Air-permeable redox mediated transcutaneous CO2 sensor.

Standard clinical care of neonates and the ventilation status of human patients affected with coronavirus disease involves continuous CO2 monitoring. However, existing noninvasive methods are inadequate owing to the rigidity of hard-wired devices, insubstantial gas permeability and high operating temperature. Here, we report a cost-effective transcutaneous CO2 sensing device comprising elastomeric sponges impregnated with oxidized single-walled carbon nanotubes (oxSWCNTs)-based composites. The proposed device features a highly selective CO2 sensing response (detection limit 155 ± 15 ppb), excellent permeability and reliability under a large deformation. A follow-up prospective study not only offers measurement equivalency to existing clinical standards of CO2 monitoring but also provides important additional features. This new modality allowed for skin-to-skin care in neonates and room-temperature CO2 monitoring as compared with clinical standard monitoring system operating at high temperature to substantially enhance the quality for futuristic applications.

Association between sleep quality, hypertensive disorders of pregnancy, and sleep-disordered breathing in pregnant women with and without obesity: An observational cross-sectional study.

AIM: To elucidate whether pregnancy and obesity are associated with poor sleep quality, and to investigate if sleep quality is associated with hypertensive disorders of pregnancy in pregnant women with obesity. METHODS: This observational cross-sectional study examined 15 obese pregnant women (body mass index ≥30 kg/m2 ) (p-Ob group), 15 nonobese pregnant women (p-nOb group), and 30 nonobese nonpregnant women (n-Pr group), using home recording devices to monitor sleep-disordered breathing (SDB): respiratory disturbance index, oxygen saturation, and sleep stage and quality. These variables were compared among the groups. Moreover, obese women with and without hypertensive disorders of pregnancy were compared. RESULTS: Significant differences in respiratory disturbance index (median: 10.3 [p-Ob], 7.1 [p-nOb], 3.5 [n-Pr]) and oxygen saturation (95.1%, 96.5%, and 96.6%) were observed among the groups. Seven participants in the p-Ob group experienced hypertensive disorders of pregnancy with SDB before or after sleep examination. Particularly, those who developed hypertensive disorders of pregnancy before sleep examination showed a lower delta power throughout the night than those without this condition. CONCLUSION: Pregnant women had poor sleep quality; those with obesity had higher frequency of SDB with worsened respiratory conditions that might cause complications. Our findings suggest that the development of hypertensive disorders of pregnancy in some obese pregnant women might be associated with insufficient delta power. Focusing on delta power may reflect subtle changes in sleep quality that occur in pregnant women. Future longitudinal studies with larger sample sizes are required to confirm these findings and investigate causality.

Automated Diseased Lung Volume Percentage Calculation in Quantitative CT Evaluation of Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis.

OBJECTIVE: Several software-based quantitative computed tomography (CT) analysis methods have been developed for assessing emphysema and interstitial lung disease. Although the texture classification method appeared to be more successful than the other methods, the software programs are not commercially available, to our knowledge. Therefore, this study aimed to investigate the usefulness of a commercially available software program for quantitative CT analyses. METHODS: This prospective cohort study included 80 patients with chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF). RESULTS: The percentage of low attenuation volume and high attenuation volume had high sensitivity and high specificity for detecting emphysema and pulmonary fibrosis, respectively. The percentage of diseased lung volume (DLV%) was significantly correlated with the lung diffusion capacity for carbon monoxide in all patients with COPD and IPF patients. CONCLUSIONS: The quantitative CT analysis may improve the precision of the assessment of DLV%, which itself could be a useful tool in predicting lung diffusion capacity in patients with the clinical diagnosis of COPD or IPF.

The effectiveness of supplemental oxygen during exercise training in patients with chronic obstructive pulmonary disease who show severe exercise-induced desaturation: a protocol for a meta-regression analysis and systematic review.

BACKGROUND: Supplemental oxygen during exercise training is used to increase the training effect of an exercise program in patients with chronic obstructive pulmonary disease (COPD) who show exercise-induced desaturation. Exercise-induced desaturation is not clearly defined in the guidelines; however, it is generally defined in clinical studies as a decrease in SpO2 of more than 4% from rest or a decrease to less than 88% during exercise. Although some meta-analyses examined the effectiveness of supplemental oxygen during exercise training, these studies concluded that it does not further improve exercise tolerance compared to exercise training alone. However, supplemental oxygen during exercise training may be effective in improving exercise tolerance in COPD patients with severe exercise-induced desaturation. Therefore, this study will be performed to elucidate the effectiveness of supplemental oxygen during exercise training and the relationship between its effectiveness and severity of exercise-induced desaturation at baseline. METHODS: We will first assess the effectiveness of supplemental oxygen during exercise training in COPD. The main outcome is the change in exercise tolerance before and after the intervention, indicated by the 6-min walking distance, the walking distance, or the walking time in incremental shuttle walking test, and analyzed as the standardized mean difference (SMD). The quality and risk of bias in individual studies will be assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system and risk-of-bias tool (RoB ver.2). If statistical heterogeneity in terms of the effectiveness of exercise tolerance is shown, we will conduct meta-regression analyses to examine the association between the effectiveness of exercise training with supplemental oxygen and severity of exercise-induced desaturation at baseline. DISCUSSION: One strength of this study is that it is a systematic review with meta-regression analysis to elucidate the effectiveness of supplemental oxygen during exercise training in patients with COPD who show severe exercise-induced desaturation. Furthermore, we will assess the severity of exercise-induced desaturation for which exercise training with supplemental oxygen is effective, the influence of acute effects at baseline, and the effect of supplemental oxygen on adverse events. SYSTEMATIC REVIEW REGISTRATION: Registration number, UMIN000039960.

A new noninvasive method for measurement of dynamic lung compliance from fluctuations on photoplethysmography in respiration.

Lung compliance is important in interstitial lung disease (ILD). However, the measurement requires placement of an esophageal pressure probe and is therefore not done in routine clinic practice. This study was performed to develop and verify a new noninvasive method for estimation of dynamic lung compliance (Cdyn) with a photoplethysmograph (PPG) of pulse wave represented as the changes of absorbance of green LED for hemoglobin and to examine its usefulness. A system for measuring Cdyn in combination with changes in estimated pleural pressure (Ppl) from the fluctuations on PPG with respiration and lung volume measured simultaneously by spirometry was developed and verified to show correspondence with the estimated Ppl and the esophageal pressure (Pes), estimated Cdyn, and Cdyn measured with an esophageal balloon. Furthermore, the estimated percentage of predicted Cdyn (%Cdyn) was compared among healthy subjects (HS) (n = 33) and patients with chronic obstructive pulmonary disease (COPD) (n = 31) and ILD (n = 30). Both estimated Ppl and Cdyn were significantly correlated with Pes (r = 0.89) and measured Cdyn (r = 0.63), respectively. The estimated %Cdyn in ILD showed significantly lower values than those in HS and COPD. The estimated %Cdyn was significantly related to percentage of predicted vital capacity (VC) (r = 0.57, P < 0.01) and percentage of predicted diffusion capacity of carbon monoxide (DlCO) (r = 0.50, P < 0.01) in patients with ILD. These findings suggested that the newly developed noninvasive and convenient method for Cdyn estimation using a combination of PPG and spirometry may be useful for the assessment of lung fibrosis in ILD.NEW & NOTEWORTHY Our newly developed method for measuring dynamic lung compliance (Cdyn) in combination with changes in estimated intrathoracic pressure from fluctuations on photoplethysmography with respiration and lung volume measured simultaneously by spirometry showed good linear regression between the estimated Cdyn and the Cdyn measured with an esophageal balloon, and the estimated percentage of predicted Cdyn (%Cdyn) showed significantly lower values in patients with interstitial lung disease (ILD) than in healthy subjects and chronic obstructive pulmonary disease (COPD) patients and significant correlations with vital capacity and lung diffusion capacity.

Metronome-Paced Incremental Hyperventilation May Predict Exercise Tolerance and Dyspnea as a Surrogate for Dynamic Lung Hyperinflation During Exercise.

Background: Dynamic lung hyperinflation (DLH) has been evaluated based on decreased inspiratory capacity (IC) during exercise load. However, this is not routinely done in clinical practice. We have developed a convenient method of metronome-paced incremental hyperventilation (MPIH) and reported its usefulness. In the present study, we compared these two methods for evaluating DLH and examined whether our MPIH method can be used to predict DLH during exercise. Methods: DLH was measured by MPIH and constant load exercise (CLE) in 35 patients with stable COPD. DLH was defined as the most decreased IC (IClowest) and the most decreases in IC from IC at rest (-IClowest), and we compared between these two methods. Results: The IClowest in CLE and the -IClowest in MPIH were significantly lower in emphysema-dominant COPD than in emphysema-nondominant COPD. Both IClowest and -IClowest showed significant correlations between the two methods (r = 0.67, p < 0.01 and r = 0.44, p < 0.01, respectively). The endurance time of CLE was significantly correlated with IClowest following MPIH (r = 0.62, p < 0.01) but not with that obtained by the CLE method. Furthermore, the IClowest of MPIH was more significantly correlated with endurance time in emphysema-dominant COPD. Weak but significant correlations between the -IClowest obtained by each method and maximum modified Borg scale were observed (MPIH: r = 0.38, p = 0.02; CLE: r = 0.37, p = 0.03). Conclusion: The MPIH method may be a convenient method to predict exercise tolerance and dyspnea as a clinically useful synergic screening surrogate for DLH during exercise.

Wireless, Portable Fiber Bragg Grating Interrogation System Employing Optical Edge Filter.

A small-size, high-precision fiber Bragg grating interrogator was developed for continuous plethysmograph monitoring. The interrogator employs optical edge filters, which were integrated with a broad-band light source and photodetector to demodulate the Bragg wavelength shift. An amplifier circuit was designed to effectively amplify the plethysmograph signal, obtained as a small vibration of optical power on the large offset. The standard deviation of the measured Bragg wavelength was about 0.1 pm. The developed edge filter module and amplifier circuit were encased with a single-board computer and communicated with a laptop computer via Wi-Fi. As a result, the plethysmograph was clearly obtained remotely, indicating the possibility of continuous vital sign measurement.

Comparison of impedance measured by the forced oscillation technique and pulmonary functions, including static lung compliance, in obstructive and interstitial lung disease.

Objective: To examine whether the parameters of impedance measured by the broadband frequency forced oscillation technique (FOT) were reflected by changes in lung compliance induced by emphysema and fibrosis, we retrospectively compared the parameters of FOT and pulmonary functions, including static lung compliance (Cst), in obstructive lung disease (OLD) and interstitial lung disease (ILD). Patients and methods: The data of 18 patients with OLD (16 with COPD, two with asthma COPD overlap), 11 with ILD, and 24 healthy volunteers, whose respiratory impedance was measured using a MostGraph-01 and other pulmonary functions including Cst and lung resistance (RL) were measured on the same day and were retrospectively collected and compared. Results: The parameters of resistance, reactance, and resonant frequency showed good correlations with ventilation unevenness (r=0.63, -0.89, 0.77, respectively) and lung elastic resistance (r=0.59, -0.80, 0.73, respectively) in all groups (N=53). These indices were significant determinants of increased respiratory resistance and more negative shift of respiratory reactance (Xrs) at lower frequency (P<0.001). Decreased functional residual capacity was also a determinant of Xrs at 5 Hz (X5) (P<0.05). The differences in mean X5 in the expiratory phase relative to those in the inspiratory phase (within-breath changes in X5) were associated with airflow obstruction (P<0.002) and lung elastic resistance (P<0.001). However, no significant correlations between Cst and any parameters of respiratory impedance were observed. Conclusions: These findings suggest that the impedance parameters measured by FOT are reflected by airway obstruction, ventilation unevenness, and lung resistance, but hardly reflected by changes in lung compliance due to emphysema or fibrosis in both CLD and ILD.

Efficacy of tiotropium and olodaterol combination therapy on dynamic lung hyperinflation evaluated by hyperventilation in COPD: an open-label, comparative before and after treatment study.

Background: Dynamic lung hyperinflation (DLH) following metronome-paced incremental hyperventilation (MPIH) was reported to be useful for assessment of pathophysiological impairment in patients with chronic obstructive pulmonary disease (COPD), and the effects of tiotropium and olodaterol on DLH following MPIH have not been reported. Methods: Treatment consisted of administration of tiotropium/olodaterol 5/5 µg inhalation solution (2.5/2.5 µg per actuation) using a soft-mist inhaler once a day. We compared outcomes before and after 8 weeks of treatment. The primary outcome was defined as a decrease in inspiratory capacity (IC) from rest by MPIH, which is an index of DLH. The secondary outcomes were COPD assessment test (CAT), forced expiratory volume in 1 s (FEV1), and 6-min walking distance (6MWD). In addition, we investigated whether there were correlations between changes with treatment in DLH and FEV1, 6MWD, and dyspnea. Results: Thirty-three of the 38 registered patients completed this study. Most of these 33 patients had mild to moderate COPD. Decreasing IC by MPIH was significantly reduced by treatment for 8 weeks, with a mean change of about -0.11 to -0.13 mL (P <0.05). In addition, CAT score, FEV1, and 6MWD improved with treatment (P <0.05). There were no significant correlations between changes in DLH, FEV1, 6MWD, or dyspnea with treatment. Conclusions: The results of this study showed that the combination of tiotropium and olodaterol is effective for improvement of DLH following hyperventilation.

Usefulness of a Newly Developed Spirometer to Measure Dynamic Lung Hyperinflation following Incremental Hyperventilation in Patients with Chronic Obstructive Pulmonary Disease.

Objective This study was performed to determine the usefulness of a newly developed spirometer for the quantitative assessment of dynamic lung hyperinflation (DLH) following incremental hyperventilation in chronic obstructive pulmonary disease (COPD). Methods The subjects were 54 patients with COPD and 25 healthy volunteers. Each subject was asked to hyperventilate for 30 seconds with stepwise increments starting at the resting respiration rate and increasing to respiratory rates of 20, 30, and finally 40 breaths/min while using a newly developed spirometer. The relationship between the observed inspiratory capacity (IC) reduction following incremental hyperventilation as an index of DLH and spirometry or the 6-minute walking distance was examined. Results The IC did not decrease significantly from the resting IC, even when the respiratory rate was increased, in the healthy volunteer group. However, in the COPD patient group, the IC decreased with increases in the respiratory rate. Significant correlations were found between all IC parameters and the severity of COPD. A significant negative correlation was also found between the decreased IC and the 6-minute walking distance. Conclusion These findings suggest that the quantitative assessment of DLH following incremental hyperventilation using the newly developed spirometer may be useful for the assessment of pathophysiological impairment in patients with COPD.

Instability of nocturnal parasympathetic nerve function in patients with chronic lung disease with or without nocturnal desaturation.

Objective/background: This study was performed to evaluate the association of nocturnal autonomic nerve (AN) dysfunction, especially parasympathetic nerve (PN) function instability, and nocturnal oxygen desaturation (NOD) in patients with chronic lung diseases (CLD). Patients and methods: Twenty-nine stable CLD patients with irreversible pulmonary dysfunction and mild-to-moderate daytime hypoxemia, 13 CLD patients receiving long-term oxygen therapy (LTOT) with maintained SpO2 >90%, and 17 senior healthy volunteers underwent two-night examinations of nocturnal AN function by pulse rate variability (PRV) instead of heart rate variation using a photoelectrical plethysmograph simultaneously monitoring SpO2 and the presence of sleep disordered breathing at home. AN function was examined by instantaneous time-frequency analysis of PRV using a complex demodulation method. Results: There were no significant differences in mean low frequency/high frequency (HF) ratio (index of sympathetic nerve activity) or mean HF amplitude (index of PN activity) among controls and CLD patients with and without NOD (defined as SpO2 <90% for at least 3% of total recording time at night). However, the relative times over which the same main HF peak was sustained for at least 20 seconds (%HF20sec) and 5 minutes in total recording time, indexes of PN function stability, were significantly reduced in CLD patients compared with controls, and further decreased in CLD patients with NOD compared with non-NOD. %HF20sec was significantly higher in the LTOT group than the NOD group. Furthermore, PaO2 at rest and nocturnal hypoxia were significantly correlated with PN function instability in CLD patients. Conclusion: PN function is unstable at night associated with nocturnal hypoxemia in CLD patients, which may reflect poor quality of sleep.

A randomized trial of symptom-based management in Japanese patients with COPD.

Background: The Global initiative for chronic Obstructive Lung Disease strategy document for COPD recommends treatment changes according to the persistence of symptoms or exacerbations. This study assessed the feasibility and outcomes of a structured step-up/step-down treatment approach in a randomized controlled clinical trial setting. Methods: Japanese patients with moderate-to-severe COPD were randomized to blinded, double-dummy treatment with twice-daily fluticasone propionate/salmeterol (FP/SAL) 250/50 µg or once-daily tiotropium bromide (TIO) 18 µg for 24 weeks (dual bronchodilator was not available). At 4-weekly intervals, patients remaining symptomatic (COPD Assessment Test score >10) or experiencing an exacerbation were offered the option to use triple therapy. Primary endpoint was the proportion of patients remaining on randomized therapy. Results: In total, 406 patients participated (mean FEV1 59%±13% predicted; COPD Assessment Test 12±6). Of these, 204 and 201 patients were included in the FP/SAL and TIO groups, respectively, of whom 67% and 63% continued treatment throughout the study; this difference was not statistically significant. Time to first therapy switch was longer with FP/SAL, but not significantly (P=0.21). More patients in Global initiative for chronic Obstructive Lung Disease (2011 criteria) groups C/D switched (FP/SAL 55%, TIO 63%) than in groups A/B (FP/SAL 27%, TIO 27%). Conclusion: Given the choice, patients with more symptoms or those experiencing an exacerbation will agree to step-up therapy. Effectiveness of disease management pathways can be tested using double-blind studies.

Diversity of respiratory impedance based on quantitative computed tomography in patients with COPD.

Introduction: This study was conducted in order to investigate the diversity of respiratory physiology, including the respiratory impedance and reversibility of airway obstruction, based on quantitative computed tomography (CT) in patients with COPD. Patients and methods: Medical records of 174 stable COPD patients were retrospectively reviewed to obtain the patients' clinical data, including the pulmonary function and imaging data. According to the software-based quantification of the degree of emphysema and airway wall thickness, the patients were classified into the "normal by CT" phenotype, the airway-dominant phenotype, the emphysema-dominant phenotype, and the mixed phenotype. The pulmonary function, including the respiratory impedance evaluated by using the forced oscillation technique (FOT) and the reversibility of airway obstruction in response to inhaled short-acting ß2-agonists, was then compared among the four phenotypes. Results: The respiratory system resistance at 5 and 20 Hz (R5 and R20) was significantly higher, and the respiratory system reactance at 5 Hz (X5) was significantly more negative in the airway-dominant and mixed phenotypes than in the other phenotypes. The within-breath changes of X5 (ΔX5) were significantly greater in the mixed phenotype than in the "normal by CT" and emphysema-dominant phenotypes. The FOT parameters (R5, R20, and X5) were significantly correlated with indices of the degree of airway wall thickness and significantly but weakly correlated with the reversibility of airway obstruction. There was no significant correlation between the FOT parameters (R5, R20, and X5) and the degree of emphysema. Conclusion: There is a diversity of respiratory physiology, including the respiratory impedance and reversibility of airway obstruction, based on quantitative CT in patients with COPD. The FOT measurements may reflect the degree of airway disease and aid in detecting airway remodeling in patients with COPD.

Verification of Non-Invasive Blood Glucose Measurement Method Based on Pulse Wave Signal Detected by FBG Sensor System.

This paper describes and verifies a non-invasive blood glucose measurement method using a fiber Bragg grating (FBG) sensor system. The FBG sensor is installed on the radial artery, and the strain (pulse wave) that is propagated from the heartbeat is measured. The measured pulse wave signal was used as a collection of feature vectors for multivariate analysis aiming to determine the blood glucose level. The time axis of the pulse wave signal was normalized by two signal processing methods: the shortest-time-cut process and 1-s-normalization process. The measurement accuracy of the calculated blood glucose level was compared with the accuracy of these signal processing methods. It was impossible to calculate a blood glucose level exceeding 200 mg/dL in the calibration curve that was constructed by the shortest-time-cut process. In the 1-s-normalization process, the measurement accuracy of the blood glucose level was improved, and a blood glucose level exceeding 200 mg/dL could be calculated. By verifying the loading vector of each calibration curve to calculate the blood glucose level with a high measurement accuracy, we found the gradient of the peak of the pulse wave at the acceleration plethysmogram greatly affected.

Efficacy of tiotropium and indacaterol monotherapy and their combination on dynamic lung hyperinflation in COPD: a random open-label crossover study.

BACKGROUND AND OBJECTIVE: The difference in efficacy of long-acting muscarinic antagonists (LAMAs) and long-acting ß2-agonists (LABAs) for dynamic lung hyperinflation (DLH) in COPD is unclear. The purpose of this study was to elucidate the difference in efficacy of LAMA and LABA alone and the combination thereof for DLH. SUBJECTS AND METHODS: Thirty stable patients were enrolled and randomly divided into two groups following baseline measurements. One group was treated with 5 µg tiotropium (Respimat inhaler) for 4 weeks following a 4-week treatment with 150 µg indacaterol, while the other group was treated with indacaterol for 4 weeks following a 4-week treatment with tiotropium. For both groups, these treatments were followed by a combination of the two drugs for 4 weeks. Pulmonary function tests, including DLH evaluated by metronome-paced incremental hyperventilation and exercise tolerance evaluated by the shuttle-walk test, were performed at the end of each treatment period. RESULTS: In total, 23 patients completed this study. Both tiotropium and indacaterol alone significantly increased forced expiratory volume in 1 second, exercise tolerance, and improved health status. Tiotropium significantly improved DLH, but indacaterol did not. The combination therapy resulted in further improvements in lung function and exercise tolerance, but not in DLH. CONCLUSION: The efficacy of tiotropium in inhibiting DLH following metronome-paced incremental hyperventilation may be superior to that of 150 µg indacaterol, although the effects on airflow obstruction were the same, and the combination therapy showed further improvement in airflow obstruction, but not in DLH.

Associations between the distance covered in the incremental shuttle walk test and lung function and health status in patients with chronic obstructive pulmonary disease.

BACKGROUND: Field walk tests such as the incremental shuttle walk test (ISWT) are simple tests for assessing the degree of disability in individuals with chronic obstructive pulmonary disease (COPD). In the present study, the correlations between exercise performance in the ISWT, lung function, and health status were examined in patients with COPD of varying severities. METHODS: A retrospective examination of 277 COPD patients was performed using the ISWT and lung function tests along with assessment of health status using St. George׳s Respiratory Questionnaire (SGRQ). In addition, we assessed the correlations between the walking distance, lung function parameters, and SGRQ scores. RESULTS: ISWT distances were poorly correlated with lung function parameters and SGRQ scores in mild COPD patients. In contrast, ISWT distances were significantly correlated with pulmonary function parameters, such as vital capacity (%predicted) and forced expiratory volume in one second, and SGRQ scores in moderate and severe COPD patients. CONCLUSIONS: The ISWT is more independent of health status and pulmonary function in patients with mild COPD compared to moderate or severe cases. Therefore, the exercise capacity of patients with mild COPD should be estimated by the ISWT.

Influence of Individual Differences on the Calculation Method for FBG-Type Blood Pressure Sensors.

In this paper, we propose a blood pressure calculation and associated measurement method that by using a fiber Bragg grating (FBG) sensor. There are several points at which the pulse can be measured on the surface of the human body, and when a FBG sensor located at any of these points, the pulse wave signal can be measured. The measured waveform is similar to the acceleration pulse wave. The pulse wave signal changes depending on several factors, including whether or not the individual is healthy and/or elderly. The measured pulse wave signal can be used to calculate the blood pressure using a calibration curve, which is constructed by a partial least squares (PLS) regression analysis using a reference blood pressure and the pulse wave signal. In this paper, we focus on the influence of individual differences from calculated blood pressure based on each calibration curve. In our study, the calculated blood pressure from both the individual and overall calibration curves were compared, and our results show that the calculated blood pressure based on the overall calibration curve had a lower measurement accuracy than that based on an individual calibration curve. We also found that the influence of the individual differences on the calculated blood pressure when using the FBG sensor method were very low. Therefore, the FBG sensor method that we developed for measuring the blood pressure was found to be suitable for use by many people.

[Value of Fractional Exhaled Nitric Oxide after Using a Beta-2 Bronchodilator in the Differential Diagnosis of Bronchial Asthma and Chronic Obstructive Pulmonary Disease].

It has been established that an increase in fractional exhaled nitric oxide (FeNO) is one of the indicators of bronchial asthma (BA) in clinical settings. However, the differential diagnosis of BA and chronic obstructive pulmonary disease (COPD) is difficult due to pathological similarities. Therefore, to determine if FeNO may be utilized in the differential diagnosis of BA and COPD, we compared FeNO values before and after inhalation of a short-acting beta-2 agonist (SABA). There were 3 groups of subjects recruited to this study: (1) 23 normal healthy controls, (2) 36 patients with BA, and (3) 13 patients with COPD. We measured FeNO, forced vital capacity, forced expiratory volume in 1 second (FEV1), and FEV1%, calculated using spirometry. Then, after the subjects inhaled the SABA, we measured these data after 10 and 30 minutes. Here we found that after inhalation of a SABA, 8 cases in the BA group who showed reversibility of airway obstruction demonstrated significantly increased FeNO values compared to the BA patients with non-reversible airway obstruction, those with COPD, and healthy subjects. This finding may be because the obstructed pulmonary peripheral airway was expanded by inhaling a SABA, and nitric oxide, which had been produced in the peripheral airway, was then exhaled. These results suggest the possibility that FeNO may be utilized in the differential diagnosis of BA and COPD.

Pulmonary function impairment in patients with combined pulmonary fibrosis and emphysema with and without airflow obstruction.

BACKGROUND: The syndrome of combined pulmonary fibrosis and emphysema (CPFE) is a recently described entity associating upper-lobe emphysema and lower-lobe fibrosis. We sought to evaluate differences in pulmonary function between CPFE patients with and without airflow obstruction. SUBJECTS AND METHODS: Thirty-one CPFE patients were divided into two groups according to the presence or absence of irreversible airflow obstruction based on spirometry (forced expiratory volume in 1 second/forced vital capacity <70% following inhalation of a ß2-agonist) as follows: CPFE patients with airflow obstruction (CPFE OB(+) group, n=11), and CPFE patients without airflow obstruction (CPFE OB(-) group, n=20). Pulmonary function, including respiratory impedance evaluated using impulse oscillometry and dynamic hyperinflation following metronome-paced incremental hyperventilation, was retrospectively analyzed in comparison with that observed in 49 chronic obstructive pulmonary disease (COPD) patients (n=49). RESULTS: In imaging findings, low-attenuation-area scores on chest high-resolution computed tomography, representing the degree of emphysema, were significantly lower in the CPFE OB(-) group than in the CPFE OB(+) and COPD groups. In contrast, the severity of pulmonary fibrosis was greater in the CPFE OB(-) group than in the CPFE OB(+) group. In pulmonary function, lung hyperinflation was not apparent in the CPFE OB(-) group. Impairment of diffusion capacity was severe in both the CPFE OB(-) and CPFE OB(+) groups. Impulse oscillometry showed that respiratory resistance was not apparent in the CPFE OB(-) group compared with the COPD group, and that easy collapsibility of small airways during expiration of tidal breath was not apparent in the CPFE OB(+) group compared with the COPD group. Dynamic hyperinflation following metronome-paced incremental hyperventilation was significantly greater in the COPD group than in the CPFE OB(-) group, and also tended to be greater in the CPFE OB(+) group than in the CPFE OB(-) group. CONCLUSION: The mechanisms underlying impairment of physiological function may differ among CPFE OB(+) patients, CPFE OB(-) patients, and COPD patients. CPFE is a heterogeneous disease, and may have distinct phenotypes physiologically and radiologically.

[Up-to-date COPD treatment].

The strategy for the treatment and management for COPD has markedly changed. COPD has been classified as a chronic respiratory disease characterized by an irreversible airflow obstruction, but active therapeutic interventions have not been established. However, the development of pharmacological and nonpharmacological therapy and the accumulation of clinical evidence have improved the situation. The newly developed long-acting muscarinic antagonists (LAMA) and beta-agonists (LABA), inhaled corticosteroids (ICS), the combination of LABA/LAMA and ICS/LABA, and comprehensive respiratory rehabilitation have significantly improved the symptoms such as cough, sputum, and dyspnea, as well as exercise tolerance, daily activity, and quality of life, and prevent the exacerbation of COPD. Furthermore, LAMA and ICS/LABA can prevent disease progression and improve the severity and survival. It has been demonstrated that inflammation of the lung in COPD affects the whole body and increases co-morbidities, which affect the QOL and survival. We should treat co-morbidities simultaneously. We should view COPD as a preventable and treatable disease, and early, active interventions involving pharmacological and non-pharmacological treatments not only improve symptoms, but also reduce disease progression and improve the survival of COPD patients.