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Featured researches published by Mei-Chen Yang.


Heart & Lung | 2012

Association of body mass index with exercise cardiopulmonary responses in lung function-matched patients with chronic obstructive pulmonary disease.

Chou-Chin Lan; Chiu-Ping Su; Lih-Lih Chou; Mei-Chen Yang; Chor-Shen Lim; Yao-Kuang Wu

BACKGROUND AND OBJECTIVES Lung function is traditionally used to define the severity of chronic obstructive pulmonary disease (COPD). However, this does not exclude other factors. This study investigated the influence of body mass index (BMI) on exercise responses and quality of life in patients with COPD matched for values of forced expiratory volume in 1 second (FEV(1)). METHODS Underweight, normal-weight, and overweight patients with COPD, matched for FEV(1), were studied. All patients were evaluated by spirometry, a cardiopulmonary exercise test, respiratory muscle strength, and, St. Georges Respiratory Questionnaire (SGRQ). RESULTS The baseline characteristics and mean FEV(1) of the 3 groups were similar (P > .05). Respiratory muscle strengths and SGRQ scores were lowest in underweight patients (P < .05). In terms of exercise response, the lowest oxygen uptake at anaerobic threshold and peak exercise, the highest ventilatory equivalent, and the lowest oxygen pulse were evident in underweight patients (P < .05). CONCLUSIONS Underweight patients with COPD had lower respiratory muscle strength, impaired exercise capacity, earlier anaerobic metabolism, ineffective ventilation, and poorer quality of life.


Respiratory Care | 2013

Factors Affecting CPAP Acceptance in Elderly Patients With Obstructive Sleep Apnea in Taiwan

Mei-Chen Yang; Chun-Yao Lin; Chou-Chin Lan; Chun-Yao Huang; Yi-Chih Huang; Chor-Shen Lim; Yu-Chih Liu; Yao-Kuang Wu

BACKGROUND: The prevalence of obstructive sleep apnea (OSA) increases with age. Treatment often includes CPAP. CPAP adherence is correlated with disease severity and symptoms. We hypothesized that CPAP acceptance rates in elderly patients with OSA would be lower than in younger patients with OSA, and examined factors associated with CPAP acceptance. METHODS: We reviewed the charts of 315 subjects with OSA (apnea-hypopnea index ≥ 5 events/h) who were treated at our hospital from 2008 to 2011 with CPAP therapy. All underwent CPAP titration testing before CPAP prescription. Subjects were grouped by age: young (25–40 y, n = 35), middle-age (41–65 y, n = 169), and elderly (> 65 y, n = 111). Demographic variables, excessive daytime sleepiness, overnight polysomnography study variables, CPAP acceptance, and CPAP adherence were compared. Regression analysis was performed to identify factors associated with acceptance. RESULTS: The elderly subjects had less excessive daytime sleepiness and less pronounced alterations in overnight polysomnography variables than the subjects in the other groups, but had more cardiovascular comorbidities. The CPAP acceptance rate (overall 125/315, 39.7%) was significantly lower in the elderly group, compared with the younger group (31.5% vs 60%, P = .01). CPAP acceptance was associated with fewer comorbidities, higher excessive daytime sleepiness, and higher apnea-hypopnea index, but not age. CPAP adherence was not associated with age. CONCLUSIONS: CPAP acceptance is low in elderly patients in Taiwan. CPAP acceptance, instead of CPAP adherence, is the critical issue with elderly patients with OSA.


Respiratory Care | 2015

Beneficial Effects of Long-Term CPAP Treatment on Sleep Quality and Blood Pressure in Adherent Subjects With Obstructive Sleep Apnea

Mei-Chen Yang; Yi-Chih Huang; Chou-Chin Lan; Yao-Kuang Wu; Kuo-Feng Huang

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased risk of cardiovascular diseases. Although CPAP is the first treatment choice for moderate-to-severe OSA, acceptance of and adherence to CPAP remain problematic. High CPAP adherence is generally defined as ≥4 h of use/night for ≥70% of the nights monitored. We investigated the long-term beneficial effects of CPAP on sleep quality and blood pressure in subjects with moderate-to-severe OSA according to high or low CPAP adherence. METHODS: We retrospectively analyzed 121 subjects with moderate-to-severe OSA from August 2008 to July 2012. These subjects were divided into 3 groups: (1) no CPAP treatment (n = 29), (2) low CPAP adherence (n = 28), and (3) high CPAP adherence (n = 64). All subjects were followed up for at least 1 y. The 3 groups were compared regarding anthropometric and polysomnographic variables, presence of cardiovascular comorbidities, and blood pressure at baseline and at the last follow-up. RESULTS: The no-treatment group showed significant increases in oxygen desaturation index and blood pressure. The high-adherence group showed significant improvement in daytime sleepiness, apnea-hypopnea index (AHI), oxygen desaturation index, and blood pressure. Although the AHI was also significantly decreased after CPAP treatment in the low-adherence group, blood pressure remained unchanged. CONCLUSIONS: CPAP treatment had beneficial effects on both sleep quality and blood pressure only in subjects with OSA and high CPAP adherence who used CPAP for ≥4 h/night for ≥70% of nights monitored. Subjects with low CPAP adherence received beneficial effects on AHI, but not blood pressure.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2012

Factors That Affect the Diagnostic Yield of Endobronchial Ultrasonography-Assisted Transbronchial Lung Biopsy

Chun-Yao Lin; Chou-Chin Lan; Yao-Kuang Wu; Chun-Yao Huang; Yi-Chih Huang; Chor-Shen Lim; Yu-Chih Liu; Mei-Chen Yang

BACKGROUND Endobronchial ultrasound (EBUS) is a relatively noninvasive procedure used to diagnose and stage lung cancer. Although EBUS-guided transbronchial lung biopsy (TBLB) procedures for peripheral lesions have higher diagnostic yields than traditional TBLB or fluoroscopy-assisted TBLB, the diagnostic yield is not 100%, and the reasons for this are not clear. SUBJECTS AND METHODS This retrospective study assessed what characteristics influence the diagnostic yield of EBUS-guided TBLB. EBUS was used to locate a single peripheral lung nodule or mass, and the lesion was biopsied and pathologically characterized. Parameters that were evaluated included patient demographics, lesion location, ease of tumor sampling, location of the EBUS probe relative to the lesion, pathological volume, tumor cell type, and whether physicians were under supervision. RESULTS Thirty-nine patients received EBUS-guided TBLB, which correctly identified 76.9% of the patients as having lung cancer. For the remaining patients, subsequent surgery indicated their tumors were malignant. Univariate logistic regression modeling indicated that only the location of the probe relative to the lesion was significantly associated with diagnostic yield of EBUS-guided TBLB. When the probe was directly within the lesion, it was 8.17 times (odds ratio 8.17; 95% confidence interval 1.41, 47.22; P=.019) more likely to have a successful TBLB than when the probe was adjacent to the lesion. CONCLUSIONS In this study, the position of the probe relative to a peripheral lung lesion was associated with the diagnostic yield of EBUS-guided TBLB. Larger prospective studies are required to further assess what influences the diagnostic yield of this technology.


Respiratory Care | 2013

Fish Fin Aspiration: An Unusual Type of Lower Airway Foreign Body in a Chinese Adult

Chun-Yao Lin; Shiu-Feng Huang; Chou-Chin Lan; Yao-Kuang Wu; Chun-Yao Huang; Yi-Chih Huang; Chor-Shen Lim; Mei-Chen Yang

Foreign body aspiration into the lower airway is rare in adults, and typically occurs in individuals of advanced age or with underlying neurological or medical conditions. The most common type of lower airway foreign body is organic substances, in particular chicken or fish bones. In many patients a history of an acute choking event is not found, and symptoms are non-specific and may be attributed to other medical conditions. Herein we report the unique case of an 80-year-old Chinese woman who aspirated a fish fin that was undiagnosed for 3 years.


BMC Pulmonary Medicine | 2014

Comparison of cardiovascular co-morbidities and CPAP use in patients with positional and non-positional mild obstructive sleep apnea.

Yi-Chih Huang; Chun-Yao Lin; Chou-Chin Lan; Yao-Kuang Wu; Chor-Shen Lim; Chun-Yao Huang; Hsuan-Li Huang; Kuan-Hung Yeh; Yu-Chih Liu; Mei-Chen Yang

BackgroundThis retrospective cohort study aimed to determine if there are differences in cardiovascular co-morbidities, blood pressure (BP) and continuous positive airway pressure (CPAP) use between patients with positional-dependent and nonpositional-dependent obstructive sleep apnea (OSA).MethodsPatients who were referred for overnight polysomnography for suspected OSA between 2007 and 2011 were screened. A total of 371 patients with OSA were included for analysis and divided into six groups according to positional-dependency and severity of OSA: positional mild (n = 52), positional moderate (n = 29), positional severe (n = 24), non-positional mild (n = 18), non-positional moderate (n = 70) and non-positional severe group (n = 178). The six groups were compared for anthropometric and polysomnographic variables, presence of cardiovascular co-morbidities, morning and evening BP and the changes between evening and morning BP, and CPAP device usage patterns.ResultsDemographic and anthropometric variables showed non-positional severe OSA had poor sleep quality and higher morning blood pressures. Positional mild OSA had the lowest cardiovascular co-morbidities. Overall CPAP acceptance was 45.6%. Mild OSA patients had the lowest CPAP acceptance rate (10%), followed by moderate group (37.37%) and severe group (61.88%, P < 0.001). However, the significant difference in CPAP acceptance across OSA severity disappeared when the data was stratified by positional dependency.ConclusionsThis study found that positional mild OSA had less cardiovascular co-morbidities compared with subjects with positional severe OSA. Independent of posture, CPAP acceptance in patients with mild OSA was low, but CPAP compliance was similar in CPAP acceptors regardless of posture dependency of OSA. Since there are increasing evidences of greater cardiovascular risk for untreated mild OSA, improving CPAP acceptance among mild OSA patients may be clinically important regardless of posture dependency.


Tzu Chi Medical Journal | 2018

Increased prevalence of obstructive sleep apnea in patients with pectus excavatum: A pilot study

Mei-Chen Yang; Yeung-Leung Cheng; I-Shiang Tzeng

Objective: Laryngomalacia is the most common congenital laryngeal anomaly and is associated with pectus excavatum (PE). Patients with laryngomalacia and patients with obstructive sleep apnea (OSA) both experience upper airway obstruction, and patients with laryngomalacia had been found to have a higher prevalence of PE. However, no studies have established the prevalence of OSA in patients with PE. We conducted this pilot study to evaluate the prevalence of OSA in patients with PE. Materials and Methods: A total of 42 patients ≥20 years old with PE who were admitted for Nuss surgery to correct PE in Taipei Tzu Chi Hospital between October 2015 and September 2016 were invited to participate in the study; 31 of the 42 patients agreed. All 31 patients completed an Epworth sleepiness scale questionnaire to evaluate excessive daytime sleepiness (EDS) and underwent overnight polysomnography to evaluate OSA before Nuss surgery. Results: The prevalence of snoring in the study participants was 100%. Ten of 31 patients (32.3%) reported EDS. The overall prevalence of OSA with an apnea/hypopnea index ≥5/h was 25.8%, and all patients with OSA were men. Conclusions: The prevalence of OSA in patients with PE seemed to be higher than that previously reported in the general population, implying that OSA might be a potential etiology or, at least, an aggravating factor for the development or progression of PE or might be responsible for the postoperative recurrence of PE in some patients. Further studies are needed to clarify this relationship.


The Journal of Thoracic and Cardiovascular Surgery | 2018

Poorer Sleep Quality among Adult Patients with Pectus Excavatum in Taiwan: A Pilot Study

Yeung-Leung Cheng; Chou-Chin Lan; Yao-Kuang Wu; Wen-Lin Su; Mei-Chen Yang

Objectives Patients with pectus excavatum have a poorer quality of life than the general population. Sleep quality is a critical component of quality of life. This pilot study compared the sleep quality of adult patients with pectus excavatum with that of the general population in Taiwan. Methods Participants comprised 30 healthy adults, 21 adult outpatients with pectus excavatum, and 33 adults with pectus excavatum receiving Nuss surgery. The Pittsburgh Sleep Quality Index measured subjective sleep quality; the Visual Analog Scale for Pain, Brief Symptom Rating Scale‐5, Beck Depression Inventory II, and 36‐Item Short Form Survey measured quality of life; and the Epworth Sleepiness Scale measured excessive daytime sleepiness. Outcome measurements were obtained at baseline for all groups and 6 months after Nuss surgery for inpatients. Results Patients with pectus excavatum had poorer sleep quality and worse quality of life than controls. Poorer sleep quality was not related to the severity of pectus excavatum per se, but to psychologic issues (beta = 0.18, P < .001 in multiple linear regression analysis). Measurement time had no effect on sleep quality (beta = 0.31, P = .594 for outpatient group; beta = 0.27, P = .665 for inpatients). Sleep quality of patients with pectus excavatum improved after Nuss surgery (Pittsburgh Sleep Quality Index: 4 vs 7, P = .002). Conclusions Our findings suggested an association between poor sleep quality and pectus excavatum; thus, sleep quality should be evaluated before and after the Nuss procedure.


The American Journal of the Medical Sciences | 2018

Cardiovascular Parameters Associated With Troponin I as Indicators for 14-Day Mortality in Patients With Septic Shock

Wen-Lin Su; Hao-Ai Shui; Chou-Chin Lan; Mei-Chen Yang; Chien-An Hsieh; Shih-Jung Jang; Hsueh-Wen Chung; Yao-Kuang Wu

Background: Troponin I is better than other troponin isoforms for monitoring cardiocyte damage, and correlates with sepsis‐related mortality. However, hemodynamic factors possibly interact with cardiac function to affect mortality in sepsis. Thus, this study used parameters from pulse‐induced contour cardiac output (PiCCO) to investigate the possibility. Methods: Patients with troponin I tests and sequential organ failure assessment score ≥2 were selected and divided into survivors and nonsurvivors groups and blood troponin I levels between them were compared. Additionally, 65 patients with septic shock and PiCCO records were selected and divided into high cardiac function index (CFI) and low CFI groups and their cardiac function associated with troponin I levels was checked. Furthermore, the patients were classified into 4 subgroups based on CFI and another hemodynamical parameter of PiCCO for identifying if any interaction between CFI and the parameter existed. Results: High blood troponin I levels correlated with high mortality, and with low cardiac function (CFI < 4.5) alone or with low CFI combined with high stroke volume variation (SVV), but did not correlate with global end‐diastolic index (GEDI), or systemic vascular resistance index. However, only the subgroup with low CFI and high SVV (CFI < 4.5 and SVV > 10) increased mortality. Conclusions: Our data give an insight into interactions between cardiac and hemodynamic factors to cause cardiocyte damage and suggest that multiple factors (i.e., low CFI and high SVV) should be considered together to evaluate cardiocyte damage and mortality in sepsis.


Journal of Clinical Sleep Medicine | 2018

Persistent High Residual AHI After CPAP Use

Leay Kiaw Er; Shinn-Kuang Lin; Stephen Shei-Dei Yang; Chou-Chin Lan; Yao-Kuang Wu; Mei-Chen Yang

ABSTRACT Treatment-emergent central sleep apnea has recently been noted after various treatment modalities for obstructive sleep apnea. It often remits spontaneously or can be treated with continuous positive airway pressure. However, we encountered a pediatric patient with obstructive sleep apnea who presented with severe complications, including growth failure, attention-deficit hyperactivity disorder, poor school performance, daytime sleepiness, and urinary difficulty that required permanent cystostomy. His obstructive sleep apnea resolved after adenotonsillectomy. However, treatment-emergent central sleep apnea developed after adenotonsillectomy and was further aggravated after continuous positive airway pressure and bilevel positive airway pressure without a backup respiratory rate use. After bilevel positive airway pressure with a backup respiratory rate treatment for 3 months initially, all his symptoms improved, except growth failure. Later, after adaptive servoventilation was used for 10 months, the patients growth began to improve.

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Chun-Yao Lin

Memorial Hospital of South Bend

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Yu-Chih Liu

Memorial Hospital of South Bend

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Hao-Ai Shui

National Defense Medical Center

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