Exertional evaluation for BT

Bronchial thermoplasty (BT) had been reported to improve the symptoms of severe asthma. However, the exertional responses of BT based on the mechanisms have not been elucidated. A 57-year-old man and a 60-year-old woman underwent BT due to intractable severe asthma. We evaluated the therapeutic effects of BT using cardiopulmonary exercise testing (CPET). After BT, the exercise time during CPET substantially prolonged reducing exertional dyspnea in the former (good), but not in the latter (poor). In the good responder, the high air remaining in the lung after expiration (i.e., inspiratory tidal volume minus expiratory tidal volume) during CPET decreased after BT. In contrast, in the poor responder, the high air remaining after expiration during exercise was not obtained before BT. Further investigations are necessary to confirm that the presence or absence of the exertional wasted ventilation on CPET may be informative to evaluate the therapeutic effects of BT

Dyspnea and the Varying Pathophysiologic Manifestations of Chronic Obstructive Pulmonary Disease Evaluated by Cardiopulmonary Exercise Testing With Arterial Blood Analysis

Background: Patients with chronic obstructive pulmonary disease (COPD) show varying mechanisms of exertional dyspnea with different exercise capacities.Methods: To investigate the pathophysiologic conditions related to exertional dyspnea, 294 COPD patients were evaluated using cardiopulmonary exercise testing (CPET) with arterial blood analyses, with the patients classified into two groups according to their exercise limitation: the leg fatigue group (n = 58) and the dyspnea group (n = 215). The dyspnea group was further subdivided into four groups based on peak oxygen uptake (V°O2 in mL/min/kg): group A (< 11), group B (11 to < 15), group C (15 to < 21), and group D (≥21).Results: In the dyspnea group, group A (n = 28) showed the following findings: (i) the forced expiratory volume in 1 s was not correlated with the peak V°O2 (p = 0.288), (ii) the arterial oxygen tension (PaO2) slope (peak minus resting PaO2/ΔV°O2) was the steepest (p < 0.0001) among all subgroups, (iii) reduced tidal volume (VT) was negatively correlated with respiratory frequency at peak exercise (p < 0.0001), and (iv) a break point in exertional VT curve was determined in 17 (61%) patients in group A. In these patients, there was a significant negative correlation between bicarbonate ion (HCO3-) levels at peak exercise and VT level when the VT-break point occurred (p = 0.032). In group D (n = 46), HCO3- levels were negatively correlated with plasma lactate levels (p < 0.0001). In all subgroups, the HCO3- level was negatively correlated with minute ventilation. The dyspnea subgroups showed no significant differences in the overall mean pH [7.363 (SD 0.039)] and Borg scale scores [7.4 (SD, 2.3)] at peak exercise.Conclusions: During exercise, ventilation is stimulated to avoid arterial blood acidosis and hypoxemia, but ventilatory stimulation is restricted in the setting of reduced respiratory system ability. These conditions provoke the exertional dyspnea in COPD. Although symptom levels were similar, the exertional pathophysiologic conditions differed according to residual exercise performance; moreover, COPD patients showed great inter-individual variability. An adequate understanding of individual pathophysiologic conditions using CPET is essential for proper management of COPD patients

Characteristic chest CT findings for progressive cavities in Mycobacterium avium complex pulmonary disease: a retrospective cohort study

BACKGROUND: Although cavities are an important finding in Mycobacterium avium complex pulmonary disease (MAC-PD), there is little information regarding the types of cavities that indicate disease progression. This study was performed to identify cavity characteristics that were associated with disease progression in patients with MAC-PD. METHODS: This retrospective cohort study included 97 patients presenting with MAC-PD with cavities between December 2006 and June 2016. We compared initial and final computed tomography (CT) findings, classified 52 and 45 patients in the progressive and non-progressive cavity groups, respectively, and examined the progression-related imaging features in initial CT images. A progressive cavity was defined by more than two-fold increase in internal diameter or emergence of a new cavity around the initial cavity. RESULTS: Patients in the progressive group were older (p < 0.001), had a lower body mass index (p = 0.043), and showed higher diabetes complication rates (p = 0.005). The initial CT in the progressive group showed a longer maximum internal diameter of the cavity (p < 0.001) and higher rates of cavities close to the chest wall (p < 0.001), multiple cavities (p = 0.023), consolidation around the cavity (p < 0.001), atelectasis (p = 0.011), and pleural thickening (p < 0.001). Multivariable logistic regression analysis revealed that the maximum internal diameter of the cavity (odds ratio [OR]: 1.11, 95% confidence interval [CI]: 1.02–1.21; p=0.012) and consolidation around the cavity (OR: 16.15, 95% CI: 4.05–64.46; p < 0.001) were significantly associated with progressive cavities. In cavities with a maximum internal diameter of ≥10 mm and simultaneous consolidation, the probability of progression was as high as 96.2%. The 10-year mortality rates in the progressive and non-progressive cavity groups were 46.7 and 9.8% (p < 0.001), respectively, while the 10-year respiratory failure rates were 28.1 and 0%, respectively (p < 0.001). CONCLUSIONS: Large cavity size and consolidation on CT showed strong relationships with disease progression, which led to respiratory failure and high mortality rate

Improvement of exertional dyspnea and breathing pattern of inspiration to expiration after bronchial thermoplasty

Abstract Background Bronchial thermoplasty (BT) is a bronchoscopic treatment that can ameliorate the symptoms of severe asthma. However, little is known about the mechanism by which BT improves exertional dyspnea without significantly changing the resting pulmonary function in asthmatics. To understand the mechanism, cardiopulmonary variables were investigated using cardiopulmonary exercise testing (CPET) in a patient with severe asthma before and after BT. Case presentation A 57-year-old Japanese man visited our hospital for consultation of the intractable asthma, which we managed with three treatment sessions of BT. Comparison of the findings pre-BT and at 1 year after BT demonstrated that (1) the resting tests for respiration showed no improvement in forced expiratory volume in 1 s, but the forced oscillation technique showed decreases in both inhalation and exhalation respiratory resistance values, and (2) the CPET results showed (i) improvement in exertional dyspnea, exercise endurance, and arterial oxygen saturation at the end of exercise; (ii) that the expiratory tidal volume exceeded the inspiratory tidal volume during exercise, which implied that a sufficient exhalation enabled longer inspiratory time and adequate oxygen absorption; and (iii) that an increase in respiratory frequency could be prevented throughout exercise. Conclusions This case report described a novel mechanism of BT in improving exertional dyspnea and exercise duration, which was brought about by ventilatory improvements related to the breathing pattern of inspiration to expiration

Dipeptidyl peptidase‐4 inhibitors‐associated bullous pemphigoid: A retrospective study of 168 pemphigoid and 9,304 diabetes mellitus patients

Abstract Aims/Introduction Bullous pemphigoid (BP) might be drug‐induced. The present study evaluated the relationship between BP and dipeptidyl peptidase‐4 inhibitors (DPP4Is). Materials and Methods We recruited patients diagnosed with BP at Ogaki Municipal Hospital from 1 December 2009 through 31 December 2017. We retrospectively collected data from medical records and divided patients into two groups based on whether they received DPP4Is. Additionally, we determined the incidence of BP in patients who were first prescribed DPP4Is at our hospital during the study period. Results Of 168 patients diagnosed with BP, 133 (79.1%) were positive for anti‐BP180NC16a antibody. A total of 32 (19.0%) patients had been prescribed a DPP4I, 21 of whom (65.6%) were positive for anti‐BP180NC16a antibody; this rate was lower than that in patients not receiving a DPP4I (82.3%; P = 0.0360). A total of 16 patients with type 2 diabetes mellitus had not been prescribed a DPP4I; only one (6.3%) was positive for anti‐BP180NC16a antibody (P = 0.0339). During the study period, 9,304 patients were prescribed DPP4Is, eight of whom developed BP; six (75.0%) had non‐inflammatory BP, and five of the six (83.3%) were negative for anti‐BP180NC16a antibody. Conclusions The positive rate of anti‐BP180NC16a antibody was lower in BP patients with DPP4I than without DPP4I, regardless of type 2 diabetes mellitus. The antibody titer was low in both the overall and type 2 diabetes mellitus populations. The prevalence of BP in 9,304 patients receiving DPP4Is was 0.0859%, which is higher than that in the general population. As DPP4Is are common diabetes treatments, we must be aware of the risk of BP

Additional file 1 of The diagnostic impact of fractional exhaled nitric oxide for asthmatic cough in nontuberculous mycobacterial pulmonary disease

Supplementary Material 1