血清IgE水平在慢性阻塞性肺疾病急性加重患者治疗中的意义

目的探讨慢性阻塞性肺疾病急性加重(AECOPD)患者吸入性糖皮质激素疗效与血IgE水平的关系。方法将176例AECOPD病例随机分为两组,均予常规抗生素、吸氧治疗,激素吸入组在此基础上增加吸入布地奈德2 mg,2次/d,治疗1 w,治疗前后行肺功能、血气分析检查并比较两组的血IgE水平;此外,激素吸入组在治疗前按疾病程度分为Ⅰ级(27例)、Ⅱ级(31例)、Ⅲ级(30例)。将AECOPD组患者按照临床及动脉血气分析指标分为改善组54例及无明显缓解组34例,比较不同分级及预后患者的血IgE水平。结果治疗前两组的血IgE水平差异无统计学意义(P>0.05),治疗前后两组内部比较IgE值均降低(均P<0.01),治疗后吸入组的血IgE水平低于常规治疗组(t=9.933,P<0.01);三组治疗前的血IgE水平比较差异无统计学意义(F=0.285,P=0.792),治疗后三组的血IgE水平下降(P<0.01),三组治疗前后差值比较差异无统计学意义(F=0.145,P>0.05);吸入组患者治疗后症状改善组血IgE水平低于无明显改善组(t=19.795,P<0.01)。结论 AECOPD患者血IgE水平升高,吸入糖皮质激素可缓解临床症状及改善肺功能,降低血IgE水平,但血IgE水平的高低与AECOPD病情的严重程度不成正比。     

慢性阻塞性肺疾病对冠心病患者冠脉粥样硬化的影响

目的 观察慢性阻塞性肺疾病(COPD)对冠心病患者冠状动脉粥样硬化、心脏结构和功能的影响,并探讨其可能机制.方法 对86例冠心病合并COPD的患者和76例单纯冠心病患者行冠状动脉造影,确定冠脉病变严重程度,并行血管内皮舒张功能、心脏结构和功能、血气分析检查.结果 冠心病合并 COPD组较单纯冠心病组冠脉三支血管病变比例升高(70.9% vs 48.7%,P<0.01),冠脉Gensini评分升高(46.36±8.15vs 38.75±7.12,P<0.05),动脉血氧分压下降[(74.56±7.93) mmHg vs (87.52±8.11) mmHg,P<0.01],肱动脉内皮舒张功能明显减弱(0.71%±3.39% vs 7.01%±1.90%,P<0.01),二尖瓣反流量增加[(6.29±4.65) ml vs (4.24±3.83) ml,P<0.05].结论 COPD加速了冠状动脉粥样硬化,预后不良,其机制可能与血管内皮功能下降有关.     

福莫特罗干粉剂治疗COPD的疗效评价

目的研究常规剂量短程吸入福莫特罗干粉剂治疗COPD。方法按对照、单盲的设计,132例COPD患者分两组分别予福莫特罗干粉剂与安慰剂治疗4周,治疗前后测定肺功能:一秒钟用力呼气容积(FEV1)、用力肺活量(FVC)、最大呼吸中段流速(MMFF)并记录临床症状计分。结果124例完成实验治疗组63例临床症状改善(治疗前5.0±0.3分,治疗后4.2±0.4分,P<0.05);FEV1显著提高(治疗前1.6±0.2L,治疗后1.8±0.2L,P<0.001);FVC显著提高(治疗前2.33±0.2L,治疗后2.3±0.18L;但MMFF与对照组差异无显著性(治疗前1.32±0.21L,P>0.05)。结论短期吸入福莫特罗干粉剂治疗COPD可缓解临床症状、提高肺功能。     

美托洛尔在治疗慢性心力衰竭中的价值——60例临床观察

目的观察美托洛尔对慢性心力衰竭患者的疗效。方法随机选择慢性心力衰竭患者60例,其中美托洛尔治疗组34例(6.25~25mg/次,bid或tid)和对照组26例。治疗6个月,观察美托洛尔对患者症状、心功能的影响。结果治疗组较对照组左心室射血分数升高(50%±2%vs43%±1%,P<0.01),左心室收缩末期容积下降(133±58vs141.2±55,P<0.01);治疗组治疗前、后比较,左心室舒张期容积下降(P<0.05)。结论常规治疗基础上,应用美托洛尔能显著改善慢性心力衰竭患者的症状及心功能。     

口服糖皮质激素治疗慢性阻塞性肺疾病急性加重的疗效和疗程研究

目的 观察口服糖皮质激素(简称激素)对COPD急性加重(AECOPD)的疗效以及7 d和14 d疗程的疗效.方法 2002年7月至2005年1月对130例住院的AECOPD患者按随机数字表法分为3组:7 d治疗组:44例(男32例,女12例),平均年龄(70±8)岁,泼尼松30 mg/d连续7 d,然后安慰剂7 d;14 d治疗组:43例(男34例,女9例),平均年龄(72±7)岁,泼尼松30 mg/d连续10 d,然后15 mg/d连续4 d;安慰剂组:43例(男32例,女11例),平均年龄(73±7)岁,口服安慰剂14 d.试验前后观察肺功能、血气分析、住院天数、症状得分、治疗失败率、激素不良反应和复发率.用SPSS11.0软件包对数据进行分析,计量资料数据以x±s表示,治疗前后比较采用配对t检验,计数资料数据采用χ2检验,多组间比较采用方差分析,其中多重比较采用SNK法,对治疗失败率、复发率和安全性评价采用Fisher精确概率检验.结果 7 d治疗组的FEV1为(0.87±0.23)L,较安慰剂组的(0.74±0.32)L明显提高(q=3.67,P<0.05);14 d治疗组的FEV1为(0.93±0.30)L,较安慰剂组的(0.74±0.32)L也日月显提高(q=4.43,P<0.01).7 d治疗组的PaO2为(79±9)mm Hg(1 mm Hg=0.133 kPa),较安慰剂组的(73±12)mm Hg明显提高(q=6.31,P<0.01);14 d治疗组的PaO2为(80±10)mm Hg,较安慰剂组的(73±12)mm Hg也明显提高(q=7.07,P<0.01).7 d治疗组的住院天数为(12.5±3.5)d,较安慰剂组的(13.5±3.6)d明显缩短(q=3.03,P<0.05);14 d治疗组的住院天数为(12.4±4.1)d,较安慰剂组的(13.5±3.6)d也明显缩短(q=3.42,P<0.05).7 d治疗组与14 d治疗组比较,各项指标无明显差别.激素组和安慰剂组的症状得分、治疗失败率、不良反应和复发率也无明显差别.结论 口服激素可以改善AECOPD的肺功能,改善PaO2和缩短住院时间,7 d和14 d疗程的疗效相同,建议采用口服激素治疗AECOPD的疗程为7 d.     

妥洛特罗贴剂治疗老年慢性阻塞性肺疾病患者急性加重期的疗效观察

目的 观察妥洛特罗贴剂治疗COPD急性加重期的疗效和安全性.方法 120例COPD急性加重期的患者随机分为2组:试验组和对照组,试验组给予妥洛特罗贴剂2 mg,每日1贴,同时吸入丙酸氟替卡松250 μg/次,每2次/d,对照组吸入沙美特罗/氟替卡松(50/250 μg),每日2吸.结果 试验组治疗后的肺功能、临床症状均显著改善,缓解药的使用及夜间憋醒次数减少.试验组使用缓解药的中位数为1次,95% CI为0～6次,较对照组(中位数为2次,95%CI为0～28次)明显减少(t=-3.652,P<0.01);试验组夜间憋醒次数(1.3±1.2)少于对照组(2.3±1.4)(t=-5.324,P<0.01);试验后试验组的FEV1为(1.19±0.03)L,较试验前提高了9.1%,明显高于对照组(1.09±0.02)L(t=-11.46,P<0.01);试验组在第2周以后呼气峰流量(PEF)为(225.4±55)L/min,较试验前提高了7.4%,明显高于对照组[(212.4±59.1)L/min](t=-10.313,P<0.001);试验组住院时间 (14.01±1.03)d,短于对照组[(18.75±1.71)d](t=-10.64,P<0.05).结论 使用妥洛特罗贴剂治疗COPD急性加重期,可以控制患者的临床症状并改善肺功能,是安全有效的.     

单用长效β2肾上腺素受体激动剂与联合糖皮质激素治疗老年中重度慢性阻塞性肺病患者的疗效比较

目的观察吸入性糖皮质激素(ICS)联合长效β2肾上腺素受体激动剂(LABA)、单独使用LABA对老年中重度COPD患者的疗效。方法选取102例稳定的老年中重度COPD患者,随机分成治疗组与对照组,治疗组吸入布地奈德福莫特罗粉吸入剂,对照组吸入福莫特罗,共治疗6个月。分别于治疗前和治疗3、6个月测定患者肺功能第1秒用力呼吸容积(FEV1)占预计值%、FEV1/用力肺活量(FVC)、检测血中白细胞介素(IL)-8、肿瘤坏死因子(TNF)-α浓度,测定外周血有核细胞糖皮质激素受体(GR)-αmRNA、GR-βmRNA百分比,并进行圣乔治呼吸问卷评分。结果无论是治疗组还是对照组,与治疗前相比,治疗3、6个月的FEV1%、FEV1/FVC%逐渐上升(P<0.05);治疗3、6个月血中TNF-α、IL-8浓度均逐渐下降(P<0.05);治疗后外周血有核细胞GR-αmRNA表达水平逐渐上升,GR-βmRNA表达水平逐渐下降(P<0.05);治疗后圣乔治评分逐渐下降(P<0.05)。与对照组相比,治疗组患者的FEV1%、FEV1/FVC%治疗后上升的幅度更大;治疗组TNF-α、IL-8下降的幅度更大(P<0.05);治疗组GR-αmRNA上升的幅度更大,GR-βmRNA下降的幅度更大(P<0.05);治疗组圣乔治评分下降的幅度更大(P<0.05)。结论 LABA、ICS/LABA都能够改善老年中重度COPD患者的肺功能,减轻炎症反应,调节GR,改善生活质量,而且ICS/LABA优于单一LABA治疗。     

无创呼吸机连接解痉剂氧喷吸入治疗COPD呼吸衰竭

临床上经人工气道机械通气中呼吸机多附带同步射流雾化吸入装置,便于湿化气道。受此启发,试行将氧射流喷雾装置与B iPAP呼吸机通气管道连接,在无创通气中将解痉剂氧喷吸入以治疗慢性阻塞性肺疾病(COPD)的呼吸衰竭。本文报告应用此方法的临床疗效,并探讨其优缺点。1对象与方法所选40例均为住院患者(2002年11月~2004年12月)。对照组(A组)20例;男15例,女5例,平均年龄(69±9)岁,实验组(B组)20例:男16例,女4例,平均年龄(68±10)岁。两组所有病例均符合COPD诊断标准、呼吸衰竭的血气分析诊断标准[1]。解痉剂采用德国勃林格殷格翰公司生产的…     

氯沙坦对慢性阻塞性肺疾病患者血液流变学的影响

慢性阻塞性肺疾病(COPD)伴低氧血症患者普遍存在继发性红细胞增多、红细胞压积(HCT)增高和血液高黏状态。本研究旨在观察氯沙坦对COPD病人HCT和血液流变学的影响。1对象与方法1.1研究对象病例选择符合以下条件:(1)中华医学会1997年制定的COPD诊断标准[1];(2)动脉血氧分压(PaO2)<60mmHg。将符合上述条件的住院患者80例,随机分为观察组40例,男17例,女13例,平均年龄70 11岁,平均PaO252.1±4.2mmHg;对照组40例,男26例,14例,平均年龄68 9岁,平均PaO253.6±3.9mmHg。两组年龄、构成和PaO2经统计学检验,无显著性差异(P>0.05)。1.2治疗…     

疏血通在老年糖尿病肾病治疗中的作用

目的 观察在西医治疗的基础上联合疏血通注射液治疗老年糖尿病肾病(DN)的疗效,及对老年糖尿病患者血液流变学的影响.方法 选择老年糖尿病患者39例,其中20例给予常规治疗,19例加用疏血通注射液治疗,比较2组疗效、血液流变学参数及尿蛋白、肾功能变化.结果 2组患者治疗后上述指标均有改善,治疗组有效率84.2%,对照组有效率35%,治疗组疗效明显优于对照组.治疗组血液流变学有明显改善,治疗前后全血黏度(高切、中切、低切)、纤维蛋白原、血浆黏度和血沉等差异有显著性(P＜0.05),与对照组相比治疗后全血黏度、纤维蛋白原、血浆黏度和血沉差异有显著性(P＜0.05或P＜0.01);2组尿素氮和肌酐治疗后均有改善,较治疗前差异有显著性(P<0.01),治疗组尿蛋白下降明显优于对照组(P＜0.01).结论 以疏血通注射液结合西医治疗老年DN疗效明显,值得临床推广使用.     

The Italian multicentre study on noninvasive ventilation in chronic obstructive pulmonary disease patients.

Chronic obstructive pulmonary disease (COPD) patients with chronic ventilatory failure (CVF) are more likely to develop exacerbations, which are an important determinant of health-related quality of life (HRQL). Long-term noninvasive positive-pressure ventilation (NPPV) has been proposed in addition to long-term oxygen therapy (LTOT) to treat CVF but little information is available on its effects on HRQL and resource consumption. Therefore, the current authors undertook a 2-yr multicentric, prospective, randomised, controlled trial to assess the effect of NPPV+ LTOT on: 1) severity of hypercapnia; 2) use of healthcare resources, and 3) HRQL, in comparison with LTOT alone. One hundred and twenty-two stable hypercapnic COPD patients on LTOT for > or = 6 months were consecutively enrolled. After inclusion and 1-month run-in, 90 patients were randomly assigned to NPPV+LTOT (n=43) or to LTOT alone (n=47). Arterial blood gases, hospital and intensive care unit (ICU) admissions, total hospital and ICU length of stay and HRQL were primary outcome measures; survival and drop-out rates, symptoms (dyspnoea and sleep quality) and exercise tolerance were secondary outcome measures. Follow-up was performed at 3-month intervals up to 2 yrs. Lung function, inspiratory muscle function, exercise tolerance and sleep quality score did not change over time in either group. By contrast the carbon dioxide tension in arterial blood on usual oxygen, resting dyspnoea and HRQL, as assessed by the Maugeri Foundation Respiratory Failure Questionnaire, changed differently over time in the two groups in favour of NPPV+LTOT. Hospital admissions were not different between groups during the follow-up. Nevertheless, overall hospital admissions showed a different trend to change in the NPPV+LTOT (decreasing by 45%) as compared with the LTOT group (increasing by 27%) when comparing the follow-up with the follow-back periods. ICU stay decreased over time by 75% and 20% in the NPPV+LTOT and LTOT groups, respectively. Survival was similar. Compared with long-term oxygen therapy alone, the addition of noninvasive positive-pressure ventilation to long-term oxygen therapy in stable chronic obstructive pulmonary disease patients with chronic ventilatory failure: 1) slightly decreased the trend to carbon dioxide retention in patients receiving oxygen at home and 2) improved dyspnoea and health-related quality of life. The results of this study show some significant benefits with the use of nocturnal, home noninvasive positive-pressure ventilation in patients with chronic ventilatory failure due to advanced chronic obstructive pulmonary disease patients. Further work is required to evaluate the effect of noninvasive positive-pressure ventilation on reducing the frequency and severity of chronic obstructive pulmonary disease exacerbation.     

Does long-term oxygen therapy reduce hospitalisation in hypoxaemic chronic obstructive pulmonary disease?

The aim of this study was to determine whether long-term oxygen therapy (LTOT) reduces hospitalisation in hypoxaemic patients with chronic obstructive pulmonary disease (COPD). The circumstances of initiation of LTOT (start during hospitalisation versus start as an outpatient) and compliance with oxygen were also investigated (continuous oxygen therapy (COT) > or = 15 h daily versus noncontinuous oxygen therapy (NCOT) <15 h daily). A total 246 COPD patients were studied, with each patient acting as their own control. Patients were divided into four groups: 125 patients on COT who started LTOT in conjunction with hospitalisation, 37 patients on COT who started LTOT as outpatients, 58 patients on NCOT who started LTOT in conjunction with hospitalisation and 26 patients on NCOT who started LTOT as outpatients. Admission rates, days spent in hospital and number of patients with at least one hospitalisation (ever hospitalised) were compared in two periods of 10 months before and after initiation of LTOT. Overall during the LTOT period, in comparison with the preoxygen period, the admission rates, hospital days and "ever hospitalised" were reduced by 23.8%, 43.5% and 31.2%, respectively. Among patients who started LTOT as outpatients, a tendency towards a higher effect in the compliant group was observed. This study shows that in hypoxaemic chronic obstructive pulmonary disease patients, long-term oxygen therapy is associated with a reduction in hospitalisation.     

Noninvasive ventilation in chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis.

Although long-term oxygen therapy (LTOT) improves survival, it has little effect on hypoventilation and other outcomes in patients with hypercapnic respiratory failure due to chronic obstructive pulmonary disease (COPD). Recent studies have shown that the use of noninvasive positive-pressure ventilation, when used in combination with LTOT in selected stable COPD patients, controls hypoventilation and improves daytime arterial blood gases, sleep quality, health status and may have a benefit in reducing exacerbation frequency and severity. Patients who show the greatest reduction in overnight carbon dioxide tension in arterial blood with ventilation are most likely to benefit from long-term ventilatory support. Some benefits have also been shown in patients with chronic respiratory failure due to bronchiectasis and cystic fibrosis, though survival is inferior in this patient group. As most studies of noninvasive positive-pressure ventilation in chronic obstructive pulmonary disease have been relatively short term, large multicentre studies with survival, exacerbations and hospital admissions as the primary end points are required to evaluate longer term effects.     

辛伐他汀治疗COPD合并肺动脉高压的临床研究

目的 探讨辛伐他汀治疗慢性阻塞性肺疾病(COPD)合并肺动脉高压(PH)患者肺动脉压、动脉血气、肺功能以及对血浆内皮素-1 (ET-1)、脑钠肽(BNP)的影响.方法 选择稳定期COPD合并PH患者36名,随机分成治疗组和对照组,两组患者均按COPD常规治疗,治疗组加用辛伐他汀40 mg/d,于治疗前及治疗三月后检测肺动脉压、动脉血气、肺功能以及血浆ET-1、BNP水平.结果 治疗组和对照组临床疗效分别66.7％和50.0％.治疗组优于对照组;两组肺动脉平均压治疗后均降低(P＜0.05),治疗组较对照组降低更显著(P＜0.05);治疗组肺功能改善较对照组更明显(P＜0.05);治疗组治疗3个月时ET-1和BNP的水平与对照组比较明显下降(P＜0.05,P ＜0.05).结论 辛伐他汀治疗COPD合并PH,可降低BNP的水平,降低肺动脉平均压及改善肺功能;并能降低ET-1改善内皮功能.     

Impact of hypoxaemia on neuroendocrine function and catecholamine secretion in chronic obstructive pulmonary disease (COPD). Effects of long-term oxygen treatment

The aim of the study was to investigate the effects of chronic hypoxaemia on neuroendocrine function in hypoxaemic chronic obstructive pulmonary disease (COPD). The stress level was assessed by measurement of daytime plasma catecholamine and nocturnal urinary catecholamine levels and endocrine function was assessed by measuring serum gonadotropins, peripheral sex hormones and peripheral thyroid hormones, and by measuring thyroid stimulating hormone (TSH), prolactin and growth hormone before and after thyroid releasing hormone challenge in 12 male, stable, hypoxaemic COPD patients before and after at least 4 months of long-term oxygen treatment (LTOT). Mean pre-treatment PaO2 was 7.39 +/- 0.78 kPa and mean nocturnal arterial oxygen saturation (MSaO2) was 86.6 +/- 3.2%. Plasma norepinephrine (NE) levels were higher than normal, while all other pre-treatment hormone levels were within normal range. Low forced expiratory volume in 1 sec (FEV1) was associated with low basal and stimulated TSH (P < 0.01). Urinary NE excretion correlated positively to nocturnal time spent with SaO2<85% (P<0.05). In similarity with normal controls, positive correlations were found between sex hormone binding globulin and testosterone both before and after LTOT (P<0.01). No significant hormonal changes were noted following an average of 8 months of LTOT for the entire study group. However, in a subgroup (n = 6) with an increase in MSaO2 exceeding 7% points following LTOT, nocturnal excretion of NE and epinephrine were reduced by 30% (P<0.05) and S-free thyroxin by 20% (P<0.05). In conclusion, patients with chronic hypoxaemia secondary to COPD exhibit elevated plasma NE levels but otherwise normal endocrine levels, including a normal hypothalamic-pituitary testicular axis. The severity of airway obstruction is associated with reduced basal and stimulated TSH. The endocrine function is not significantly changed following LTOT except for a subgroup with severe nocturnal hypoxaemia, where elevated nocturnal NE excretion was noted, which was reduced only if whole night oxygenation was normalized during oxygen therapy.     

Long-term oxygen therapy stops the natural decline of endurance in COPD patients with reversible hypercapnia

BACKGROUND: Respiratory muscle weakness is one of the most important causes of hypercapnia in patients with COPD. There is evidence that stable hypercapnic patients will benefit from long-term oxygen therapy (LTOT). OBJECTIVES: The prognostic role of reversible hypercapnia in COPD is still unclear. Early implementation of LTOT in these patients may influence endurance time and mortality. METHODS: In this pilot study, we investigated 28 patients (26 males, 49-74 years) with COPD, advanced airflow limitation [forced expiratory volume in 1 s (percentage of predicted value) 40.8 +/- 10.2] and mild hypoxaemia (pO(2) 66.5 +/- 6.3 mm Hg). All patients had developed a moderate reversible hypercapnia during an acute exacerbation or during exercise testing (peak pCO(2) 48.0 +/- 2.5 mm Hg). Patients were allocated randomly to a control group (n = 14) or an LTOT group (n = 14). The two groups were well matched in terms of physiological data. Lung function, endurance time (cycle ergometer), dyspnoea score, blood gases and LTOT compliance were measured at baseline and every 6 months over a period of 3 years. RESULTS: Endurance time increased from 6.4 +/- 2.7 min at baseline to 7.1 +/- 2.7 min after 1 year in the LTOT group and decreased from 6.1 +/- 3.0 to 4.9 +/- 3.8 min in the controls (p < 0.05). After 1 year, the end-exercise dyspnoea score was significantly lower in the LTOT group (4.5 +/- 1.5) than in the controls (5.7 +/- 1.9). CONCLUSION: COPD patients with reversible hypercapnia and mild hypoxaemia benefit from LTOT in terms of endurance time and a reduction of exertional dyspnoea after 1 year.     

长期家庭氧疗联合肺康复训练对慢阻肺合并呼吸衰竭患者的疗效观察

目的探讨长期家庭氧疗联合肺康复训练在慢阻肺合并呼吸衰竭患者康复治疗中的疗效。方法选取48例慢阻肺合并呼吸衰竭患者,按照计算机随机方法分为研究组与对照组,每组24例。对照组患者给予常规治疗,研究组患者在此基础上予以长期家庭氧疗和肺康复训练治疗,对两组患者进行为期12个月随访,对比两组患者肺功能、血气分析、6分钟步行距离、生存质量评分以及血清炎症因子水平。结果研究组与对照组患者的生活质量评分、动脉血气分析、肺功能、6分钟步行距离、炎症因子CRP及TNF-α水平检测值相比较,研究组比对照组患者上述指标具有明显改善,差异具有统计学意义,P0.05。结论长期家庭氧疗联合肺康复训练对慢阻肺疾病合并呼吸衰竭患者具有积极作用,值得推广。     

Acute effect of oxygen on pulmonary arterial pressure does not predict survival on long-term oxygen therapy in patients with chronic obstructive pulmonary disease.

The growing number of patients treated with long-term oxygen therapy (LTOT) poses the question which physiologic variables could predict the patients who may benefit the most from this cumbersome and expensive treatment. We wanted to verify if the acute effect of oxygen on pulmonary arterial pressure (PAP) is related to survival on LTOT as was suggested recently in the literature. We studied 46 chronic obstructive pulmonary disease (COPD) patients qualified for LTOT. The acute effects of O2 on pulmonary hemodynamics were assessed by pressure and flow measurements before and after 30 min of O2 breathing via 28% Ventimask. Thirty-nine patients reacted with a fall of the mean PAP of less than 0.7 kPa 5 (mm Hg). These were termed nonresponders (NR). In seven patients, mean PAP fell greater than or equal to 0.7 kPa 5 (mm Hg). They were called responders (R). After the initial investigations, patients were followed up on LTOT for 2 yr or until death. During the first year, four patients died; three from the NR and one from the R group. After 2 yr of LTOT, 15 patients died (12 from NR and 3 from R groups). The 2-yr survival rate was 69% in NR and 57% in R groups, respectively. We conclude that survival on LTOT is not related to the acute effect of oxygen on the PAP in COPD patients investigated in the steady-state period of the disease.