20 años en enfermedad pulmonar obstructiva crónica (EPOC) / 20 years in chronic pulmonary obstructive disease (COPD)

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Sleep disordered breathing and nocturnal hypoxemia are very prevalent in a lung cancer screening population and may condition lung cancer screening findings: results of the prospective Sleep Apnea In Lung Cancer Screening (SAILS) study.

OBJECTIVE: Obstructive sleep apnea (OSA) can influence the appearance and proliferation of some tumors. The Sleep Apnea In Lung Cancer Screening (SAILS) study (NCT02764866) evaluated the prevalence of OSA and nocturnal hypoxemia in a high-risk population enrolled in a lung cancer screening program. METHODS: This was a prospective study of the prevalence of OSA in a lung cancer screening program. Subjects met the National Lung Screening Trial (NLST) age and smoking criteria (age 55-75 years; pack-years >30). Participants in the study were offered annual screening with low-dose computed tomography (LDCT) and pulmonary function testing, as well as home sleep apnea testing (HSAT) and a sleep-specific questionnaire. Sleep study-related variables, symptoms, and epidemiologic data were recorded. RESULTS: HSAT was offered to 279 subjects enrolled in our lung cancer screening program. HSAT results were available for 236 participants (mean age 63.6 years; mean tobacco exposure: 45 pack-years), of whom 59% were male and 53% were active smokers. Emphysema (74%) and chronic obstructive pulmonary disease (COPD) (62%) were common and in most cases mild in severity. OSA, including moderate to severe disease, was very common in this patient population. AHI distributions were as follows: AHI <5 (22.5%); 5-15 (36.4%); 15-30 (23.3%); and >30 (17.8%). Nocturnal hypoxemia (T90) (p = 0.003), diffusing capacity for carbon monoxide (DLCO) (p = 0.01), tobacco exposure (p = 0.024), and COPD (p = 0.023) were associated with OSA severity. Positive screening findings (nodules ≥6 mm) were associated with nocturnal hypoxemia on multivariate analysis adjusted for confounders (OR = 2.6, 95% CI = 1.12-6.09, p = 0.027). CONCLUSION: Moderate to severe OSA is very prevalent in patients enrolled in a lung cancer screening program. Nocturnal hypoxemia more than doubles the risk of positive screening findings.

Situación actual de la rehabilitación respiratoria en los hospitales de la Comunidad de Madrid / No disponible

Introducción: A pesar de que la rehabilitación respiratoria (RR) es considerada como una intervención terapéutica con alto nivel de evidencia científica, la estructura y la organización de las unidades de RR pueden repercutir en sus resultados. Nuestra intención era conocer la situación actual de las unidades de RR de la Comunidad de Madrid. Material y métodos: Análisis de los resultados de la encuesta distribuida a todos los hospitales de la Comunidad de Madrid mediante correo electrónico desde la Sociedad Madrileña de Neumología y Cirugía Torácica (NEUMOMADRID) y la Sociedad Española de Rehabilitación Cardiorrespiratoria (SORECAR). La encuesta fue diseñada de acuerdo a los estándares de calidad asistencial en RR propuestos por la Sociedad Española de Neumología y Cirugía Torácica (SEPAR). Resultados: Once (61,6%) hospitales señalaron que contaban con una unidad de RR y en el 54,5% de ellas no existía acceso desde atención primaria. El 72,7% de unidades indicó que la derivación de pacientes no era adecuada. Casi todas las unidades ofrecían programas de fisioterapia, entrenamiento aeróbico, de fuerza muscular y soporte educativo, sin embargo solo el 27,3% daba soporte nutricional y 18,2% apoyo psicosocial. El 45,4% usaba la prueba de esfuerzo progresivo para pautar el entrenamiento. Existían 3 cicloergómetros (rango intercuartílico 2-5) y 1 tapiz rodante (0-2) por unidad. Todas las unidades contaba con médicos rehabilitadores y fisioterapeutas y en el 60% también participaban neumólogos. Conclusiones: No todos los hospitales de la Comunidad de Madrid cuentan con unidades de RR. Además, el análisis de los indicadores de calidad asistencial en RR demuestran limitaciones en protocolos, evaluación del paciente, componentes y características de los programas, y aspectos administrativos y de investigación

Introduction: Although respiratory rehabilitation (RR) is considered as a therapeutic intervention with a high level of scientific evidence, the structure and organization of the RR units may have repercussions on its results. Our intention was to know the current situation of RR units in the Community of Madrid. Material and Methods: Analysis of results of the survey distributed to all hospitals in the Community of Madrid by email from the Sociedad Madrileña de Neumología y Cirugía Torácica (NEUMOMADRID) and the Sociedad Española de Rehabilitación Cardiorrespiratoria (SORECAR). The survey was designed according to the standards of care quality in RR proposed by the Sociedad Española de Neumología y Cirugía Torácica (SEPAR). Results: 11 (61.6%) hospitals reported that they had a RR unit. 54.5% of them did not have an access from primary care. 72.7% of the units indicated that referral of patients was not adequate. Almost all the units offered programs of physical therapy, aerobic training, muscular strength and educational support, however only 27.3% gave nutritional support and 18.2% psychosocial support. Progressive incremental test was used by 45.4% RR units. There were 3 cycle ergometers (interquartile range 2-5) and 1 treadmill (0-2) per unit. All units had rehabilitation physicians and physiotherapists, and 60% also had pulmonologists. Conclusions: Not all hospitals in the Community of Madrid have RR units. Moreover, the analysis of the indicators of care quality of the RR shows limitations in protocols, patient evaluation, components and characteristics of the programs, administrative and research aspects

A metabolomic approach shows sphingosine 1-phosphate and lysophospholipids as mediators of the therapeutic effect of liver growth factor in emphysema.

Tobacco smoke exposure is the principal cause of lung tissue destruction, which in turn results in emphysema that leads into shortness of breath. Liver growth factor (LGF, a cell and tissue regenerating factor with therapeutic activity in several organs) has antifibrotic and antioxidant properties that could be useful to promote lung tissue regenerating capacity in damaged lungs. The current study has examined differences in metabolite profiles (fingerprints) of plasma from mice (strain C57BL/6J, susceptible to develop emphysema) exposed to tobacco smoke during six months. One group of mice received a treatment with Liver Growth Factor (LGF) after emphysema was established, whereas the other group did not receive the treatment. Age and sex-matched mice not exposed to smoke were also maintained with or without treatment as controls. Metabolic fingerprints (untargeted analysis) of plasma after protein precipitation were obtained by LC-QTOF-MS. The signals were processed and a large number of possible metabolites were found (23944). Multivariate data analysis provided models that highlighted the differences between control and smoke exposed mice in both conditions. Accurate masses of features (possible compounds) representing significant differences were searched using online public databases. Lipid mediators, related to intracellular signaling in inflammation, were found among the metabolites putatively identified as markers of the different conditions and among them, sphingosine, sphingosine 1-phosphate and lysophospholipids point at the relevance of such metabolites in the regulation of the processes related to tissue regeneration mediated by LGF. These results also suggest that metabolomic fingerprinting could potentially guide the characterization of relevant metabolites leading the regeneration of lungs in emphysema disease.

Errores de estadificación del carcinoma pulmonar no microcítico en la TC comparado con la PET-TC / No disponible

Introducción: La PET-TC parece ser más exacta que la TC en el estudio de extensión del carcinoma pulmonar no microcítico (CPNM). Nuestro objetivo fue comparar la utilidad diagnóstica de la TC y la PET-TC en la estadificación clínica y patológica del CPNM. Material y métodos: Estudio observacional y retrospectivo de pacientes diagnosticados de CPNM. Se incluyeron 24 pacientes con diagnóstico y estudio de extensión mediante TC y PET-TC y que fueron sometidos a cirugía de resección pulmonar con intención curativa. Se compararon los datos de estadificación clínica prequirúrgica del estadio T y N con los de estadificación patológica posquirúrgica en ambas pruebas de imagen. También se comparó la sensibilidad, la especificidad, el VPP y el VPN de la TC y de la PET-TC en el estadio N preoperatorio. Resultados: Se observó una mayor tasa de discrepancias entre el estadiaje clínico y el patológico de la T por TC (41,6%) que por PET-TC (37,5%) y de la N por TC (37,5%) que por PET-TC (20,8%), ambas sin significación estadística. En el estadiaje de la N la PET-TC presentó mayor sensibilidad (50%) y especificidad (81%) que la TC (33% y 66%, respectivamente) y también mayor VPP (20% con PET-TC y 12% con TC) y VPN (94% con PET-TC y 87% con TC). Conclusiones: Los errores en la estadificación TNM del estudio de extensión del CPNM son menores con el uso de la PET-TC que con la TC. La principal aportación de la PET-TC está en la estadificación ganglionar

Introduction: PET-CT appears to be more accurate than CT in the extension study of nonsmall cell lung cancer (NSCLC). Our goal was to compare the diagnostic utility of CT and PET-CT for clinical and pathological staging of NSCLC. Methods: Retrospective and observational study of patients diagnosed with NSCLC. We included 24 patients with a diagnosis and extension study using CT and PET-CT and who underwent lung resection with curative intent. Preoperative clinical data of T and N staging were compared with postsurgical pathologic stages in both imaging technics. We also compared sensitivity, specificity, PPV and NPV of CT and PET-CT in preoperative N staging. Results: There was a higher rate of discrepancies between clinical and pathologic T staging with CT (41.6%) than with PET-CT (37.5%) and between N staging with CT (37.5%) than with PET-CT (20.8%), both without statistical significance. In the N staging, PET-CT had a higher sensitivity (50%) and specificity (81%) than CT (33% and 66%, respectively) and higher PPV (20% with PET-CT and 12% with TC) and NPV (94% with PET-CT and 87% for CT). Conclusions: Errors in TNM staging of NSCLC extension study are lower with the use of PET-CT than with CT. The main contribution of PET-CT is in nodal staging

Apparent diffusion coefficient of hyperpolarized (3)He with minimal influence of the residual gas in small animals.

The apparent diffusion coefficient (ADC) of hyperpolarized (HP) gases is a parameter that reflects changes in lung microstructure. However, ADC is dependent on many physiological and experimental variables that need to be controlled or specified in order to ensure the reliability and reproducibility of this parameter. A single breath-hold experiment is desirable in order to reduce the amount of consumed HP gas. The application of a positive end-expiratory pressure (PEEP) causes an increase in the residual gas volume. Depending on the applied PEEP, the ratio between the incoming and residual gas volumes will change and the ADC will vary, as long as both gases do not have the same diffusion coefficient. The most standard method for human applications uses air for breathing and a bolus of pure HP (3)He for MRI data acquisition. By applying this method in rats, we have demonstrated that ADC values are strongly dependent on the applied PEEP, and therefore on the residual gas volume in the lung. This outcome will play an important role in studies concerning certain diseases, such as emphysema, which is characterized by an increase in the residual volume. Ventilation with an oxygen-helium mixture (VOHeM) is a proposed single breath-hold method that uses two different gas mixtures (O(2)-(4)He for ventilation and HP (3)He-N(2) for imaging). The concentration of each gas in its respective mixture was calculated in order to obtain the same diffusion coefficient in both mixtures. ADCs obtained from VOHeM are independent of PEEP, thus minimizing the effect of the different residual volumes.

Análisis de la actividad de una Unidad de Cuidados Intermedios Respiratorios en Madrid / Analysis of the activity of an Intermediate Respiratory Care Unit in Madrid

El objetivo del presente análisis es comparar retrospectivamente el número de pacientes y sus características ingresados en una unidad de cuidados intermedios respiratorios (UCIR) en un hospital terciario antes y después de su dotación en equipos de elevadas prestaciones y personal. Para ello se comparó el número de ingresos, exitus e intubaciones así como la gravedad de los sujetos al ingreso, su estancia media, los parámetros ventilatorios utilizados y su origen entre los meses de enero y diciembre de 2007 con respecto a años previos. Se detectó que el número de ingresos dobló al de años anteriores. La gravedad de los pacientes ingresados era mayor y sin embargo se redujo notablemente la mortalidad y la estancia media. Globalmente aumentó la demanda entre los diferentes servicios del hospital. Los parámetros ventilatorios fueron sensiblemente menos agresivos. En conclusión, la dotación de equipos de altas prestaciones y un personal dedicado y especializado en ventilación mecánica no invasiva son vitales para implementar la eficacia de la unidad (AU)

The main objective of the present paper is to analyze in a retrospecive manner the number and characteristics of patients admitted to our Intermediate Respiratory Unit before and after the installation of new equipment and staff specially dedicated to non invasive ventilation treatment. We performed a comparison of the number of admittance, mortality and intubation rates, source of patients, ventilatory settings, severity scores, mean stay between January to 1st September 2007 compared to same period of previous years. We observed that in 2007 we received the double of admittances, patients were more severe but mortality rates, mean stay were lower. The ventilatory settings were in this 2007 period less aggressive than previously. As a conclusion, to improve our respiratory intermediate units specialized equipment and staff are critical (AU)

Increased collagen deposition correlated with lung destruction in human emphysema.

BACKGROUND: To study the relationship between collagen amount and degree of emphysema as assessed by mean linear intercept (Lm) and correlating these with lung function test workup in patients with and without COPD. METHODS: Lung function tests were assessed in 16 smokers or ex-smokers and 1 non-smoker in order to separate them into two groups: COPD (FEV1/FVC lower than 70%) and non-COPD. A piece of lung tissue was used to analyse the collagen amount (HYP) by means of a colorimetric method. Morphometry was assessed to divide patients into two groups according to Lm: Lm > 260 micrometers was considered non-emphysema and Lm < 260 mm mild-emphysema. RESULTS: The non-emphysema group had a mean Lm value of 246.08+/-3.12 micrometers and the mild-emphysema group of 276.29+/-4.26 micrometers. The amount of hydroxyproline was significantly higher in the mild-emphysema group than in the non-emphysema group (7.82+/-0.67 vs. 5.50+/-0.54 microgram/g tissue). There was a clear positive correlation between Lm and HYP (r=0.55) and a negative correlation between Lm and DlCO (R=-0.5092). No correlation was found between the functional test and HYP, nor were there significant differences between COPD and non-COPD patients for Lm and HYP. CONCLUSIONS: Emphysema is associated with collagen deposition in the lungs, and air space size correlates with the amount of lung collagen even when there is no emphysema.

¿Qué se esconde detrás de estas dos figuras? / What is hidden behind these two figures?

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Sedación para adaptación a ventilación mecánica no invasiva en paciente crítico / Sedation for adaptation to non-invasive mechanical ventilation in a critical patient

Presentamos el caso de un paciente con enfermedad pulmonar tipo enfisema con limitación grave del flujo aéreo ingresado por agudización de su enfermedad pulmonar en situación de acidosis respiratoria severa (pH 7,20 PaCO2 98) y un cuadro de agitación asociado. Dada la mala condición fisiológica y el deterioro importante de la función pulmonar (EPOCgrave con FEV1 de 840 mL –30%), insuficiencia respiratoria crónica con oxigenoterapia domiciliaria, disnea grado IIIII y múltiples agudizaciones previas, a pesar de la situación crítica, el paciente no era candidato a intubación orotraqueal y ventilación mecánica e ingreso en UVI por lo que se realizó con éxito ventilación mecánica no invasiva (VNI) modo BIPAP con sedación. La consideración de someter al paciente a una sedación superficial (Ramsay 2-4) se sustentó en la situación de agitación psicomotriz provocada por la acidosis, la cual le impedía una adecuada adaptación a la VNI

We present the case of a patient with emphysema type lung disease with serious limitation of air flow hospitalized due to deterioration of his lung disease in situation of severe respiratory acidosis (pH 7.20 PaCO2 98) and a picture of associated agitation. Given his bad physiological condition and important deterioration of the lung function (serious COPD withFEV1 of 840 mL –30%), chronic respiratory failure with home oxygen therapy, grade II-III dyspnea and multiple previous deteriorations, and in spite of the critical situation, the patient was not a candidate for orotracheal intubation and mechanical ventilation. he was admitted to the ICA so non-invasive mechanical ventilation (NIV) mode BIPAP with sedationwas done. The consideration of subjecting the patient to superficial sedation (Ramsay 2-4) was supported in the situationof psychomotor agitation provoked by the acidosis. This prevented adequate adaptation to the NIV

Effect of pulmonary perfusion on the slopes of single-breath test of CO2.

The objective of this study was to evaluate the effects of lung perfusion on the slopes of phases II (S(II)) and III (S(III)) of a single-breath test of CO(2) (SBT-CO(2)). Fourteen patients submitted to cardiac surgery were studied during weaning from cardiopulmonary bypass (CPB). Pump flow was decreased in 20% steps, from 100% (total CPB = 2.5 l.min(-1).m(-2)) to 0%. This maneuver resulted in a progressive and opposite increase in pulmonary blood flow (PBF) while maintaining ventilator settings constant. SBT-CO(2), respiratory, and hemodynamic variables remained unchanged before and after CPB, reflecting a constant condition at those stages. S(III) was similar before and after CPB (19.6 +/- 2.8 and 18.7 +/- 2.1 mmHg/l, respectively). S(III) was lowest during 20% PBF (8.6 +/- 1.9 mmHg/l) and increased in proportion to PBF until exit from CPB (15.6 +/- 2.2 mmHg/l; P < 0.05). Similarly, S(II) and the CO(2) area under the curve increased from 163 +/- 41 mmHg/l and 4.7 +/- 0.6 ml, respectively, at 20% PBF to 313 +/- 32 mmHg/l and 7.9 +/- 0.6 ml (P < 0.05) at CPB end. When S(II) and S(III) were normalized by the mean percent expired CO(2), they remained unchanged during the protocol. In summary, the changes in PBF affect the slopes of the SBT-CO(2). Normalizing S(II) and S(III) eliminated the effect of changes in the magnitude of PBF on the shape of the SBT-CO(2) curve.

Lower pulmonary diffusing capacity in the prone vs. supine posture.

We evaluated the effect of prone positioning on gas-transfer characteristics in normal human subjects. Single-breath (SB) and rebreathing (RB) maneuvers were employed to assess carbon monoxide diffusing capacity (DlCO), its components related to capillary blood volume (Vc) and membrane diffusing capacity (Dm), pulmonary tissue volume (Vti), and cardiac output (Qc). Alveolar volume (Va) was significantly greater prone than supine, irrespective of the test maneuver used. Nevertheless, Dl(CO) was consistently lower prone than supine, a difference that was enhanced when appropriately corrected for the higher Va prone. When adequately corrected for Va, diffusing capacity significantly decreased by 8% from supine to prone [SB: Dl(CO,corr) supine vs. prone: 32.6 +/- 2.3 (SE) vs. 30.0 +/- 2 ml x min(-1) x mmHg(-1) stpd; RB: Dl(CO,corr) supine vs. prone: 30.2 +/- 2.2 (SE) vs. 27.8 +/- 2.0 ml x min(-1) x mmHg(-1) stpd]. Both Vc and Dm showed a tendency to decrease from supine to prone, but neither reached significance. Finally, there were no significant differences in Vti or Qc between supine and prone. We interpret the lower diffusing capacity of the healthy lung in the prone posture based on the relatively larger space occupied by the heart in the dependent lung zones, leaving less space for zone 3 capillaries, and on the relatively lower position of the heart, leaving the zone 3 capillaries less engorged.

Helium-3 MRI diffusion coefficient: correlation to morphometry in a model of mild emphysema.

Hyperpolarised gases have been most recently used in magnetic resonance imaging to demonstrate new image-derived pulmonary function parameters. One of these parameters is the apparent diffusion coefficient, which reflects the sizes of the structures that compartmentalise gas within the lung (i.e. alveolar space). In the present study, noninvasive parameters were compared to microscopic measurements (mean linear intercept and mean alveolar internal area). Nonselective helium-3 gas density coronal ex vivo images and apparent diffusion maps were acquired in control and elastase-induced panacinar emphysema rats. Total lung capacity was considered the reference for both imaging experiments and lung fixation. A mild degree of emphysema was found based on mean linear intercept (134 +/- 25 microm) versus control (85 +/- 14 microm). The apparent diffusion coefficients were significantly different between the two groups (0.18 +/- 0.02 and 0.15 +/- 0.01 cm2 x s(-1) for elastase and control, respectively). A significant correlation between the apparent diffusion coefficient and corresponding morphometric parameters in mild emphysema was demonstrated for the first time. This study opens the possibility of estimating absolute airspace size using noninvasive techniques.

Nuevas aplicaciones de la resonancia magnética en el tórax / New applications of magnetic resonance imaging for the thorax

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[Non-invasive ventilation in patients with severe hypercapnic encephalopathy in a conventional hospital ward]. / Ventilación no invasiva en pacientes con encefalopatía hipercápnica grave en una sala de hospitalización convencional.

OBJECTIVE: To report our experience with non-invasive ventilation (NIV) at two levels of pressure (Bi-PAP) on a general respiratory medicine ward with patients in hypercapnic impaired consciousness and/or coma who had not previously been in an intensive care unit (ICU). METHODS: This was a prospective study of 13 patients, mean age 81 years (65-96), treated with NIV through a face mask. Ten had chronic obstructive pulmonary disease, with a mean FEV1 in stable condition of 35.2 14.6%. Glasgow scores upon admission were >/= 7. Arterial gases were monitored until suspension of NIV. RESULTS: After NIV for a mean 19 5 h/day in the first 48 hours and later of 6 1 h/day until a total of 74 9 h, 9 patients (69%) survived. The mean initial pH for these patients was 7.17 0.028 and the mean initial pCO2 was 101 9 mm Hg. In 7 cases (78%), coma was reversed in the first 48 h and a significant improvement in pH was observed in the 12-24 h analysis. Mean pH upon discharge was 7.44 0.013 and mean pCO2 was 54 2.8 mmHg. Four patients died, even though their initial or subsequent arterial gases at 12-24 h were not significantly different from those of the survivors. CONCLUSION: NIV on a general respiratory medicine ward can offer an alternative to oro-tracheal intubation for patients with hypercapnic impaired consciousness and/or coma who do not meet the criteria for admission to the ICU.

Ventilación no invasiva en pacientes con encefalopatía hipercápnica grave en una sala de hospitalización convencional / Non-invasive ventilation in patients with severe hypercapnic encephalopathy in a conventional hospital ward

OBJETIVO: Mostrar nuestra experiencia con la ventilación no invasiva (VNI) con doble nivel de presión (BIPAP) en una sala general de neumología en pacientes en estupor o coma hipercápnicos sin criterios de ingreso en unidad de cuidados intensivos (UCI).MATERIAL Y MÉTODOS: Estudio prospectivo de 13 pacientes, edad media 81 años (límites, 65-96), 10 pacientes presentaban exacerbación de enfermedad pulmonar obstructiva crónica (EPOC) con volumen espiratorio forzado en el primer segundo (FEV1) medio en situación estable de 35,2 ñ 14,6 per cent, índice de Glasgow ingreso 7, tratados con VNI mediante mascarilla facial. Se realizaron controles gasométricos hasta la suspensión de la VNI.RESULTADOS: Tras una media de ventilación de 19 ñ 5 h/día en las primeras 48 h y posteriormente 6 ñ 1 h/día hasta un promedio total de 74 ñ 9 h, sobrevivieron 9 pacientes (69 per cent).En este grupo los valores iniciales medios de pH y pCO2 fueron de 7,17 ñ 0,028 y 101 ñ 9 mmHg, respectivamente; de ellos en 7 casos (78 per cent) se revirtió el coma en las primeras 48 h y se observó una mejoría significativa en el valor de pH en el control de las 12-24 h. Los valores medios al alta de pH y pCO2 fueron 7,44 ñ 0,013 y 54 ñ 2,8 mmHg, respectivamente.Fallecieron 4 pacientes, cuyos valores gasométricos iniciales o evolutivos hasta las primeras 12-24 h no presentaron diferencia significativa con el grupo de supervivientes.CONCLUSIÓN: La aplicación de la VNI en una sala general de neumología puede constituir una alternativa a la intubación orotraqueal (IOT) en pacientes en situación de estupor o coma hipercápnicos que no cumplen criterios de ingreso en UCI (AU)

Similar ventilation distribution in normal subjects prone and supine during tidal breathing.

Multiple-breath washout (MBW) tests, with end-expiratory lung volume at functional residual capacity (FRC) and 90% O(2), 5% He, and 5% SF(6) as an inspired gas mixture, were performed in healthy volunteers in supine and prone postures. The semilog plot of MBW N(2) concentrations was evaluated in terms of its curvilinearity. The MBW N(2) normalized slope analysis yielded indexes of acinar and conductive ventilation heterogeneity (Verbanck S, Schuermans D, Van Muylem A, Paiva M, Noppen M, and Vincken W. J App Physiol 83: 1907-1916, 1997). Also, the difference between SF(6) and He normalized phase III slopes was computed in the first MBW expiration. Only MBW tests with similar FRC in the prone and supine postures (P > 0.1; n = 8) were considered. Prone and supine postures did not reveal any significant differences in curvilinearity, N(2) normalized slope-derived indexes of conductive or acinar ventilation heterogeneity, nor SF(6)-He normalized phase III slope difference in the first MBW expiration (P > 0.1 for all). The absence of significant changes in any of the MBW indexes suggests that ventilation heterogeneity is similar in the supine and prone postures of normal subjects breathing near FRC.

Effectiveness of continuous positive airway pressure in mild sleep apnea-hypopnea syndrome.

The aim of this trial was to evaluate the effectiveness of continuous positive airway pressure (CPAP) in patients with mild sleep apnea- hypopnea syndrome (SAHS). One hundred forty-two consecutive patients with mild SAHS (apnea-hypopnea index 10-30, without severe sleepiness) were randomly assigned to receive conservative treatment (CT)-sleep hygiene and weight loss-(65 patients) or CT plus CPAP (77 patients), and 125 patients (86% males, age: 54 +/- 9 yr, BMI: 29 +/- 4 kg/m(2), AHI: 20 +/- 6, ESS: 12 +/- 4) completed the follow-up. The following outcomes were assessed at inclusion and after 3 and 6 mo of treatment: sleepiness (Epworth scale, multiple sleep latency test [MSLT]), other symptoms related to SAHS, cognitive function, and perceived health status (Functional Outcomes of Sleep Questionnaire [FOSQ], Nottingham Health profile). The relief of SAHS-related clinical symptoms was significantly greater in the CPAP group than in the CT group; the Epworth scale and FOSQ also showed more improvement in the CPAP group but did not reach significance. There were no significant differences in the other tests performed probably because the baseline values were normal. CPAP compliance was 4.8 +/- 2.2 h and treatment continuation was accepted by 62% of the patients at the end of the study. These results suggest that CPAP can be considered in treating patients with mild SAHS on the basis of an improvement in symptoms.