The effect of aging on respiratory muscle function

To elucidate the effect of aging on respiratory muscle function, the authors performed respiratory muscle function tests in 116 normal subjects. Respiratory muscle function was evaluated with maximal expiratory mouth pressure at the TLC level (PEmax) and maximal inspiratory mouth pressure at the RV level (PImax). PEmax and PImax in both sexes showed significant correlations with age. PEmax in males was significantly higher than that in females (123.6 +/- 29.7 cmH2O and 79.0 +/- 21.1 cmH2O, p less than 0.01, respectively). PImax in males was also significantly higher than that in females (98.4 +/- 26.0 cmH2O and 71.9 +/- 26.4 cmH2O, p less than 0.01, respectively). PEmax correlated significantly with TLC, and PImax showed a significant inverse correlation with RV/TLC. Furthermore, there was a significant inverse correlation between RV/TLC and age. Our data suggest that inspiratory muscle weakness in aging may be responsible for the increase in RV/TLC.     

Comparison of two different mouthpieces for the measurement of Pimax and Pemax in normal and weak subjects

We investigated the effect of mouthpiece design on maximum static expiratory (PEmax) and inspiratory (PImax) mouth pressures. We measured PEmax from total lung capacity (TLC) and PImax from residual volume (RV) in 21 healthy volunteers, and in 40 patients referred for respiratory muscle testing. We compared two different mouthpieces, a semi-rigid plastic flanged type fitting inside the lips, and a 4 cm diameter rubber tube held against the lips. The tube mouthpiece gave significantly higher values for PEmax (p less than 0.02) in all subjects. PImax was also significantly higher (p less than 0.005) with the tube mouthpiece in subjects who recorded normal pressures. We conclude that maximum pressures are obtained in all normal subjects with the rubber tube mouthpiece, and that differences in quoted normal ranges of maximum static respiratory pressures reflect in part the design of the mouthpiece and the way in which it was used.     

LUNG FUNCTION AND RESPIRATORY MUSCLE STRENGTH AFTER PROPRANOLOL IN THYROTOXICOSIS

Thirty-five thyrotoxic patients were assessed before treatment, after treatment with propranolol, and after antithyroid drugs. The first group of patients ( n = 17) performed the following tests at all three assessment points: forced expiratory volume in the first second (FEV,), vital capacity (VC), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), maximal mid-expiratory flow rate (MMFR), diffusing capacity for carbon monoxide (DLCO), and maximum static inspiratory and expiratory mouth pressures (Plmax and PEmax). Arterial blood gas analysis was also performed for the first group of patients. No significant changes were seen either after propranolol or after antithyroid drugs in the FRC, RV, TLC, MMFR, DLCO, or blood gases. The remaining 18 patients, group 2, performed only the FEV₁, VC, Plmax, and PEmax tests at each assessment. The only index of respiratory function that improved significantly after propranolol was Plmax (from 46.5 ± 16.5 to 53.2 ± 22 cmH₂O, p < 0.01). This suggests that adrenergic excess may play a role in thyrotoxic inspiratory muscle weakness. After antithyroid drugs, Plmax, PEmax, FEV₁, and VC all increased significantly as expected. (Aust NZ J Med 1986; 16: 496–500.)     

Respiratory muscle strength in hyperthyroidism before and after treatment.

We undertook this study to investigate respiratory muscle strength in relation to thyroid function in 20 thyrotoxic patients and in a group of 20 normal subjects matched for age and sex. Global respiratory muscle strength was assessed by measuring mouth pressure during maximal static inspiratory (PImax) and expiratory (PEmax) efforts. We also measured VC, FVC, and FEV1 as well as thyroid-related hormones (T3, T4, TSH). Measurements were made once in normal subjects and twice in thyrotoxic patients, before and 3 months after medical treatment. Our results showed that both maximal pressures were significantly reduced (p less than 0.0001) before treatment in thyrotoxic patients in relation to the mean values of the normal subjects (p less than 0.0001), and they increased significantly (p less than 0.0003) after treatment. Lung volumes were significantly reduced (p less than 0.0001) before and increased significantly (p less than 0.008) after treatment. The ratio FEV1/FVC did not change. A statistically significant linear relationship was found when PImax of patients with thyrotoxicosis before treatment and of normal subjects were plotted against thyroid hormones (T3, T4) (r = -0.746 and r = -0.745, respectively, p less than 0.001). Similarly, a statistically significant linear relationship was found between PEmax and T3 and T4 (r = -0.837 and r = -0.838, respectively, p less than 0.001). No relationship was found between maximal pressures and TSH. Finally, a significant linear relationship was found between PImax and PEmax (r = 0.872, p less than 0.001). Our results confirm that in thyrotoxicosis respiratory muscle weakness occurs that affects both inspiratory and expiratory muscles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lung function disturbances versus respiratory muscle fatigue in patients with systemic lupus erythematosus

In 23 consecutive patients (mean age, 38.6 years) with systemic lupus erythematosus (SLE) and in 17 healthy subjects (mean age, 37.5 years) fatigue of respiratory (diaphragm, musculi intercostales externi) and leg muscles (musculus gastrocnemius) was determined comparatively by electromyography. Additionally, routine lung function parameters, including maximum inspiratory (PImax) and expiratory (PEmax) mouth pressures, were measured. The SLE patients showed lower values of vital capacity (VC), total lung capacity (TLC), thoracic gas volume (TGV), FEV1, PImax and PEmax than the healthy controls, while FEV1/VC, residual volume and specific airway conductance were not significantly different in either group. Lung compliance, corrected for TGV, was normal in the SLE group. Breathing through stenoses with increasing resistances resulted in fatigue of the diaphragm in 73% of the SLE group and in 41% of the control group. The corresponding values of the external intercostal muscles were 74% (SLE group) and 29% (control group). Electromyographic signs of respiratory and leg muscle fatigue occurred at lower loads in the SLE group than in the healthy subjects. The pattern of lung function data in patients with SLE was characteristic neither of lung restriction nor of airway obstruction. Respiratory muscle weakness can explain the decrease in TLC, VC, TGV, FEV1, PImax and PEmax.     

Maximal respiratory pressure: normal values and changes in chronic obstructive pulmonary disease (COPD)

The measurement of maximal inspiratory and expiratory pressures generated at the mouth (PImax and PEmax)respectively is an accepted noninvasive clinical method for evaluating the strength of respiratory muscles, however at present the normal values have been not unified. We measured PImax and PEmax in 50 healthy subjects and 50 patients with stable chronic obstructive pulmonary disease (COPD). The results showed that our normal values of PImax and PEmax approximated to the lower end of the ranges of normal values in healthy subjects and the PImax and PEmax of patients with moderate reported in foreign countries COPD were lower than healthy subjects.     

Respiratory muscle strength in congestive heart failure

In experimental animals, conditions which drastically decrease cardiac output may reduce the strength and endurance of respiratory muscles leading to hypercapnic respiratory failure. Because patients with chronic CHF have reduced cardiac output and vital capacity (FVC), we measured PImax and PEmax and maximal handgrip force in 16 patients with CHF and 18 AMNs. The patients with CHF had a mean left ventricular ejection fraction of 26 +/- 7 percent. Maximal respiratory pressures were significantly reduced; group mean values (+/- SD) for PImax at FRC were 41.4 +/- 5.6 cm H2O (CHF) and 102.1 +/- 27.4 cm H2O (AMN) (p less than 0.001), with PImax values in five patients with CHF as low as 20 to 30 cm H2O. In most patients, PEmax was comparably reduced. Handgrip force was less dramatically reduced, suggesting selective respiratory muscle weakness. Possible explanations include reduction in respiratory muscle blood flow or generalized muscular atrophy and weakness related to cardiac cachexia.     

Inspiratory muscle strength is a determinant of maximum oxygen consumption in chronic heart failure.

OBJECTIVE--To investigate the significance of respiratory muscle weakness in chronic heart failure and its relation both to maximum oxygen consumption during cardiopulmonary exercise testing and to skeletal muscle (quadriceps) strength. SUBJECTS--Seven healthy men aged 54.9 (SEM 4.3) years and 20 men with chronic heart failure aged 61.4 (1.6) years (P = 0.20) with radionuclide left ventricular ejection fraction of 25.4 (3.0)%. METHODS--Mouth pressures during maximum static inspiratory effort (PImax) at functional residual capacity (FRC) and residual volume (RV) were measured in all subjects and taken as indices of inspiratory muscle strength. Similarly, mouth pressures during maximum static expiratory effort (PEmax) at FRC and total lung capacity (TLC) were taken as indices of expiratory muscle strength. Cardiopulmonary exercise testing was performed in all subjects. All controls and 15 heart failure patients also had their right quadriceps muscle strength measured. RESULTS--There was respiratory muscle weakness in heart failure patients, with reduction of PImax at FRC (59.7) (6.3) v 85.6 (9.6) cm H2O, P = 0.045), PEmax at FRC (94.8 (6.2) v 134.6 (9.1) cm H2O, P = 0.004), and PEmax at TLC (121.7 (8.5) v 160.7 (13) cm H2O, P = 0.028). PImax at RV was also reduced but this did not reach statistical significance (77.3 (6.6) v 89.3 (13) cm H2O, P = 0.44). There was also significant weakness of the right quadriceps muscle (308.5 (22) v 446.2 (28) N, P = 0.001). PImax at both FRC and RV correlated with maximum oxygen consumption (r = 0.59, P = 0.006, and r = 0.45, P = 0.048 respectively) but not PEmax. There was, however, no significant correlation between PImax and right quadriceps strength. CONCLUSIONS--Respiratory muscle weakness is seen in chronic heart failure. The results suggest that inspiratory muscles are important in determining maximum oxygen consumption and exercise tolerance in these patients. The lack of correlation between respiratory and right quadriceps muscle strength further suggests that the magnitude and time course of respiratory and locomotor muscle weakness may differ in individual patients. Treatment aimed at improving the function of the involved muscle groups may alleviate symptoms.     

Contribution of lung function to exercise capacity in patients with chronic heart failure

BACKGROUND: The importance of exercise capacity as an indicator of prognosis in patients with heart disease is well recognized. However, factors contributing to exercise limitation in such patients have not been fully characterized and in particular, the role of lung function in determining exercise capacity has not been extensively investigated. OBJECTIVE: To examine the extent to which pulmonary function and respiratory muscle strength indices predict exercise performance in patients with moderate to severe heart failure. METHODS: Fifty stable heart failure patients underwent a maximal symptom-limited cardiopulmonary exercise test on a treadmill to determine maximum oxygen consumption (VO2max), pulmonary function tests and maximum inspiratory (PImax) and expiratory (PEmax) pressure measurement. RESULTS: In univariate analysis, VO2max correlated with forced vital capacity (r = 0.35, p = 0.01), forced expiratory volume in 1 s (r = 0.45, p = 0.001), FEV1/FVC ratio (r = 0.37, p = 0.009), maximal midexpiratory flow rate (FEF25-75, r = 0. 47, p < 0.001), and PImax (r = 0.46, p = 0.001), but not with total lung capacity, diffusion capacity or PEmax. In stepwise linear regression analysis, FEF25-75 and PImax were shown to be independently related to VO2max, with a combined r and r2 value of 0. 56 and 0.32, respectively. CONCLUSIONS: Lung function indices overall accounted for only approximately 30% of the variance in maximum exercise capacity observed in heart failure patients. The mechanism(s) by which these variables could set exercise limitation in heart failure awaits further investigation.     

The evaluation of dyspnea and quality of life in COPD

Dyspnea defined as an uncomfortable sensation of breathing is the main cause of disability in chronic obstructive pulmonary disease (COPD) patients. There is evidence that the underlying mechanisms of dyspnea are multifactorial. The aim of this study was to investigate these mechanisms causing dyspnea in COPD patients and the relationship between functional parameters, dyspnea scales and quality of life questionnaire. For this purpose 56 patients (11 female, 45 male) were recruited. Pulmonary function tests including airflow rates, lung volumes, maximal respiratory muscle forces, diffusing capacity, breathing pattern, arterial blood gas analyses as well as dyspnea scales MRC, baseline dyspnea index (BDI) and The Saint George Respiratory Questionnaire (SGRQ) were performed. The overall group showed moderate obstructive disease (FEV1%= 59.02 +/- 3.30) and mild hypoxemia with some air trapping (RV/TLC%= 52.00 +/- 2.00). MRC scale did not show any significant correlation with pulmonary function parameters. There was significant positive correlation between BDI and airflow rates, PImax, DLCO and air trapping. Breathing pattern parameters (Ti/Ttot, VT/Ti) also correlated with BDI. There was positive correlation between PaO2 and BDI (p< 0.001). SGRQ scores correlated significantly with FEV1, PImax, RV/TLC and P 0.1. There was also strong correlation between BDI and SGRQ scores. In conclusion, dyspnea is the result of multiple factors such as airflow limitation, decreased respiratory muscle strength, changes breathing pattern, hypoxemia, and air trapping which in turn affects quality of life in patients with COPD.     

Respiratory muscle strength in hypothyroidism.

To investigate respiratory muscle strength in patients with hypothyroidism, global respiratory muscle strength was assessed by measuring mouth pressure during PImax and PEmax efforts. Maximum pressures, VC, FEV1, FVC, T3, T4, and TSH were measured in 43 hypothyroid patients. Measurements were made before and three months after replacement therapy with thyroxine. The results showed that the mean value of PImax and PEmax increased after treatment. Significant change was found in the mean value of VC, FEV1, and FVC after treatment but not in the FEV1/FVC ratio. A highly statistically significant linear relationship was found between PImax and TSH and between PEmax and TSH as well as between PImax and T3 and PEmax and T3. We conclude that hypothyroidism affects respiratory muscle strength and that this weakness is linearly related to thyroid hormone levels. Respiratory muscle weakness is present in both inspiratory and expiratory muscles and is reversible with treatment.     

肺泡蛋白沉着症肺功能检查特点:附27例分析

目的 肺泡蛋白沉着症(PAP)在临床上极为罕见,其肺功能检查特点的报道也极少,本研究目的在于探讨肺功能检查在PAP诊断和治疗中的价值.方法 回顾性分析本院呼吸疾病研究所经肺组织病理(过碘酸雪夫反应阳性)确诊的27例PAP患者的临床资料.全部病例均给予肺通气和弥散功能测试,其中12例进行了肺容积测试.比较了10例行支气管肺泡灌洗(BAL)治疗的患者在灌洗前、后肺功能的改变情况.结果 27例患者入院后的基础通气肺功能情况:用力肺活量(FVC):(79.67±16.21)%;第1秒用力呼气容积(FEV1):(83.94±16.07)%,一秒率(FEV1/FVC):(89.20±5.50)%;最大呼气流量(PEF):(107.64±17.73)%;肺一氧化碳弥散量(DLCO):(49.27±21.83)%;DLCO与肺泡通气量比值(DLCO/VA):(69.92±20.11)%.肺总量(TLC):(80.60±19.56)%;残气容积(RV):(86.03±38.10)%;残总比(RV/TLC):(32.73±9.48)%;功能残气量(FRC):(84.91±28.08)%.27例患者基础肺功能下降的异常率:FVC:55.6%(15例);FEV1:44.4%(12例);FEV1/FVC:0%(0例);PEF:3.7 %(1例);DLCO:88.9%(24例);DLCO/VA:70.4%(19例).12例患者肺容积的异常率:TLC下降者占50%(6例);RV下降者占41.7%(5例),升高者占16.7%(2例);RV/TLC升高者占50%(6例);FRC下降者占33.3%(4例).10例进行BAL治疗的患者术后肺功能改善率:FVC:5.47%;FEV1:5.50%;DLCO:31.07%;DLCO/VA:20.35%.灌洗前后DLCO及DLCO/VA差异有统计学意义(t=-3.551,-3.159;P=0.006,0.012).结论 PAP的肺功能检查以肺限制性通气功能障碍及肺弥散功能障碍为常见,尤其为弥散功能障碍.PAP经BAL治疗后肺弥散功能有显著性改善.     

Changes in respiratory muscle function after neostigmine injection in patients with myasthenia gravis

In sixteen patients with myasthenia gravis, the weakness of respiratory muscles, especially of expiratory, caused some disturbances in lung function. Thirty minutes after injection of neostigmine, general improvement of muscle function was accompanied by an increase of strength and endurance of respiratory muscles. The mean value of maximal inspiratory mouth pressure (PImax) increased by 33%, maximal expiratory mouth pressure (PEmax) by 23.5% and maximal voluntary ventilation (MVV) by 21%. As a consequence of these changes amelioration of lung function indices was found, vital capacity increasing on average by 13% and residual volume decreasing by 12.5%. We concluded that patients with generalized myasthenia gravis have disturbances in lung function which may be partially improved by neostigmine injection or other anticholinesterase agents.     

Respiratory muscle strength and control of ventilation in patients with neuromuscular disease

To assess the relationship between respiratory mechanics and muscle strength and control of ventilation in patients with neuromuscular disease (NMD), we compared PImax and PEmax at RV, FRC and TLC, total respiratory elastance (Ers) with VT, TI, TT, VE, VT/TI, TI/TT, P.01, and P.01/(VT/TI) effective impedance in 21 patients with NMD and 21 healthy control (C) subjects, in seated position breathing room air. Ers in NMD patients was 79 percent higher than in the C subjects. While TI, TT, and VT in NMD were approximately half the corresponding C values, P.01 was 66 percent greater than in the C subjects (both p less than 0.001). NMD PImax and PEmax ranged from 37 to 52 percent of corresponding C values, respectively. Despite significant respiratory muscle weakness, only 7 of 16 patients demonstrated a PaCo2 greater than 45 mm Hg. Ventilatory output in NMD was modulated by respiratory mechanics as indicated by the increased P.01. In spite of muscle weakness, central drive in patients with NMD is not decreased, and in fact, is often increased. VE is not an accurate measure of central drive because of abnormal intrinsic respiratory mechanics and the effects of conscious responses or reflexes.     

Relationship between respiratory muscle strength, nutritional status, and lung volume in cystic fibrosis and asthma

We measured static inspiratory and expiratory pressures (PImax and PEmax) in 29 patients with asthma for comparison with a previously reported group of 25 patients with cystic fibrosis (CF) and 80 normal control subjects. The purpose of the study was to assess the relationship between respiratory muscle strength, nutritional status, lung volumes, and training effect of the increased work of breathing in patients with chronic air-flow limitation. PEmax was similar in the asthma group, CF group, and normal control subjects despite a significant degree of malnutrition in the CF group (mean body mass percentile (BMP), 78 versus 107% in the asthma group, p less than 0.001). There was no correlation between BMP and PImax or PEmax in either study group. PImax, when corrected for lung volume, was greater than age- and sex-matched control values in 24% of the patients with CF and 48% of the patients with asthma. We conclude that respiratory muscle strength is not related to nutritional status (as measured by BMP) in patients with CF and asthma. Above-normal inspiratory muscle strength may result from a training effect of the increased work of breathing in both CF and asthma, regardless of nutritional status.     

Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise

The aim of this study was twofold: first, to determine the breathing strategies of children with cystic fibrosis (CF) during exercise, and secondly, to see if there was a correlation with lung function parameters. We determined the tension-time index of the inspiratory muscles (T(T0.1)) during exercise in nine children with CF, who were compared with nine healthy children with a similar age distribution. T(T0.1) was determined as followed T(T0.1) = P0.1/PImax . T(I)/T(TOT), where P0.1 is mouth occlusion pressure, PImax is maximal inspiratory pressure, and T(I)/T(TOT) is the duty cycle. CF children showed a significant decrease of their forced expiratory volume in 1 sec (FEV1), forced vital capacity (FCV), and FEV1/FVC, whereas the residual volume to total lung capacity ratio (RV/TLC) ratio and functional residual capacity (FRC) were significantly increased (P < 0.001). Children with CF showed mild malnutrition assessed by actual weight expressed by percentage of ideal weight for height, age, and gender (weight/height ratio; 82.3 +/- 3.6%). Children with CF showed a significant reduction in their PImax (69.3 +/- 4.2 vs. 93.8 +/- 7 cmH2O). We found a negative linear correlation between PImax and weight/height only in children with CF (r = 0.9, P < 0.001). During exercise, P(0.1), P0.1/PImax, and T(T0.1) were significantly higher, for a same percent maximal oxygen uptake in children with CF. On the contrary, T(I)/T(TOT) ratio was significantly lower in children with CF compared with healthy children. At maximal exercise, children with CF showed a T(T0.1) = 0.16 vs. 0.14 in healthy children (P < 0.001). We observed at maximal exercise that P0.1/PImax increased as FEV1/FVC decreased (r = -0.90, P < 0.001), and increased as RV/TLC increased (r = 0.92, P < 0.001) only in children with CF. Inversely, T(I)/T(TOT) decreased as FEV1/FVC decreased (r = 0.89, P < 0.001), and T(I)/T(TOT) decreased as RV/TLC increased (r = -0.94, P < 0.001). These results suggest that children with CF adopted a breathing strategy during exercise in limiting the increase of the duty cycle. Two determinants of this strategy were degrees of airway obstruction and hyperinflation.     

结节病患者肺功能与支气管肺泡灌洗液细胞学关系的研究

目的 探讨结节病患者不同影像分期之间肺功能指标、支气管肺泡灌洗液细胞学的改变以及两者的相关性.方法 回顾性调查71例结节病患者肺功能以及支气管肺泡灌洗液检查的资料.结果 在结节病患者不同影像分期之间肺功能指标用力肺活量(FVC)占预计值%、第1秒用力呼气容积(FEV1)占预计值%、肺总量(TLC)占预计值%以及肺一氧化...     

Effects of severity of long-standing congestive heart failure on pulmonary function

To investigate the effects of severity of long-standing congestive heart failure (CHF) on pulmonary function, we studied 53 (47 men) consecutive patients, all heart transplant candidates. Their mean (+/- SD) age and ejection fraction were 47 +/- 12 years and 23 +/- 7%, respectively. All patients underwent spirometry, lung volume, diffusion capacity (DLCO), maximum inspiratory (PImax) and expiratory pressure (PEmax) measurement. Maximum cardiopulmonary exercise test on a treadmill was also performed to determine maximum oxygen consumption (VO2max). On the basis of VO2max, the patients were then divided into those with a VO2max > 14 ml min-1 kg-1 (group 1, n = 30) and those with a VO2max < or = 14 ml min-1 kg-1 (group 2, n = 23). In comparison with group 1, group 2 patients had lower FEV1/FVC (70 +/- 8% vs 75 +/- 7%, P = 0.008), lower FEF25-75 (46 +/- 21 vs 70 +/- 26%pred, P < 0.001), lower TLC (76 +/- 15 vs 85 +/- 13%pred, P = 0.02) and lower PImax (68 +/- 20 vs 87 +/- 22 cmH2O, P = 0.003), but comparable DLCO (84 +/- 15 vs 88 +/- 20%pred, P = N.S.), and PEmax (99 +/- 25 vs 96 +/- 22 cmH2O, P = N.S.). In conclusion, our data suggest that respiratory abnormalities, such as restrictive defects, airway obstruction, and inspiratory muscle weakness, are more pronounced in patients with severe CHF than in those with mild-to-moderate disease. Further studies are required to investigate the extent to which these abnormalities contribute to dyspnoea during daily activities in patients with heart failure.     

Relation between pulmonary ventilation parameters,exercise tolerance and quality of life in patients with chronic obstructive lung disease

Patients with chronic obstructive pulmonary disease (COPD) do usually have decreased tolerance of exercise capacity and impaired quality of life. Several studies have shown that exercise capacity is related relatively weakly to lung functions in this group of patients. The aim of the present study was to find parameter which could better reflect or predict maximal exercise capacity. 19 patients with the diagnosis COPD with mean value of forced expiratory volume in one second (FEV1) 46% predicted (range 21-79%) entering pulmonary rehabilitation program were included into the study. Enrolled patients were chosen to cover the whole range of airway obstruction severity. Post-bronchodilator static and dynamic ventilation parameters were used for evaluation and calculation. Quality of live was measured using St. George's respiratory questionnaire (SGRQ), evaluating symptoms, activity and impact of the disease with range from 0 (the best level) to 100 (the worst level). Values of FEV1 (p < 0.001) and ratio of FEV1 to vital capacity (FEV1/VC, p < 0.001) were significantly positively correlated with 6 minute walking distance (6MWD). FEV1/VC were closely related to 6MWD then FEV1. The degree of hyperinflation expressed by residual volume (RV, p < 0.005) and by ratio of residual volume to total lung capacity (RV/TLC, p < 0.001) significantly negatively correlated with 6MWD. Maximal occlusion mouth pressures (PImax, p < 0.05) were positively related to 6MWD. Total score of SGRQ correlated significantly to maximal exercise capacity. Pulmonary function tests and respiratory muscle function have important impact on exercise tolerance in patients with COPD. Tolerance of exercise capacity is significantly reflected by total score of quality of life in this group of patients.     

COPD合并慢性肺源性心脏病与否的肺功能对比分析

目的 通过对单纯COPD与肺心病患者的肺功能进行对比分析,了解COPD合并肺心病与否时的肺功能改变.方法 对所有入选的COPD患者进行肺功能和心脏超声检查,COPD患者GOLD分级为Ⅱ～Ⅳ级.根据有无肺心病将入选患者分为单纯COPD组和COPD合并肺心病组.单纯COPD组37例;COPD合并肺心病组31例.结果 COPD合并肺心病组DLCO% pred显著低于单纯COPD组(P<0.05);两组间FEV1% pred、FVC% pred、FEV1/FVC、RV% pred、TLC% pred、RV/TLC和共振频率无显著差异(P＞0.05).结论 COPD合并肺心病患者较单纯COPD患者肺弥散功能的损害更为显著.