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Relation between clinical and roentgenological scores and measures of lung function in cystic fibrosis, with special reference to pulmonary Xenon133 elimination.

Regional lung function (RLF) with Xenon133 was investigated in 40 patients with cystic fibrosis (CF) aged 5-28 years (mean 13) at 1-5 occasions during a 3-year period. The RLF was determined with a 4-collimator system and evaluated with a score based on the following parameters: (1) time of elimination of injected isotope and (2) of inhaled isotope, (3) regional ventilation, (4) regional perfusion and (5) ventilation-perfusion ratios. The results were related to spirometry, X-ray score (according to a modification of Chrispin and Norman) and clinical score (according to Shwachman and excluding X-ray), which were all assessed in the same day. RLF correlated to clinical (P less than 0.01) and radiological score (P less than 0.01) and to residual volume (P less than 0.001) and the ratio between one second forced expiratory volume to vital capacity (FEV%) (P less than 0.01), but much higher correlations were found between X-ray score, clinical score and different spirometric variables. We therefore conclude that RLF can be used in patients too young to cooperate in spirometry but that it is of less clinical value in older patients with CF.

Adolescent↗

Risk of developing diabetes is inversely related to lung function: a population-based cohort study.

AIM: To investigate whether reduced lung function is a risk factor for developing diabetes. METHODS: Non-diabetic men (n = 382) from the population-based cohort 'Men Born in 1914' were examined with spirometry at age 55 years. The cohort was re-examined at 68 years. Diabetes and fasting plasma glucose at follow-up were studied in relation to vital capacity (VC) and forced expiratory volume (FEV1.0) at baseline. RESULTS: Fifteen men developed diabetes during the follow-up. The percentage with diabetes in the 1st, 2nd, 3rd and top quartile of vital capacity were 7%, 5%, 2%, and 1%, respectively (P for trend = 0.01). Fasting glucose (log transformed, mmol/l) at follow-up was 1.63 +/- 0.16, 1.62 +/- 0.18, 1.61 +/- 0.11 and 1.60 +/- 0.11, respectively (P for trend = 0.11). The longitudinal associations between VC and diabetes (P = 0.001) and log glucose (P = 0.036) were significant after adjustments for several potential confounders. FEV(1.0) at baseline showed similar associations with diabetes at follow-up. CONCLUSIONS: The risk of developing diabetes is inversely associated with pulmonary function among middle-aged men.

Blood Glucose↗

Repeatability of lung function tests during methacholine challenge in wheezy infants.

BACKGROUND: The repeatability of lung function tests and methacholine inhalation tests was evaluated in recurrently wheezy infants over a one month period using the rapid thoracic compression technique. METHODS: Eighty-one wheezy, symptom free infants had pairs of methacholine challenge tests performed one month apart. Maximal flow at functional residual capacity (VmaxFRC) and transcutaneous oxygen tension (Ptco2) were measured at baseline and after methacholine inhalation. Provocative doses of methacholine causing a 15% fall in Ptco2 (PD15 Ptco2) or a 30% fall in VmaxFRC (PD30 VmaxFRC) were determined. RESULTS: Large changes in VmaxFRC were measured from T1 to T2 with a mean difference between measurements (T2-T1) of 7 (113) ml/s and a 95% range for a single determination for VmaxFRC of 160 ml/s. The mean (SD) difference between pairs of PD30 VmaxFRC measurements was 0.33 (1.89) doubling doses with a 95% range for a single determination of 2.7 doubling doses. Repeatability of PD15Ptco2 was similar. A change of 3.7 doubling doses of methacholine measured on successive occasions represents a significant change. CONCLUSIONS: Baseline VmaxFRC values are highly variable in wheezy, symptom free infants. Using either VmaxFRC or Ptco2 as the outcome measure for methacholine challenges provided similar repeatability. A change of more than 3.7 doubling doses of methacholine is required for clinical significance.

Asthma↗

Socioeconomic status and lung function among primary school children in Canada.

We examined the relationship of lung function level to socioeconomic status (SES) using a cross-sectional design among 989 primary school children selected from 18 Montreal schools and studied between April 1990 and November 1992. Information on each child's health, demographics, home exposure to tobacco smoke, pets, and cooking and heating fuel used in the child's home was collected by questionnaire. Spirometry was performed at school. Parental occupation was used to establish SES. After adjusting for personal, familial, and environmental factors, in boys but not in girls, FEV1 and FVC were progressively larger in higher categories of SES (p < 0.001 for linear trend). After taking into account the effect of multiple comparisons and adjusting for personal, familial, and environmental factors, boys from families in the lowest category of SES were found to have an FEV1 lower by 8.2% (95% CI, -13.8 to -2.1) and an FVC lower by 8.1% (95% CI, -13.4 to -2.6) when compared with the most advantaged. These results provide evidence that socioeconomic status, independent of common indoor exposures, is a risk factor for lower FEV1 and FVC among boys.

Canada↗

Lung function in sickle cell hemoglobinopathy patients compared with healthy subjects.

Previous studies of lung function tests performed on patients with sickle cell disease have shown a restrictive ventilatory defect, usually a diffusion defect, and mild hypoxia at rest. The present study was undertaken to explain the pathophysiology of these changes and to extend these studies to include functional measurements not reported previously.Lung function studies were performed at rest and during treadmill walking on 66 patients with sickle cell anemia and on 16 healthy control subjects. Patients had restrictive ventilatory defects, decreased lung compliance, and uneven ventilation-perfusion ratios. These abnormalities caused an increased alveolar-arterial oxygen tension difference that caused hypoxemia. The diffusion defects were because of the sickle cell disease.Carboxyhemoglobin levels were increased in patients with sickle cell disease. This increase may be caused by a combination of factors, including increased cigarette smoking, hemolysis, and preferential survival of red blood cells that contain carbon monoxide and which do not sickle. During treadmill walking, the patients with sickle cell disease showed a decreased work tolerance caused by impaired oxygen delivery. The anaerobic threshold is reached sooner in patients with sickle cell disease and may also account for the limitations in work capacity of these patients.

Adult↗

Ventilation-perfusion imaging in evaluating regional lung function in nonpenetrating injury to the chest.

The extent of chest wall and lung injury after nonpenetrating injury to the chest (NIC) determine how aggressive and invasive management modalities should be. We investigated the value of ventilation (133Xe) and perfusion (99mTc) studies as indicators of extent of lung injury in 28 patients with moderate to severe unilateral NIC. The ventilation-perfusion (V/Q) abnormalities were compared with parameters conventionally used to evaluate NIC. All studies were carried out within 24 h of NIC and repeated 24 h later. Ventilation (p less than 0.001) and perfusion (p less than 0.01) abnormalities were more extensive soon after NIC than suggested by chest roentgenograms. Chest x-ray film changes lagged behind V/Q changes on admission and also after 24 h. The extent of ventilation, perfusion, and chest x-ray film abnormalities on admission were all predictors of increased morbidity. V/Q studies may be useful to define the extent as well as the changes in regional lung function following NIC.

Adult↗

Lung function abnormalities in cystic fibrosis and changes during growth.

Static lung volumes (VC, TLC, FRC, RV), elastic recoil pressure of the lungs (Pst(1) at 100, 90, and 60% of TLC), static lung compliance [Cst(1)], specific airway conductance at FRC level (Gaw/TGVex), forced expiratory volume in the first second (FEV1), maximal expiratory flows (Vmax.) at 25 and 50% of VC and at 60% of TLC, and "upstream" airway conductance (Gus) at 60% of TLC were studied in 28 patients with cystic fibrosis, 5 to 25 years old, over a period of 1 to 5 years. The data were compared individually with normal values, related to body height in the form of regression equations and expressed in percentage of predicted values. From the indices assessing airway function, Vmax. at low lung volumes, Gus at 60% TLC, RV and RV/TLC were the functional parameters most consistently abnormal. Among the indices characterizing lung elasticity, Pst(1) at 60% TLC was the most abnormal. Generally, the values of the majority of lung function indices [VC, TLC, FRC, Pst(1)] declined during growth. Vmax. at all lung volumes and Gus at 60% TLC did not deteriorate with growth probably due to the great abnormality of these parameters already in young patients. It was also observed that lung function did not change significantly over a period of 1 to 5 years corresponding to a 10 cm increase in body height. However, over that period, lung function improved in some of the subjects, did not change in over 50% of the cases and deteriorated in the others.

Adolescent↗

Lung function and nervous system involvement in asbestosis.

A group of 115 patients with asbestosis of the lungs was tested in detail for neurological functions and lung functions in order that any possible impaired pulmonary function and neurological signs (especially peripheral neuropathy) could be discovered. Attention was also paid to finding out whether peripheral neuropathy, which is frequently encountered among asbestosis patients, had any role in decreased pulmonary function. A slight trend towards lowered spirometrical values (vital capacity, forced expiratory volume in one second, maximal mid-expiratory flow and maximal expiratory flow at 25% of vital capacity) was found for the group of patients with peripheral neuropathy. No differences in diffusing capacity were found between the groups of patients either with or without peripheral neuropathy. We concluded that the spirometrical findings are more indicative of a parallel phenomenon than a causal factor. Nor was the involvement of the central nervous system associated with decreased pulmonary function. In short, the pulmonary dysfunction of our asbestosis patients did not appreciably contribute to the occurrence of nervous system involvement, whether central or peripheral.

Adult↗

Effects of delivery by caesarean section on lung function in healthy newborn infants.

With the aim of extending previous studies showing differences in lung function after birth between infants delivered vaginally (VD) and by Caesarean section (CS) we investigated lung volumes, ventilation, efficiency of ventilation, and lung mechanics in 24 healthy, full term infants with no clinical signs of respiratory disease, 12 after VD and 12 after CS. Measurements were made on two occasions: 2 and 26 hours after birth. At 2 hours no differences in any measured quantity were found between the groups. The only difference found 24 hours later was that the average thoracic gas volume (TGV), was lower in infants after CS than after VD. The difference in functional residual capacity was, however, not significant. This means that the difference in TGV, previously also found by other workers, did not affect the ventilated air space. Our results do not support the theory of general inferiority in lung performance after birth in healthy, full term infants without respiratory disease delivered by CS.

Cesarean Section↗

[The clinical significance of changes in lung function, oxygen consumption and some bio-active substances in immigrants into high altitude].

Lung function was assayed in 40 healthy adults who moved to high altitude area (Lhasa, 3,658 m above sea level, Group A) recently and 160 who had lived for a long period of time (Group B). Oxygen consumption was also measured and serum triiodothyronine (T3), thyroxin (T4), reverse triiodothyronine (rT3), endogenous digitalis factors (EDF), plasma renin activity (PRA), angiotensin II (AII), aldosterone (ALD) and the concentration of atrial natriuretic peptide (ANP) were determined with radioimmunoassay in 80 of them. The results showed: (1) In both groups, lung volume was increased, flow rate of ventilation markedly quickened and diffusion enhanced as compared with the normal value; (2) Thyroid function was reduced; (3) ANP and EDF were markedly increased and ALD was reduced. AII was markedly increased and PRA was normal in Group A but on the contrary in Group B. The possible relation of these changes with the length of time of stay at high altitude is discussed.

Adaptation, Physiological↗

Increased nonspecific bronchial reactivity in cigarette smokers with normal lung function.

Seventeen lifetime nonsmoking male teachers and 17 smoking male teachers with normal lung function were compared. The smokers showed a significantly greater prevalence of cough (p < 0.01), sputum production (p < 0.05), and wheezing (p < 0.01), but not dyspnea. There was no difference in the prevalence of a history of allergy, or the number of positive reactions to allergy prick skin tests, or in elevated serum IgE. Lung volumes, expiratory flow rates, specific airway conductance (SGaw), and the slope of phase III of the single breath O2 test were not significantly different. The geometric mean provocation concentration of histamine required to reduce the SGaw by 35% (PC35) was significantly lower in the smokers (1.84 mg/ml) than in the nonsmokers (4.83 mg/ml) (p < 0.005). Increased nonspecific bronchial reactivity may be a factor contributing to the development of airway obstruction in smokers.

Bronchi↗

Regional lung function in unilateral diaphragmatic paralysis.

Radioactive xenon-133 was used to study the regional lung function of five patients with unilateral diaphragmatic paralysis unassociated with intrathoracic disease. All patients showed a reduction in total lung capacity to which the affected side contributed an average of 37%. There was a decrease in the amount of inhaled xenon and a lesser decrease in the amount of injected xenon reaching the lung base on the paralysed side.The distribution in the opposite lung did not differ significantly from that found in normal subjects although the proportion of inhaled xenon reaching the lung base was rather less than in the normal group. The washout of injected xenon was normal except for slight impairment at the lung base on the paralysed side in one patient and at both bases in another.

Adult↗

Lung function 8-18 years after intermittent positive pressure ventilation for hyaline membrane disease.

Lung function and respiratory symptoms were studied in 40 children aged 8-18 years who had been ventilated for hyaline membrane disease after birth; 11 had had bronchopulmonary dysplasia. Also studied were 38 age matched children who had had hyaline membrane disease but had not required ventilation, 25 unmatched children who were born prematurely but did not develop hyaline membrane disease, and 39 randomly selected pupils of similar age. There was no difference in thoracic gas volume, total lung capacity, inspiratory vital capacity, residual volume, or transfer factor for carbon monoxide between the groups. Respiratory symptoms during the three years before the study and the frequency of clinically diagnosed asthma in patients and their family were similar in all the children with hyaline membrane disease irrespective of whether they had been ventilated or had had bronchopulmonary dysplasia. The children with bronchopulmonary dysplasia, however, had a lower forced expiratory volume in one second (FEV1) before bronchodilator (73% predicted) than the other groups (88-95% predicted). Children who had required ventilation had lower values for specific airways conductance (sGaw) and a greater increase in FEV1 (delta FEV1) after salbutamol (13%) than non-ventilated children (6%); delta FEV1 was associated with the peak pressure of intermittent positive pressure ventilation, a family history of asthma and a history of wheezing, recurrent respiratory illnesses, and a doctor's diagnosis of asthma during the three years before the study. These findings indicate that after eight years of age patients with bronchopulmonary dysplasia have more reversible airways obstruction, compatible with increased bronchial smooth muscle tone.

Adolescent↗

Respiratory function in esophageal hiatus hernia. II. Regional lung function.

64 subjects with hiatus hernia (34 sliding, 22 mixed, and 8 of paraesophageal variety) were divided into 3 groups according to the transverse diameter of the thoracic loculus and examined by 133Xe-radio-spirometry in the supine position. 48 subjects (22 sliding, 18 mixed, and 8 or paraesophageal variety) showed a significant reduction in the regional ventilation, perfusion or lung volume. Significant correlations were found between the diameter of the thoracic loculus and the reduction in these vairables of the affected lung.

Adult↗

[Lung function and operability. Importance of preoperative right heart catheterization in patients with bronchial cancer].

Lung resection may be followed by pulmonary hypertension leading to cardio-respiratory insufficiency. Therefore, pulmonary arterial pressure should be known before operation. To test the presence of pulmonary hypertension, results of lung function studies and right heart catheterization were compared in 100 patients with bronchogenic carcinoma. Mean pulmonary arterial pressure could be correlated with arterial partial pressures of oxygen and carbon dioxide as well as with total airway resistance and the Tiffeneau-test (FEV1/VC). A multiple regression analysis including 5 non hemodynamic variables, however, demonstrated a standard estimation error of mean pulmonary arterial pressure of 4.4 mmHg at rest and 8.0 mmHg during exercise thus proving that the multiple regression is of no clinical significance. Also by a discriminant analysis, patients could not be identified with clinically sufficient reliability as hemodynamically normal or pathological. Thus, right heart catheterization is an indispensable prerequisite to lung resection.

Airway Resistance↗

Lung function in acute paraquat intoxication.

Functional and morphological examination of the lungs was performed in rats 48 hours after intratracheal injection of 0.5 mg/kg of the herbicide paraquat. Pronounced tachypnoea was observed (235+/-20 c/min), which also persisted under urethane anaesthesia (210+/-18 c/min). In control rats the mean breathing rate was 115+/-11 and 90+/-9 c/min in wake and anaesthetized rats respectively. The rate of breathing decreased to comparable values in experimental and control rats after bilateral cervical vagotomy. The functional residual lung capacity was significantly increased in experimental rats. After vagotomy also this increase of functional residual capacity became normalized. Histologically the disease was characterized by focal formation of hyaline membranes and oedema with occasional haemorrhages and signs of inflammation. The significant role fo vagal function in lung pathology is demonstrated.

Animals↗