鈴木 拓児

INTRODUCTION: Secondary spontaneous pneumothorax (SSP) occurs as one of the complications associated with interstitial pneumonia (IP). Chest drainage is performed when there is a large volume of air in the pleural space. Notably, SSP with IP (SSP-IP) is frequently not curable by chest drainage only. A digital drainage system (DDS) provides an objective evaluation of air leakage and maintains a pre-determined negative pressure, compared to an analog drainage system (ADS). Few studies have reported the effectiveness of DDS in the treatment of SSP-IP. This study aimed to assess the usefulness of DDS for SSP-IP. METHODS: This retrospective study included patients with SSP-IP who had undergone chest drainage. We reviewed the included patients' medical records, laboratory data, computed tomography findings, and pulmonary function data. RESULTS: DDS was used in 24 patients and ADS in 49 patients. The mean duration of chest drainage was 11.4 ± 1.9 days in the DDS group and 14.2 ± 1.3 days in the ADS group, which was not significantly different (p = 0.218). Surgery, pleurodesis, and/or factor XIII administration were performed in 40 patients. Additionally, five (20.8%) patients in the DDS group and nine (18.4%) in the ADS group had a recurrence of pneumothorax within 4 weeks (p = 1.000). One patient (14%) in the DDS group and six (12.2%) in the ADS group (p = 0.414) were cured of pneumothorax but later died. CONCLUSION: DDS did not demonstrate a significant difference in the shortening of chest drainage duration. Further study is needed to validate the results of this study.

背景.気管支鏡検査は呼吸器疾患診療において重要である.その指導には学修者の能力とニーズに応じた指導計画が望ましいが,これらを詳細に調査した研究はない.我々は,気管支鏡の手技習得に関連した自己評価とニーズ調査を行った.方法.千葉大学医学部附属病院およびその関連病院の呼吸器内科医師に無記名式アンケートを実施した.背景因子の調査と共に気管支鏡実施に対する意識を評価した.また,気管支鏡の実施に必要な手技に関連して,理解・実践度およびセミナー,ワークショップの開催希望があるかについても評価した.得られた回答について,苦手群と得意群にわけ解析した.結果.42名の医師より回答を得た.気管支鏡実施に対する意識は,苦手群12名(28.6%),得意群8名(19.0%)であった.苦手群では,女性,若手,専門医未取得の医師が多い傾向にあったが,得意群と比較して有意差はみられなかった.理解・実践度について,全ての項目で苦手群の方が得意群よりも低い数値を示し,多くの項目で有意差がみられた.セミナーやワークショップの開催希望は,感染症対策,気管支鏡挿入,内腔観察,ガイドシースの適切な留置,経気管支肺生検の項目で,苦手群で開催希望が強くあったが,有意な差はみられなかった.結語.気管支鏡の手技を苦手とする群は,気管支鏡に関連した多くの手技に対して苦手意識を持っていたが,実手技を中心としたオンサイトでの指導を希望する傾向があった.実技の修得には知識が必要であるため,事前学習と実技指導を組み合わせたカリキュラムの作成が必要である.(著者抄録)

教育の質を向上させるには学習者の状況やニーズの把握が必要だが,臨床研修医の呼吸器内科研修に対するニーズや呼吸器内科医(指導医)が習得を望む学習項目との乖離は明らかでない.大学病院および臨床研修病院の呼吸器内科で研修した臨床研修医と指導した呼吸器内科医にアンケートを行い,研修医のニーズと呼吸器内科医が習得を必要と考える項目を調査した.研修医のニーズは内科一般知識で高く,呼吸器内科医が重視する項目に比べ限定的だった.研修医のニーズと呼吸器内科医が考える習得すべき項目には乖離があった.(著者抄録)

教育の質を向上させるには学習者の状況やニーズの把握が必要だが,臨床研修医の呼吸器内科研修に対するニーズや呼吸器内科医(指導医)が習得を望む学習項目との乖離は明らかでない.大学病院および臨床研修病院の呼吸器内科で研修した臨床研修医と指導した呼吸器内科医にアンケートを行い,研修医のニーズと呼吸器内科医が習得を必要と考える項目を調査した.研修医のニーズは内科一般知識で高く,呼吸器内科医が重視する項目に比べ限定的だった.研修医のニーズと呼吸器内科医が考える習得すべき項目には乖離があった.(著者抄録)

The pathogenesis of pulmonary fibrosis involves complex interplay between cell types and signaling pathways. Recurrent alveolar epithelial injury can occur during pulmonary inflammation, causing dysregulation of epithelial repair. Dysregulated repair interacts with mesenchymal, inflammatory, and endothelial cells to trigger fibroblast-to-myofibroblast activation. CD26/dipeptidyl peptidase-4 (DPP4) is a type II membrane protein mediating pleiotropic effect. However, the mechanistic role of CD26/DPP4 in pulmonary fibrosis remains unclear. In this study, we aimed to characterize Dpp4 deficiency in a mouse bleomycin (BLM)-induced pulmonary fibrosis model and in cell culture systems of human lung fibroblasts (HLFs). Dpp4 knockout (Dpp4 KO) mouse lungs exhibited lower Ashcroft scale indices, collagen content, and numbers of fibroblasts and myofibroblasts compared with those in C57BL/6 wild-type (WT) mice. Upregulation of Tgfb1 and Tgfb2 mRNA levels in the lungs after BLM treatment was lower in Dpp4 KO mice compared with those in WT mice. Although TGF-β-driven endothelial-to-mesenchymal transition (EndMT) has been implicated as one of the mechanisms of pulmonary fibrosis, a number of partial EndMT cells in lungs did not differ between Dpp4 KO mice and WT mice. The proliferation capacity and mRNA levels of COL1A1, a collagen deposition-related gene, in cultured HLFs were suppressed in DPP4 small interfering RNA-treated cells. This study indicates that the genetic deficiency of DPP4 has protective effects against BLM-induced pulmonary fibrosis, partly through the reduction in TGF-β expression and inhibition of fibroblast activation in the lung. Our study suggests that CD26/DPP4 inhibition is a potential therapeutic strategy for pulmonary fibrosis.

BACKGROUND Reports of venous stenting for inferior vena cava (IVC) syndrome (IVCS) due to sarcoma are limited, and the treatment's efficacy and safety are not clear. CASE REPORT A 36-year-old woman with myxoid liposarcoma was admitted to the Department of Respiratory Medicine for treatment of bilateral lower-leg edema and to be evaluated for acute liver dysfunction. She was 13 years old when she was diagnosed with myxoid liposarcoma. Over the next 18 years, she had 4 tumor resections and 1 round of radiation therapy. She had been on chemotherapy for 4 years and then pazopanib at the age of 35. The edema did not improve after admission despite treatment with diuretics. Computed tomography revealed a huge liposarcoma occupying the right thoracic cavity and a compressed IVC, which caused the edema. Although doxorubicin was administered as fifth-line treatment, there was no response. Since there was no additional chemotherapy regimen, her prognosis was considered to be less than 6 months. She could not be discharged to her home since she was unable to walk due to the edema; therefore, IVC stenting was performed to improve her dysmotility. After IVC stenting, the lower-leg edema improved without any adverse events, enabling her to walk and eventually return home. CONCLUSIONS In patients with IVCS caused by rare malignancies such as myxoid liposarcoma, an IVC stent can be safely implanted and can help to alleviate symptoms. IVC stenting can improve symptoms and allow for home care, resulting in improved quality of life.

RNF213 p.Arg4810Lys is linked to various vascular diseases, including pulmonary arterial hypertension (PAH); however, its pathogenesis remains unclear. Here, we report the unique features of two cases of severe PAH with this variant: one is the first reported case with stenosis of the thoracic and abdominal aorta, femoral arteries, and subclavian veins. Coexistence of severe and continuous eosinophilic inflammation, which has been suspected to be implicated in the pathogenesis of PAH in previous fundamental studies, was also present in both cases. Further studies are needed to clarify the pathogenetic mechanisms in vascular lesions with this variant.

INTRODUCTION: In the current era of the severe acute respiratory syndrome-coronavirus-2 epidemic, the need for respiratory care, including mechanical ventilatory (MV) management, has increased. However, there are no well-developed educational strategies for training medical personnel dealing with respiratory care in MV management. METHODS: A novel mixed-methods hands-on seminar for learning MV management was conducted for the residents at Chiba University Hospital in March 2022. The seminar lasted approximately 2 hours. The learning goal for the residents was to develop skills and knowledge in performing basic respiratory care, including MV, during an outbreak of a respiratory infection. The seminar with a flipped classroom consisted of e-learning, including modules on respiratory physiology and MV management, hands-on training with a low-fidelity simulator (a lung simulator), and hands-on training with a high-fidelity simulator (a human patient simulator). The effectiveness of the seminar was evaluated using closed questions (scored on a five-point Likert scale: 1 [minimum] to 5 [maximum]) and multiple-choice questions (maximum score: 6) at the pre- and post-seminar evaluations. RESULTS: Fourteen residents at Chiba University Hospital participated in the program. The questionnaire responses revealed that the participants' motivation for learning about MV was relatively high in the pre-seminar period (seven participants [50%] selected level 5 [very strong]), and it increased in the post-seminar period (all participants selected level 5) (p = 0.016). The responses to the multiple-choice questions revealed that the participants did not have enough knowledge to operate a mechanical ventilator, while the total score significantly improved from the pre- to post-seminar period (pre-seminar: 3.3 ± 1.1, post-seminar: 4.6 ± 1.0, p = 0.003). CONCLUSIONS: The seminar implemented in this study helped increase the residents' motivation to learn about respiratory care and improved knowledge of MV management in a short time. In particular, the flipped classroom may promote the efficiency of education on MV management.

PURPOSE: In COPD, exacerbation of the disorder causes a deterioration in the quality-of-life and worsens respiratory dysfunction, leading to a poor prognosis. In recent years, nutritional indices have been reported as significant prognostic factors in various chronic diseases. However, the relationship between nutritional indicators and prognosis in elderly subjects with COPD has not been investigated. PATIENTS AND METHODS: We enrolled 91 subjects who received COPD assessment tests (CAT), spirometry, blood tests, and multidetector computed tomography (MDCT). We divided the subjects into two groups according to age (<75 years (n=57) and ≥ 75 years (n=34)). The prognostic nutritional index (PNI) was used to assess immune-nutritional status and was calculated as 10 x serum albumin + 0.005 x total lymphocyte count. We then examined the relationship between PNI and clinical parameters, including exacerbation events. RESULTS: There was no significant correlation between the PNI and CAT, the FEV1%pred, or low attenuation volume percentage (LAV%). In the elderly group, there were significant differences between the groups with or without exacerbation in the CAT and PNI (p=0.008, p=0.004, respectively). FEV1%pred, neutrophil-to-lymphocyte ratio (NLR) and LAV% did not differ between the two groups. The analytical model combining CAT and PNI improved the prediction of exacerbations in the elderly subjects (p=0.0068). CONCLUSION: In elderly subjects with COPD, CAT were associated significantly with the risk of COPD exacerbation, with PNI also a potential predictor. The combined assessment of CAT and PNI may be a useful prognostic tool in subjects with COPD.

INTRODUCTION: The study aimed to evaluate visualization-based training's effects on lung auscultation during clinical clerkship (CC) in the Department of Respiratory Medicine on student skills and confidence. METHODS: The study period was December 2020-November 2021. Overall, 65 students attended a lecture on lung auscultation featuring a simulator (Mr. Lung™). Among them, 35 (visualization group) received additional training wherein they were asked to mentally visualize lung sounds using a graphical visualized lung sounds diagram as an example. All students answered questions on their self-efficacy regarding lung auscultation before and after four weeks of CC. They also took a lung auscultation test with the simulator at the beginning of CC (pre-test) and on the last day of the third week (post-test) (maximum score: 25). We compared the answers in the questionnaire and the test scores between the visualization group and students who only attended the lecture (control group, n = 30). The Wilcoxon signed-rank test and analysis of covariance were used to compare the answers to the questionnaire about confidence in lung auscultation and the scores of the lung auscultation tests before and after the training. RESULTS: Confidence in auscultation of lung sounds significantly increased in both groups (five-point Likert scale, visualization group: pre-questionnaire median 1 [Interquartile range 1] to post-questionnaire 3 [1], p<0.001; control group: 2 [1] to 3 [1], p<0.001) and was significantly higher in the visualization than in the control group. Test scores increased in both groups (visualization group: pre-test 11 [2] to post-test 15 [4], p<0.001; control group: 11 [5] to 14 [4], p<0.001). However, there were no differences between both groups' pre and post-tests scores (p = 0.623). CONCLUSION: Visualizing lung sounds may increase medical students' confidence in their lung auscultation skills; this may reduce their resistance to lung auscultation and encourage the repeated auscultation necessary to further improve their long-term auscultation abilities.

Abstract Background The prognostic value of mixed venous oxygen tension (PvO₂) at pulmonary hypertension diagnosis treated with selective pulmonary vasodilators remains unclear. This study sought to investigate the association of PvO₂ with long-term prognosis in pulmonary arterial hypertension (PAH) and medically treated chronic thromboembolic pulmonary hypertension (CTEPH) and to identify the distinct mechanisms influencing tissue hypoxia in patients with CTEPH or PAH. Methods We retrospectively analyzed data from 138 (age: 50.2 ± 16.6 years, 81.9% women) and 268 (age: 57.4 ± 13.1 years, 72.8% women) patients with PAH and CTEPH, respectively, diagnosed at our institution from 1983 to 2018. We analyzed the survival rates of patients with/without tissue hypoxia (PvO₂ &lt; 35 mmHg) and identified their prognostic factors based on the pulmonary hypertension risk stratification guidelines. Results Survival was significantly poorer in patients with tissue hypoxia than in those without it for PAH (P = 0.001) and CTEPH (P = 0.017) treated with selective pulmonary vasodilators. In patients with PAH, PvO₂ more strongly correlated with prognosis than other hemodynamic prognostic factors regardless of selective pulmonary vasodilators usage. PvO₂ was the only significant prognostic factor in patients with CTEPH treated with pulmonary hypertension medication. Patients with CTEPH experiencing tissue hypoxia exhibited significantly poorer survival than those in the intervention group (P &lt; 0.001). PvO₂ more strongly correlated with the cardiac index (CI) than the alveolar-arterial oxygen gradient (A-aDO₂) in PAH; whereas in CTEPH, PvO₂ was more strongly correlated with A-aDO₂ than with CI. Conclusions PvO₂ may represent a crucial prognostic factor for pulmonary hypertension. The prognostic impact of tissue hypoxia affects different aspects of PAH and CTEPH, thereby reflecting their distinct pathogenesis.

Abstract Background The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be associated with chronic inflammation; however, the underlying mechanism remains unclear. Recently, altered gut microbiota were found in patients with pulmonary arterial hypertension (PAH) and in experimental PAH models. The aim of this study was to characterize the gut microbiota in patients with CTEPH and assess the relationship between gut dysbiosis and inflammation in CTEPH. Methods In this observational study, fecal samples were collected from 11 patients with CTEPH and 22 healthy participants. The abundance of gut microbiota in these fecal samples was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing. Inflammatory cytokine and endotoxin levels were also assessed in patients with CTEPH and control participants. Results The levels of serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were elevated in patients with CTEPH. Plasma endotoxin levels were significantly increased in patients with CTEPH (P &lt; 0.001), and were positively correlated with TNF-α, IL-6, IL-8, and MIP-1α levels. The 16S rRNA gene sequencing and the principal coordinate analysis revealed the distinction in the gut microbiota between patients with CTEPH (P &lt; 0.01) and control participants as well as the decreased bacterial alpha-diversity in patients with CTEPH. A random forest analysis for predicting the distinction in gut microbiota revealed an accuracy of 80.3%. Conclusion The composition of the gut microbiota in patients with CTEPH was distinct from that of healthy participants, which may be associated with the elevated inflammatory cytokines and endotoxins in CTEPH.

A chronic expanding haematoma (CEH) is an encapsulated mass that gradually increases in size from repeated internal bleeding and neovascularization. We herein report a 69-year-old man who was admitted with dyspnoea on exertion after undergoing thymic carcinoma resection 17 years ago. Chest computed tomography showed a heterogeneous mass in the anterior mediastinum and compression of the right ventricle, and pulmonary artery. Right cardiac catheterisation revealed pulmonary hypertension that was relieved after resection of the diagnosed CEH mass. This report highlights the mechanism underlying anterior mediastinal CEH-induced stenotic compression of the right ventricle-pulmonary artery outflow and subsequent pulmonary hypertension.

BACKGROUND AND OBJECTIVE: The possibility of combination therapy with atomoxetine (ATO) and oxybutynin (OXY) has been suggested for obstructive sleep apnoea (OSA). However, the effectiveness of this treatment remains uninvestigated in Japanese OSA patients. Therefore, we performed a randomized, crossover, phase II, single-centre prospective trial to examine the effects of ATO-OXY therapy in Japanese OSA patients. METHODS: In total, 17 OSA patients participated in this study. The effects of one night of 80-mg ATO plus 5-mg OXY administration were compared with those of no medication administered before sleep. The primary and secondary outcomes comprised the apnoea-hypopnoea index (AHI) and nadir SpO2 , SpO2 drop time and sleep architecture, respectively. The safety endpoints included drug side effects and adverse events. RESULTS: The values of AHI, nadir SpO2 , 3% oxygen desaturation index (ODI), 4% ODI, and SpO2 drop time of <90% did not significantly differ between patients receiving ATO-OXY administration and no medication. Sleep architecture exhibited a significant change: ATO-OXY increased sleep stage N1 (p < 0.0001) and decreased stage N2 (p = 0.03), rapid eye movement (p < 0.0001) and sleep efficiency (p = 0.02). However, the subanalysis demonstrated an obvious decrease in AHI in five responder patients. Total sleep time and basal sleep efficiency tended to be lower in the responders compared with nonresponders (p = 0.065). No patients experienced severe adverse events or side effects. CONCLUSION: Overall, ATO-OXY therapy does not reduce AHI in Japanese OSA patients, although AHI was decreased in a proportion of patients. Future studies for identifying treatment response group characteristics are warranted.