Características clínicas y polisomnográficas del síndrome de apneas durante el sueño localizado en la fase REM

Objective

The aim of this study was to analyze the clinical and polysomnographic features of rapid eye movement (REM)–specific sleep disordered-breathing (SDB).

Patients and methods

All cases of sleep apnea-hypopnea syndrome (SAHS) (apnea-hypopnea index [AHI]?>10/h) diagnosed using overnight polysomnography during the period 2004 to 2006 were analyzed retrospectively. Those cases in which the ratio of AHI during REM sleep to AHI during non-REM sleep was more than 2 were classified as REM-specific SDB. We recorded the following data: clinical signs and symptoms related to SAHS, PSG results, cardiovascular risk factors, and previous cardiovascular events. Logistic regression analysis was used to identify predictors of REM-specific SDB and to analyze the possible interactions between variables.

Results

A total of 419 patients were analyzed, of whom 138 (32.9%) presented REM-specific SDB. This condition was more common in patients with mild to moderate SAHS than in those with more severe cases (odds ratio, 8.21; 95% confidence interval, 4.83–14.03). The variables independently associated with REM-specific SDB in the logistic regression analysis were female sex, lower AHI, and higher body mass index. No interactions between the main variables studied were found. There were no differences between patients with REM-specific SDB and those with non-REM-specific SDB with regard to signs and symptoms related to SAHS, excessive daytime sleepiness, sleep architecture, cardiovascular risk factors, or history of cardiovascular episodes.

Conclusions

REM-specific SDB could be considered an initial stage of SAHS that mainly affects obese women with mild to moderate sleep disorders, and that does not differ from non-REM-specific SDB in terms of clinical presentation, sleep architecture, or cardiovascular comorbidity.     

Variabilidad de la señal de frecuencia de pulso obtenida mediante pulsioximetría nocturna en pacientes con síndrome de apnea hipopnea del sueño

Introduction

The measurement of central tendency (MCT) is a non-linear analysis technique which applied to second order differences diagrams enables the degree of variability to be quantified in a data series. In the present study an attempt is made to quantify and characterise the changes in heart rate obtained by pulse oximetry in patients with a clinical suspicion of sleep apnoea/hypoapnoea syndrome (SAHS) using the MCT and to evaluate its diagnostic use.

Patients and Methods

A total of 187 patients were included in the study, on whom a nocturnal polysomnographic and pulse oximetry study was performed. To evaluate the variability of the heart rate the MCT applied to graphs of second order differences obtained from the heart rate record.

Result

Patients with SAHS had a higher heart rate variablity than patients without SAHS (0.449 vs. 0.666, P<0.001. In the multivariate analysis, the heart rate, the minimum saturation and the desaturation index of 4% were independently associated with the heart rate variability. As a diagnostic method, the MCT of the heart rate gives a sensitivity of 69.3%, a specificity of 77.6% and a diagnostic precision of 72.7%

Conclusions

Patients with SAHS have a greater variabilityin heart rate during the night, evaluated by applying the MCT of the heart rate to diagrams of second order differences. As a screening method, the MCT applied to the heart rate has a moderate sensitivity and specificity.     

Variación de la expresión proteica en función de la gravedad del síndrome de apnea-hipopnea del sueño

Objective

A prospective study with a consecutive sample and a control group to determine whether protein expression in patients with sleep apnoea-hypopnoea syndrome (SAHS) is different from that of the control group (IAH ≤5).

Patients and methods

A total of 32 patients aged between 35 and 60 years who had a polysomnograph performed were included. Patients with an acute or chronic were excluded. The first dimension of the proteomic study was carried out on IPG strips (18 cm, pH 4–7) and the second on SDS-PAGE gels in triplicate for each group. The gels were stained with SYPRO-Ruby (Bio-Rad^®), the images obtained with an FX-Imager laser scanner and the spots were analysed using ProteomWeaver v. 4.0 (Bio-Rad^®) software. Significant changes between the gels were analysed by replicates and separately, being considered a significant change if the relative intensity of the spots was three times higher or lower than that of the control and if it was observed in 2 of the 3 replicates of each group, with a coefficient of variation of <20%.

Results

The patients were divided into 8 subjects per group (control, mild, moderate and severe). The comparison of the gels showed significant differences between the control group and the 3 clinical groups, with significant over-expression being observed in 3 spots, and under-expression in 7 spots in the control group.

Conclusion

There are significant changes in protein expression between a control group and patients in different stages of disease. The proteomic study can identify biomarkers associated with the diagnosis and severity of the SAHS.     

Pronóstico tras una agudización grave de la EPOC tratada con ventilación mecánica no invasiva

Introduction

Patients with chronic obstructive pulmonary disease (COPD) who survived an acute exacerbation with acute respiratory failure that required non-invasive mechanical ventilation (NIMV) are a group with a poor medium-term prognosis.

Objective

To identify re-admission and mortality rates within one year from discharge and to analyse factors associated with both events in a consecutive series of COPD patients treated with NIMV.

Methods

A cohort of 93 COPD patients who survived an acute exacerbation and who required NIMV was followed up after discharge. Re-admissions due to respiratory causes and survival were measured and the outcomes were analysed against possible factors associated to such events using multivariate Cox proportional risk regression analysis.

Results

Over the year following discharge, 61 patients (66%) had to be re-admitted into hospital due to respiratory complications. Upon multivariate analysis, a low FEV₁ value in stable phase and a high average length of stay were associated independently with a high risk of hospital readmission. The probability of survival at 1 year was 0.695. Age, PaCO₂ prior to initiation of NIMV and the number of hospitalisation days in the previous year were associated independently with a high mortality risk.

Conclusions

This group of COPD patients has a high mortality rate and need for re-hospitalisation in the ensuing year following discharge. The variables relating to the severity of the baseline disease and the actual exacerbation have been shown to be associated with these events, and could be applied to this subgroup of patients in specific follow-up programs.     

Uso precoz de la ventilación mecánica no invasiva en pacientes con insuficiencia respiratoria hipercápnica aguda ingresados en una sala de neumología: estudio prospectivo

Background

In recent years, the optimal location for noninvasive mechanical ventilation (NIMV) has been a matter of debate. Our aim was to detect the effectiveness of NIMV in acute hypercapnic respiratory failure (AHRF) in respiratory ward and factors associated with failure.

Methods

69 patients treated with NIMV in respiratory ward were prospectively evaluated. The success of NIMV was defined as absence of need for intensive care unit (ICU) transfer with patient's dishcarge from hospital (group 1), failure of NIMV was defined as need for ICU transfer (group 2).

Results

The mean age was significantly higher in group 2. The cause of respiratory failure was COPD in 51 patients, obesity-hypoventilation syndrome in 14 and kyphoscoliosis in 4 patients. NIMV was successful in 55 patients and unsuccessful in 14. There was no significant difference between the two groups for pretreatment pH, PaCO₂ and PaO₂/FiO₂. After 1 h and 3 h of NIMV there was significant improvement in group 1. After 3 h of NIMV, in group 1 respiratory rate was significantly decreased. The pretreatment APACHE II score, respiratory rate, frequency of pneumoniae, associated complication and comorbid disease was significantly higher in group 2. The success rate was higher in patients with good compliance to NIMV.

Conclusion

NIMV can be succesfully applied in patients with AHRF in respiratory ward. The associated factors with NIMV failure are absence of early improvement in blood gases and respiratory rate, bad compliance to NIMV, older age, presence of associated complication, comorbid disease, pneumonia and high baseline respiratory rate.     

Consistencia interna y validez de la versión española del cuestionario de calidad de vida específico para el síndrome de apnea del sueño: Sleep Apnoea Quality of Life Index

Introduction

The objective of the present study was to validate the Spanish version of the SAQLI, which is a health-related quality of life (HRQL) questionnaire specific for sleep apnea-hypopnea syndrome (SAHS), and to assess its sensitivity to change.

Material and methods

A multicenter study performed in a group of patients with SAHS (apnea-hypopnea index [AHI] ≥5) who had been referred to the centers’ Sleep Units. All patients completed the following questionnaires: SF-36, FOSQ, SAQLI and Epworth scale. The psychometric properties (internal consistency, construct validity, concurrent validity, predictive value, repeatability and responsiveness to change) of the SAQLI were assessed (four domains: daily function, social interactions, emotional function and symptoms; an optional fifth domain is treatment-related symptoms).

Results

One hundred sixty-two patients were included for study (mean age: 58 ± 12; Epworth: 10 ± 4; BMI: 33 ± 5.9 kg m⁻²; AHI: 37 ± 15 hour⁻¹). The factorial analysis showed a construct of four factors with similar distribution to the original questionnaire domains. Internal consistency (Cronbach's alpha between 0.78 and 0.82 for the different domains), concurrent validity for SF-36, Epworth scale and FOSQ, and test-retest reliability were appropriate. The predictive validity of the questionnaire showed no significant correlations with the severity of SAHS. SAQLI showed good sensitivity to change in all the domains of the questionnaire (p < 0,01).

Conclusions

The Spanish version of the SAQLI is a valid HRQL measurement with appropriate psychometric properties for use in patients with SAHS and it is sensitive to change.     

Diferencias geográficas en la prevalencia de EPOC en España: relación con hábito tabáquico,tasas de mortalidad y otros determinantes

Background

The EPI-SCAN study (Epidemiologic Study of COPD in Spain), conducted from May 2006 to July 2007, determined that the prevalence of COPD in Spain according to the GOLD criteria was 10.2% of the 40 to 80 years population. Little is known about the current geographical variation of COPD in Spain.

Objectives

We studied the prevalence of COPD, its under-diagnosis and under-treatment, smoking and mortality in the eleven areas participating in EPI-SCAN. COPD was defined as a post-bronchodilator FEV₁/FVC ratio <0.70 or as the lower limit of normal (LLN).

Results

The ratio of prevalences of COPD among the EPI-SCAN areas was 2.7-fold, with a peak in Asturias (16.9%) and a minimum in Burgos (6.2 %) (P<0.05). The prevalence of COPD according to LLN was 5.6% (95% CI 4.9–6.4) and the ratio of COPD prevalence using LLN was 3.1-fold, but with a peak in Madrid-La Princesa (10.1%) and a minimum in Burgos (3.2%) (P<0.05). The ranking of prevalences of COPD was not maintained in both sexes or age groups in each area. Variations in under-diagnosis (58.6% to 72.8%) and under-treatment by areas (24.1% to 72.5%) were substantial (P<0.05). The prevalence of smokers and former smokers, and cumulative exposure as measured by pack-years, and the age structure of each of the areas did not explain much of the variability by geographic areas. Nor is there any relation with mortality rates published by Autonomous Communities.

Conclusion

There are significant variations in the distribution of COPD in Spain, either in prevalence or in under-diagnosis and under-treatment     

¿Cuándo remitir al cardiólogo al paciente con síndrome de apneas-hipopneas durante el sueño? Utilidad del NT-proBNP

Introduction and objective

When sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.

Patients and methods

NT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.

Results

Data for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular end-diastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801–0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.

Conclusions

NT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.     

Apnea del sueño en individuos de edad avanzada. Actividad asistencial (2002–2008) en España

Introduction and objective

There is a significant lack of scientific evidence on the role of SAHS in the elderly despite the increasing ageing of the population. The objective of the present study is to analyse the current healthcare situation in Spain on the diagnosis and treatment of sleep apnea in the population ≥65 years and its progress over the last few years.

Material and method

Cross-sectional study. Healthcare information was collected on the diagnosis and treatment of patients of both sexes and ≥65 years suspected with having SAHS and referred to sleep units (SU) between 2002 and 2008.

Results

There were 51,229 sleep studies performed in 16 SU. Of these, 24.3% were performed on subjects ≥ 65 years (64.9% males), of which 71.5% had an AHI (apnoea-hypopnoea index) >10 (68.6% treated with CPAP). There were no differences over time as regards mean age, mean AHI or percentage of studies done. A significant decrease was observed in the number of CPAP prescribed to males ≥65 years from 2002 to 2005 (p=0.01) which subsequently increased up to 2008 (p=0.01). This phenomenon was not observed in women ≥65 years.

Conclusion

Despite the lack of evidence on the subject, healthcare activity due to suspected SAHS in the elderly population is intense, therefore it should be a priority to start clinical studies that may be able to answer key questions on the diagnosis and treatment of SAHS in this age group.     

Nocardiosis pulmonar en pacientes con EPOC: características y factores pronósticos

Introduction

Pulmonary nocardiosis (PN) is a severe infection with a high morbidity and mortality that mainly affects immunocompromised patients. In recent years, an increase in PN cases has been detected among patients with chronic obstructive pulmonary disease (COPD). The factors that are associated with its presence and determine its prognosis remain unknown.

Methods

Retrospective study of COPD patients diagnosed with PN over the period from 1997-2009 at the Hospital de la Santa Creu i Sant Pau, in Barcelona (Spain). Demographic, clinical, microbiological and evolution data were evaluated in all cases

Results

Thirty patients were identified with PN and COPD. Mean age (standard deviation) was 76 (7) years and the mean FEV₁ was 40 (14)%. Chronic respiratory failure was observed in 56,7% patients and 51,7% had received systemic corticosteroid therapy previous to the PN diagnosis. The most common symptoms were cough and dyspnea (90%). Alveolar infiltrates were observed in 60% of the cases. The most frequently isolated Nocardia species was N. cyriacigeorgica (68%). The one-month mortality rate was 17%, while the one-year mortality rate was 33%. The factors associated with mortality within the first year included previous systemic corticosteroid treatment, less than three months of specific antibiotic therapy and active associated neoplasm.

Conclusions

PN affects patients with moderate-severe COPD and has high short- and mid-term mortality rates. Previous corticosteroid treatment, specific antibiotic therapy for less than 3 months and active neoplasia were factors associated with mortality.     

Causas de muerte en pacientes con EPOC grave. Factores pronósticos

Objective

The objective of this study was to assess the causes of death and risk factors for mortality in a cohort of patients with severe chronic obstructive pulmonary disease (COPD).

Patients and methods

We studied 203 patients with severe COPD (forced expiratory volume in 1 second [FEV₁] <50%), who were attended in our respiratory department day hospital (2001–2006). Clinical variables were recorded on inclusion, and clinical course and causes of death were retrospectively reviewed.

Results

The mean (SD) age of patients was 69 (8) years and the mean FEV₁ was 30.8% (8.2%). One-hundred and nine patients died (53.7%); death was attributed to respiratory causes in 72 (80.9%), with COPD exacerbation being the most frequent specific cause within this category (48.3%). During follow-up, 18.7% required admission to the intensive care unit (ICU). Survival at 1, 3, and 5 years was 80%, 53%, and 26%, respectively. The multivariate analysis showed that mortality was associated with age, stage IV classification according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), cor pulmonale, and hospital admission during the year prior to inclusion. Need for admission to the ICU during follow-up was a factor independently associated with higher mortality.

Conclusions

Mortality in patients with severe COPD was high and exacerbation of the disease was one of the most frequent causes of death. Age, GOLD stage, cor pulmonale, prior admission to hospital, and need for admission to the ICU during follow-up were independent predictors of mortality.     

Infradiagnóstico de la enfermedad pulmonar obstructiva crónica en mujeres: cuantificación del problema,determinantes y propuestas de acción

Introduction

The distribution of chronic obstructive pulmonary disease (COPD) in women, and its underdiagnosis and determinants in the general population, have not been well described. The EPI-SCAN study is an epidemiologic, observational study conducted at 11 Spanish centers on the general population aged 40 to 80.

Patients and method

This paper describes the rates and extrapolates the population burden from the 3,802 participants of the EPI-SCAN study.

Results

With 2,005 female and 1,797 male participants, there was a lower prevalence of COPD in women (5.7%; 95% CI, 4.7-6.7) than in men (15.1%; 95% CI, 13.5-16.8; P < .05). Among the 386 participants with COPD, 114 (29.5%) were women, who were younger, currently smoked less and had lower tobacco smoke exposure, while reporting a lower level of education (P < .05). As for the respiratory symptoms, there were no differences between sexes for cough, dyspnea or wheezing, but the women with COPD reported sputum less frequently (P < .05). There were no differences in the spirometric severity of COPD between women and men. Overall, 73% of the patients with a spirometric COPD criteria were underdiagnosed, and this percentage is unevenly distributed by sex, being 1.27 times more frequent in women (86.0%) than in men (67.6%) (P < .05). By extrapolating the rates of prevalence and underdiagnosis of COPD to the general population, we estimate that there are 628,102 Spanish women between the ages of 40 and 80 with COPD, 540,168 of whom still have not been diagnosed.

Conclusions

There is a greater underdiagnosis of COPD in women than in men in Spain.     

Asincronía e hiperinsuflación en pacientes con enfermedad pulmonar obstructiva crónica durante 2 tipos de ejercicio de las extremidades superiores

Introduction

Occurrence of dynamic hyperinflation during upper-limbs exercises in chronic obstructive pulmonary disease (COPD) patients it is not well established. We hypothesized that dynamic hyperinflation and thoracoabdominal asynchrony occurs in COPD patients accomplishing arms exercises. We assessed the occurrence and association of dynamic hyperinflation and thoracoabdominal asynchrony in COPD patients during the accomplishment of two arm exercises.

Patients and methods

This was a prospective study with 25 COPD patients. A maximal and a sub-maximal upper limbs exercise test with 50% load were performed with the diagonal technique and the arm cycle ergometer technique. Respiratory pattern, thoracoabdominal configuration and dynamic hyperinflation were assessed in the exercise tests.

Results

Thirty per cent and 60% of patients hyperinflated at the end of the sub-maximum exercise tests with the diagonal and cycle ergometer techniques, respectively. Thoracoabdominal asynchrony occurred in 80% and 100% of patients who hyperinflated with the diagonal and cycle ergometer techniques, respectively. For both exercises we found enhancement of pulmonary ventilation, dyspnea, central respiratory drive and shortening of expiratory time (P < .05). Upper-limbs exercises with the diagonal technique presented less number of patients with these alterations.

Conclusions

Dynamic pulmonary hyperinflation and thoracoabdominal asynchrony association occurred in both upper-limbs exercises; however, the diagonal technique developed less dynamic hyperinflation and thoracoabdominal asynchrony in COPD patients than the arm cycle ergometer.     

Variability of respiratory symptoms in severe COPD

Introduction

While it is known that asthma symptoms have a very variable pattern, the general belief is that the respiratory symptoms in COPD patients usually present little or no variability. Nevertheless, COPD patients report having “bad days”. The objective of this present study was to evaluate the variability of the respiratory symptoms and their impact on the daily activities of a cohort of Spanish COPD patients.

Method

We present the results of the Spanish patients who participated in a cross-sectional epidemiological study carried out in 17 European countries. Pulmonologists and Family Care physicians recruited patients with stable severe COPD (FEV1 < 50%). The perception of the patients on the variation in their symptoms was recorded by telephone interviews.

Results

A total of 472 patients provided data that was valid for analysis. Mean age was 68.6; 93% were men; mean FEV1(%) was 41%. 84.1% of the patients experimented at least one respiratory symptom in the previous week and 60.9% affirmed that their symptoms varied over the course of the day or week. The moment of the day when the symptoms were perceived to be more intense was during the morning.

Conclusions

An important proportion of severe COPD patients perceive variability in their respiratory symptoms, with a greater intensity in the morning. The observation can have implications in treating patients with severe COPD as variability can be an initial sign of decompensation of the disease.     

Cáncer de pulmón y EPOC: una asociación frecuente

Background and objective

To analyse frequency, characteristics and patient survival with lung cancer (LC) and COPD, comparing them with patients without COPD.

Material and methods

A retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. The statistical analysis was carried out using SPSS 15.0.

Results

A total of 996 patients were diagnosed, 39.8% COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, small cell carcinoma 22.5%. Survival was longer in the COPD group.

Conclusions

LC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group.     

COPD in chronic heart failure: Less common than previously thought?

Background

Using a fixed ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁/FVC) < 0.70 instead of the lower limit of normal (LLN) to define chronic obstructive pulmonary disease (COPD) may lead to overdiagnosis of COPD in elderly patients with heart failure (HF) and consequently unnecessary treatment with possible adverse health effects.

Objective

The aim of this study was to determine COPD prevalence in patients with chronic HF according to two definitions of airflow obstruction.

Methods

Spirometry was performed in 187 outpatients with stable chronic HF without pulmonary congestion who had a left ventricular ejection fraction <40% (mean age 69 ± 10 years, 78% men). COPD diagnosis was confirmed 3 months after standard treatment with tiotropium in newly diagnosed COPD patients.

Results

COPD prevalence varied substantially between 19.8% (LLN-COPD) and 32.1% (GOLD-COPD). Twenty-three of 60 patients (38.3%) with GOLD-COPD were potentially misclassified as having COPD (FEV₁/FVC < 0.7 but > LLN). In contrast to patients with LLN-COPD, potentially misclassified patients did not differ significantly from those without COPD regarding respiratory symptoms and risk factors for COPD.

Conclusions

One fifth, rather than one third, of the patients with chronic HF had concomitant COPD using the LLN instead of the fixed ratio. LLN may identify clinically more important COPD than a fixed ratio of 0.7.     

Ventilación mecánica no invasiva en una población anciana que ingresa en una unidad de monitorización respiratoria: causas,complicaciones y evolución al año de seguimiento

Objective

To determine the usefulness of non-invasive ventilation (NIV) in elderly patients (≥75) admitted to a respiratory monitoring unit (RMU) during hospitalization and one year later in comparison with the results from the younger age group (<75).

Material and methods

Ours is a prospective observational study carried out at the Hospital Universitario La Princesa (Madrid, Spain). We recruited all patients who were ≥75 years old and were admitted to our RMU during the period 2008-2009 with respiratory acidosis (pH <7.35 and PaCO₂ >45 mmHg) requiring NIV. We gathered data for basic variables as well as sociodemographics, history of previous pathologies, reason for hospitalization and severity, analysis upon admission and the evolution of blood gases at the start of NIV (within the first hour and after 24 hours), complications and evolution at the one-year follow-up.

Results

Mean age of the sample was 80.6 years. The Charlson index was 3.27. About half of the patients had some limitation for performing daily activities. The main reasons for admission were COPD exacerbation and heart failure. There were complications in 36% of the cases (11 renal failure and 6 atrial fibrillation). The survival rate at the one-year follow-up was 63.21%.

Conclusions

NIV is a good alternative in elderly patients admitted to the hospital with respiratory acidosis. We did not detect differences in mortality during admission between the two groups. The elderly patients were more frequently re-admitted than the younger group in the 6-12 months after hospital discharge. This could be due to their poorer functional state after hospitalization requiring NIV.     

Enfermedad pulmonar obstructiva crónica en pacientes con tromboembolia de pulmón aguda sintomática

Background

The diagnosis of pulmonary embolism (PE) is often complicated by the presence of chronic obstructive pulmonary disease (COPD). Some studies have suggested that patients with PE and concomitant COPD have a worse prognosis than patients without COPD.

Patients and methods

Outpatients diagnosed with acute symptomatic PE at a university tertiary care hospital were prospectively included in the study. Clinical characteristics, time between onset of symptoms and diagnosis, and outcome were analyzed according to presence or absence of COPD. The primary endpoint was all-cause deaths at 3 months.

Results

Of 882 patients with a confirmed diagnosis of acute symptomatic PE, 8% (95% confidence interval [CI], 6%–9%) had COPD. Patients with COPD were significantly more likely to have a delay in diagnosis of more than 3 days and to have a low pretest probability of pulmonary embolism according to a standardized clinical score. The total number of deaths during 3 months of follow-up was 128 (14%; 95% CI, 12%–17%). Factors significantly associated with mortality from all causes were a history of cancer or immobilization, systolic blood pressure less than 100 mm Hg, and arterial oxyhemoglobin saturation less than 90%. COPD was significantly associated with PE-related death in the logistic regression analysis (relative risk, 2.2; 95% CI, 1.0–5.1).

Conclusions

Patients with COPD and PE more often have a lower pretest probability and a longer delay in diagnosis of PE. COPD is significantly associated with PE-related death in the 3 months following diagnosis.     

Internal consistency and validity of the Spanish version of the "Quebec Sleep Questionnaire" quality-of-life questionnaire for obstructive sleep apnea

Introduction

There is no specific health-related quality of life (HRQL) questionnaire that has been validated in Spanish for its use in patients with sleep apnea-hypopnea syndrome (SAHS). The objective of the present study was to validate the Spanish version of the Quebec Sleep Questionnaire (QSQ).

Patients and methods

A multi-center study including a group of patients with SAHS (AHI ≥ 5) referred to the Sleep Unit. All patients completed the following questionnaires: SF-36, FOSQ, QSQ and Epworth scale. Internal consistency, construct validity, concurrent validity, predictive validity, repeatability and responsiveness to change of the QSQ (32 items in five domains: daytime sleepiness, diurnal symptoms, nocturnal symptoms, emotions, and social interactions) were assessed.

Results

A hundred twenty one patients were included in the study (mean age: 57 ± 13; mean Epworth: 9 ± 4; mean Body Mass Index (BMI): 28 ± 3 kg · m⁻² and mean AHI: 36 ± 20 hour⁻¹). The factorial analysis showed a construct of five factors with similar distribution to the original questionnaire domains. Internal consistency (Cranach's alpha between 0.78 and 0.93 for the different domains), concurrent validity (compared to SF-36, Epworth scale and FOSQ), predictive validity of SAHS severity and test-retest reliability were appropriate. The test showed good responsiveness to change in diurnal (P = .003) and nocturnal symptoms domains (P = .02).

Conclusions

The Spanish version of the QSQ is a valid HRQL measure with appropriate psychometric properties for use in patients with SAHS and is responsive to change in symptoms domains.     

Utilización de glucosa en los músculos de pacientes con enfermedad pulmonar obstructiva crónica

Introduction

Muscle dysfunction is one of the most extensively studied manifestations of COPD. Metabolic changes in muscle are difficult to study in vivo, due to the lack of non-invasive techniques. Our aim was to evaluate metabolic activity simultaneously in various muscle groups in COPD patients.

Methods

Thirty-nine COPD patients and 21 controls with normal lung function, due to undergo computed axial and positron emission tomography for staging of localized lung lesions were included. After administration of 18-fluordeoxyglucose, images of 2 respiratory muscles (costal and crural diaphragm, and rectus abdominus) and 2 peripheral muscles (brachial biceps and quadriceps) were obtained, using the standard uptake value as the glucose metabolism index.

Results

Standard uptake value was higher in both portions of the diaphragm than in the other muscles of all subjects. Moreover, the crural diaphragm and rectus abdominus showed greater activity in COPD patients than in the controls (1.8 ± 0.7 vs 1.4 ± 0.8; and 0.78 ± 0.2 vs 0.58 ± 0.1; respectively, P < .05). A similar trend was observed with the quadriceps. In COPD patients, uptake in the two respiratory muscles and the quadriceps correlated directly with air trapping (r = 0.388, 0.427 and 0.361, respectively, P < .05).

Conclusions

There is greater glucose uptake and metabolism in the human diaphragm compared to other muscles when the subject is at rest. Increased glucose metabolism in the respiratory muscles (with a similar trend in their quadriceps) of COPD patients is confirmed quantitatively, and is directly related to the mechanical loads confronted.