoxemia. METHODS: Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. RESULTS: A mean overnight beat-by-beat series interval (RR) reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due to RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. CONCLUSIONS: The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Immediate effect of CPAP titration on perceived health related quality of life: a prospective observational study.

BACKGROUND: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). This study examines changes in HRQoL aspects occurring immediately after CPAP titration. Furthermore, we analyzed variations in each gender and in patients undergoing home or laboratory-based CPAP titration pathways. METHODS: Twohundredfive outpatients (151 M) (56.7 ± 10.3 years) were evaluated, before first visit and nocturnal diagnostic examination (T0), and the morning after CPAP titration (T1). Two self-reported HRQoL questionnaires were administered: Psychological General Well-Being Index (PGWBI), composed by six subscales, and 12-Item Short-Form Health Survey (SF-12), including Physical (PCS) and Mental Component Summaries (MCS). CPAP titration was performed using auto-adjusting CPAP units at patients' home or in the sleep laboratory. RESULTS: PGWBI scores at T1 improved compared to T0 (p < 0.0001). A similar improvement was observed in SF-12 MCS (p = 0.0011), but not in SF-12 PCS. Changes were independent from anthropometric parameters, OSA severity and excessive daytime sleepiness. Gender comparisons showed better HRQoL in males at both times. At T0, patients who received home or laboratory CPAP titration pathways did not show any differences in PGWBI and SF-12 scores. At T1, PGWBI and SF-12 MCS improved in both home and laboratory groups. CONCLUSIONS: This study gives evidence that first time CPAP application for titration can lead to a general increase in perceived well-being. Gender comparisons showed better perceived HRQoL with more subscales improvements in males after CPAP titration. The improvement was similar with both home and laboratory CPAP titration pathways.

Effect of obstructive sleep apnea diagnosis on health related quality of life.

BACKGROUND: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). To our knowledge, no study has analyzed the effect of OSA diagnosis communication on HRQoL. We evaluated self-perceived HRQoL in patients afferent to our sleep center, in order to examine the effect of the diagnosis disclosure on their HRQoL. METHODS: Two hundred ninety-seven consecutive outpatients (227 M) (mean age 54.1 ± 11.6 yrs, range 23-80 yrs) were evaluated, before first clinical visit and nocturnal diagnostic examination (Time A), and after diagnosis disclosure (Time B), with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), consisting of anxiety, depressed mood, positive well-being, self-control, general health, vitality subscales, and 12-Item Short-Form Health Survey (SF-12), comprising Physical (PCS) and Mental Component Summaries (MCS). RESULTS: Comparison of mean HRQoL scores at Time A with reference values, showed worse scores. Mean PGWBI Total and subscales scores improved at Time B. Similar improvement was observed for SF-12 MCS (p = 0.0148), but nor for SF-12 PCS. At Time B, Anxiety, Depression and Well-being PGWBI subscales became similar to reference values, while the scores in the other PGWBI subscales and SF-12 remained worse. Comparison between males and females showed higher HRQoL values for males at both times. Score changes were independent from age, gender, BMI, AHI, TSat90 and excessive daytime sleepiness. CONCLUSIONS: Diagnosis communication improves patients' HRQoL, regardless of the severity. Changes in HRQoL after diagnosis disclosure may be due to patients' motivation for medical check and diagnostic expectations.

Usefulness of reinforcing interventions on continuous positive airway pressure compliance.

BACKGROUND: Obstructive sleep apnea (OSA) is a high prevalence sleep disorder characterized by upper airway obstruction during sleep, nocturnal intermittent hypoxemia, poor sleep quality, risk for cardiovascular and metabolic diseases. The adherence to CPAP is the key for an effective management of these patients.The aim of the study was to assess the adherence to CPAP therapy with and without early reinforcing interventions, consisting of motivational reinforcement and technical support in the first month of therapy. METHODS: Forty patients with OSA undergoing counseling and a one year follow-up on a quarterly basis were included in the study. Twenty subjects (intervention group) underwent reinforcing interventions with telephone interviews in the first month of therapy, and twenty (control group) remained without reinforcing interventions. The two populations were homogeneous for age, severity of illness and BMI. RESULTS: During the first month, intervention group patients showed a higher number of nights with a device use ≥4 hours. Average treatment adherence in the first month (days of therapy with at least 4 hours per night on the total number of days from device delivery) was 77.5% in the intervention group and 55.7% in the control group (p = 0.022). At one year the differences between the two groups were not significant. CONCLUSIONS: Our findings suggest that it is important that adequate time and effort is spent to ensure patient comfort at the time of CPAP therapy start to optimize acceptance and adherence to treatment, and suggest that it is necessary to maintain reinforcing interventions over time.

Comorbidities and survival in obstructive sleep apnoea beyond the age of 50.

BACKGROUND: Although mortality risk associated with obstructive sleep apnoea (OSA) tends to disappear from the age of 50, it has been suggested that OSA treatment by continuous positive airway pressure (CPAP) improves survival even in older subjects. Life expectancy of subjects with several diseases is worse if OSA coexists. The objectives of this study were to evaluate the relevance of comorbidities in the relationship between OSA and mortality, and in the effect of CPAP on survival, in subjects ≥ 50 years old. METHODS: Data from 810 patients studied by polysomnography for suspected OSA between 1991 and 2000 were retrospectively evaluated. In 2009, state of survival and use of CPAP were enquired. Three hundred and thirteen subjects were < 50 and 497 were ≥ 50 years at diagnosis. RESULTS: Age and comorbidities, but not apnoea/hypopnoea index (AHI) or lowest nocturnal arterial oxygen saturation (Nadir SaO(2)), predicted mortality in the whole sample. Nadir SaO(2) was related to mortality among the younger subjects without comorbidities (P = 0·01), but not among the older subjects. In the older patients with an AHI > 30 CPAP treatment was associated with a better survival only if comorbidities coexisted. CONCLUSIONS: Unlike in younger subjects, in subjects ≥ 50 years old, comorbidities do not mask an effect of OSA on mortality. Among OSA subjects ≥ 50 years old, comorbidities could separate those who may expect an improvement in survival with CPAP treatment from those who may not. Possibly, after the age of 50, OSA per se does not affect survival, but worsens prognosis of subjects with coexisting diseases.

Quality of life in patients at first time visit for sleep disorders of breathing at a sleep centre.

INTRODUCTION: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstructive sleep apnea (OSA) patients have several typical symptoms including habitual snoring, excessive daytime sleepiness, fatigue, lack of concentration, memory impairment, and at times psychological disturbances. We evaluated different aspects in the health related quality of life (HRQoL) in subjects referred to our sleep laboratory for their first examination for suspicion of OSA. METHODS: One hundred ninety-eight consecutive outpatients (152 M) (mean age 52.7 ± 12.8 years, range 18-82 years; mean BMI 31.0 ± 6.5 kg/m(2), range 17.3-57.8 kg/m(2) were evaluated with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), that asses anxiety, depressed mood, positive well-being, self-control, general health, vitality, and 12-Item Short-Form Health Survey (SF-12), consisting assesses of Physical and Mental Component Summaries (PCS and MCS). Epworth Sleepiness Scale (ESS) was used to assess daytime sleepiness before nocturnal diagnostic examination. RESULTS: Subjects showed variable HRQoL scores. HRQoL was worse in women than men and it decreased with age. No relation was found with AHI severity (range 0-129 n/h). BMI and TSat90 (range 0-87.9%) affected physical health perception (SF-12 PCS). Furthermore TSat90 influenced PGWBI Vitality subscale. Subjects with ESS > 10 showed a worse HRQoL profile (p < 0.001) in SF-12 and in PGWBI. Multiple regression analysis showed that age, BMI and ESS were significant predictors of SF-12 PCS (p < 0.001; r(2) = 0.23). CONCLUSIONS: A worse HRQoL perception among subjects referred for OSA suspicion was not related to disease severity. BMI and hypoxemia influenced only some HRQoL dimensions, while excessive daytime sleepiness worsens all HRQoL components considered.

Rewiring innate and adaptive immunity with TLR9 agonist to treat osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary bone tumor in children and adolescent. Surgery and multidrug chemotherapy are the standard of treatment achieving 60-70% of event-free survival for localized disease at diagnosis. However, for metastatic disease, the prognosis is dismal. Exploiting immune system activation in the setting of such unfavorable mesenchymal tumors represents a new therapeutic challenge. METHODS: In immune competent OS mouse models bearing two contralateral lesions, we tested the efficacy of intralesional administration of a TLR9 agonist against the treated and not treated contralateral lesion evaluating abscopal effect. Multiparametric flow cytometry was used to evaluate changes of the tumor immune microenviroment. Experiments in immune-deficient mice allowed the investigation of the role of adaptive T cells in TLR9 agonist effects, while T cell receptor sequencing was used to assess the expansion of specific T cell clones. RESULTS: TLR9 agonist strongly impaired the growth of locally-treated tumors and its therapeutic effect also extended to the contralateral, untreated lesion. Multiparametric flow cytometry showed conspicuous changes in the immune landscape of the OS immune microenvironment upon TLR9 engagement, involving a reduction in M2-like macrophages, paralleled by increased infiltration of dendritic cells and activated CD8 T cells in both lesions. Remarkably, CD8 T cells were needed for the induction of the abscopal effect, whereas they were not strictly necessary for halting the growth of the treated lesion. T cell receptor (TCR) sequencing of tumor infiltrating CD8 T cells showed the expansion of specific TCR clones in the treated tumors and, remarkably, their selected representation in the contralateral untreated lesions, providing the first evidence of the rewiring of tumor-associated T cell clonal architectures. CONCLUSIONS: Overall these data indicate that the TLR9 agonist acts as an in situ anti-tumor vaccine, activating an innate immune response sufficient to suppress local tumor growth while inducing a systemic adaptive immunity with selective expansion of CD8 T cell clones, which are needed for the abscopal effect.

SANReSP: A new Italian questionnaire to screen patients for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is a common, prevalent, and underdiagnosed disorder. Its lack of diagnosis and treatment is associated with increased morbidity and mortality. Previous screening questionnaires investigated parameters including body mass index, age, neck circumference, and sex, in addition to symptoms. This study aimed to validate a new Italian, self-administered, and easy-to-use six-item questionnaire that evaluates only subjective symptoms. PATIENTS AND METHODS: The present study included 2622 patients (male, 2011; female, 611). Patients who were at least 18 years old, spoke Italian, referred to our sleep clinic for possible OSA, and completed the self-administered SANReSP questionnaire were recruited for the study. The predictive performance of the questionnaire was also evaluated. RESULTS: Nocturnal study showed 89.9% of OSA patients had apnea-hypopnea index (AHI) ≥ 5/h; 68.7%, AHI ≥ 15/h; and 48.2%, AHI ≥ 30/h. The optimal SANReSP score for AHI ≥ 5/h was >3 with a sensitivity and specificity of 74.76% and 67.92%, respectively, and an area under receiver operating characteristic curve (ROC) of 0.76. For moderate-severe OSA, the optimal SANReSP score was >3 (sensitivity, 78.18%; specificity, 46.53%; ROC, 0.66). For severe OSA, the optimal SANReSP score was >4 (sensitivity, 59.10%; specificity, 64.73%; ROC, 0.65). The probability of OSA increased with higher SANReSP scores (98.7% and 97.9% in men and women, respectively). CONCLUSION: The SANReSP questionnaire is a short, easy-to-use, and self-administered screening tool for OSA. Its performance is similar to that of other widely used questionnaires; furthermore, it is advantageous in that it does not require anthropometric measurements.

Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers--protocol study.

BACKGROUND: Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances. METHODS/DESIGN: An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow. DISCUSSION: Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers. TRIAL REGISTRATION: Registro Brasileiro de Ensaios Clinicos (local acronym RBEC) [Internet]: Rio de Janeiro (RJ): Instituto de Informaçao Cientifica e Tecnologica em Saude (Brazil); 2010 - Identifier RBR-7dq5xx. Cross-sectional study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers; 2011 May 31 [7 pages]. Available from http://www.ensaiosclinicos.gov.br/rg/RBR-7dq5xx/.

Blood pressure changes after automatic and fixed CPAP in obstructive sleep apnea: relationship with nocturnal sympathetic activity.

Treatment of obstructive sleep apnea (OSA) by continuous positive airway pressure (CPAP) usually causes a reduction in blood pressure (BP), but several factors may interfere with its effects. In addition, although a high sympathetic activity is considered a major contributor to increased BP in OSA, a relationship between changes in BP and in sympathetic nervous system activity after OSA treatment is uncertain. This study was undertaken to assess if, in OSA subjects under no pharmacologic treatment, treatment by CPAP applied at variable levels by an automatic device (APAP) may be followed by a BP reduction, and if that treatment is associated with parallel changes in BP and catecholamine excretion during the sleep hours. Nine subjects underwent 24-h ambulatory BP monitoring and nocturnal urinary catecholamine determinations before OSA treatment and 2 months following OSA treatment by APAP (Somnosmart2, Weinmann, Hamburg, Germany). Eight control subjects were treated by CPAP at a fixed level. After APAP treatment, systolic blood pressure (SBP) decreased during sleep (p < 0.05), while diastolic blood pressure (DBP) decreased both during wakefulness (p < 0.05) and sleep (p < 0.02). Similar changes were observed in subjects receiving fixed CPAP. Nocturnal DBP changes were correlated with norepinephrine (in the whole sample: r = .61, p < 0.02) and normetanephrine (r = .71, p < 0.01) changes. In OSA subjects under no pharmacologic treatment, APAP reduces BP during wakefulness and sleep, similarly to CPAP. A reduction in nocturnal sympathetic activity could contribute to the reduction in DBP during sleep following OSA treatment.

Automatic titration and calculation by predictive equations for the determination of therapeutic continuous positive airway pressure for obstructive sleep apnea.

BACKGROUND: It is unknown to what extent therapeutic continuous positive airway pressure (CPAP) levels obtained by various methods for the treatment of obstructive sleep apnea syndrome (OSAS) differ. This study aimed to explore the relationships among pressures titrated by an automatic CPAP (APAP) device and those calculated using different predictive equations, and to compare different ranges of calculated pressures with pressure values titrated by APAP. METHODS: In 140 OSAS patients, the 95th percentile pressure delivered by an APAP device (AutoSet T; ResMed; Sydney, NSW, Australia) during polysomnography, and pressures calculated by three equations (equation 1, Hoffstein and Miljetig [1994]; equation 2, Sériès et al [2000]; and equation 3, Stradling et al [2004]) were compared. RESULTS: Titrated and calculated pressures were weakly correlated. Significant differences were found between the mean (+/- SD) pressures (11.1 +/- 1.6, 8.3 +/- 1.8, 10.5 +/- 1.6, and 10.3 +/- 1.3 cm H(2)O, respectively) for 95th percentile APAP, and pressures calculated by equations 1, 2, and 3, except between values calculated by equations 2and 3. Differences between the calculated and APAP-derived pressures were negative for the low calculated values, and were progressively attenuated, or became positive, for the high values. The differences were smallest for calculated pressures from 11 to > 13 cm H(2)O, which were represented to a greater extent among the values calculated by equations 2 and 3 than by those calculated by equation 1. CONCLUSIONS: Considerably different therapeutic CPAP levels may be determined using various methods. The differences between the calculated and APAP-derived pressures are largest for calculated values of < 9 or > 15 cm H(2)O. The clinical consequences of these findings deserve further evaluation. Caution is still required before treating OSAS patients with calculated pressures.

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

OBJECTIVE:: 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. OBJETIVO:: Determinar se o uso de um travesseiro de gel com recortes laterais para acomodar a máscara de continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) e diminuir a temperatura em torno da cabeça melhora a eficácia do tratamento com auto-CPAP e a adesão dos pacientes ao tratamento. MÉTODOS:: Foram incluídos no estudo 23 pacientes consecutivos com apneia obstrutiva do sono que nunca haviam recebido tratamento com CPAP. Os pacientes receberam um aparelho de auto-CPAP com uma máscara apropriada e foram instruídos a usar CPAP durante 15 noites. Foram também instruídos a dormir com seu próprio travesseiro (o travesseiro controle) nas 5 primeiras noites e com um travesseiro de espuma ou um travesseiro de gel, ambos com recortes laterais, durante 5 noites consecutivas cada, em ordem aleatória. Depois da 15ª noite, os dados registrados nos aparelhos de auto-CPAP foram baixados e os pacientes determinaram seu grau de satisfação com cada travesseiro por meio de uma escala visual analógica. RESULTADOS:: Vinte e dois pacientes completaram o protocolo. Não houve diferenças entre os períodos durante os quais cada travesseiro foi usado quanto às pressões administradas, índice de apneia-hipopneia residual, vazamentos de ar e média de duração da CPAP. Os pacientes ficaram significativamente mais satisfeitos com o travesseiro de gel do que com o travesseiro controle e o travesseiro de espuma (p = 0,022 e p = 0,004, respectivamente), com correlação entre o grau de satisfação com o travesseiro de gel e a sonolência diurna excessiva (r2 = 0,19; p = 0,0443). CONCLUSÕES:: Em pacientes com apneia obstrutiva do sono tratados com CPAP nasal, o uso de um travesseiro de gel com recortes laterais aparentemente não tem nenhum impacto na eficácia do tratamento. No entanto, esses pacientes aparentemente preferem um travesseiro de gel a outros tipos de travesseiros.

A new method of negative expiratory pressure test analysis detecting upper airway flow limitation to reveal obstructive sleep apnea.

BACKGROUND: Expiratory flow limitation (EFL) by negative expiratory pressure (NEP) testing, quantified as the expiratory flow-limited part of the flow-volume curve, may be influenced by airway obstruction of intrathoracic and extrathoracic origins. NEP application during tidal expiration immediately determines a rise in expiratory flow (V) followed by a short-lasting V drop (deltaV), reflecting upper airway collapsibility. PURPOSES: This study investigated if a new NEP test analysis on the transient expiratory DeltaV after NEP application for detection of upper airway V limitation is able to identify obstructive sleep apnea (OSA) subjects and its severity. METHODS: Thirty-seven male subjects (mean +/- SD age, 46 +/- 11 years; mean body mass index [BMI], 34 +/- 7 kg/m2) with suspected OSA and with normal spirometric values underwent nocturnal polysomnography and diurnal NEP testing at - 5 cm H2O and - 10 cm H2O in sitting and supine positions. RESULTS: deltaV (percentage of the peak V [%Vpeak]) was better correlated to apnea-hypopnea index (AHI) than the EFL measured as V, during NEP application, equal or inferior to the corresponding V during control (EFL), and expressed as percentage of control tidal volume (%Vt). AHI values were always high (> 44 events/h) in subjects with BMI > 35 kg/m2, while they were very scattered (range, 0.5 to 103.5 events/h) in subjects with BMI < 35 kg/m2. In these subjects, AHI still correlated to deltaV (%Vpeak) in both sitting and supine positions at both NEP pressures. CONCLUSIONS: OSA severity is better related to deltaV (%Vpeak) than EFL (%Vt) in subjects referred to sleep centers. DeltaV (%Vpeak) can be a marker of OSA, and it is particularly useful in nonseverely obese subjects.

Role of different nocturnal monitorings in the evaluation of CPAP titration by autoCPAP devices.

The aim of the study was to assess how the analysis of different signals recorded during application of automatic continuous positive airway pressure (autoCPAP) devices improves the evaluation of pressure titration in patients with obstructive sleep apnea syndrome (OSAS) naive to treatment. Seventy-two patients underwent nocturnal polysomnography during autoCPAP (Autoset T, ResMed, Sydney, Australia) application. Progressively more complex combinations of signals were analysed in consecutive steps. According to the analysis of oxyhemoglobin saturation (SaO(2)) alone, a fixed CPAP level suitable for treatment could not be identified in 3 subjects. When analysis of posture was added, titration was considered unsatisfactory in 1 more subject, due to a short time spent supine. Further, addition of flow and respiratory movements led to consider titration unsatisfactory in 1 more subject. Analysis of all polysomnographic signals demonstrated a not fully reliable titration in 9 subjects: 1 with short sleep duration, 2 without REM sleep, 4 with a short sleep time spent supine, and 3 subjects (already identified by SaO(2)) with insufficient correction of respiratory disorders even when a relatively high CPAP was administered. Mask leaks did not hamper titration. CPAP titration by automatic devices alone results in imperfect titration in >10% subjects naive to ventilatory treatment. Only polysomnographic recording ensures titration reliability in all patients. Further research is needed to identify simple and economic methods to reliably start the CPAP treatment.

Obstructive Sleep Apnea Is Associated with Liver Damage and Atherosclerosis in Patients with Non-Alcoholic Fatty Liver Disease.

BACKGROUND/AIMS: We assessed whether obstructive sleep apnea (OSA) and nocturnal hypoxemia are associated with severity of liver fibrosis and carotid atherosclerosis in patients with biopsy-proven NAFLD and low prevalence of morbid obesity. Secondary aim was to explore the association of OSA and hypoxemia with NASH and severity of liver pathological changes. METHODS: Consecutive patients (n = 126) with chronically elevated ALT and NAFLD underwent STOP-BANG questionnaire to estimate OSA risk and ultrasonographic carotid assessment. In patients accepting to perform cardiorespiratory polygraphy (PG, n = 50), OSA was defined as an apnea/hypopnea index ≥5. A carotid atherosclerotic plaque was defined as a focal thickening >1.3 mm. RESULTS: Prevalence of high OSA risk was similar in patients refusing or accepting PG (76% vs 68%, p = 0.17). Among those accepting PG, overall OSA prevalence was significantly higher in patients with F2-F4 fibrosis compared to those without (72% vs 44%; p = 0.04). Significant fibrosis was independently associated with mean nocturnal oxygen saturation (SaO2)<95% (OR 3.21, 95%C.I. 1.02-7.34; p = 0.04). Prevalence of OSA tended to be higher in patients with, than in those without, carotid plaques (64% vs 40%; p = 0.08). Carotid plaques were independently associated with %time at SaO2<90% >1 (OR 6.30, 95%C.I. 1.02-12.3; p = 0.01). CONCLUSIONS: In NAFLD patients with chronically elevated ALT at low prevalence of morbid obesity, OSA was highly prevalent and indexes of SaO2 resulted independently associated with severity of liver fibrosis and carotid atherosclerosis. These data suggest to consider sleep disordered breathing as a potential additional therapeutic target in severe NAFLD patients.

Sleep structure correlates of continuous positive airway pressure variations during application of an autotitrating continuous positive airway pressure machine in patients with obstructive sleep apnea syndrome.

STUDY OBJECTIVES: To evaluate the relationship between sleep structure and continuous positive airway pressure (CPAP) delivered by an automatic CPAP (auto-CPAP) machine in patients with obstructive sleep apnea syndrome (OSAS). DESIGN: Nocturnal polysomnography was performed during CPAP administration by an auto-CPAP machine (Autoset Clinical 1; ResMed; Sydney, Australia). SETTING: Sleep-disorders center in a research institute. PATIENTS: Fifteen subjects with newly diagnosed OSAS deserving home CPAP treatment. MEASUREMENTS AND RESULTS: During the night, in most cases, the lowest CPAP level was recorded during a prolonged nonrapid eye movement (NREM) sleep period uninterrupted by arousals, whereas the highest level during wake-sleep transitions or NREM sleep fragmented by arousals. In four subjects, rapid eye movement sleep was always associated with increasing CPAP. Sleep efficiency was negatively correlated with CPAP variability, evaluated as the SD of the mean nocturnal CPAP level averaged epoch by epoch (r = 0.63, p < 0.02). Eighty-eight percent of rapid CPAP augmentations (increases by at least 2 cm H(2)O in less-than-or-equal 2 min) were observed during sleep-wake transitions or after arousals/awakenings (Ar/Aw); 63% of such Ar/Aw were not preceded by any detectable respiratory abnormality. CONCLUSIONS: CPAP levels and variations during auto-CPAP application may be mainly related to sleep continuity and efficiency. The recording of a highly variable pressure during auto-CPAP administration in an unattended environment must raise the question whether the patient's sleep quality was acceptable. A poor sleep quality during an autotitration night could lead to an undesirable overestimation of the CPAP level needed for use with fixed-level CPAP machines.