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.

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.

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.

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.

Hydrogen peroxide content and pH of expired breath condensate from patients with asthma and COPD.

BACKGROUND: Oxidative stress is implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Analysis of the expired breath condensate (EBC) has been suggested to provide non-invasive inflammatory markers that reflect oxidative stress in the airways. OBJECTIVE: The present study attempts to elucidate whether the hydrogen peroxide (H2O2) levels and pH values in EBC may be useful as biomarkers of the activity or severity of asthma and COPD. METHODS: We measured the H2O2 levels and pH values using a derivatives of reactive oxygen metabolites exhalation test kit (Diacron) and a pH analyser, respectively, in EBC obtained using an EcoScreen from 29 patients with asthma, 33 with COPD, and 33 healthy individuals (all non-smokers). We then examined the relationships among oxidative stress and the asthma control test (ACT) or COPD assessment test (CAT) scores, pulmonary function, fractional exhaled nitric oxide (FeNO), and the extent of low attenuation areas on HRCT. RESULTS: The H2O2 levels were elevated and pH was lower in both asthma (H2O2; 8.75 ± 0.88 µM, p < 0.01, pH; 7.14 ± 0.07, p < 0.05) and COPD (H2O2; 7.44 ± 0.89 µM, p < 0.01, pH; 6.87 ± 0.10, p < 0.01) compared with control subjects (H2O2; 3.42 ± 0.66 µM, pH; 7.35 ± 0.04). Neither the H2O2 levels nor pH correlated with the ACT scores and FeNO in asthma patients. Neither the H2O2 levels nor pH significantly correlated with the pulmonary function in asthma and COPD. However, the CAT scores significantly correlated with the H2O2 levels in patients with COPD (r = 0.52, p < 0.01). CONCLUSIONS: These findings suggest that oxidative stress is involved in the pathogenesis of asthma and COPD and that the H2O2 levels in EBC might reflect the health status in COPD.

[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.

[Current status of "hospital-clinic" and "hospital-pharmacy" cooperation for inhalation therapy -based on hospital surveys throughout Japan].

BACKGROUND: The "zero death from asthma strategy" in the medical treatment for bronchial asthma has been promoted by the Ministry of Health, Labour, and Welfare from 2006, and it indicates that medical and non-medical specialists, as well as pharmacists, should cooperate, and strives to build cooperation which is suited the actual conditions of an area. It is also important for COPD. Although hospitals in some areas cooperate with clinics and pharmacies, the overall concept of cooperation appears to be absent in most Japanese hospitals. METHOD: A questionnaire was administered in early March, 2012 to 477 allergology institutions, and was authorized by an educational establishment. RESULT: Among 246 replies from the institutions, cooperation between hospitals and clinics was carried out by 98 institutions (39.8%) specializing in bronchial asthma, and in 64 institutions (37.2%) specializing in COPD. However, cooperation tools were used in only 37 of these institutions (15.0%). The ability to fill prescriptions outside the hospital was available in 209 institutions (85.0%). One-hundred and seventeen institutions (47.6%) replied that they have no tools for hospital-pharmacy cooperation. Direct indications were written in prescriptions by 82 institutions (33.3). CONCLUSION: In order to build inter-regional association and to equalize medical treatment, we suggest that developing tools and organization for cooperation between health professionals who treat patients with bronchial asthma and COPD is necessary.

Accuracy of ECG-based screening for sleep-disordered breathing: a survey of all male workers in a transport company.

PURPOSE: Sleep-disordered breathing (SDB) is associated with increased risk for cardiovascular morbidity and mortality and for sleepiness-related accidents, but >75 % of the patients remain undiagnosed. We sought to determine the diagnostic accuracy of ECG-based detection of SDB when used for population-based screening. METHODS: All male workers, mostly truck drivers, of a transport company (n = 165; age, 43 ± 12 years) underwent standard attended overnight polysomnography. Cyclic variation of heart rate (CVHR), a characteristic pattern of heart rate associated with SDB, was detected from single-lead ECG signals during the polysomnography by a newly developed automated algorithm of autocorrelated wave detection with adaptive threshold (ACAT). RESULTS: Among 165 subjects, the apnea-hypopnea index (AHI) was ≥5 in 62 (38 %), ≥15 in 26 (16 %), and ≥30 in 16 (10 %). The number of CVHR per hour (CVHR index) closely correlated with AHI [r = 0.868 (95 % CI, 0.825-0.901)]. The areas under the receiver operating characteristic curves for detecting subjects with AHI ≥5, ≥15, and ≥30 were 0.796 (95 % CI, 0.727-0.855), 0.974 (0.937-0.993), and 0.997 (0.971-0.999), respectively. With a predetermined criterion of CVHR index ≥15, subjects with AHI ≥15 were identified with 88 % sensitivity and 97 % specificity (likelihood ratios for positive and negative test, 30.7 and 0.12). The classification performance was retained in subgroups of subjects with obesity, hypertension, diabetes mellitus, dyslipidemia, and decreased autonomic function. CONCLUSIONS: The CVHR obtained by the ACAT algorithm may provide a useful marker for screening for moderate-to-severe SDB among apparently healthy male workers.

Increased human Ca²âº-activated Cl⁻ channel 1 expression and mucus overproduction in airway epithelia of smokers and chronic obstructive pulmonary disease patients.

BACKGROUND: The mechanisms underlying the association between smoking and mucus overproduction remain unknown. Because of its involvement in other airway diseases, such as asthma, we hypothesized that Ca²âº-activated Cl⁻ channel 1 (CLCA1) was associated with overproduction of mucus in the airways of smokers and COPD patients. METHODS: Using real-time quantitative PCR analyses, we compared the CLCA1 mRNA expression levels in induced-sputum cells from COPD patients (n = 20), smokers without COPD (n = 5), and non-smokers (n =13). We also examined the relationship between CLCA1 protein expression and mucus production in lung airway epithelia of COPD patients (n = 6), smokers without COPD (n = 7), and non-smokers (n = 7). RESULTS: CLCA1 mRNA expression was significantly up-regulated in the induced-sputum cells of COPD patients compared with cells of non-smokers (p = 0.02), but there was no significant difference compared with cells of smokers without COPD. Using immunostaining with an anti-CLCA1 antibody, semi-quantitative image analyses of airway epithelium demonstrated significantly increased CLCA1 expression in smokers without COPD (p = 0.02) and in COPD patients (p = 0.002) compared with non-smokers. There were significant negative correlations between CLCA1 protein expression and FEV1/FVC (r = -0.57, p = 0.01) and %predicted FEV1 (r = -0.56, p = 0.01). PAS staining for mucus showed that there was a significant positive correlation between CLCA1 protein expression and mucus production (r = 0.67, p = 0.001). These markers were significantly increased in smokers without COPD (p = 0.04) and in COPD patients (p = 0.003) compared with non-smokers (non-smokers < smokers ≤ COPD). CONCLUSIONS: CLCA1 expression is significantly related to mucus production in the airway epithelia of smokers and COPD patients, and may contribute to the development and pathogenesis of COPD by inducing mucus production.

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.

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.

Iodine-123 metaiodobenzylguanidine scintigraphic assessment of pulmonary vascular status in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: Lung uptake of iodine-123 metaiodobenzylguanidine (¹²³I-MIBG) is used as an indicator of pulmonary endothelial function. Decreased lung uptake of ¹²³I-MIBG has been demonstrated in patients with COPD as compared with normal subjects. The present study was performed to examine the relationship between lung uptake of ¹²³I-MIBG and pulmonary artery pressure (Ppa) at rest and during exercise, in patients with COPD. METHODS: ¹²³I-MIBG scintigraphy was performed in 19 patients with COPD. Anterior planar images were acquired 15 min after the injection of ¹²³I-MIBG, and the total lung to upper mediastinum ratio (LMR) was calculated for both lungs. Right heart catheters were used to monitor Ppa continuously at rest and during exercise. Exercise was performed on an electrically braked bicycle ergometer at a constant workload of 25 W for 3 min. RESULTS: In COPD patients the LMR were not correlated with the pulmonary function parameters measured before exercise, including FEV1, PaO2, DL(CO), or Ppa at rest. However, the percentage increase in Ppa during exercise was significantly correlated with LMR. CONCLUSIONS: Evaluation of the kinetics of lung uptake of ¹²³I-MIBG may be a novel scintigraphic tool for the assessment of exercise-induced pulmonary hypertension in patients with COPD.

Clinical characteristics of combined pulmonary fibrosis and emphysema.

UNLABELLED: This study describes the clinical characteristics of patients with CPFE and compares these with patients with COPD. It should therefore be noteworthy that the prevalence of lung cancer might be high in CPFE patients. BACKGROUND AND OBJECTIVE: Patients with combined pulmonary fibrosis and emphysema (CPFE) are sometimes seen, and we speculate that these patients have some different clinical characteristics from COPD patients. This study clarifies the clinical characteristics of CPFE patients. METHODS: This was a retrospective study of 47 stable patients with concurrent emphysema and diffuse parenchymal lung disease with fibrosis, based on the findings of chest CT (CPFE patients). The clinical characteristics of CPFE patients were compared with those of emphysema-dominant COPD patients without parenchymal lung disease (COPD patients). RESULTS: Forty-six of the 47 CPFE patients were male. Paraseptal emphysema was particularly common in the CPFE group. Honeycombing, ground-glass opacities and reticular opacities were present in 75.6%, 62.2% and 84.4% of CPFE patients, respectively. Twenty-two of the 47 CPFE patients (46.8%) had lung cancer. Pulmonary function tests showed that the CPFE group had milder airflow limitation and lower diffusing capacity than the COPD group. Desaturation during 6-min walking test in CPFE patients tended to be more severe than in COPD patients, if the level of FEV1 or 6MWD was equal. CONCLUSIONS: CPFE patients had some different clinical characteristics in comparison with COPD patients and may also have a high prevalence of lung cancer.

Identification of occult parechymal disease such as emphysema or airway disease using screening computed tomography.

RATIONALE: Chronic obstructive pulmonary disease (COPD) is a major public health problem. This study was performed to determine whether the low attenuation area (LAA) and visual score provided by low-dose computed tomography (CT) can be used to detect occult parenchymal disease, such as insidious COPD. METHODS: Each participant underwent low-dose CT scan and pulmonary function tests. The LAA% of the corresponding lung area was calculated. The cut-off level between the normal lung density area and LAA was defined as -960 HU, and the severity of emphysematous change (visual score) and LAA% were evaluated on three same chest CT slices obtained at full inspiration. RESULTS: Forty-eight of 2,247 individuals including 1058 non-smokers and 1189 smokers were diagnosed with COPD. Chest CT findings in individuals diagnosed with COPD showed centrilobular emphysema (50%), however, 17 of the subjects diagnosed with COPD had normal screening CT findings. Thirty-one subjects diagnosed with COPD showed a positive visual score, and 27 individuals with COPD showed LAA% of more than 30. Nine of 17 subjects with a negative visual score showed LAA% of more than 30. The visual score in smokers was significantly higher than that of non-smokers. The lung function in smokers was lower than that of non-smokers. Smokers also showed higher frequencies of chest CT abnormalities. CONCLUSION: Low-dose CT scans detected LAA and a positive visual score before COPD associated with an impaired lung function develops. Smokers with normal spirometry had a potential to develop an airflow obstruction accompanied with abnormal CT findings.

[Survey of patients with obstructive ventilatory disturbance by spirometry and cooperation among departments in university hospital].

The purpose in this study was to reveal the number of chronic obstructive pulmonary diseases (COPD) among the patients who examined spirometry in Shinshu University Hospital. We prospectively picked up the patients over 40 years of age who showed obstructive ventilatory disturbance on spirometry who examined for about 6 months, and send the results with the comments to introduce the patients to the department of respiratory medicine to the doctors who ordered spirometry. Spirometry was examined in 1,657 patients, and 246 patients (14.8%) who showed their FEV1/FVC < 70%. Among 246 patients, 177 patients were ordered spirometry from the departments (83.6%; pre-operative spirometry) except for respiratory medicine. Seventy-two of 177 patients (40.7%) were introduced to the department of respiratory medicine following the comments, and 43 and 13 patients were diagnosed as COPD and asthma, respectively. These findings suggest that laboratory technologist can contribute to the early intervention of COPD by supporting corporation among departments in hospital.

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.

Airway hyper-responsiveness in young adults with asthma that remitted either during or before adolescence.

BACKGROUND AND OBJECTIVE: More than 50% of patients with childhood asthma enter clinical remission by puberty, although 40-50% of these people will probably develop asthma symptoms during early adulthood. The mechanism of relapsing asthma in early adulthood remains unclear. This study determined the characteristics of young adults whose asthma remitted either during or before adolescence. METHODS: A comparative study was performed on 24 students whose childhood asthma had gone into clinical remission by puberty (remission group), 25 atopic students with no history of asthma (atopy group) and 19 non-atopic students without allergic diseases (control group). Examinations included spirometry, levels of serum-specific IgE-antibodies, airway responsiveness to methacholine, exhaled nitric oxide (eNO) and evidence of airway inflammation in induced sputum. RESULTS: Airway responsiveness (P < 0.01), eosinophil counts in sputum (P < 0.05) and the prevalence of sensitization to Dermatophagoides forinae (P < 0.01) were significantly higher, and FEF(25-75%) and FEF(75%) (P < 0.01) were significantly lower in the remission group than in the atopy and control groups. Furthermore, 50% and 33% of the remission group had airway hyper-responsiveness (AHR) and sputum eosinophilia, respectively. The eNO levels in the remission (P < 0.01) and atopy (P < 0.05) groups were significantly higher than in controls. Remission group members with AHR had a significantly longer period of childhood asthma, a shorter period of remission and greater airway eosinophilic inflammation than those without AHR (P < 0.05). CONCLUSION: One half of young adults with childhood asthma that remitted either during or before adolescence continued to have evidence of AHR and airway eosinophilic inflammation, and might be at risk of future relapse.