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At least 685 records · Page 38Linked to original sources
PubMed2006

The structural basis of airways hyperresponsiveness in asthma.

We hypothesized that structural airway remodeling contributes to airways hyperresponsiveness (AHR) in asthma. Small, medium, and large airways were analyzed by computed tomography in 21 asthmatic volunteers under baseline conditions (FEV1 = 64% predicted) and after maximum response to albuterol (FEV1 = 76% predicted). The difference in pulmonary function between baseline and albuterol was an estimate of AHR to the baseline smooth muscle tone (BSMT). BSMT caused an increase in residual volume (RV) that was threefold greater than the decrease in forced vital capacity (FVC) because of a simultaneous increase in total lung capacity (TLC). The decrease in FVC with BSMT was the major determinant of the baseline FEV1 (P < 0.0001). The increase in RV correlated inversely with the relaxed luminal diameter of the medium airways (P = 0.009) and directly with the wall thickness of the large airways (P = 0.001). The effect of BSMT on functional residual capacity (FRC) controlled the change in TLC relative to the change in RV. When the FRC increased with RV, TLC increased and FVC was preserved. When the relaxed large airways were critically narrowed, FRC and TLC did not increase and FVC fell. With critical large airways narrowing, the FRC was already elevated from dynamic hyperinflation before BSMT and did not increase further with BSMT. FEV1/FVC in the absence of BSMT correlated directly with large airway luminal diameter and inversely with the fall in FVC with BSMT. These findings suggest that dynamic hyperinflation caused by narrowing of large airways is a major determinant of AHR in asthma.

Adrenergic beta-Agonists↗
PubMed1995

Analysis of pulmonary function and chest cage dimension changes after thoracoplasty in idiopathic scoliosis.

STUDY DESIGN: A prospective study of 19 adolescents and seven adults with idiopathic scoliosis undergoing posterior spinal fusion with segmental spinal instrumentation and a concomitant thoracoplasty had pulmonary function evaluation before surgery and at selected time points up to a minimum 2 years after surgery. OBJECTIVES: The objectives were to determine the effects thoracoplasty had on pulmonary function and chest cage dimension changes at a minimum 2-year follow-up in idiopathic scoliosis patients. SUMMARY OF BACKGROUND DATA: The cosmetic benefits of thoracoplasty on the rib hump deformity are well accepted. The rib resection procedure allowed for procurement of autogenous bone used for the arthrodesis. Short- and long-term pulmonary function evaluation was necessary to determine proper patient selection and any potential sequelae from the rib resection procedure. METHODS: All patients had pulmonary function tests consisting of forced vital capacity, forced expiratory volume in 1 second, and total lung capacity performed before surgery and 3 months, 1 year, and 2 years after surgery. Ten adolescents also had computed tomographic scans before and after surgery to evaluate chest cage dimension changes after the procedure. RESULTS: The 3-month postoperative pulmonary function test values of the 19 adolescents experienced a statistically significant decline, averaging 16% (P < 0.05), however, the mean values for each parameter returned to just slightly below the preoperative value at 2-years follow-up. The pulmonary function test values of the seven adults experienced a 27% initial decline 3 months after surgery and a residual 23% decline 2 years after surgery; both values were statistically significant (P < 0.05). CONCLUSIONS: We reserve the thoracoplasty procedure for adolescents and adults with preoperative pulmonary function values that will tolerate the morbidity associated with the rib resection. Adolescent patients appear to normalize their pulmonary function tests by 2 years follow-up, whereas long-term pulmonary function in the adult patient remains a concern.

Adolescent↗
PubMed2001

Pulmonary function tests in beta thalassemia.

To study pulmonary function tests (PFT) in multiple transfusion recipient thalassemics, PFTs were done for 30 thalassemics and 20 matched controls. Confirmed cases of thalassemia on regular transfusion therapy were the subject of study. Apart from history and physical examination of the thalassemics, serum ferritin estimation and spirometry were done. Parameters studied included lung volumes--functional residual capacity (FRC), forced vital capacity (FVC), residual volume (RV) and total lung capacity (TLC); and flow rates--forced expiratory volume in one second (FEV1), forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC), peak expiratory flow 25-75 (PEF 25-75%) and peak expiratory flow rate (PEFR). Single breath carbon monoxide diffusing capacity (DLco) and arterial blood gas (ABG) were also analysed. The mean height and weight of thalassemics were below that of age matched controls. A restrictive abnormality in PFT was found in 86.6% cases. These patients were found to have a decrease in all the lung volumes namely FVC, FRC, RV and TLC with a proportional decrease in the flow rates, FEV1, PEF 25-75% and PEF with a normal (> 0.75) FEV1/FVC ratio. DLco was decreased in all the patients with restrictive lung disease and fall in DLco showed a good correlation (r = 0.7, P < .001) with the severity of restrictive disease suggesting that some intrapulmonary pathology is likely to be responsible for the restrictive pattern. None of the cases had an obstructive or mixed pattern of pulmonary dysfunction. No correlation was found between severity of restrictive disease and the serum ferritin levels. A negative correlation with degree of hepatosplenomegaly was found. No correlation was found between severity of the defect and age, number of blood transfusions received and hemoglobin at the time of doing the test. To conclude, restrictive lung disease is the predominant abnormality in multi-transfused thalassemics, which is probably due to pulmonary parenchymal pathology. The abnormality of PFTs is not directly related to iron overload.

Adolescent↗
PubMed2001

Tests of forced expiration and inspiration.

Analysis of the volume versus time curve during a maximum effort forced expiratory vital capacity maneuver started from total lung capacity (TLC) is by far the most performed test of respiratory mechanics, having spread from the laboratory to the wards and outpatient clinics and gradually into the offices of general practitioners. In particular, forced expiratory volume in 1 second (FEV1) is the best characterized test of respiratorv function; information on changes with age, gender, ethnic group, growth and disease is more developed than for any other test, repeatability is good, and it provides useful information across the whole range from normal to advanced disease.

Forced Expiratory Flow Rates↗
PubMed1982

Respiratory mechanics in supine subjects during progressive partial curarization.

Respiratory mechanics were studied in six supine conscious volunteers during progressive muscle weakness produced by infusion of d-tubocurarine. Partial curarization was carried out to the point of abolishing head lift ability and handgrip strength. At all levels of partial paralysis, expiratory muscle strength was significantly more impaired than inspiratory strength. Despite this, subjects maintained relatively normal maximal expiratory flow rates, whereas inspiratory flows decreased significantly. The diminished inspiratory flows are not fully explained by decreased driving pressures during force inspiration, since inspiratory resistance increased significantly with the decreased flow. Inspiratory flow patterns suggest a variable extrathoracic obstruction most likely due to the absence of normal airway abductor activity during inspiration. Maximal respiratory muscle weakness decreased forced vital capacity by 29% and total lung capacity by 15%. The decreased level of lung inflation did not alter lung elastic recoil. Functional residual capacity was unchanged, but inspiratory capacity decreased by 25% and residual volume increased by 38%. These changes are in accord with predictions based on the decreased muscle strength and normal respiratory system recoil.

Adult↗
PubMed1987

Effects of acute hyperinflation on chest wall mechanics in dogs.

We studied chest wall mechanics at functional residual capacity (FRC) and near total lung capacity (TLC) in 14 supine anesthetized and vagotomized dogs. During breathing near TLC compared with FRC, tidal volume decreased (674 +/- 542 vs. 68 +/- 83 ml; P less than 0.025). Both inspiratory changes in gastric pressure (4.5 +/- 2.5 vs. -0.2 +/- 2.0 cmH2O; P less than 0.005) and changes in abdominal cross-sectional area (25 +/- 17 vs. -1.0 +/- 4.2%; P less than 0.001) markedly decreased; they were both often negative during inspiration near TLC. Parasternal intercostal shortening decreased (-3.0 +/- 3.7 vs. -2.0 +/- 2.7%), whereas diaphragmatic shortening decreased slightly more in both costal and crural parts (costal -8.4 +/- 2.9 vs. -4.3 +/- 4.1%, crural -22.8 +/- 13.2 vs. -10.0 +/- 7.5%; P less than 0.05). As a result, the ratio of parasternal to diaphragm shortening increased near TLC (0.176 +/- 0.135 vs. 0.396 +/- 0.340; P less than 0.05). Electromyographic (EMG) activity in the parasternals slightly decreased near TLC, whereas the EMG activity in the costal and crural parts of the diaphragm slightly increased. We conclude that 1) the mechanical outcome of diaphragmatic contraction near TLC is markedly reduced, and 2) the mechanical outcome of parasternal intercostal contraction near TLC is clearly less affected.

Abdomen↗
PubMed1976

Static and dynamic lung compliance in asthmatic symptom-free children.

The static lung compliance was studied in 27 symptom-free asthmatic children, 6-14 years old. The technique of so-called end-expiratory compliance measurement as well as that of the 'zero volume' in the balloon at barometric pressure, used in this study, have been previously discussed. The static lung compliance value is larger than the dynamic lung compliance value, this difference being larger in asthmatic than in healthy children. This difference is explained by higher static lung compliance values in asthmatic than in healthy children, whereas dynamic lung compliance values are only slightly lower in the group of asthmatic patients compared to healthy children. Static lung compliance per unit of lung volume (specific static lung compliance) is identical in both groups. Static recoil pressure at 80% of total lung capacity (TLC) is similar in asthmatic and healthy children. However, in symptom-free asthmatic children with hyperinflated lungs [functional residual capacity (FRC) higher than 25% of predicted value and FRC/TLC ratio higher than 0.45], static recoil pressure at 80% TLC is lower than the predicted value, this difference being not significant.

Adolescent↗
PubMed1982

Dose response of elastase-induced emphysema in hamsters.

Elastase-induced emphysema in hamsters was studied using pulmonary function tests in an effort to develop techniques for determining the effects of air pollutants on the progression of this disease. Single intratracheal injections of 6, 12, or 24 units of porcine pancreatic elastase produced dose-related changes in pulmonary function after 4 wk when compared with sham-injected control animals. Boyle's law end-expiratory volume and residual volume, measured by gas dilution, increased (p less than 0.05) at 12 and 24 units, respectively, whereas vital capacity, determined plethysmographically, and total lung capacity wee increased (p less than 0.05) at all 3 elastase doses. Respiratory system compliance, calculated by a nonlinear least squares regression fit of the deflation pressure-volume curve, increased (p less than 0.05) at 24 units only. The multiple-breath nitrogen washout slope (N2 slope) and the single-breath diffusing capacity for carbon monoxide (DLCO) decreased (p less than 0.05) at all 3 doses of elastase. Both histologic and physiologic evaluation showed dose-related pulmonary impairment. It appears, therefore, that as little as 6 units of elastase produces mild emphysema in hamsters, which is detectable by pulmonary function testing. Of these tests, the DLCO and N2 slope were the most effective in detecting the degree of impairment.

Animals↗
PubMed2005

Effects of imposed pursed-lips breathing on respiratory mechanics and dyspnea at rest and during exercise in COPD.

STUDY OBJECTIVES: To investigate the effect of volitional pursed-lips breathing (PLB) on breathing pattern, respiratory mechanics, operational lung volumes, and dyspnea in patients with COPD. SUBJECTS: Eight COPD patients (6 male and 2 female) with a mean (+/-SD) age of 58 +/- 11 years and a mean FEV1 of 1.34 +/- 0.44 L (50 +/- 21% predicted). METHODS: Wearing a tight-fitting transparent facemask, patients breathed for 8 min each, with and without PLB at rest and during constant-work-rate bicycle exercise (60% of maximum). RESULTS: PLB promoted a slower and deeper breathing pattern both at rest and during exercise. Whereas patients had no dyspnea with or without PLB at rest, during exercise dyspnea was variably affected by PLB across patients. Changes in the individual dyspnea scores with PLB during exercise were significantly correlated with changes in the end-expiratory lung volume (EELV) values estimated from inspiratory capacity maneuvers (as a percentage of total lung capacity; r2 = 0.82, p = 0.002) and with changes in the mean inspiratory ratio of pleural pressure to the maximal static inspiratory pressure-generating capacity (PcapI) [r2 = 0.84; p = 0.001], measured using an esophageal balloon, where PcapI was determined over the range of inspiratory lung volumes and adjusted for flow. CONCLUSION: PLB can have a variable effect on dyspnea when performed volitionally during exercise by patients with COPD. The effect of PLB on dyspnea is related to the combined change that it promotes in the tidal volume and EELV and their impact on the available capacity of the respiratory muscles to meet the demands placed on them in terms of pressure generation.

Adult↗
PubMed1984

Ventilatory regulation in eucapnic morbid obesity.

In morbid obesity, there is an increased hindrance to breathing caused by the effects of the increased mass on the chest wall and abdomen; subjects with morbid obesity can maintain eucapnia by increasing inspiratory neuromuscular drive and/or by altering central breath timing. We studied 23 eucapnic, obese subjects (greater than 190% predicted ideal weight), 7 males and 16 females with a mean age of 36.6 +/- 9.2 yr and 18 healthy, normal male subjects. Total lung capacity, functional residual capacity, and total thoracic compliance were significantly (p less than 0.05) reduced in the obese subjects. At rest, minute ventilation was significantly increased because of an increase in respiratory frequency, which in turn was due to a significant decrease in the expiratory time (TE) per breath; the ratio of inspiratory to expiratory time (TI/TE) was thus significantly altered, indicating an alteration in central breath timing. Resting inspiratory neuromuscular drive (as represented by mouth occlusion pressure) was significantly increased in the obese subjects, but tidal volume was not significantly altered. There was an increased ventilatory responsiveness to hypoxia and relatively decreased ventilatory responsiveness to hypercapnia in the obese subjects. These results indicate that morbidly obese subjects maintain eucapnia primarily by an alteration in central breath timing. Although these subjects have decreased responsiveness to CO2, putting them at some risk of developing respiratory failure under conditions of hypercapnic/hypoxic stress, it is possible that this is counteracted by the increased responsiveness to hypoxia.

Adult↗
PubMed1986

Pulmonary function tests in the detection of left heart failure: correlation with pulmonary artery wedge pressure.

Standard pulmonary function tests, including lung volumes measured by three fundamentally different techniques, were performed in 40 patients undergoing cardiac catheterization. These were compared with clinical and radiologic evaluations in detecting left heart failure (LHF). Patients with elevation in mean pulmonary artery wedge pressure (PAWM) greater than or equal to 20 mm Hg had significant restrictive changes with reduction in vital capacity (VC), forced expiratory volume in 1 s (FEV1.0), and total lung capacity (TLC) measured by helium dilution and body plethysmography. Radiographic TLC was not reduced in these patients or correlated with PAWM. Obstructive changes were not present. Radiologic gradings by 5 different observers were reasonably accurate in detecting LHF but varied between observers. VC and TLC measured by helium dilution and body plethysmography were slightly less sensitive but more specific in detecting PAWM elevation. Clinical classification was sensitive but nonspecific; in addition, clinical signs were not reliable indicators of elevated PAWM. We conclude that pulmonary function testing may provide objective, accurate, and useful information in the evaluation of cardiac patients for LHF. However, radiographic measurement of thoracic cage volume does not reflect the changes in lung gas volume measured by gas dilution or plethysmographic techniques in patients with chronic congestive heart failure.

Adult↗
PubMed1994

Interrelationships between pulmonary and extrapulmonary involvement in systemic sclerosis. A longitudinal analysis.

PURPOSE: (1) To evaluate the relationship between the degree of pulmonary involvement by systemic sclerosis (SSc) and the degree of involvement of other organ systems by SSc at baseline. (2) To assess the degree of impairment in lung function at presentation and the annual rate of change in lung function to predict the rate of progression of involvement of extrapulmonary organ systems by SSc over time. (3) To determine whether survival in patients with SSc can be predicted from the degree of lung function impairment at baseline or from the annual rate of change in lung function. METHODS: Semiquantitative indices of pulmonary and extrapulmonary involvement and pulmonary function tests (PFTs) were analyzed and compared in 62 nonsmoking scleroderma patients enrolled in a 3-year prospective drug trial, vs 47 in a "study group" who underwent serial evaluation. The other 16 "early withdrawals" withdrew prior to the second evaluation. The indices of organ system involvement were based on clinical, physiologic, and biochemical findings as previously published. The PFTs included total lung capacity (TLC), forced vital capacity (FVC), FEV1, and single-breath diffusing capacity for carbon monoxide (Dsb). Annualized rates of change in PFTs and indices of extrapulmonary involvement were calculated for each subject from data collected on at least 2 separate occasions at least 6 months apart. Spearman rank correlations were performed between individual baseline PFTs (expressed as percent predicted) and (a) indices of extrapulmonary involvement at baseline, (b) annualized rates of change in PFTs, and (c) annualized rates of change in indices of extrapulmonary involvement. Correlations also were performed between the rate of change in each lung function measure and rates of change in indices of extrapulmonary involvement. The ability of PFTs at baseline and their rates of change to predict cumulative survival was assessed by Cox stepwise regression. RESULTS: The degree of impairment in baseline PFTs was related to involvement of the right side of the heart but not to other extrapulmonary system involvement. Baseline PFTs were not related to the rate of subsequent decline of lung function or worsening of extrapulmonary organ system involvement. Subsequent annual rates of decline in lung function were related to worsening skin and upper gastrointestinal involvement. Cumulative survival may be related to the rate of decline in DCO, TLC, and FVC, but was not predicted by impairment in any measure of lung function. CONCLUSION: With the exception of involvement of the right side of the heart consistent with cor pulmonale, the degree of pulmonary involvement by SSc was not correlated with the extent of extrapulmonary involvement. The degree of pulmonary involvement by SSc did not predict subsequent worsening of either pulmonary or extrapulmonary involvement. Worsening pulmonary involvement by SSc, in general, does not correlate with worsening involvement of extrapulmonary organ systems, except for the skin and upper gastrointestinal tract. A rapid decline in DCO or lung volumes may predict poor survival.

Bone Diseases↗
PubMed2004

Involvement of pulmonary endothelial cell injury in the pathogenesis of pulmonary fibrosis: clinical assessment by 123I-MIBG lung scintigraphy.

PURPOSE: Pulmonary microvascular endothelial injury may be involved in the pathogenesis of pulmonary fibrosis (PF). The aim of this study was to evaluate the pulmonary vascular status in patients with PF by lung scintigraphic assessment of 123I-metaiodobenzylguanidine (123I-MIBG), which reflects latent endothelial cell lesions. METHODS: We assessed lung 123I-MIBG kinetics and clinical indices in 23 PF patients and 16 controls. Mean uptake ratios of lung to mediastinum (L/M) were calculated in anterior planar images at 30 (early image) and 270 (delayed image) min after intravenous injection of 123I-MIBG. The pulmonary mean washout rate (WR) of 123I-MIBG was also calculated. RESULTS: The L/M ratio in early images, but not in delayed images, was significantly lower in the PF patients than in the controls (L/M(early) 1.41+/-0.14 vs 1.53+/-0.10, p<0.01; L/M(delayed) 1.28+/-0.10 vs 1.33+/-0.07, p=NS). WR was significantly reduced in the PF patients compared with the controls (28.6%+/-3.1% vs 34.2%+/-5.1%, p<0.001). In the study subjects (PF patients plus controls) there were significant relationships between lung WR of (123)I-MIBG and other diagnostic parameters for the severity of PF, such as vital capacity (r=0.625, p<0.0001), total lung capacity (r=0.691, p<0.0001), carbon monoxide diffusing capacity (r=0.622, p<0.0001), serum angiotensin-converting enzyme activity (r=0.422, p<0.01), carbohydrate antigen KL-6 levels (r=-0.495, p<0.01) and surfactant protein-D levels (r=-0.461, p<0.01). When control subjects were excluded, similar significant correlations were observed between WR and %TLC (r=0.508, p<0.05), DL(CO) (r=0.593, p<0.01) and serum ACE activity (r=0.515, p<0.05) in the PF patients. CONCLUSION: These results suggest that endothelial cell injury plays a significant role in the pathogenesis of PF, and that lung WR of 123I-MIBG, which is a specific marker of endothelial damage, can serve as a novel diagnostic tool to evaluate the functional severity of PF.

3-Iodobenzylguanidine↗
PubMed1994

Clinical application of 131I-HIPDM in the patients with chronic obstructive pulmonary disease.

N,N,N'-trimethyl-N'-2 hydroxy-3-methyl-5-iodobenzyl-1,3-propanediamine iodine-131 (HIPDM) as a lung imaging and metabolic tracer in patients with chronic obstructive pulmonary disease (COPD) were used. 0.4 mCi 131I-HIPDM was rapidly injected into the antecubital vein. The imaging of 131I-HIPDM in the lung was different in various groups. 131I-HIPDM of the clearance by the lungs was a biphasic curve (rapid phase and slow phase). It was displayed that rapid phase of the clearance curve of 131I-HIPDM in the lungs in subjects with chronic obstructive pulmonary emphysema, especially those of smokers were very slow. The rapid phase of the 131I-HIPDM of the right lung clearance was significantly correlated with Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Functional Residual Capacity (FRC), Residual Volume (RV), Total Lung Capacity (TLC) p < 0.01; Peak Expiratory Flow Rate (PEFR), Vital Capacity (VC), Maximum Ventilatory Volume (MVV), Arterial oxygen tension (PaO2) p < 0.05. Smoking influence on clearance of 131I-HIPDM of the lung including normal smokers with normal lung function. It was considered that the analysis of the lung release of 131I-HIPDM forms a new lung dysfunction index and it was useful that found early lung damage.

Adult↗
PubMed1977

Hypothermic lung preservation functions, six or more years later.

The functions of each lung were measured 41 and 79 months following hypothermic twenty-four four lung preservation and autotransplantation in six and four dogs respectively. Functional results were compared with long-term autotransplanted canine lungs. Compliance, total lung capacity, functional reserve capacity and ventilation of preserved lungs were similar to autotransplanted lungs, and only slightly decreased as compared with normal animals. There was no statistically significant difference between the pulmonary diffusion capacity and oxygen uptake of the preserved and autotransplanted lungs group and autotransplants alone. However, in both groups, diffusion capacity and oxygen uptake were decreased as compared with intact animals. Pulmonary hypertension was found on occlusion of the contralateral lung's artery: it was due to increased pulmonary vascular resistance. No gross narrowing of the pulmonary artery or venous anastomosis was found that could explain the increased resistance. Diffuse emphysema of various degrees was observed in all animals. This study seems to indicate that hypothermic preservation of the lung does not affect significantly the long-term functional ability of the organ, and probably will have practical value in future clinical lung transplantation.

Animals↗
PubMedDate not supplied

Effects of electric arc welding on ventilatory lung function.

Respiratory symptoms, spirometry, forced expiratory flows, and the nitrogen closing volume test were studied in 119 welders and 90 controls, matched with respect to age, height, and smoking habits. Respiratory symptoms according to a questionnaire were more prevalent in the welders. No short-term changes of the measured variables during the day or week attributable to welding were found in twenty-one nonsmoking welders. Compared to the controls, closing volume and closing capacity (i. e., closing volume + residual volume) were significantly higher, and total lung capacity and the amplitude of the cardiogenic oscillations in the nitrogen curve were significantly lower in the welders who were nonsmokers or exsmokers, whereas there were no differences among smokers. These findings in welders may be attributable to deposition of welding fume particles in peripheral small airways or alveoli.

Aerosols↗
PubMed1994

The upper limit of alveolar capillary recruitment in a young man with lung growth impairment.

In order to obtain further insight into the adaptive mechanisms relating to gas exchange in anatomically small lungs, tests of mechanical lung function and gas exchange were made in an active young man, whose lung growth had been severely impaired due to pectus excavatum developed in childhood. We found our patient to have small (total lung capacity, 59% of predicted) but mechanically normal lungs. He had a normal cardiac output, a normal single-breath diffusing capacity (100% pred), and a high diffusion coefficient (148% pred) associated with a high pulmonary capillary blood volume (131% pred) at rest. Pulmonary distensibility (K) and elastic recoil were normal. During steady-state exercise he was unable to recruit further reserves of pulmonary capillaries, but this was not reflected in a plateau for oxygen consumption, which was presumably the result of an increased pulmonary capillary blood flow rather than volume. The recruitment of pulmonary capillary reserves in this young man has enabled him to maintain a normal maximum exercise capacity. In addition, the high stroke volume and a haemoglobin level in the high normal range (176 g.l-1) may have maintained his maximal exercise function, despite fewer alveolar units. This study suggests that, contrary to previous findings, loss of a major proportion of lung tissue need not impair exercise capacity. Patients with either small lungs or following pneumonectomy may benefit from physical training sufficient to optimize both an increase in cardiac output and recruitment of their existing alveolar capillary reserves.

Adult↗
PubMed1987

Pulmonary function in thalassemia major.

Pulmonary function tests were evaluated in 28 Chinese patients with beta-thalassemia major receiving regular transfusions and desferoxamine, and in 34 height-matched normal Chinese children. Comparison of lung function using analysis of covariance with reference to standing height showed that patients with thalassemia had a proportional decrease in forced vital capacity and forced expiratory flow volume in 1 second, whereas their expiratory flow rates, residual volume, and total lung capacity were comparable to those in normal children. The single-breath carbon monoxide diffusion capacity was normal. Our findings suggest that children with thalassemia major have mild restrictive lung disease. The previous controversy regarding the presence of restrictive or obstructive lung disease in patients with thalassemia may be related to the use of inappropriate control values.

Adolescent↗