Monitoring Noninvasive Ventilation in Patients with Obesity Hypoventilation Syndrome: Comparison between Ventilator Built-in Software and Respiratory Polygraphy.

BACKGROUND: Polygraphy (PG) remains the standard method of assessing noninvasive ventilation (NIV) effectiveness. Built-in software (BIS) of recent NIV equipment provides estimates of some ventilator parameters, but their usefulness is unclear. OBJECTIVES: To assess the reliability of BIS compared with PG in a cohort of obesity hypoventilation syndrome (OHS) patients on NIV. METHODS: Thirty stable OHS patients on NIV were evaluated in an outpatient setting with simultaneous PG and BIS recordings. The automated apnea-hypopnea event index (EIAUT) provided by Rescan and manual scoring based on available traces obtained from the software (EIBIS) were compared with manual PG scoring (EIPG). Each manual scoring was separately performed by 2 trained operators. Agreement between the 2 operators was assessed using the kappa coefficient. Pearson correlation and Bland-Altman plots were used to evaluate agreement between EIAUT, EIBIS, and EIPG. RESULTS: Twenty-six cases were valid for analysis (age ±61 years, 17 men). All patients were ventilated in the spontaneous/timed mode (mean inspiratory positive airway pressure 17 ± 3 cm H2O, mean expiratory positive airway pressure 10 ± 3 cm H2O). Cohen's kappa agreement between the operators was 0.7 for EIBIS and 0.84 for EIPG. EIBIS showed good correlation with EIPG (r2 = 0.79 p < 0.001), better than scoring provided by the automated analysis (r2 = 0.71, p < 0.006 for EIAUT vs. EIPG). CONCLUSIONS: In stable OHS patients on NIV, unattended home-based monitoring using Rescan is reproducible and reliable to assess quality of ventilation when compared with PG. In addition, manual scoring of events using data obtained with this device is more consistent than software-based automated analysis.

Impact of environmental air pollutants on disease control in asmathic patients.

PURPOSE: Asthmatics are adversely affected by the presence of air pollutants, the concentrations of which can nowadays be measured. However, the utility of this information in clinical practice has not been defined in a group of asthmatics in stable condition. Our objective was to determine what impact the level of air pollutants had on the control of their asthma and the degree of airway inflammation. METHODS: We performed a cross-sectional study of adult asthmatics in stable condition. From the regional environmental authority, we obtained the concentrations of ambient nitric oxide (NO2), ozone (O3), suspended particulate matter up to 10 micrometers in diameter (PM10) and sulphur dioxide (SO2) at fixed geographical points. Disease control was assessed using asthma control test (ACT) scores, and airway inflammation using fraction of exhaled nitric oxide (FeNO) values. Correlation and linear regression studies were performed using ACT scores as the dependent variable. RESULTS: The study included 99 asthmatics, aged 39 years (SD 8), 55% women. Mean ACT value was 17.2 (SD 6.5), and FeNO 33.7 (SD 16). Of the pollutants studied, only NO2 was correlated with ACT scores (CC = 0.45, p < 0.001). We found no relationship between pollutants and airway inflammation. Multivariate analysis showed that ACT score was predicted by ambient air NO2 concentration and, to a lesser extent, mean FeNO. CONCLUSIONS: Information on the concentration of ambient NO2 in our environment can help the clinician to interpret the evolution of asthmatic patients.

Pulmonary function testing prior to reduced intensity conditioning allogeneic stem cell transplantation in an unselected patient cohort predicts posttransplantation pulmonary complications and outcome.

Pretransplant pulmonary function tests (PFTs) have been checked mostly in myeloablative allogeneic stem cell transplantation (Allo-SCT). Their value in the setting of reduced intensity conditioning Allo-SCT (Allo-RIC) has been less explored. We retrospectively evaluated the predictive value of PFTs on posttransplant pulmonary complications (PPC) and outcomes in 195 consecutive Allo-RIC patients, based on fludarabine plus busulphan or melphalan. PFT parameters included forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC ratio, total lung capacity (TLC), residual volume, and diffusion capacity for carbon monoxide (DLCo) corrected for the hemoglobin levels. Pretransplant PFTs abnormalities were observed in 130 patients (66%). The most frequent abnormalities were abnormal DLCO (n = 83, 44%), followed by FEV1/FVC (n = 75, 38%) and FVC (n = 47, 24%). The abnormalities were severe in 25 (13%) patients, moderate in 65 (33%) and mild in 40 patients (21%). Multivariate analysis showed that TLC was significantly associated with PPC, nonrelapse mortality and overall survival (OS), (HR 4.2, 95% CI. 2-8.5; HR 3.8, 95% CI. 1.7-8.5; HR 2.3, 95% CI. 1.3-4.1, respectively, P = 0.01), while abnormal FVC had a negative impact on PPC and OS (HR 1.8, 95% CI. 0.98-3.6, P = 0.06 and HR 1.7, 95% CI. 1.1-2.6, P = 0.008). This study emphasizes the valuable role of PFTs in identifying patients at risk for PPC, NRM, and lower OS in the Allo-RIC setting.

Nasal versus oronasal mask in home mechanical ventilation: the preference of patients as a strategy for choosing the interface.

INTRODUCTION: In home mechanical ventilation (HMV), the mask is a key factor for patient comfort and therapeutic adherence. There is no evidence on the best strategy for choosing the mask in HMV. OBJECTIVE: To explore patient preference when prescribing the mask for HMV treatment and assess its relationship with effectiveness. METHODS: A prospective study with repeated measures in stable patients receiving home nocturnal ventilation. Alternating oronasal mask (ONM) and nasal mask (NM) were tested in day and overnight sessions, with arterial blood gas measured and S(pO(2)) monitored. At the end of each evening session, patients rated interface comfort using a visual analog scale. At 3 months we evaluated adherence and effectiveness of the treatment. RESULTS: Twenty-nine subjects (mean ± SD age 65 ± 13 y, 44% male) completed the study. Initial functional values were P(CO(2)) 57.4 ± 5.2 mm Hg and time with S(pO(2)) < 90% (T90) 81.5 ± 9.5%. Both ONM and NM significantly decreased P(CO(2)) and T90. Over a third (38%) of our subjects preferred ONM, while NM was deemed more comfortable in general. At 3 months, effectiveness and adherence showed no differences between those treated with NM or ONM. CONCLUSIONS: Patient choice is an effective criterion for selecting the interface in HMV treatment.

Nocturnal home pulse oximetry: variability and clinical implications in home mechanical ventilation.

BACKGROUND: Nocturnal home pulse oximetry (NHPO) provides information by measuring a series of variables: time spent with SaO(2) <90% expressed as percentage (T90) or in minutes (Tm90), mean SaO(2) (MnS), and lowest SaO(2) (LwS.) The presence of significant nocturnal desaturation has been proposed as a parameter in decision making with regard to initiating home mechanical ventilation (HMV) or monitoring HMV effectiveness. However, there is limited information on the possible variability of the test, and this could influence the interpretation of results. OBJECTIVES: To explore the variability between 2 consecutive measurements of NHPO and to determine clinical applications in HMV. METHODS: The patients presented diseases susceptible to HMV treatment and were enrolled in stable condition without respiratory failure. NHPO was conducted on 2 consecutive nights. The variables analyzed were: T90, Tm90, Mns, and LwS. The coefficient of variation (CV), a concordance coefficient (CC), and the Bland-Altman method were used in order to explore the variability. RESULTS: We studied 40 cases. Two were excluded, and the remaining 38 were aged 58 ± 16 years (19 males). Eighteen were receiving HMV. CV values exceeded 100% for T90 and Tm90 and were below 5% for MnS and LwS. The CC for T90, Tm90, and LwS showed confidence intervals with lower limits below 0.5, while for MnS the value was 0.88 (0.79-0.93). CONCLUSIONS: There is a wide variability in NHPO recordings for T90, Tm90, and LwS, so a single determination to detect nocturnal desaturation may not be valid for decision making; the parameter with the least interindividual variability and intraindividual variability was MnS.

[Determining the alveolar component of nitric oxide in exhaled air: procedures and reference values for healthy persons]. / Determinación de la concentración de óxido nítrico alveolar en aire espirado: procedimiento y valores de referencia en personas sanas.

Nitric oxide (NO) production has been described using a 2-compartment model for the synthesis and movement of NO in both the alveoli and the airways. The alveolar concentration of NO (Ca(NO)), an indirect marker of the inflammatory state of the distal portions of the lung, can be deduced through exhalation at multiple flow rates. Our objective was to determine reference values for Ca(NO). The fraction of exhaled NO (Fe(NO)) was measured in 33 healthy individuals at a rate of 50mL/s; the subjects then exhaled at 10, 30, 100, and 200mL/s to calculate Ca(NO). A chemiluminescence analyzer (NIOX Aerocrine) was used to perform the measurements. The mean (SD) Fe(NO) was 15 (6)ppb. The mean Ca(NO) was 3.04 (1.30)ppb. These values of Ca(NO) measured in healthy individuals will allow us to analyze alveolar inflammatory behavior in respiratory and systemic processes.

Cost-effectiveness of the COPD Patient Management European Trial home-based disease management program.

Purpose: Efficient management of COPD represents an international challenge. Effective management strategies within the means of limited health care budgets are urgently required. This analysis aimed to evaluate the cost-effectiveness of a home-based disease management (DM) intervention vs usual management (UM) in patients from the COPD Patient Management European Trial (COMET). Methods: Cost-effectiveness was evaluated in 319 intention-to-treat patients over 12 months in COMET. The analysis captured unplanned all-cause hospitalization days, mortality, and quality-adjusted life expectancy. Costs were evaluated from a National Health Service perspective for France, Germany, and Spain, and in a pooled analysis, and were expressed in 2015 Euros (EUR). Quality of life was assessed using the 15D health-related quality-of-life instrument and mapped to utility scores. Results: Home-based DM was associated with improved mortality and quality-adjusted life expectancy. DM and UM were associated with equivalent direct costs (DM reduced costs by EUR -37 per patient per year) in the pooled analysis. DM was associated with lower costs in France (EUR -806 per patient per year) and Spain (EUR -51 per patient per year), but higher costs in Germany (EUR 391 per patient per year). Evaluation of cost per death avoided and cost per quality-adjusted life year (QALY) gained showed that DM was dominant (more QALYs and cost saving) in France and Spain, and cost-effective in Germany vs UM. Nonparametric bootstrapping analysis, assuming a willingness-to-pay threshold of EUR 20,000 per QALY gained, indicated that the probability of home-based DM being cost-effective vs UM was 87.7% in France, 81.5% in Spain, and 75.9% in Germany. Conclusion: Home-based DM improved clinical outcomes at equivalent cost vs UM in France and Spain, and in the pooled analysis. DM was cost-effective in Germany with an incremental cost-effectiveness ratio of EUR 2,541 per QALY gained. The COMET home-based DM intervention could represent an attractive alternative to UM for European health care payers.

[Assessment of differential lung function by electrical impedance tomography]. / Evaluación de la función pulmonar unilateral mediante tomografía por impedancia eléctrica.

OBJECTIVE: To compare unilateral lung function estimated by 2 methods: electrical impedance tomography (EIT) and ventilation-perfusion lung scintigraphy. PATIENTS AND METHODS: This prospective clinical study was carried out in the pulmonary function laboratory of a general hospital. Twenty patients diagnosed with lung cancer (17 men and 3 women, ranging in age from 25 to 77 years) who were candidates for lung resection underwent ventilation-perfusion lung scanning breathing a radioactive gas. Differential lung function was estimated based on images taken at 2 intercostal spaces in which ventilation and perfusion were represented by changes in bioelectrical impedance. Each lung's contribution to overall respiratory function was also calculated based on scintigraphy. RESULTS: The right lung contributed a mean (SD) of 54% (9%) of ventilation (range, 32%-71%) according to EIT. Scintigraphy similarly estimated the right lung's contribution to be 52% (10%) of total ventilation (range, 31%-80%) and 50% (9%) of perfusion (range, 37%-71%). The difference between the 2 estimates was not significant (t test), and the correlation coefficients between them were r=0.90 for ventilation and r=0.72 for perfusion (P< .05 in both cases). The analysis of agreement showed that the mean difference between the methods was 1.9% (95% confidence interval [CI], 10.5% to -6.8%) for ventilation and 3.4% (95% CI, 17.1% to -10.3%) for perfusion. CONCLUSIONS: EIT is able to estimate differential lung function as accurately as ventilation-perfusion scintigraphy.

Spontaneous regression of metastatic squamous cell lung cancer.

Spontaneous regression (SR) of cancer is a rare but confirmed spectacular phenomenon, and it is even rarer in the context of advanced NSCLC. It is essential to understand this phenomenon in order to elucidate the nature of neoplastic disease and develop new treatment methods.

Diagnostic utility of inflammatory biomarkers in asthma: exhaled nitric oxide and induced sputum eosinophil count.

BACKGROUND: Even though an inflammatory process is known to be the underlying cause of asthma, diagnosis is based on clinical history, reversible airway obstruction and bronchial hyperresponsiveness according to international guidelines. The fraction of exhaled nitric oxide (FE(NO)) and induced sputum eosinophil count (Eos%) have been used as non-invasive inflammatory biomarkers. OBJECTIVES: The aim of this study was to compare the sensitivity and specificity of FE(NO), Eos% and spirometry and to assess whether their combined use in clinical practice would improve diagnostic yield. METHODS: In 50 patients with asthma symptoms we performed spirometry, a methacholine challenge test, FE(NO) measurement and assessment of Eos% in induced sputum. The standard diagnosis of asthma followed the guidelines of the Global Initiative for Asthma. RESULTS: Twenty-two of the 50 patients were diagnosed with asthma. The sensitivity and diagnostic accuracy were higher for FE(NO) measurement (77%; area under the receiver operating curve [AUC], 0.8) than for spirometry (22%; AUC, 0.63). The sensitivity and specificity of Eos% in induced sputum were 40% and 82%, respectively, and the diagnostic accuracy of Eos% was lower (AUC, 0.58). When both inflammatory biomarkers were used together specificity increased to 76%. CONCLUSIONS: The diagnostic accuracy of FE(NO) measurement was superior to that of the standard diagnostic spirometry in patients with symptoms suggestive of asthma. The use of FE(NO) measurement and induced sputum Eos% together to diagnose asthma in clinical practice is more accurate than spirometry or FE(NO) assessment alone and easier to perform.

Clinical outcomes of expiratory muscle training in severe COPD patients.

UNLABELLED: The most common symptoms in chronic obstructive pulmonary disease (COPD) patients are breathlessness and exercise limitation. Although both general and inspiratory muscle training have shown clinical benefits, the effects of specific expiratory muscle training remain controversial. OBJECTIVE: To investigate the effects of expiratory training on lung function, exercise tolerance, symptoms and health-related quality of life in severe COPD patients. METHODS: Sixteen patients (FEV(1), 28+/-8% pred.) were randomised to either expiratory muscle or sham training groups, both completing a 5-week programme (30 min sessions breathing through an expiratory threshold valve 3 times per week) (50% of their maximal expiratory pressure (MEP) vs. placebo, respectively). Lung function, exercise capacity (bicycle ergometry and walking test), and clinical outcomes (dyspnoea and quality of life (St. George Respiratory Questionnaire (SGRQ)) were evaluated both at baseline and following the training period. RESULTS: Although lung function remained roughly unchanged after training, exercise capacity, symptoms and quality of life significantly improved. The improvement in both walking distance and the SGRQ score significantly correlated with changes in MEP. CONCLUSION: Our results confirm that a short outpatient programme of expiratory training can improve symptoms and quality of life in severe COPD patients. These effects could be partially explained by changes in expiratory muscle strength.

[Measurement of fraction of exhaled nitric oxide with the portable NIOX-MINO monitor in healthy adults]. / Determinación de óxido nítrico en aire espirado (FENO).

Measurement of the fraction of exhaled nitric oxide (FENO) provides a noninvasive way to monitor asthma treatment in clinical practice. The aim of this study was to determine FENO reference values for measurements recorded with the portable NIOX MINO monitor in a group of healthy volunteers. We also assessed the association between values recorded by the portable monitor and the N-6008 chemiluminescence analyzer used in our pulmonary function laboratory. The FENO values obtained with the portable monitor were consistently higher than those recorded by the N-6008 analyzer; the cutoff value for the portable monitor was 34 ppb (mean + 2 SD). We detected a direct correlation (r=0.92) between the FENO measurements recorded by the 2 monitors (P=.001). The following equation expresses the relationship between measurements from the 2 devices: FENO(NIOX MINO) = 10 + [1.5 FENO(N-6008)]. We did not observe statistically significant correlations between FENO measurements and age, sex, body mass index, or spirometry.

[Oxygen-conserving devices: a forgotten resource]. / Sistemas de ahorro de oxígeno. Una realidad olvidada.

Oxygen-conserving devices include transtracheal catheters, reservoir cannulas, and demand oxygen delivery systems. They are designed to extend the amount of time portable oxygen cylinders will last and correct hypoxemia with a lower flow of oxygen. Transtracheal catheters increase the fraction of inspired oxygen by delivering oxygen directly to the trachea, bypassing the dead space of the oropharynx and improving the efficiency of the upper airway as a reservoir. Reservoir cannulas increase the fraction of inspired oxygen at the beginning of the inspiratory phase. Demand oxygen delivery systems have a valve that is activated during inspiration, meaning that oxygen is only delivered during this stage of the respiratory cycle. Each system has advantages and disadvantages arising from differing design features. Prescription should be based on individual tests in all cases to ensure optimal oxygen delivery during rest, exercise, and sleep.

[Pulmonary calcifications and chronic kidney failure]. / Calcificaciones pulmonares asociadas a insuficiencia renal crónica.

Pulmonary calcification is relatively uncommon and typically asymptomatic. A number of diseases are associated with this disorder, including chronic kidney failure, infections, and lung amyloidosis. There are, moreover, a number of conditions, such as hypercalcemia, hyperphosphatemia, alkalosis, and alveolar damage, which predispose a patient to calcification. We describe a case of pulmonary calcifications associated with chronic kidney failure which had required hemodialysis and a subsequent kidney transplant.

[Risk factors for mortality in chronic obstructive pulmonary disease]. / Factores de riesgo de mortalidad en la EPOC.

OBJECTIVE: Although the factors predictive of survival in patients with chronic obstructive pulmonary disease (COPD) have been widely studied, full consensus has yet to be reached. The objective of this study was to further clarify how lung function parameters, exercise tolerance, and quality of life influence survival in patients with COPD. PATIENTS AND METHODS: This prospective study included 60 patients diagnosed with COPD. At the start of the study, patients underwent respiratory function tests, exercise testing, and 6-minute walk test. They also answered a chronic respiratory disease questionnaire to measure health-related quality of life. Follow-up lasted 7 years. RESULTS: Five of the 60 patients withdrew from the study. Twenty-six of the remaining 55 patients (47%) died during the study. Univariate Cox regression analysis showed a correlation between survival and age, degree of obstruction, inspiratory capacity, carbon monoxide diffusing capacity, and peak exercise tolerance. No correlation was found between survival and body mass index, PaO2, PaCO2, total lung capacity, residual volume, maximal respiratory pressures, 6-minute walk distance, or health-related quality of life. Age, degree of obstruction (measured as the ratio of forced expiratory volume in 1 second to forced vital capacity after administration of bronchodilator), and maximum minute ventilation in the exercise test were introduced initially in the multivariate Cox stepwise regression analysis, but only maximum minute ventilation remained in the final model (relative risk, 0.926; P< .001). CONCLUSIONS: Our findings show that peak exercise tolerance is the best predictor of survival in patients with COPD.

[Monitoring of breathing pattern at rest by electrical impedance tomography]. / Seguimiento del patrón ventilatorio en reposo mediante tomografía por impedancia eléctrica.

OBJECTIVE: Electrical impedance tomography (EIT) involves the application of a small alternating current to produce a series of chest images that can be used to monitor breathing pattern. The relation between chest images and tidal volume has not been sufficiently validated. The aim of the present study was to analyze the correlation between EIT images and the volume-time signal measured with a pneumotachometer in 13 healthy volunteers. MATERIAL AND METHODS: The following measurement devices were used: a) MedGraphics preVent Pneumotach, with special software for recording the volume-time signal (reference test), and b) EIT-4, a fourth-generation prototype unit designed by the Department of Electronic Engineering at the Universidad Politécnica de Cataluña, Spain that records the volume-time signal and produces a graphic depiction of a cross section of the thorax at the sixth intercostal space. RESULTS: The mean (SD) tidal volume measured by the pneumotachometer and the EIT-4 was 0.523 (0.102) L and 0.527 (0.106) L, respectively (P value not significant). The linear correlation coefficient between the 2 measurements was 0.923 (P=.001), and the mean of the differences between the 2 procedures was -0.003 L (95% confidence interval, -0.045 to 0.038). The greatest differences were associated with female gender, body mass index, and chest circumference. In view of these differences, a different equation based on these variables was needed for calibration of the EIT-4. CONCLUSIONS: The EIT-4 provides an alternative means of monitoring breathing pattern, although a number of issues related to the circumference of the rib cage need to be resolved.

Design of a numerical model of lung by means of a special boundary condition in the truncated branches.

BACKGROUND: The need for a better understanding of pulmonary diseases has led to increased interest in the development of realistic computational models of the human lung. METHODS: To minimize computational cost, a reduced geometry model is used for a model lung airway geometry up to generation 16. Truncated airway branches require physiologically realistic boundary conditions to accurately represent the effect of the removed airway sections. A user-defined function has been developed, which applies velocities mapped from similar locations in fully resolved airway sections. The methodology can be applied in any general purpose computational fluid dynamics code, with the only limitation that the lung model must be symmetrical in each truncated branch. RESULTS: Unsteady simulations have been performed to verify the operation of the model. The test case simulates a spirometry because the lung is obliged to rapidly perform both inspiration and expiration. Once the simulation was completed, the obtained pressure in the lower level of the lung was used as a boundary condition. The output velocity, which is a numerical spirometry, was compared with the experimental spirometry for validation purposes. CONCLUSIONS: This model can be applied for a wide range of patient-specific resolution levels. If the upper airway generations have been constructed from a computed tomography scan, it would be possible to quickly obtain a complete reconstruction of the lung specific to a specific person, which would allow individualized therapies.

Impact of pulmonary rehabilitation on psychosocial morbidity in patients with severe COPD.

STUDY OBJECTIVE: To assess the effect of pulmonary rehabilitation (PR) on psychosocial morbidity, functional exercise capacity, and health-related quality of life (HRQL) in patients with severe COPD. DESIGN: A prospective, randomized, controlled trial with blinding of outcome assessment and data analysis. SETTING: A tertiary-care respiratory service. PATIENTS: Forty patients (mean age, 65 +/- 8 years [+/- SD]) with severe chronic flow limitation (FEV(1), 35 +/- 13%) without respiratory failure (Pao(2), 72 +/- 9 mm Hg; Paco(2), 42 +/- 5 mm Hg) were randomized either to a control group or to a PR group (PRG). INTERVENTIONS: Sixteen weeks of PR that included breathing retraining and exercise. MEASUREMENTS: At baseline and 16 weeks, we evaluated psychosocial morbidity using two questionnaires (the Millon Behavior Health Inventory [MBHI] and the Revised Symptom Checklist [SCL-90-R]) and measured 6-min walk distance (6WMD) and HRQL using the Chronic Respiratory Questionnaire (CRQ). RESULTS: We found differences in favor of the PRG in the following MBHI domains: introversive, forceful, and sensitive personality styles (all p

[Electrical impedance tomography: standardizing the procedure in pneumology]. / Tomografía por impedancia eléctrica. Estandarización del procedimiento para su aplicación en neumología.

The following conditions are optimal for obtaining an adequate number of informative images by electric impedance tomography: a) patient seated or standing with hands at the nape of the neck; b) breathing at rest; c) recording of at least 300 images (at a frequency of 10 Hz), and d) readings taken at the sixth intercostal space.

[Domiciliary respiratory muscle training in myotonic dystrophy]. / Entrenamiento muscular respiratorio domiciliario en la distrofia muscular miotónica.

A 42-year-old man diagnosed with myotonic dystrophy experienced loss of respiratory muscle strength over a period of 6 months. We report the application of a domiciliary training program targeting both inspiratory and expiratory muscles. Maximal inspiratory and expiratory pressures, forced vital capacity, and forced midexpiratory flow rate were measured 6 months before start of training, just before commencement of the program, and immediately after 12 weeks of training. Adherence to the program was satisfactory. Inspiratory muscle training was efficacious in increasing respiratory muscle strength. Expiratory muscle training, which made use of the Threshold PEP bronchial hygiene device incorporating an adapted flutter valve, was not efficacious in increasing maximal expiratory pressure or halting its loss. However, decreased obstruction of medium-caliber airways was observed with use of the device.