A normal FEV1/VC ratio does not exclude airway obstruction

BACKGROUND: A decreased forced expiratory volume in 1 s/vital capacity (FEV(1)/VC) ratio is the hallmark of the definition of airway obstruction. We recently suggested that a lung function pattern, we called small airways syndrome (SAOS), has a normal FEV(1)/VC and total lung capacity (TLC) and reflects obstruction of small airways. OBJECTIVES: To substantiate our hypothesis we measured and compared lung function tests including maximal expiratory flow rates (MEFR), sensitive indicators of airway obstruction, in SAOS subjects and in matched controls. METHODS: We selected 12 subjects with the pattern of SAOS, but without chronic lung or heart disease (average age: 40.7 +/- 7.8 years) and 36 age-matched subjects with normal lung function (42.8 +/- 6.3 years). We measured static and dynamic lung volumes, MEFR and lung diffusing capacity (DL(CO)). RESULTS: SAOS subjects were heavier smokers (p < 0.05) and body mass index was less than in control subjects (p < 0.01). Both FEV(1)/VC ratio and TLC were comparable in the two groups. However, FEV(1), VC, DL(CO), and MEFR were lower and residual volume (RV) and RV/TLC ratio were higher (p < 0.05) in the SAOS group than in the control one. Furthermore, the MEFR curve of the SAOS group was displaced to the left without any change in slope, suggesting premature airway closure. CONCLUSION: Our results suggest that a normal FEV(1)/VC ratio does not exclude airway obstruction. A decrease of FEV(1), provided TLC is normal, reflects small airway obstruction.     

50例健康老年人肺功能10年随访观察

目的为临床和基础研究提供健康老年人肺功能各项指标随增龄改变的参考资料。方法采用日本Ｃｈｅｓｔａｃ６５型肺功能检查仪,按常规方法进行肺功能检查。结果用力肺活量（ＦＶＣ）每年下降００３２Ｌ,第１秒用力呼气量（ＦＥＶ１）每年下降００３Ｌ,ＦＥＶ１占用力肺活量比值（ＦＥＶ１％）每年下降０１５１％,呼气流量峰值（ＰＥＦＲ）每年下降０１１８Ｌ／ｓ,最大呼气中段流量（ＭＭＥＦ）每年下降００４Ｌ／ｓ,最大通气量（ＭＶＶ）每年下降０８７６Ｌ,肺活量（ＶＣ）每年下降００４Ｌ,残气容积（ＲＶ）每年升高００３３Ｌ,功能残气量（ＦＲＣ）每年升高００３３Ｌ,残气容积／肺总量（ＲＶ／ＴＬＣ）每年升高０５９６％。戒烟组的健康老年人ＶＣ、ＦＶＣ、ＦＥＶ１、ＲＶ、ＲＶ／ＴＬＣ与从不吸烟健康老年人比较差异有显著性;不同年龄组的健康老年人肺功能下降不明显。结论肺功能各项指标随增龄而改变,健康老年人各年龄组肺功能改变不明显,吸烟对健康老年人肺功能改变有一定影响。     

Restrictive impairment in patients with asthma

BACKGROUND: Patients with asthma have intermittent or persistent airflow obstruction, most often manifested spirometrically by reduced forced expiratory volume in 1s (FEV(1)) and FEV(1)/vital capacity (VC) ratio. In some patients, the VC may be reduced by air trapping, with an increase in functional residual capacity (FRC) and residual volume (RV) (pseudorestriction). We have reported 12 asthmatic patients with reduced VC and no increase in RV, i.e., a true restrictive impairment [Gill et al. True restrictive impairment in bronchial asthma. Am J Respir Crit Care Med 1999:159:A652]. OBJECTIVES: To confirm previous observations of true restrictive impairment (not attributable to air trapping) in patients with asthma, and to estimate its frequency in an asthmatic population. METHODS: Review of pulmonary function tests and clinical records of all post-pubertal patients diagnosed as asthma between January 2000 and September 2003 in a 184 bed inner city teaching hospital in Jamaica, Queens, New York. The clinical diagnosis of asthma was accepted when one or more of the following pulmonary function criteria were met: Positive bronchodilator response (BD), positive methacholine, repeated variability in spirometric values. Restriction was defined as decrease in total lung capacity (TLC) or decrease in VC with no increase in functional residual capacity (FRC) plus normal or high FEV(1)/FVC ratio. Patients with any clinical finding consistent with restriction, including a decreased diffusing capacity (DL) or obesity (BMI >30) were excluded. RESULTS: A total of 100 of 413 (24%) patients with asthma had restriction; 21 of these met all exclusions (including DL and BMI) and 11 (of 46) patients with an increased BMI and normal DL normalized their FVC on BD therapy, demonstrating that their pre-BD restrictive impairment could not be attributed to obesity. Plethysmographic FRC was measured in 81 of the 100 patients with restriction and was increased in only seven. CONCLUSION: True restrictive impairment was noted in at least 32 of 413 asthmatics (8%), consistent with previous observations in asthma and reactive airways dysfunction syndrome. This finding is not widely recognized and should not preclude the diagnosis of asthma, BD testing or appropriate therapy for asthma.     

Lung hyperinflation and its reversibility in patients with airway obstruction of varying severity

The natural history of lung hyperinflation in patients with airway obstruction is unknown. In particular, little information exists about the extent of air trapping and its reversibility to bronchodilator therapy in those with mild airway obstruction. We completed a retrospective analysis of data from individuals with airway obstruction who attended our pulmonary function laboratory and had plethysmographic lung volume measurements pre- and post-bronchodilator (salbutamol). COPD was likely the predominant diagnosis but patients with asthma may have been included. We studied 2,265 subjects (61% male), age 65 ± 9 years (mean ± SD) with a post-bronchodilator FEV(1)/FVC <0.70. We examined relationships between indices of airway obstruction and lung hyperinflation, and measured responses to bronchodilation across subgroups stratified by GOLD criteria. In GOLD stage I, vital capacity (VC) and inspiratory capacity (IC) were in the normal range; pre-bronchodilator residual volume (RV), functional residual capacity (FRC) and specific airway resistance were increased to 135%, 119% and 250% of predicted, respectively. For the group as a whole, RV and FRC increased exponentially as FEV(1) decreased, while VC and IC decreased linearly. Regardless of baseline FEV(1), the most consistent improvement following bronchodilation was RV reduction, in terms of magnitude and responder rate. In conclusion, increases (above normal) in airway resistance and plethysmographic lung volumes were found in those with only minor airway obstruction. Indices of lung hyperinflation increased exponentially as airway obstruction worsened. Those with the greatest resting lung hyperinflation showed the largest bronchodilator-induced volume deflation effects. Reduced air trapping was the predominant response to acute bronchodilation across severity subgroups.     

Effect of chronic airways obstruction on measurement of the single-breath carbon-monoxide-diffusing capacity

We have examined the effect of chronic airways obstruction on the measurement of the single-breath carbon-monoxide-diffusing capacity (DLCLSB). We reviewed the results of 136 consecutive pulmonary function tests (comprising standard spirometry, helium dilution lung volumes and DLCOSB) obtained in patients who had an FEV1/FVC less than 70%. We calculated DLCOSB using two different values for alveolar volume (VA). In the first method (HeDL), VA was measured by single-breath dilution of helium during the test. In the second method (RbDL), VA was measured as the sum of the inspiratory vital capacity, performed during the test, and the residual volume, determined separately by helium rebreathing. The mean HeDL/RbDL, reflecting disparity between computations of DLCOSB in individual subjects was 0.85 +/- 0.13 in patients with moderate obstruction (40 less than or equal to FEV1/FVC% less than 60) and was 0.80 +/- 0.14 in those with severe obstruction (FEV1/FVC% less than 40). The mean HeDL/RbDL was lowest (0.73 +/- 0.12) in those with severe elevation of RV/TLC (RV/TLC% greater than 60). HeDL/RbDL correlated best with RV/TLC (r = -0.71, p less than 0.001). Unexplained variance in HeDL/RbDL was not significantly reduced by including the relationship between HeDL/RbDL and pulmonary function indices commonly used to measure airways resistance. These data suggest (1) the difference between HeDL and RbDL in patients with moderate and severe chronic airways obstruction is greater than previously reported; (2) the disparity between HeDL and RbDL stems from slow space ventilation rather than from increased resistance to air flow, and (3) HeDL underestimates gas transfer in poorly ventilated lung compartments.     

Bronchodilator response in residual volume in irreversible airway obstruction

BACKGROUND: Although airway obstruction, as defined by improvement of forced expiratory volume in one second (FEV1) and/or forced vital capacity (FVC), is irreversible in patients with COPD, they clearly seem to benefit from treatment with inhaled bronchodilators. AIMS: To assess the response pattern of residual volume (RV) compared to FEV1 after bronchodilation in patients with reversible and irreversible airway obstruction. METHODS: Changes in static lung volumes were compared with improvement in dynamic lung volumes in 396 consecutive patients undergoing reversibility testing with repeat bodyplethysmography. Reversibility was defined as improvement of FEV1 >200 ml and >12% after inhalation of fenoterol hydrobromide. RESULTS: Irreversibility was found in 297 out of 396 patients with airway obstruction. Except for total lung capacity (TLC), all parameters (residual volume [RV], vital capacity [VC], forced inspiratory vital capacity [IVC], forced vital capacity [FVC], forced expiratory volume in one second [FEV1] and the FEV1/VC ratio) showed statistically significant changes after bronchodilation in 396 patients. The multiple linear regression model adjusted for age, sex and BMI showed a non-linear relationship between DeltaFEV1 or DeltaVC compared to DeltaRV after bronchodilation. If the increase in DeltaFEV1 is lower than 0.1 L, DeltaRV remains constant. However, if the increase in DeltaFEV1 is more than 0.1 L, DeltaRV decreases too. The same is found at an increase in VC of 0.3 L. CONCLUSION: In summary, in patients with irreversible airway obstruction DeltaRV cannot be predicted by DeltaFEV1 or DeltaVC after bronchodilation. Therefore, spirometric assessment should be complemented by bodyplethysmography.     

Pulmonary function following mild respiratory tract infections ("common cold") in teenagers

Ventilatory function--forced vital capacity (VC)--forced expiratory volume (in 1-sec forced expiratory flows) static lung volumes, closing volume, and phase III slope (single-breath N2 test) were compared in 94 children with and 436 children without a history of recent mild acute respiratory infection. Their age ranged from 10 to 16 years; subjects with symptoms on the day of the study were excluded. We found no difference in lung function between the two groups, with the exception of a slight (inconsistently significant) increase in closing volume (CV) and the CV/VC ratio. Although the influence of a persistent increase in interstitial lung pressure leading to early small airways closure cannot be ruled out, this isolated functional abnormality probably represents a spurious positive result, arising by chance when a large number of statistical tests are done.     

Pulmonary function in adolescents with ataxia telangiectasia

INTRODUCTION: Pulmonary complications are common in adolescents with ataxia telangiectasia (A-T), however objective measurements of lung function may be difficult to obtain because of underlying bulbar weakness, tremors, and difficulty coordinating voluntary respiratory maneuvers. To increase the reliability of pulmonary testing, minor adjustments were made to stabilize the head and to minimize leaks in the system. Fifteen A-T adolescents completed lung volume measurements by helium dilution. To assess for reproducibility of spirometry testing, 10 A-T adolescents performed spirometry on three separate occasions. RESULTS: Total lung capacity (TLC) was normal or just mildly decreased in 12/15 adolescents tested. TLC correlated positively with functional residual capacity (FRC), a measurement independent of patient effort (R2=0.71). The majority of individuals had residual volumes (RV) greater than 120% predicted (10/15) and slow vital capacities (VC) less than 70% predicted (9/15). By spirometry, force vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) values were reproducible in the 10 individuals who underwent testing on three separate occasions (R=0.97 and 0.96 respectively). Seven of the 10 adolescents had FEV1/FVC ratios>90%. CONCLUSION: Lung volume measurements from A-T adolescents revealed near normal TLC values with increased RV and decreased VC values. These findings indicate a decreased ability to expire to residual volume rather then a restrictive defect. Spirometry was also found to be reproducible in A-T adolescents suggesting that spirometry testing may be useful for tracking changes in pulmonary function over time in this population.     

Respiratory function in children undergoing bone marrow transplantation.

We conducted a prospective study of respiratory function in children undergoing bone marrow transplantation (BMT) for onco-hematological disorders. Each child was evaluated before and 100 days after BMT. The investigations included clinical examination, chest X-ray, and pulmonary function tests (PFT) to determine: slow vital capacity (VC), functional residual capacity (FRC), total lung capacity (TLC), forced expiratory volume in 1 s (FEV1), carbon monoxide diffusing capacity (DLCO), ratio of residual volume (RV) to TLC, and FEV1/VC. The values obtained before and after BMT were compared to predicted values, and the post-BMT values were compared to the pre-BMT values (Student's t-test). From 1986 to 1995, 77 children underwent BMT, of whom 39 were available for testing. The pre-BMT VC (P = 0.0234) and DLCO (P < 0.0001) were lower and FRC higher (P < 0.0001) than predicted values. After BMT, the VC (P = 0.004), TLC (P = 0.044), and FEV1 (P = 0.012) were lower, and the RV/TLC ratio was higher (P = 0.043), compared with pre-BMT data. The observed respiratory abnormalities were not clinically relevant. The only identifiable risk factor for a decrease in lung function was age at BMT. This study shows that some lung dysfunction may be present before BMT and be further altered by BMT. This stresses the need for longitudinal respiratory monitoring and follow up to detect such dysfunctions and to insure an optimal treatment program for these children.     

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.     

Abnormalities of respiratory function in civil defence firefighter-submarine divers. Respective role of diving and occupational exposure related to occupational firefighter's functions

Lung function was studied in 20 firemen-submarine divers (mean age 36 +/- 1.2 years) of the French civil defence undergoing the medical check-up compulsory for professional divers (lung function tests are not systematically performed in ordinary firemen). Compared with the CECA standards: (1) vital capacity (VC) was increased, residual volume (RV) was decreased and total lung capacity (TLC) was unchanged; (2) with the exception of peak respiratory flow, all expiratory flow values (FEV1, MEF50, MEF25) were decreased; (3) the permeability factor (KCO) was decreased. These functional abnormalities were moderately worse in subjects who smoked. Some abnormalities (increased VC, decreased RV) are typical of diving activities, but the deterioration of effort-dependent expiratory flow values and alveolar-capillary diffusion must be ascribed to specific nuisances (fumes, polluants, toxic substances) associated with fireman's activities. Monitoring lung function in all professional firemen therefore seems to be necessary, if not indispensable.     

Determination of static pulmonary volumes after bronchodilator therapy.

Increased (more positive) end-expiratory and decreased (more negative) end-inspiratory values for intrapleural pressure (PpI) invariably accompany acute bronchoconstriction. We hypothesize that both the increase in vital capacity (VC) and the decrease in residual volume (RV) observed after dilation of the central airways in patients with reversible obstruction of the airways result, in part, from a restoration of normal PpI during unforced exhalation. To test this hypothesis, we examined the end-expiratory PpI during breathing at rest in ten emphysematous and eight asthmatic subjects before and after inhalation of isoproterenol. The VC increased by 0.38 L after therapy, and the specific airway resistance and the RV decreased by 6.8 cm H2O.sec and 0.63 L, respectively. Total lung capacity was unchanged. The response of the VC to administration of isoproterenol is an important sequel to dilation of the large airways. Bronchioles close at a critical PpI during exhalation. Because PpI normalizes with administration of isoproterenol, this closure may be delayed to a lower pulmonary volume even if improvement in the function of peripheral airways does not occur.     

Lung mechanics and their relationship to lung volumes in pulmonary sarcoidosis

Pulmonary sarcoidosis was studied with respect to lung mechanical properties and to the influence of these on lung volumes. Sixty-six patients, with histological support for the diagnosis of sarcoidosis, and radiological signs of pulmonary involvement, i.e., stage II or III, were studied. The static pressure/volume (P/V) curves showed that the static elastic recoil pressure (PelL) tended to be increased at a given percentage of predicted total lung capacity (TLC). Reduction of static lung compliance (CstL) was a typical finding. At maximal inspiration PelL was abnormally low in 20 subjects, including in the main those with recent onset of the disease and older patients. The possibility of a greater inflammatory activity at the site of mechanical receptors in the lungs and airways of these patients is proposed. Pulmonary resistance, measured at a given PelL, was usually increased signifying bronchial involvement. TLC, residual volume (RV) and functional residual capacity (FRC) were lower in current smokers and ex-smokers than in lifelong nonsmokers. This may be due to synergistic effects of the inflammatory processes caused by smoking and sarcoidosis. A reduced vital capacity (VC) mainly reflected a low CstL but also obstruction with increased RV. Forced expiratory volume in one second (FEV1) reflected lung stiffness and obstruction equally. Lung mechanics revealed functional abnormalities which were not obvious from the standard tests, particularly in patients with respiratory symptoms.     

Functional significance of the decreased attenuation sign on expiratory CT in pulmonary sarcoidosis : report of four cases

We describe four patients with proven sarcoidosis and minor pulmonary involvement according to high-resolution CT (HRCT) findings in whom the recently described sign of decreased attenuation on expiratory HRCT scan appeared associated with the reduction of the single-breath diffusing capacity of the lung for carbon monoxide (DLCO) and the DLCO adjusted for alveolar volume. These alterations were, in part, reversible under steroid treatment. Major indexes of airway obstruction (FEV(1)/vital capacity ratio and FEV(1)) were normal, while the maximum expiratory flow at 25% above the residual volume of FVC was reduced. These observations suggest that an expiratory HRCT mosaic pattern and diffusion impairment may be early findings in pulmonary sarcoidosis and may be useful for its detection and follow-up.     

Single-breath nitrogen washout; effects of alterations of lung volumes and elastic recoil.

Strapping of the chest causes decreased lung volumes and increased elastic recoil pressure. Such strapping was used in conjunction with single-breath nitrogen washout to study the effects of changes in these factors on the dynamics of the small airways. Studies consisted of simultaneous measurements of the quasistatic lung pressure-volume curve and single-breath nitrogen washout. Strapping caused significant reductions in all lung volumes and in lung compliance at 50 percent of the total lung capacity (TLC). The volume of phase 4 was not changed; however, the ratio of closing capacity to control TLC decreased from 29.9 +/- 6 percent to 24.2 +/- 4 percent with strapping (P less than 0.02). This observation indicates that the onset of closing volumes occurred at a lower absolute lung volume during strapping, compared with control. The closing pressure of 2.1 +/- 0.8 cm H2O was not altered by strapping of the chest. The slope of phase 3 of the single-breath nitrogen-washout test and the average alveolar concentration of nitrogen were increased during strapping. A similar phenomenon occurred in three subjects who performed the single-breath nitrogen-washout test following partial vital capacities. A reduction of the onset of closure of the airways without a change in closing pressure suggests that restrictions of the chest wall caused no change in mechanical properties of the small airways. Elevation of the slope of the alveolar plateau is probably due to exaggeration of the apex-to-base nitrogen difference consequent to the strapping-associated decreased lung and alveolar compliance.     

Multi-breath and single breath helium dilution lung volumes as a test of airway obstruction

Total lung capacity (TLC) and residual volume (RV) measurements derived from multi-breath and single breath helium dilution methods were combined to produce four indices of gas mixing: single breath volume/multi-breath volume ratio (TLCr, RVr) or multi-breath volume minus single breath volume difference (TLCd, RVd). The reproducibility of these indices and their sensitivity and specificity in discriminating between normal subjects and those with mild asthma and severe chronic obstructive pulmonary disease (COPD) was assessed. The total lung capacity ratio (TLCr) was the superior variable overall, providing a single range for both sexes with a specificity and sensitivity similar to that of the forced expiratory volume in one second (FEV1) in the diagnosis of airflow obstruction. Despite the similar sensitivity, correlation between TLCr and FEV1 was only moderate (r = 0.56). This may reflect greater influence of peripheral rather than central airflow obstruction on TLCr. Combining both tests improved sensitivity in the detection of airways obstruction in the asthmatic and COPD groups studied.     

Pulmonary function test before and after operation of coronary artery by-pass surgery

Respiratory complications after successful CABG operation continuous to have on influence on the immediate recovery of a patient. It was reported that the mortality risk of the CABG patients increased, proportional to the reduction of pulmonary function tests (PFT). In the present study we aimed to investigate PFT values (vital capacity: VC, total lung capacity: TLC, residual volume: RV, functional residual capacity: FRC, force expiratory volume first second: FEV1, force mid expiratory flow: FEF25-75, duration force expiratory flow in vital capacity 25%: FEF25, duration force expiratory flow in vital capacity 50%: FEF50, duration force expiratory flow in vital capacity 75%: FEF75, peak expiratory flow: PEF, RV/TLC, FEF/FIF, FEV1/FVC) and arterial blood gases (pH, PaCO2, PaO2, SaO2) pre- and postoperatively which undergo CABG. The PFT and arterial blood gases values of 20 patients, age between 39-74 years, were measured that were undergo CABG operation before a week and three months after.The measured PFT values of 20 patients were recorded by system 2400 computerized and sensor medix 6200 and arterial blood gases analysed by radiometer ABL 300. The results were compared by the time and periods of before and after CABG operation, statistically evaluated the pearson's correlation and Student's t-test. In the results the postoperative PFT values were significantly decreased (p< 0.05, p< 0.001). But the RV, RV% and RV/TLC values were not changed significantly. In arterial blood gases values were not significantly changes. To avoid the postoperative complications we suggested that should be done the PFT and arterial blood gases measurement preoperatively.     

Maximal inspiratory flow rates in patients with COPD

OBJECTIVES: To assess the relevance of maximal inspiratory flow rates (MIFR) in the assessment of airway obstruction in COPD. SETTING: University teaching hospital. PARTICIPANTS: Ten consecutive COPD patients (O group; mean [+/- SD] age, 58.5+/-8.3 years) and 10 matched healthy subjects (H group; mean age, 58.7+/-7.4 years). MEASUREMENTS: Lung volumes, FEV(1), specific airway conductance, single-breath lung diffusing capacity, MIFR, and maximal expiratory flow rates (MEFR). RESULTS: Mean FEV(1)/vital capacity (VC) was 74.7% in the H group and 37.8% in the O group (p<0.001). Total lung capacity was higher (p<0.001) in the O group compared with the H group. Lung diffusing capacity was less than half in the O group compared with the H group (p<0.001). MEFR at all lung volumes were lower in the O group (p<0.001). MIFR were comparable in the two groups, except at 25% inspired VC, where MIFR were lower in the O group (p< 0.05). CONCLUSION: MIFR are less sensitive than MEFR to detect airway obstruction in COPD patients. Yet, the interest of MIFR lay in the possibility to separate intrinsic from extrinsic involvement of airways. A normal MIFR associated with low MEFR, as in the present study, suggests either a lack of parenchymal support, an increased collapsibility of the airways, or a reversible peripheral airway narrowing. A fixed, generalized airway narrowing would be associated with a decrease of both MIFR and MEFR.     

Pulmonary function and morbidity in 40 adult patients with cystic fibrosis.

Pulmonary function and cardiopulmonary complications were studied in a group of 40 patients with cystic fibrosis who reached the age of 25 years. Mean values for vital capacity (VC), functional residual capacity, residual volume (RV), the ratio of RV over total lung capacity (RV/TLC), conductance, and the ratio of the forced expiratory volume in one second over VC were abnormal. There was a variable pattern of progression from patient to patient. The men differed from the women only in that they had a significantly larger TLC and inspiratory capacity than the women. The resultant preservation of VC may have an advantage for survival in those patients in whom it is observed. Pseudomonas aeruginosa was encountered with increasing frequency with age. Massive hemoptysis did not result in early death. The occurrence of rightsided heart failure secondary to cor pulmonale, with or without respiratory failure, was a poor prognostic sign.     

Relationship between lung volume, maximal expiratory flow, forced expiratory volume in one second, and tracheal area in normal men and women

Tracheal area at different lung volumes was measured using acoustic reflection technique, flow-volume curves, and lung volumes by body plethysmography in 24 healthy adults (14 men, 10 women) in order to study the relationship between tracheal area and lung volume, and between tracheal area and maximal expiratory flow rates. Each individual tracheal area was greatest at TLC and lowest at RV; this lung volume dependence was significantly greater in men than in women. When tracheal areas versus absolute lung volumes were plotted for the entire group and the linear regression analysis on the data was performed, no significant correlation between lung volume and tracheal area in men was found, but a highly significant correlation was found in women. Using the analysis proposed by Mead (Am Rev Respir Dis 1980; 121:339-42) in his assessment of dysanapsis, the ratio of tracheal area/lung volume versus lung volume was plotted and the slope was found to be negative (and close to -1) in men and positive in women. Therefore it was concluded that the relationship between tracheal area and lung volume is consistent with the hypothesis that in men and women lung parenchyma grows independently of the airways; furthermore, in women the airways grow faster than the lung parenchyma. In addition, in women there was good correlation between tracheal area and FEV1, as well as maximal expiratory flow rates at 50 and 25% of VC. For men, these correlations were less consistent and depended on the lung volume at which tracheal area was measured.