European Respiratory Society statement on sleep apnoea, sleepiness and driving risk.

Obstructive sleep apnoea (OSA) is highly prevalent and is a recognised risk factor for motor vehicle accidents (MVA). Effective treatment with continuous positive airway pressure has been associated with a normalisation of this increased accident risk. Thus, many jurisdictions have introduced regulations restricting the ability of OSA patients from driving until effectively treated. However, uncertainty prevails regarding the relative importance of OSA severity determined by the apnoea-hypopnoea frequency per hour and the degree of sleepiness in determining accident risk. Furthermore, the identification of subjects at risk of OSA and/or accident risk remains elusive. The introduction of official European regulations regarding fitness to drive prompted the European Respiratory Society to establish a task force to address the topic of sleep apnoea, sleepiness and driving with a view to providing an overview to clinicians involved in treating patients with the disorder. The present report evaluates the epidemiology of MVA in patients with OSA; the mechanisms involved in this association; the role of screening questionnaires, driving simulators and other techniques to evaluate sleepiness and/or impaired vigilance; the impact of treatment on MVA risk in affected drivers; and highlights the evidence gaps regarding the identification of OSA patients at risk of MVA.

Long-term clinical effectiveness of continuous positive airway pressure therapy versus non-invasive ventilation therapy in patients with obesity hypoventilation syndrome: a multicentre, open-label, randomised controlled trial.

BACKGROUND: Obesity hypoventilation syndrome is commonly treated with continuous positive airway pressure or non-invasive ventilation during sleep. Non-invasive ventilation is more complex and costly than continuous positive airway pressure but might be advantageous because it provides ventilatory support. To date there have been no long-term trials comparing these treatment modalities. We therefore aimed to determine the long-term comparative effectiveness of both treatment modalities. METHODS: We did a multicentre, open-label, randomised controlled trial at 16 clinical sites in Spain. We included patients aged 15-80 years with untreated obesity hypoventilation syndrome and an apnoea-hypopnoea index of 30 or more events per h. We randomly assigned patients, using simple randomisation through an electronic database, to receive treatment with either non-invasive ventilation or continuous positive airway pressure. Both investigators and patients were aware of the treatment allocation. The research team was not involved in deciding hospital treatment, duration of treatment in the hospital, and adjustment of medications, as well as adjudicating cardiovascular events or cause of mortality. Treating clinicians from the routine care team were not aware of the treatment allocation. The primary outcome was the number of hospitalisation days per year. The analysis was done according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, number NCT01405976. FINDINGS: From May 4, 2009, to March 25, 2013, 100 patients were randomly assigned to the non-invasive ventilation group and 115 to the continuous positive airway pressure group, of which 97 patients in the non-invasive ventilation group and 107 in the continuous positive airway pressure group were included in the analysis. The median follow-up was 5·44 years (IQR 4·45-6·37) for all patients, 5·37 years (4·36-6·32) in the continuous positive airway pressure group, and 5·55 years (4·53-6·50) in the non-invasive ventilation group. The mean hospitalisation days per patient-year were 1·63 (SD 3·74) in the continuous positive airway pressure group and 1·44 (3·07) in the non-invasive ventilation group (adjusted rate ratio 0·78, 95% CI 0·34-1·77; p=0·561). Adverse events were similar between both groups. INTERPRETATION: In stable patients with obesity hypoventilation syndrome and severe obstructive sleep apnoea, non-invasive ventilation and continuous positive airway pressure have similar long-term effectiveness. Given that continuous positive airway pressure has lower complexity and cost, continuous positive airway pressure might be the preferred first-line positive airway pressure treatment modality until more studies become available. FUNDING: Instituto de Salud Carlos III, Spanish Respiratory Foundation, and Air Liquide Spain.

Self-setup of home respiratory polygraphy for the diagnosis of sleep apnea syndrome: cost-efficiency study.

PURPOSE: To evaluate the differences in reliability and costs of home respiratory polygraphy (HRP) when installed by the patient and by a nurse, in order to determine the factors affecting and to consider the possible generalization of self-setup procedure. Several HRP devices have been validated for obstructive sleep apnea (OSA) diagnosis but convenience of a nurse intervention in HRP installation has been scarcely studied. METHODS: This is a prospective and interventional study. About 301 participants were assigned to 2 groups: self-setup and nurse intervention. Sleep study, questionnaires, and diagnostic procedures were performed following the clinical practice in 2016. Signals were considered lost above 3 min, and success of the test was established according to guidelines. Costs were calculated according to a previous multicenter study. RESULTS: Both groups (self-setup and nurse intervention) resulted homogeneous in age, gender, BMI, and final diagnosis of OSA. Signal losses during the test were similar in both groups. Slightly higher percentage of unsuccessful tests were obtained in the self-setup procedure (5.3 vs 2.0%, p = 0.121). The costs were similar (107 vs 105 €) in the self-setup group as compared to the nurse setup group. CONCLUSIONS: The setup of HRP by either the patient or nurse had similar costs and data acquisition. Both installation procedures of HRP were similar regarding test reliability and costs. Main findings are that self-installation by the patient could be similarly reliable and economic as installation by a nurse, as far as consensus guidelines are followed. This study demonstrates that self-setup of HRP is a potentially viable option for the diagnosis of OSA.

Echocardiographic changes with non-invasive ventilation and CPAP in obesity hypoventilation syndrome.

RATIONALE: Despite a significant association between obesity hypoventilation syndrome (OHS) and cardiac dysfunction, no randomised trials have assessed the impact of non-invasive ventilation (NIV) or CPAP on cardiac structure and function assessed by echocardiography. OBJECTIVES: We performed a secondary analysis of the data from the largest multicentre randomised controlled trial of OHS (Pickwick project, n=221) to determine the comparative efficacy of 2 months of NIV (n=71), CPAP (n=80) and lifestyle modification (control group, n=70) on structural and functional echocardiographic changes. METHODS: Conventional transthoracic two-dimensional and Doppler echocardiograms were obtained at baseline and after 2 months. Echocardiographers at each site were blinded to the treatment arms. Statistical analysis was performed using intention-to-treat analysis. RESULTS: At baseline, 55% of patients had pulmonary hypertension and 51% had evidence of left ventricular hypertrophy. Treatment with NIV, but not CPAP, lowered systolic pulmonary artery pressure (-3.4 mm Hg, 95% CI -5.3 to -1.5; adjusted P=0.025 vs control and P=0.033 vs CPAP). The degree of improvement in systolic pulmonary artery pressure was greater in patients treated with NIV who had pulmonary hypertension at baseline (-6.4 mm Hg, 95% CI -9 to -3.8). Only NIV therapy decreased left ventricular hypertrophy with a significant reduction in left ventricular mass index (-5.7 g/m2; 95% CI -11.0 to -4.4). After adjusted analysis, NIV was superior to control group in improving left ventricular mass index (P=0.015). Only treatment with NIV led to a significant improvement in 6 min walk distance (32 m; 95% CI 19 to 46). CONCLUSION: In patients with OHS, medium-term treatment with NIV is more effective than CPAP and lifestyle modification in improving pulmonary hypertension, left ventricular hypertrophy and functional outcomes. Long-term studies are needed to confirm these results. TRIAL REGISTRATION NUMBER: Pre-results, NCT01405976 (https://clinicaltrials.gov/).

Nocturnal Oximetry-based Evaluation of Habitually Snoring Children.

RATIONALE: The vast majority of children around the world undergoing adenotonsillectomy for obstructive sleep apnea-hypopnea syndrome (OSA) are not objectively diagnosed by nocturnal polysomnography because of access availability and cost issues. Automated analysis of nocturnal oximetry (nSpO2), which is readily and globally available, could potentially provide a reliable and convenient diagnostic approach for pediatric OSA. METHODS: Deidentified nSpO2 recordings from a total of 4,191 children originating from 13 pediatric sleep laboratories around the world were prospectively evaluated after developing and validating an automated neural network algorithm using an initial set of single-channel nSpO2 recordings from 589 patients referred for suspected OSA. MEASUREMENTS AND MAIN RESULTS: The automatically estimated apnea-hypopnea index (AHI) showed high agreement with AHI from conventional polysomnography (intraclass correlation coefficient, 0.785) when tested in 3,602 additional subjects. Further assessment on the widely used AHI cutoff points of 1, 5, and 10 events/h revealed an incremental diagnostic ability (75.2, 81.7, and 90.2% accuracy; 0.788, 0.854, and 0.913 area under the receiver operating characteristic curve, respectively). CONCLUSIONS: Neural network-based automated analyses of nSpO2 recordings provide accurate identification of OSA severity among habitually snoring children with a high pretest probability of OSA. Thus, nocturnal oximetry may enable a simple and effective diagnostic alternative to nocturnal polysomnography, leading to more timely interventions and potentially improved outcomes.

Effect of continuous positive airway pressure on blood pressure and metabolic profile in women with sleep apnoea.

Continuous positive airway pressure (CPAP) reduces blood pressure levels in hypertensive patients with obstructive sleep apnoea (OSA). However, the role of CPAP in blood pressure and the metabolic profile in women has not yet been assessed. In this study we investigated the effect of CPAP on blood pressure levels and the glucose and lipid profile in women with moderate-to-severe OSA.A multicentre, open-label, randomised controlled trial was conducted in 307 women diagnosed with moderate-to-severe OSA (apnoea-hypopnoea index ≥15 events·h-1) in 19 Spanish Sleep Units. Women were randomised to CPAP (n=151) or conservative treatment (n=156) for 12 weeks. Changes in office blood pressure measures as well as in the glucose and lipid profile were assessed in both groups.Compared with the control group, the CPAP group achieved a significantly greater decrease in diastolic blood pressure (-2.04 mmHg, 95% CI -4.02- -0.05; p=0.045), and a nonsignificantly greater decrease in systolic blood pressure (-1.54 mmHg, 95% CI -4.58-1.51; p=0.32) and mean blood pressure (-1.90 mmHg, 95% CI -4.0-0.31; p=0.084). CPAP therapy did not change any of the metabolic variables assessed.In women with moderate-to-severe OSA, 12 weeks of CPAP therapy improved blood pressure, especially diastolic blood pressure, but did not change the metabolic profile, compared with conservative treatment.

Circulating Plasma Extracellular Microvesicle MicroRNA Cargo and Endothelial Dysfunction in Children with Obstructive Sleep Apnea.

RATIONALE: Obese children are at increased risk for developing obstructive sleep apnea (OSA), and both of these conditions are associated with an increased risk for endothelial dysfunction (ED) in children, an early risk factor for atherosclerosis and cardiovascular disease. Although weight loss and treatment of OSA by adenotonsillectomy improve endothelial function, not every obese child or child with OSA develops ED. Exosomes are circulating extracellular vesicles containing functional mRNA and microRNA (miRNA) that can be delivered to other cells, such as endothelial cells. OBJECTIVES: To investigate whether circulating exosomal miRNAs of children with OSA differentiate based on endothelial functional status. METHODS: Obese children (body mass index z score >1.65) and nonobese children were recruited and underwent polysomnographic testing (PSG), and fasting endothelial function measurements and blood draws in the morning after PSG. Plasma exosomes were isolated from all subjects. Isolated exosomes were then incubated with confluent endothelial cell monolayer cultures. Electric cell-substrate impedance sensing systems were used to determine the ability of exosomes to disrupt the intercellular barrier formed by confluent endothelial cells. In addition, immunofluorescent assessments of zonula occludens-1 tight junction protein cellular distribution were conducted to examine endothelial barrier dysfunction. miRNA and mRNA arrays were also applied to exosomes and endothelial cells, and miRNA inhibitors and mimics were transfected for mechanistic assays. MEASUREMENTS AND MAIN RESULTS: Plasma exosomes isolated from either obese children or nonobese children with OSA were primarily derived from endothelial cell sources and recapitulated ED, or its absence, in naive human endothelial cells and also in vivo when injected into mice. Microarrays identified a restricted signature of exosomal miRNAs that readily distinguished ED from normal endothelial function. Among the miRNAs, expression of exosomal miRNA-630 was reduced in children with ED and normalized after therapy along with restoration of endothelial function. Conversely, transfection of exosomes from subjects without ED with an miRNA-630 inhibitor induces the ED functional phenotype. Gene target discovery experiments further revealed that miRNA-630 regulates 416 gene targets in endothelial cells that include the Nrf2, AMP kinase, and tight junction pathways. CONCLUSIONS: These observations elucidate a novel role of exosomal miRNA-360 as a putative key mediator of vascular function and cardiovascular disease risk in children with underlying OSA and/or obesity, and identify therapeutic targets.

Continuous Positive Airway Pressure Improves Quality of Life in Women with Obstructive Sleep Apnea. A Randomized Controlled Trial.

RATIONALE: Continuous positive airway pressure (CPAP) is the treatment of choice in patients with symptomatic obstructive sleep apnea (OSA). CPAP treatment improves quality of life (QoL) in men with OSA, but its role in women has not yet been assessed. OBJECTIVES: To investigate the effect of CPAP on QoL in women with moderate to severe OSA. METHODS: We conducted a multicenter, open-label randomized controlled trial in 307 consecutive women diagnosed with moderate to severe OSA (apnea-hypopnea index, ≥15) in 19 Spanish sleep units. Women were randomized to receive effective CPAP therapy (n = 151) or conservative treatment (n = 156) for 3 months. The primary endpoint was the change in QoL based on the Quebec Sleep Questionnaire. Secondary endpoints included changes in daytime sleepiness, mood state, anxiety, and depression. Data were analyzed on an intention-to-treat basis with adjustment for baseline values and other relevant clinical variables. MEASUREMENTS AND MAIN RESULTS: The women in the study had a mean (SD) age of 57.1 (10.1) years and a mean (SD) Epworth Sleepiness Scale score of 9.8 (4.4), and 77.5% were postmenopausal. Compared with the control group, the CPAP group achieved a significantly greater improvement in all QoL domains of the Quebec Sleep Questionnaire (adjusted treatment effect between 0.53 and 1.33; P < 0.001 for all domains), daytime sleepiness (-2.92; P < 0.001), mood state (-4.24; P = 0.012), anxiety (-0.89; P = 0.014), depression (-0.85; P = 0.016), and the physical component summary of the 12-item Short Form Health Survey (2.78; P = 0.003). CONCLUSIONS: In women with moderate or severe OSA, 3 months of CPAP therapy improved QoL, mood state, anxiety and depressive symptoms, and daytime sleepiness compared with conservative treatment. Clinical trial registered with www.clinicaltrials.gov (NCT02047071).

Non-invasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea.

BACKGROUND: Non-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure. METHODS: Between May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis. RESULTS: A total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of -6 (95% CI -7.7 to -4.2) mm Hg versus -2.8 (95% CI -4.3 to -1.3) mm Hg, (p<0.001) and serum bicarbonate of -3.4 (95% CI -4.5 to -2.3) versus -1 (95% CI -1.7 to -0.2 95% CI)  mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group. CONCLUSIONS: NIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality. TRIAL REGISTRATION NUMBER: NCT01405976; results.

Treatment outcomes of obstructive sleep apnoea in obese community-dwelling children: the NANOS study.

The first line of treatment of obstructive sleep apnoea syndrome (OSAS) in children consists of adenotonsillectomy (T&A). The aim of the present study was to evaluate treatment outcomes of OSAS among obese children recruited from the community.A cross-sectional, prospective, multicentre study of Spanish obese children aged 3-14 years, with four groups available for follow-up: group 1: non-OSAS with no treatment; group 2: dietary treatment; group 3: surgical treatment; and group 4: continuous positive airway pressure treatment.117 obese children (60 boys, 57 girls) with a mean age of 11.3±2.9 years completed the initial (T0) and follow-up (T1) assessments. Their mean body mass index (BMI) at T1 was 27.6±4.7 kg·m(-2), corresponding to a BMI Z-score of 1.34±0.59. Mean respiratory disturbance index (RDI) at follow-up was 3.3±3.9 events·h(-1). Among group 1 children, 21.2% had an RDI ≥3 events·h(-1) at T1, the latter being present in 50% of group 2, and 43.5% in group 3. In the binary logistic regression model, age emerged as a significant risk factor for residual OSAS (odds ratio 1.49, 95% confidence interval 1.01-2.23; p<0.05) in obese children surgically treated, and RDI at T0 as well as an increase in BMI emerged as significant risk factors for persistent OSAS in obese children with dietary treatment (OR 1.82, 95% CI 1.09-3.02 (p<0.03) and OR 8.71, 95% CI 1.24-61.17 (p=0.03)).Age, RDI at diagnosis and obesity are risk factors for relatively unfavourable OSAS treatment outcomes at follow-up.

Sleepiness at the wheel across Europe: a survey of 19 countries.

The European Sleep Research Society aimed to estimate the prevalence, determinants and consequences of falling asleep at the wheel. In total, 12 434 questionnaires were obtained from 19 countries using an anonymous online questionnaire that collected demographic and sleep-related data, driving behaviour, history of drowsy driving and accidents. Associations were quantified using multivariate logistic regression. The average prevalence of falling asleep at the wheel in the previous 2 years was 17%. Among respondents who fell asleep, the median prevalence of sleep-related accidents was 7.0% (13.2% involved hospital care and 3.6% caused fatalities). The most frequently perceived reasons for falling asleep at the wheel were poor sleep in the previous night (42.5%) and poor sleeping habits in general (34.1%). Falling asleep was more frequent in the Netherlands [odds ratio = 3.55 (95% confidence interval: 1.97; 6.39)] and Austria [2.34 (1.75; 3.13)], followed by Belgium [1.52 (1.28; 1.81)], Portugal [1.34 (1.13, 1.58)], Poland [1.22 (1.06; 1.40)] and France [1.20 (1.05; 1.38)]. Lower odds were found in Croatia [0.36 (0.21; 0.61)], Slovenia [0.62 (0.43; 0.89)] and Italy [0.65 (0.53; 0.79)]. Individual determinants of falling asleep were younger age; male gender [1.79 (1.61; 2.00)]; driving ≥20 000 km year [2.02 (1.74; 2.35)]; higher daytime sleepiness [7.49 (6.26; 8.95)] and high risk of obstructive sleep apnea syndrome [3.48 (2.78; 4.36) in men]. This Pan European survey demonstrates that drowsy driving is a major safety hazard throughout Europe. It emphasizes the importance of joint research and policy efforts to reduce the burden of sleepiness at the wheel for European drivers.

Inflammatory markers and obstructive sleep apnea in obese children: the NANOS study.

INTRODUCTION: Obesity and obstructive sleep apnea syndrome (OSA) are common coexisting conditions associated with a chronic low-grade inflammatory state underlying some of the cognitive, metabolic, and cardiovascular morbidities. AIM: To examine the levels of inflammatory markers in obese community-dwelling children with OSA, as compared to no-OSA, and their association with clinical and polysomnographic (PSG) variables. Methods. In this cross-sectional, prospective multicenter study, healthy obese Spanish children (ages 4-15 years) were randomly selected and underwent nocturnal PSG followed by a morning fasting blood draw. Plasma samples were assayed for multiple inflammatory markers. RESULTS: 204 children were enrolled in the study; 75 had OSA, defined by an obstructive respiratory disturbance index (RDI) of 3 events/hour total sleep time (TST). BMI, gender, and age were similar in OSA and no-OSA children. Monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) levels were significantly higher in OSA children, with interleukin-6 concentrations being higher in moderate-severe OSA (i.e., AHI > 5/hrTST; P < 0.01), while MCP-1 levels were associated with more prolonged nocturnal hypercapnia (P < 0.001). CONCLUSION: IL-6, MCP-1, and PAI-1 are altered in the context of OSA among community-based obese children further reinforcing the proinflammatory effects of sleep disorders such as OSA. This trial is registered with ClinicalTrials.gov NCT01322763.

Reliability of telemedicine in the diagnosis and treatment of sleep apnea syndrome.

BACKGROUND: Advances in information technology and telecommunications have provided the option of making it easier to diagnose and treat obstructive sleep apnea syndrome (OSAS) using telemedicine techniques. This study assessed the feasibility and reliability of respiratory polygraphy and prescription of treatment by pressure adjustment with auto-continuous positive airway pressure (CPAP) systems, both being transmitted telematically to the Sleep Unit, with teleconsultation as a support method. SUBJECTS AND METHODS: Forty patients were studied from a population 80 km from the Sleep Unit using respiratory polygraphy transmitted in real time. They were divided into two groups: one was seen by conventional consultation, and the other was seen using teleconsultation. We also estimated satisfaction with this system and its costs. RESULTS: The mean patient age was 53 ± 10.3 years, with a body mass index of 31 ± 6.2 kg/m(2) and an Epworth score of 12 ± 5.3. In total, 35 patients were diagnosed with OSAS, with an Apnea-Hypopnea Index of ≥10, and CPAP treatment was started in 16 of them. The agreement in the Apnea-Hypopnea Index, total apneas and hypopneas, mean oxygen saturation, and time with an oxygen saturation <90% was greater than 90% between the studies transmitted in real time and those stored in the polygraph. The level of compliance with CPAP treatment was 85% for the patients who were seen in a conventional clinic and 75% in those seen by teleconsultation. CONCLUSIONS: The use of telematic techniques is useful to establish a diagnostic and therapeutic strategy for OSAS with the creation of a Wide Core Sleep Laboratory as a process controller.

[Retropharyngeal liposarcoma: apropos of a case of apnoeas and hypopnoea during sleep]. / Liposarcoma retrofaríngeo: a propósito de un caso de apneas-hipopneas durante el sueño.

Liposarcomas rarely occur in the head and neck. We report a case of myxoid liposarcoma occurring in the retropharyngeal space in a middle-aged male with clinical symptoms of obstructive sleep apnoea.

[Reliability of home respiratory polygraphy for the diagnosis of sleep apnea-hypopnea syndrome: analysis of costs]. / Fiabilidad de la poligrafía respiratoria domiciliaria para el diagnóstico del síndrome de apneas-hipopneas durante el sueño. Análisis de costes.

OBJECTIVES: To evaluate the reliability of home respiratory polygraphy for the diagnosis of sleep apnea-hypopnea syndrome (SAHS) and to compare the cost of this technique with that of nighttime polysomnography performed in a sleep laboratory. PATIENTS AND METHODS: This was a prospective study of a random sample of patients with clinically suspected SAHS in which the participants who underwent both home respiratory polygraphy and nighttime polysomnography were blinded as to the results of their first test. Costs were calculated based on a theoretical population of 1000 individuals. A t test for paired samples, the Pearson correlation coefficient, and a receiver operator characteristic curve were used for the statistical analysis. RESULTS: The study population was composed of 45 patients with a mean (SD) age of 52.3 (11) years of whom 21 (46.6%) were diagnosed with SAHS, defined by an apnea-hypopnea index greater than 10 in nighttime polysomnography. Comparison of the results obtained in both recordings revealed statistically significant correlations for all comparisons. The optimal cutoff in this population was a respiratory disturbance index of 13.7 or more, for which the area under the receiver operating characteristic curve was 87.5% (95% confidence interval, 74.2%-95.4%). The mean cost of home respiratory polygraphy in a patient with suspected SAHS was euro69, whereas that of polysomnography was euro179. CONCLUSIONS: Home respiratory polygraphy is a reliable technique for the diagnosis of SAHS. Using this technique routinely in patients suspected of SAHS will be more economical than using nighttime polysomnography. Uncertain results must be verified by nighttime polysomnography.

[Reliability of respiratory polygraphy for the diagnosis of sleep apnea-hypopnea syndrome in children]. / Fiabilidad de la poligrafía respiratoria para el diagnóstico del síndrome de apneas-hipopneas durante el sueño en niños.

OBJECTIVE: Overnight polysomnography (PSG) is the gold standard diagnostic tool for sleep apnea-hypopnea syndrome (SAHS) in children. The aim of the present study was to evaluate the usefulness of diagnostic respiratory polygraphy in children with clinically suspected SAHS referred to our sleep-disordered breathing clinic. PATIENTS AND METHODS: We studied 53 children referred with clinical suspicion of SAHS; 29 (54.7%) were boys and the mean (SD) age was 6.4 (2.9) years. After a medical history was taken and a physical examination performed, patients underwent respiratory polygraphy (Edentec) simultaneously with overnight PSG in the sleep laboratory. The 2 diagnostic tools were compared using statistical analysis. RESULTS: SAHS was defined by an obstructive apnea-hypopnea index (OAHI) of 3 or more in overnight PSG and a respiratory disturbance index (RDI) of 3 or more in respiratory polygraphy. The rate of diagnostic agreement was 84.9%. The difference between the mean OAHI and RDI values was not significant (0.7 +/- 5.4; P=.34). The intraclass correlation coefficient between the OAHI and RDI was 89.4 (95% confidence interval, 82.4-93.7; P< .001). When receiver operating characteristic curves were calculated for the OAHI cutoff points used for the diagnosis of SAHS (> or =1, > or =3, and > or =5), the best RDI cutoff for all 3 OAHI values considered was found to be 4.6. When age strata were considered, in children 6 years or older the best RDI cutoff for the 3 OAHI values was 2.1. In children younger than 6 years the best RDI cutoff was 3.35 for OAHI > or =1 and 5.85 for OAHI > or =3 and > or =5. CONCLUSIONS: Respiratory polygraphy in the sleep laboratory is a valid method for the diagnosis of SAHS in children.

[Resources and delays in the diagnosis of sleep apnea-hypopnea syndrome]. / Recursos y demoras en el diagnóstico del síndrome de apneas-hipopneas durante el sueño (SAHS).

OBJECTIVE: The demand for consultations and diagnostic studies for sleep apnea-hypopnea syndrome (SAHS) has increased, and this has led to considerable delays. We therefore need an updated evaluation of the diagnostic situation to serve as a management tool for specialists and health care administrations responsible for solving the problem. The objective of the present study was to carry out a descriptive analysis of the situation regarding the diagnosis of SAHS in Spanish hospitals. METHODS: We undertook a descriptive cross-sectional observational study. Public and private hospitals listed in the Ministry of Health's 2005 catalog of health care institutions were contacted, and those that routinely evaluate patients for SAHS were included in the study. The person in charge of each hospital filled in a questionnaire concerning the availability of resources and waiting periods for diagnosis. RESULTS: Of the 741 hospitals we contacted, 217 routinely evaluated patients for SAHS. In 88% of these, respiratory polygraphy (RP) (n=168) or polysomnography (PSG) (n=97) was available. The mean waiting period was 61 days for consultation and 224 days for RP. The mean number of RP systems was 0.99 per 100,000 inhabitants, while the recommended number is 3 per 100,000 inhabitants. The mean waiting period for PSG was 166 days. The mean number of PSG beds was 0.49 per 100,000 inhabitants, while the recommended number is 1 per 100,000. CONCLUSIONS: We observed a marked inadequacy of resources that has led to unacceptable waiting periods. While there has been a favorable change in the situation regarding SAHS diagnosis compared to previous studies, there is still room for improvement and it is urgent that healt hcare authorities allocate more resources to this public health problem.

Sleep Apnea and Driving. Recommendations for Interpreting Spanish Regulations for Drivers. / Apnea del sueño y conducción de vehículos. Recomendaciones para la interpretación del nuevo Reglamento General de Conductores en España.

Road traffic accidents are one of the main causes of death worldwide and are clearly associated with sleepiness. Individuals with undiagnosed sleep apnea-hypopnea syndrome (SAHS) are among the population with a high risk of experiencing sleepiness at the wheel and, consequently, road traffic accidents. Treatment with continuous positive airway pressure (CPAP) has been shown to reduce the risk of accidents among drivers with SAHS. For this reason, the European Union has included this disease in the psychological and physical criteria for obtaining or renewing a driving license. To comply with this European Directive, Spain has updated its driving laws accordingly. To facilitate the implementation of the new regulations, a group of experts from various medical societies and institutions has prepared these guidelines that include questionnaires to screen for SAHS, diagnostic and therapeutic criteria, and physician's report templates.

Automated Screening of Children With Obstructive Sleep Apnea Using Nocturnal Oximetry: An Alternative to Respiratory Polygraphy in Unattended Settings.

STUDY OBJECTIVES: Nocturnal oximetry has become known as a simple, readily available, and potentially useful diagnostic tool of childhood obstructive sleep apnea (OSA). However, at-home respiratory polygraphy (HRP) remains the preferred alternative to polysomnography (PSG) in unattended settings. The aim of this study was twofold: (1) to design and assess a novel methodology for pediatric OSA screening based on automated analysis of at-home oxyhemoglobin saturation (SpO2), and (2) to compare its diagnostic performance with HRP. METHODS: SpO2 recordings were parameterized by means of time, frequency, and conventional oximetric measures. Logistic regression models were optimized using genetic algorithms (GAs) for three cutoffs for OSA: 1, 3, and 5 events/h. The diagnostic performance of logistic regression models, manual obstructive apnea-hypopnea index (OAHI) from HRP, and the conventional oxygen desaturation index ≥ 3% (ODI3) were assessed. RESULTS: For a cutoff of 1 event/h, the optimal logistic regression model significantly outperformed both conventional HRP-derived ODI3 and OAHI: 85.5% accuracy (HRP 74.6%; ODI3 65.9%) and 0.97 area under the receiver operating characteristics curve (AUC) (HRP 0.78; ODI3 0.75) were reached. For a cutoff of 3 events/h, the logistic regression model achieved 83.4% accuracy (HRP 85.0%; ODI3 74.5%) and 0.96 AUC (HRP 0.93; ODI3 0.85) whereas using a cutoff of 5 events/h, oximetry reached 82.8% accuracy (HRP 85.1%; ODI3 76.7) and 0.97 AUC (HRP 0.95; ODI3 0.84). CONCLUSIONS: Automated analysis of at-home SpO2 recordings provide accurate detection of children with high pretest probability of OSA. Thus, unsupervised nocturnal oximetry may enable a simple and effective alternative to HRP and PSG in unattended settings.