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2.
Sleep Breath ; 21(4): 893-900, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28493047

ABSTRACT

PURPOSE: The aim of the study is to compare the effects of continuous positive airway pressure (CPAP) on the nasal cavities of patients with obstructive sleep apnoea (OSA) and with or without allergic rhinitis (AR/nonAR). METHODS: This paper is a prospective, longitudinal study. Thirty-four consecutive CPAP treatment-adherent patients with OSA (17 AR and 17 nonAR) were evaluated before and 2 months after treatment, by means of clinical (otorhinolaryngological symptoms, daytime sleepiness, overall and rhinoconjunctivitis-specific quality of life), anatomical (otorhinolaryngological examination), functional (auditory function, tubal function, nasal airflow, and mucociliary clearance), and biological variables (nasal cytology). No humidifier or anti-allergy medicines were used during treatment. RESULTS: Before treatment, patients with AR presented a higher score, compared to nonAR in rhinitis symptoms (4.82 ± 2.53 vs. 0.93 ± 1.02, p = 0.000), otologic symptoms (2.06 ± 1.95 vs. 0.44 ± 0.72, p = 0.004), cutaneous/ocular symptoms (2.12 ± 2.17 vs. 0.65 ± 1.17, p = 0.052), immunoglobulin E (181.82 ± 126.09 vs. 66.13 ± 97.97, p = 0.004), and nasal neutrophils (14.42 ± 31.94 vs. 0.16 ± 0.39, p = 0.031). After treatment, nonAR and AR groups improved in daytime sleepiness (11.53 ± 4.60 vs. 7.53 ± 2.87, p = 0.000 and 13.76 ± 4.93 vs. 7.53 ± 4.41, p = 0.001) respectively and increased nasal neutrophil (0.16 ± 0.39 vs. 5.78 ± 9.43, p = 0.001 and 14.42 ± 31.94 vs. 79.47 ± 202.08, p = 0.035). The symptoms and quality of life improved in patients with AR. NonAR patients, significantly increase nasal dryness (1.65 ± 1.27 vs. 0.00, p = 0.002) and mucociliary clearance times (38.59 ± 24.90 vs. 26.82 ± 23.18, p = 0.016). CONCLUSIONS: CPAP produces inflammation with increased nasal neutrophil levels in AR and nonAR patients. Nevertheless, patients with AR observed an improvement in nasal symptoms and quality of life, whereas in patients without AR, a relevant worsening of nasal dryness and mucociliary transport was observed.


Subject(s)
Continuous Positive Airway Pressure , Rhinitis, Allergic/complications , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/therapy , Continuous Positive Airway Pressure/adverse effects , Female , Humans , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Quality of Life
3.
Sleep Med ; 27-28: 25-27, 2016.
Article in English | MEDLINE | ID: mdl-27938914

ABSTRACT

BACKGROUND: Continuous positive airway pressure (CPAP) is the most commonly used treatment in obstructive sleep apnea. In a previous rat model study, we demonstrated that nasal CPAP induces early rhinitis expressed by nasal neutrophil extravasation. Here we hypothesized that nasal CPAP would worsen nasal inflammation on a previously inflamed mucosa. The objective of this study was to evaluate the early nasal CPAP effects of allergic rhinitis (AR) in a rodent model. METHODS: Twenty Sprague-Dawley rats were sensitized with intraperitoneal ovalbumin (OVA). Nasal inflammation was induced by the administration of intranasal OVA during consecutive days. The same procedure was performed in 20 control rats treated with saline solution. The allergic (AR) and non-allergic (NAR) rats were then randomized to nasal CPAP at 10 cm H2O for five hours or to sham CPAP. The degree of nasal inflammation was assessed by evaluating the percentage of neutrophils, eosinophils, basophils, and lymphocytes in the nasal mucosa. An unpaired Mann-Whitney test was used to analyze differences between groups. RESULTS: The greatest inflammation was observed in the group of AR without CPAP (1.24% ± 0.94%), followed by NAR with CPAP (0.64% ± 0.30%), AR with CPAP (0.64% ± 0.40%), and NAR without CPAP (0.21% ± 0.29%). CONCLUSIONS: Administration of nasal CPAP or allergy sensitization can produce, individually, neutrophil extravasation on the nasal mucosa of a rat model. The application of both stimuli is not responsible for increased inflammation. Therefore, this study suggests that rhinitis is not a major limitation for CPAP administration.


Subject(s)
Continuous Positive Airway Pressure , Nasal Mucosa/immunology , Nasal Mucosa/pathology , Rhinitis, Allergic/therapy , Administration, Intranasal , Animals , Continuous Positive Airway Pressure/methods , Disease Models, Animal , Ovalbumin , Random Allocation , Rats, Sprague-Dawley , Rhinitis, Allergic/immunology , Rhinitis, Allergic/pathology , Time Factors
5.
COPD ; 9(4): 382-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22497560

ABSTRACT

BACKGROUND: Automatic CPAP devices have demonstrated good results in obtaining optimal fixed CPAP pressure to eliminate respiratory events in patients with sleep apnea-hypopnea syndrome (SAHS). However, automatic CPAP has not been fully studied in patients with COPD plus SAHS. OBJECTIVES: To analyse the performance of an automatic CPAP in severe COPD patients compared with SAHS patients with no associated co-morbidity. METHODS: We compared 10 consecutive patients with SAHS and no associated co-morbidity and 10 patients with SAHS plus severe COPD who required CPAP titration. Automatic CPAP performance was studied during full-night PSG. Inadequate pressure increase periods, absence of pressure increases in reaction to respiratory events, air leak periods, and pressure behaviour in the face of erratic breathing periods were analysed. RESULTS: The SAHS patients without co-morbidities vs. SAHS plus COPD patients presented: mean sleep efficiency, 80.2 (11.5)% vs. 76.5 (12.1)%; residual AHI, 6.3 (5.2) vs. 5.1 (7.7); residual CT90, 1 (3)% vs. 14 (1)%. The device´s performance demonstrates a mean of 1.2 (1.5) vs. 1.3 (1.2) periods of inadequate pressure increases; absence of pressure increases in reaction to respiratory events, 4.1 (5.4) vs. 0.6 (0.7) times; periods of air leaks, 1.3 (3.8) vs. 13.9 (11.7); mean optimal pressure, 9.1 (1.4) vs. 9.0 (1.9) cm H(2)O. CONCLUSION: Titration with automatic CPAP could be as effective in patients with SAHS plus severe COPD as in patients with SAHS without COPD. However, the presence of more leakages must be taken into account.


Subject(s)
Continuous Positive Airway Pressure/methods , Pulmonary Disease, Chronic Obstructive/complications , Sleep Apnea, Obstructive/therapy , Aged , Female , Humans , Male , Middle Aged , Polysomnography , Sleep Apnea, Obstructive/complications , Treatment Outcome
7.
Eur Respir J ; 39(4): 906-12, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21965227

ABSTRACT

Obstructive sleep apnoea (OSA) is a risk factor for stroke, but little is known about the effect of OSA and continuous positive airway pressure (CPAP) on the incidence of long-term, nonfatal cardiovascular events (CVE) in stroke patients. A prospective observational study was made in 223 patients consecutively admitted for stroke. A sleep study was performed on 166 of them. 31 had an apnoea/hypopnoea index (AHI) <10 events · h(-1); 39 had an AHI between 10 and 19 events · h(-1) and 96 had an AHI ≥ 20 events · h(-1). CPAP treatment was offered when AHI was ≥ 20 events · h(-1). Patients were followed up for 7 yrs and incident CVE data were recorded. The mean ± SD age of the subjects was 73.3 ± 11 yrs; mean AHI was 26 ± 16.7 events · h(-1). Patients with moderate-to-severe OSA who could not tolerate CPAP (AHI ≥ 20 events · h(-1); n = 68) showed an increased adjusted incidence of nonfatal CVE, especially new ischaemic strokes (hazard ratio 2.87, 95% CI 1.11-7.71; p = 0.03), compared with patients with moderate-to-severe OSA who tolerated CPAP (n = 28), patients with mild disease (AHI 10-19 events · h(-1); n = 36) and patients without OSA (AHI <10 events · h(-1); n = 31). Our results suggest that the presence of moderate-to-severe OSA is associated with an increased long-term incidence of nonfatal CVE in stroke patients and that CPAP reduces the excess of incidence seen in these patients.


Subject(s)
Brain Ischemia/epidemiology , Continuous Positive Airway Pressure/statistics & numerical data , Sleep Apnea, Obstructive/epidemiology , Sleep Apnea, Obstructive/therapy , Stroke/epidemiology , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Female , Follow-Up Studies , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Prospective Studies , Risk Factors , Secondary Prevention
8.
Eur Respir J ; 39(3): 746-67, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21920888

ABSTRACT

A European Respiratory Society research seminar on "Metabolic alterations in obstructive sleep apnoea (OSA)" was jointly organised in October 2009 together with two EU COST actions (Cardiovascular risk in the obstructive sleep apnoea syndrome, action B26, and Adipose tissue and the metabolic syndrome, action BM0602) in order to discuss the interactions between obesity and OSA. Such interactions can be particularly significant in the pathogenesis of metabolic abnormalities and in increased cardiovascular risk in OSA patients. However, studying the respective role of OSA and obesity is difficult in patients, making it necessary to refer to animal models or in vitro systems. Since most OSA patients are obese, their management requires a multidisciplinary approach. This review summarises some aspects of the pathophysiology and treatment of obesity, and the possible effects of sleep loss on metabolism. OSA-associated metabolic dysfunction (insulin resistance, liver dysfunction and atherogenic dyslipidaemia) is discussed from the perspective of both obesity and OSA in adults and children. Finally, the effects of treatment for obesity or OSA, or both, on cardio-metabolic variables are summarised. Further interdisciplinary research is needed in order to develop new comprehensive treatment approaches aimed at reducing sleep disordered breathing, obesity and cardiovascular risk.


Subject(s)
Adipose Tissue/physiopathology , Obesity/physiopathology , Sleep Apnea, Obstructive/physiopathology , Animals , Dyslipidemias/enzymology , Dyslipidemias/physiopathology , Female , Humans , Hypoxia/physiopathology , Inflammation/physiopathology , Insulin Resistance/physiology , Lipoxygenase/physiology , Male , Mice , Oxidative Stress/physiology , Rats
10.
Neurocirugia (Astur) ; 22(5): 401-17; discussion 417-8, 2011 Oct.
Article in Spanish | MEDLINE | ID: mdl-22031159

ABSTRACT

INTRODUCTION. Esthesioneuroblastoma (ENB) is a very uncommon malignant tumor with a neuroectodermal origin that usually involves the anterior cranial fossa and nasal cavity. OBJECTIVES. To review our experience in the management of ENB and assess the validity of the histopathological diagnosis, modality of treatment and prognostic factors of the disease comparing our findings with the literature. METHODS. A retrospective study of 11 cases with the diagnosis of esthesioneuroblastoma treated in our hospital between 2000 and 2008. Statistical analysis was performed in search for prognostic factors. The bibliography about ENB published between 1990 and 2009 was reviewed RESULTS. There were 3 women and 8 men, with a mean age of 42 years old (range 20-71y). Their symptoms upon admission were nasal obstruction (81%), epistaxis (27%), visual loss (18%), headache and others. According to the Kadish Stage, 2 were stage B and 9 were stage C. Dulguerov and Calcaterra Classification was also used: 2 were T2, 3 were T3 and 6 were T4. The hystopathological result according to the Hyams classification was: 2 cases in stage I, 4 in stage II, 3 in stage III and 2 in stage IV. The two cases classified in stage IV changed the diagnosis to undifferenciate tumor in the second biopsy. A subcranial approach was performed in 8 cases combined with endonasal endoscopy to confirm the total removal, followed by radiotherapy in all and chemotherapy in one case, resulting on 62% (5 patients) being alive without disease, 12,5% (1 p) alive with disease, and 25% (2 p) dead of disease. Another patient was operated by a single endonasal endoscopic approach and a subtotal removal was achieved. This patient is alive without disease. The other 2 patients were treated by biopsy plus radiotherapy and chemotherapy, because they were considered unresectable, and one of them is alive with disease and the other one is dead of disease. Radiotherapy was performed in all cases and chemotherapy in 5 cases. The hystopathological grading system of Hyams was considered statistically significant as a prognostic factor of disease-free survival. CONCLUSIONS. When the hystopathological diagnosis of ENB is considered, the Hyams classification can be valid considering grade IV as an advanced stage that is sometimes difficult to differentiate from other undiferentiated tumors. The subcranial approach or craneofacial resection in advanced stages (Kadish C and some B) should be considered as the first treatment of choice. Radiotherapy is indicated in all cases and chemotherapy in selected cases. Hyams' classification was the only staging system that proved useful as a prognostic factor in our series.


Subject(s)
Esthesioneuroblastoma, Olfactory/pathology , Esthesioneuroblastoma, Olfactory/therapy , Nasal Cavity/pathology , Nose Neoplasms/pathology , Nose Neoplasms/therapy , Adult , Aged , Cranial Fossa, Anterior/pathology , Humans , Male , Middle Aged , Retrospective Studies , Skull Base Neoplasms/pathology , Skull Base Neoplasms/therapy , Spain , Survival Rate , Young Adult
11.
Neurocir. - Soc. Luso-Esp. Neurocir ; 22(5): 401-418, sept.-oct. 2011. ilus, graf, tab
Article in Spanish | IBECS | ID: ibc-104726

ABSTRACT

Introducción. El estesioneuroblastoma (ENB) es un tumor maligno de origen neuroectodérmico poco habitual que afecta principalmente a la fosa craneal anterior y cavidad nasal. Objetivos. Revisar nuestra experiencia en el manejo de los ENB, evaluar la validez del diagnóstico anatomopatológico, el tipo de tratamiento y factores pronósticos de la enfermedad comparando nuestros hallazgos con los descritos en la literatura. Material y métodos. Estudio retrospectivo de 11 casos de ENB tratados en nuestro hospital en el periodo comprendido entre 2000 y 2008. Se realiza análisis estadístico sobre la existencia de factores pronósticos. Se revisa la bibliografía publicada sobre el ENB entre 1990 y 2009.Resultados. Se trataron 3 mujeres y 8 hombres, cuya edad media fue 42 años (rango 20-71 años). El síntoma inicial fue la obstrucción nasal (81%), epistaxis (27%), disminución de agudeza visual (18%), cefalea y otros. Según la clasificación de Kadish, 2 son estadío B y 9 estadío C; según la clasificación de Dulguerov, 2 son T2, 3 son T3 y 6 son T4. El resultado histológico según la clasificación de Hyams fue de 2 casos en grado I, 4 en grado II, 3 en grado III y 2 en grado IV. Dos de los casos inicialmente catalogados en grado IV cambiaron de diagnóstico en la segunda (..) (AU)


Introduction. Esthesioneuroblastoma (ENB) is a very uncommon malignant tumor with a neuroectodermal origin that usually involves the anterior cranial fossa and nasal cavity. Objectives. To review our experience in the management of ENB and assess the validity of the histopathological diagnosis, modality of treatment and prognostic factors of the disease comparing our findings with the literature. Methods. A retrospective study of 11 cases with the diagnosis of esthesioneuroblastoma treated in our hospital between 2000 and 2008. Statistical analysis was performed in search for prognostic factors. The bibliography about ENB published between 1990 and 2009 (..) (AU)


Subject(s)
Humans , Male , Female , Young Adult , Adult , Middle Aged , Aged , Esthesioneuroblastoma, Olfactory/epidemiology , Skull Neoplasms/epidemiology , Retrospective Studies , Survival Rate
13.
Respir Med ; 105(12): 1954-60, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21889324

ABSTRACT

BACKGROUND: Obstructive sleep apnea (OSA) is related to obesity and metabolic disorders. The main clinical symptoms are excessive daytime sleepiness (EDS) and snoring. However, not all patients with OSA manifest EDS. Hypocretin-1, neuropeptide Y, leptin, ghrelin and adiponectin are implicated in both metabolic and sleep regulation, two conditions affected by OSA. We hypothesized that levels of these peptides may be related to EDS in OSA patients. METHODS: We included 132 patients with EDS, as defined by an Epworth Sleepiness Scale (ESS) score ≥ 13 (mean ± SD, 15.7 ± 2.3) and 132 patients without EDS as defined by an ESS score ≤ 9 (6.5 ± 1.9). All patients had an apnea-hypopnea index (AHI) ≥ 20 h(-1). Both groups were matched for gender (males; 83.3% vs. 85.6%), age (50.15 ± 11.2 yrs vs. 50.7 ± 9.9 yrs), body mass index (BMI) (31.8 ± 5.6 kg m(-2) vs. 32.1 ± 4.8 kg m(-2)), and apnea-hypopnea index (AHI) (45.5 ± 19.1 h(-1) vs. 43 ± 19.2 h(-1)). RESULTS: OSA patients with EDS showed significantly higher plasma hypocretin-1 levels (p < 0.001) and lower plasma ghrelin levels (p < 0.001) than OSA patients without EDS. There were no statistically significant differences in neuropeptide Y (p = 0.08), leptin (p = 0.07) and adiponectin (p = 0.72) between the two groups. In the multiple linear regression model ESS score was associated with plasma levels of hypocretin-1, ghrelin and total sleep time. CONCLUSION: Our study shows that EDS in patients with OSA is associated with increased circulating hypocretin-1 and decreased circulating ghrelin levels, two peptides involved in the regulation of body weight, energy balance, sympathetic tone and sleep-wake cycle. This relationship is independent of AHI and obesity (two key phenotypic features of OSA).


Subject(s)
Disorders of Excessive Somnolence/blood , Ghrelin/blood , Intracellular Signaling Peptides and Proteins/blood , Neuropeptides/metabolism , Sleep Apnea, Obstructive/blood , Sleep Apnea, Obstructive/complications , Biomarkers/blood , Body Mass Index , Disorders of Excessive Somnolence/etiology , Disorders of Excessive Somnolence/physiopathology , Female , Humans , Male , Middle Aged , Neuropeptides/blood , Orexins , Polysomnography , Risk Factors , Sleep Apnea, Obstructive/physiopathology
14.
Eur Respir J ; 38(3): 635-42, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21622583

ABSTRACT

The European Sleep Apnoea Database (ESADA) reflects a network of 22 sleep disorder centres in Europe enabled by a COST action B26 programme. This ongoing project aims to describe differences in standard clinical care of patients with obstructive sleep apnoea (OSA) and to establish a resource for genetic research in this disorder. Patients with suspected OSA are consecutively included and followed up according to local clinical standards. Anthropometrics, medical history, medication, daytime symptoms and sleep data (polysomnography or cardiorespiratory polygraphy) are recorded in a structured web-based report form. 5,103 patients (1,426 females, mean±sd age 51.8±12.6 yrs, 79.4% with apnoea/hypopnoea index (AHI) ≥5 events·h(-1)) were included from March 15, 2007 to August 1, 2009. Morbid obesity (body mass index ≥35 kg·m(-2)) was present in 21.1% of males and 28.6% of females. Cardiovascular, metabolic and pulmonary comorbidities were frequent (49.1%, 32.9% and 14.2%, respectively). Patients investigated with a polygraphic method had a lower AHI than those undergoing polysomnography (23.2±23.5 versus 29.1±26.3 events·h(-1), p<0.0001). The ESADA is a rapidly growing multicentre patient cohort that enables unique outcome research opportunities and genotyping. The first cross-sectional analysis reveals a high prevalence of cardiovascular and metabolic morbidity in patients investigated for OSA.


Subject(s)
Sleep Apnea Syndromes/diagnosis , Sleep Apnea Syndromes/epidemiology , Adolescent , Adult , Aged , Anthropometry/methods , Cohort Studies , Comorbidity , Databases, Factual , Europe , Female , Humans , Male , Middle Aged , Models, Genetic , Obesity, Morbid/complications , Risk Factors , Sleep Apnea Syndromes/physiopathology , Surveys and Questionnaires
15.
Eur Respir J ; 38(5): 1089-97, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21622590

ABSTRACT

Obstructive sleep apnoea (OSA) seems to worsen metabolism. This effect has not been evaluated in morbid obesity (MO). We hypothesised that the metabolic profile is more impaired in MO patients with OSA than in those without, and investigated whether any specific metabolic dysfunction is related to OSA in MO. A prospective multicentre cross-sectional study was conducted in consecutive subjects before bariatric surgery. OSA was defined as apnoea/hypopnoea index (AHI) ≥15 by overnight polysomnography. Anthropometrical, blood pressure (BP) and fasting blood measurements were obtained the morning after. Metabolic syndrome (MetS) was defined according to National Cholesterol Education Program Adult Treatment Panel III modified criteria. 159 patients were studied: 72% were female and 72% had OSA. MetS prevalence was 70% in OSA versus 36% in non-OSA (p<0.001). As AHI severity increased, metabolic parameters progressively worsened, even in those without type 2 diabetes (DM2). AHI was independently associated with systolic and diastolic BP, triglycerides and the percentage of glycosylated haemoglobin (HbA1c) in the total sample, and with systolic BP, high-density lipoprotein cholesterol and HbA1c in those samples without DM2. OSA increased the adjusted odds ratio of having MetS by 2.8 (95% CI 1.3-6.2; p=0.009). In MO, OSA is associated with major metabolic impairment caused by higher BP and poorer lipid and glucose control, independent of central obesity or DM2.


Subject(s)
Metabolic Syndrome/complications , Obesity, Morbid/complications , Sleep Apnea, Obstructive/complications , Adolescent , Adult , Blood Glucose/analysis , Blood Pressure , Diabetes Mellitus, Type 2/complications , Female , Glycated Hemoglobin/analysis , Humans , Lipids/blood , Male , Middle Aged , Obesity, Morbid/metabolism , Oxygen/blood , Polysomnography , Sleep Apnea, Obstructive/physiopathology , Young Adult
16.
Sleep Med ; 12(2): 190-7, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21167776

ABSTRACT

OBJECTIVES: In Europe, the services provided for the investigation and management of obstructive sleep apnoea (OSA) varies from country to country. The aim of this questionnaire-based study was to investigate the current status of diagnostic pathways and therapeutic approaches applied in the treatment of OSA in Europe, qualification requirements of physicians involved in diagnosis and treatment of OSA, and reimbursement of these services. METHODS: Two questionnaires were sent to 39 physicians in 22 countries in Europe. In order to standardize the responses, the questionnaire was accompanied by an example. RESULTS: Sleep centers from 21 countries (38 physicians) participated. A broad consistency among countries with respect to the following was found: pathways included referral to sleep physicians/sleep laboratories, necessity for objective diagnosis (primarily by polysomnography), use of polygraphic methods, analysis of polysomnography (PSG), indications for positive airway pressure (PAP) therapy, application of standard continuous PAP (CPAP) therapy (100% with an CPAP/APAP ratio of 2.24:1), and the need (90.5%) and management of follow-up. Differences were apparent in reimbursement of the diagnostic procedures and follow-up, in the procedures for PAP titration from home APAP titration with portable sleep apnea monitoring (38.1%) up to hospital monitoring with PSG and APAP (85.7%), and in the qualification requirements of sleep physicians. CONCLUSIONS: Management of OSA in different European countries is similar except for reimbursement rules, qualification of sleep specialists and procedures for titration of the CPAP treatment. A European network (such as the one accomplished by the European Cooperation in Science and Technology [COST] B26 Action) could be helpful for implementing these findings into health-service research in order to standardize management in a cost effective perspective.


Subject(s)
Continuous Positive Airway Pressure , Health Care Surveys , Polysomnography , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/therapy , Certification , Europe , Humans , Internationality , Medicine/standards , Professional Practice , Surveys and Questionnaires
17.
Opt Express ; 18(3): 2230-5, 2010 Feb 01.
Article in English | MEDLINE | ID: mdl-20174051

ABSTRACT

This study reports the estimation of the inverted Er fraction in a system of Er doped silicon oxide sensitized by Si nanoclusters, made by magnetron sputtering. Electroluminescence was obtained from the sensitized erbium, with a power efficiency of 10(-2)%. By estimating the density of Er ions that are in the first excited state, we find that up to 20% of the total Er concentration is inverted in the best device, which is one order of magnitude higher than that achieved by optical pumping of similar materials.

18.
Respiration ; 80(6): 495-9, 2010.
Article in English | MEDLINE | ID: mdl-19955707

ABSTRACT

BACKGROUND: To improve the performance of simplified sleep studies, it is essential to properly estimate the sleep time. OBJECTIVES: Our aim is to estimate sleep efficiency on the basis of flow breathing signal characteristics. METHODS: Twenty subjects with sleep apnea-hypopnea syndrome diagnosed by polysomnography were studied. A characteristic pattern of flow signal defined our criteria for wakefulness and sleep. Sleep was analyzed in 2 different runs: (1) in the usual manner (neurological and respiratory variables), and (2) only the nasal cannula flow signal was displayed on the computer screen and the sleep and wakefulness periods were scored according to our criteria. At the end of the scoring process, all the signals were displayed on the screen to analyze the concordance. RESULTS: Three thousand and sixty-nine screens were analyzed. The polysomnography sleep efficiency measured was 80.8%. The estimated sleep efficiency measured by nasal prongs was 78.9%. The detection and concordance of wakefulness had a sensitivity of 58.7%, a specificity of 96.4%, a positive predictive value of 81.3% and a negative predictive value of 89.6%. CONCLUSIONS: Our criteria for sleep and wakefulness based on airflow waveform morphology are a helpful parameter for estimating sleep efficiency in a simplified sleep study.


Subject(s)
Polysomnography , Respiration , Sleep Apnea Syndromes/physiopathology , Sleep/physiology , Wakefulness/physiology , Adult , Female , Humans , Male , Middle Aged
20.
Eur Respir J ; 34(1): 156-61, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19213784

ABSTRACT

Obstructive nonapnoeic event (ONE) scoring is shrouded in confusion. This is important in patients with mild disease, in whom precision is crucial. The aims of the present study were: 1) to identify ONEs using oesophageal pressure (OP) (OP-ONEs) and a noninvasive (NI) method (NI-ONEs); 2) to compare both methods of scoring; and 3) to determine the contribution of ONE definitions to clinical findings. Patients with suspected sleep apnoeas (respiratory disturbance index

Subject(s)
Polysomnography/methods , Respiration Disorders/diagnosis , Respiration , Sleep Apnea Syndromes/diagnosis , Adult , Arousal , Cohort Studies , Esophagus/pathology , Female , Humans , Male , Middle Aged , Prospective Studies , Respiration Disorders/pathology , Sleep , Sleep Apnea Syndromes/physiopathology , Sleep Stages
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