Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pulmonary Diffusing Capacity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,801 records · Page 100Linked to original sources
PubMed1991

Cardiopulmonary exercise testing in children following surgery for tetralogy of Fallot.

The purpose of this study was to compare the cardiopulmonary responses at rest and during exercise of children following surgical correction of tetralogy of Fallot. The physiologic measurements assessed at rest and during maximal treadmill exercise included diffusing capacity of the lung for carbon monoxide, heart rate, oxygen consumption, minute ventilation, and cardiac output. Twenty children with repaired tetralogy of Fallot served as the study group, and 20 normal boys and girls served as controls. Subjects with tetralogy of Fallot had significantly lower values than those of control subjects for maximal cardiac output and somewhat lower values for diffusing capacity of the lung for carbon monoxide and heart rate. We conclude that the exercise cardiac function of children with surgically corrected tetralogy of Fallot is somewhat diminished compared with that of control children. This information is necessary to establish safe, yet effective exercise guidelines for this select population.

Angiography↗
PubMed1981

Design of the mammalian respiratory system. IX. Functional and structural limits for oxygen flow.

This paper presents the synthesis and interpretation of a series of correlated studies of the mammalian respiratory system--measurements of maximal rate of O2 consumption, the lung's diffusing capacity, the mitochondrial volume, and the capillary number and length in skeletal muscle. It discusses the results with respect to the principle of symmorphosis, i.e. of morphogenesis adapted to functional needs. We find that the accumulated evidence supports this principle at all organizational levels considered, although the models used for structure-function correlation need further refinement.

Aerobiosis↗
PubMed1986

Lung volumes and diffusion capacity in sickle cell trait.

Patients with sickle cell anemia have a restrictive ventilatory pattern, with reduction in diffusion capacity of the lung (DLco) and lung volumes. Diffusion capacity and lung volumes are reported as either normal or reduced in subjects with sickle cell trait. Thirteen subjects with sickle cell trait, age range 25 to 79 years, were compared with 13 normal subjects matched for age, sex, height, and smoking patterns. There was no significant difference in mean values of DLco or lung volume for the two groups. Neither was there a consistent difference for age-matched individuals. Normal lung function in sickle cell trait as opposed to sickle cell disease is probably related to the fact that the former have fewer, if any, pulmonary infectious and infarctive episodes.

Adult↗
PubMed1982

[The influence of helium concentration in determining respiratory function parameters].

Before a research about normals values of lung diffusing capacity for CO in Italian people, the Authors investigate if different concentration of Helium in respiratory gases could have any influence on data. Experiments were performed by testing 8 male subjects. Each one repeated lung function tests three times using gas mixtures with different Helium percentage. Results were evaluated by meaning of t Studnt's and Bartlett's Chi-square tests. Results show no significant difference.

Adult↗
PubMed1979

Effect of carboxyhemoglobin on the single breath diffusing capacity: derivation of an empirical correction factor.

The effect on measured DLco of different blood concentrations of COHb produced by breathing CO was studied in 19 healthy nonsmoking subjects. The DLco calculated without adjustment for blood COHb was found to be spuriously reduced by approximately 1% of the observed baseline value for each percent increase in blood COHb saturation. When measuring DLco of subjects who are likely to have elevated COHb blood levels, it is recommended that either blood COHb concentration or equilibrated alveolar PCO be determined in order to correct the DLco for the effect of COHb.

Adult↗
PubMed1987

Functional changes in the lungs of guinea pigs exposed to sodium sulfite aerosols.

Guinea pigs were exposed head only for 1 hr to submicrometer sodium sulfite aerosols (mass median aerodynamic diameter = 0.36 micron, sigma g = 2.96) at 474, 669, and 972 micrograms SO3(2-)/m3. Respiratory mechanics were measured in unanaesthetized animals before, during, and after exposure. Dose-related increases in resistance and decreases in compliance were observed. At 972 micrograms SO3(2-)/m3, the sodium sulfite aerosol caused a 50% increase in resistance and a 19% decrease in compliance. These changes were still present 1 hr after the end of exposure. The results were used to assess the irritant potency of sodium sulfite aerosol. Another group of guinea pigs was exposed whole body for 1 hr to the same aerosol at 0, 204, 395, and 1152 micrograms SO3(2-)/m3. Immediately after the exposures, lung volume, diffusion capacity for carbon monoxide (DLCO), and wet lung weight were evaluated in anesthetized, tracheotomized animals. As compared to controls, total lung capacity, vital capacity, functional residual capacity, residual volume, and DLCO were all decreased with increasing concentrations of sodium sulfite. Dose-related increases in wet lung weights were also observed. These results were compared with the irritant responses of animals exposed to zinc oxide and sulfur dioxide mixed under different conditions of temperature and humidity.

Aerosols↗
PubMedDate not supplied

[Disorders of the ventilation-diffusion correlations and of the gas-transport function of the blood in the acute period of burn trauma in children].

External respiration and blood gas composition were examined in 187 children aged 1 to 14 years during the acute period of burn disease (burn shock and toxemia). The patients were divided into three groups with different area of thermal injury to the skin. Group 1 were children with burns of up to 10% of body surface area. The ventilation parameters in this group were changed just negligibly, and the diffusion capacity of the lungs and gas composition of arterial blood were within the normal range of values both during shock and toxemia. In patients with burns involving 11 to 20% of body surface the ventilation parameters were changed appreciably and did not compensate for each other, as was observed in group 1. The diffusion capacity of the lungs and blood gas composition values were moderately decreased. During toxemia the minute-consumption of oxygen was decreased and alveolar oxygen tension remained unchanged. As a result of this, the diffusion capacity of the lungs and blood gas parameters continued to decrease. The most dynamic changes were observed in children with burns involving 21 to 45% of body surface. The ventilation-diffusion disorders and blood gas composition were altered, particularly so during toxemia; the changes consisted in a decrease of the minute ventilation volume and oxygen tension in arterial blood and a moderate increase of alveolar oxygen tension, which led to further decrease of the diffusion capacity of the lungs. In parallel with the disorders in the above parameters, x-ray changes in the lungs were observed, which were characterized by a vascular-interstitial pattern in group 2 and infiltrative changes in group 3. In children with burn wounds of 35 to 45% of body surface these changes presented as the developing lung edema.

Acute Disease↗
PubMed1978

[Exogenous allergic alveolitis during childhood (author's transl)].

Four children aged 31/2 to 13 years, who developed allergic alveolitis as a result of antigenic exposure in a domestic situation are described. The clinical symptoms consisted of gradual onset of increasing dyspnoea, chronic cough and weight loss. Lung function tests showed characteristic reduction in vital and diffusion capacity. Serologically, antibodies against animal antigens were demonstrated in all patients. Radiologically there were pronounced reticular changes in both lungs affecting mostly the middle and lower zones. Occasionally there were miliary and sometimes confluent shadows. In differential diagnosis, virus infections, pneumocystis carinii, fungus infections, dermatomyositis, sarcoidosis and tuberculosis had to be considered. Apart from a short course of steroid treatment, it is necessary to make certain that the children are no longer exposed to the causal antigen. Under these conditions the prognosis is good, but otherwise the disease, as in adults who are continuously exposed to the antigen, results in pulmonary fibrosis.

Adolescent↗
PubMed1977

Pulmonary dysfunction after lymphangiography.

Pulmonary function tests were done on 15 patients before and after bipedal lymphangiography. Lymphangiography was associated with an approximate 10 per cent reduction in lung volume. This phenomenon persisted for 48 to 72 hours. The probable mechanism for this reduction is closure of terminal airways or alveolar ducts or both and is reversible by beta-adrenergic drugs. The reduction does not correlate with the severity of pre-existing pulmonary disease. The degree of pulmonary impairment can be assessed roughly by measurement of the vital capacity. An operation can be performed safely 3 to 5 days after lymphangiography.

Aged↗
PubMedDate not supplied

[Correlation of the size of the residual volume measured by whole body plethysmography and the single breath helium dilution method].

The value of residual volume, intrathoracic gas volume, functional residual capacity and total lung capacity obtained by the method of body plethysmography and helium dilution method was correlated by single-breath diffusing capacity. These parameters were correlated in 22 patients who had had complete functional diagnostics of the lung: spirometry, flow volume curve, body plethysmography and single-breath diffusing capacity. All findings were within normal limits, which was a condition for selection of patients for our group. Statistically significant differences (p = 0.01) of t-test were established between residual volumes by the plethysmographic and helium dilution method of single-breath diffusing capacity. The residual volume obtained by body plethysmography showed higher values for 526 ml, or 30%. The intrathoracic gas volume showed higher values for 682 ml, or 17%. Inspite of the fact that values of RV obtained by two methods had statistically significant differences, they were still within normal limits, if presented as percent of the predicted value.

Adult↗
PubMed2004

Improvement of alveolar-capillary membrane diffusing capacity with exercise training in chronic heart failure.

Chronic heart failure (CHF) may impair lung gas diffusion, an effect that contributes to exercise limitation. We investigated whether diffusion improvement is a mechanism whereby physical training increases aerobic efficiency in CHF. Patients with CHF (n = 16) were trained (40 min of stationary cycling, 4 times/wk) for 8 wk; similar sedentary patients (n = 15) were used as controls. Training increased lung diffusion (DlCO, +25%), alveolar-capillary conductance (DM, +15%), pulmonary capillary blood volume (VC, +10%), peak exercise O2 uptake (peak VO2, +13%), and VO2 at anaerobic threshold (AT, +20%) and decreased the slope of exercise ventilation to CO2 output (VE/VCO2, -14%). It also improved the flow-mediated brachial artery dilation (BAD, from 4.8 +/- 0.4 to 8.2 +/- 0.4%). These changes were significant compared with baseline and controls. Hemodynamics were obtained in the last 10 patients in each group. Training did not affect hemodynamics at rest and enhanced the increase of cardiac output (+226 vs. +187%) and stroke volume (+59 vs. +49%) and the decrease of pulmonary arteriolar resistance (-28 vs. -13%) at peak exercise. Hemodynamics were unchanged in controls after 8 wk. Increases in DlCO and DM correlated with increases in peak VO2 (r = 0.58, P = 0.019 and r = 0.51, P = 0.04, respectively) and in BAD (r = 0.57, P < 0.021 and r = 0.50, P = 0.04, respectively). After detraining (8 wk), DlCO, DM, VC, peak VO2, VO2 at AT, VE/VCO2 slope, cardiac output, stroke volume, pulmonary arteriolar resistance at peak exercise, and BAD reverted to levels similar to baseline and to levels similar to controls. Results document, for the first time, that training improves DlCO in CHF, and this effect may contribute to enhancement of exercise performance.

Bicycling↗
PubMed1986

The relationship between alveolar oxygen tension and the single-breath carbon monoxide diffusing capacity.

The effects of alveolar oxygen tension (PAO2) on the single-breath carbon monoxide diffusing capacity (DLCO) were quantified and a factor was derived to accommodate for differences in PAO2 over commonly encountered altitudes and/or varying concentrations of oxygen in the test gas mixture (FIO2) We performed duplicate measurements of DLCO in 7 normal subjects with 6 different oxygen fractions (0.176, 0.196, 0.211, 0.22, 0.25, and 0.27). The PAO2 for each test was measured as the PO2 in the alveolar gas sample bag. DLCO varied inversely with PAO2 and changed by 0.35% for each mmHg change in PAO2 (r = -0.62, p less than 0.001). At an FIO2 of 0.25, PAO2 varied between subjects and was highly correlated with each subject's residual volume to total lung capacity ratio (r = -0.84, p less than 0.001). We suggest that laboratories can adjust the measured DLCO when PAO2 is not congruent to 120 mmHg by the following formula: DLCO (corrected = DLCO (measured) x [1.0 + 0.0035 (PAO2 - 120)].

Adult↗
PubMed1980

The lung of shrews: morphometric estimation of diffusion capacity.

The lungs of 16 shrews from 8 species (Sorex minutus, Neomys fodiens, Suncus etruscus, Crocidura russula, C. juvenetae, C. poensis, C. flavescens, C. giffardi) ranging in body weight from 2.2 to 100 g were studied by morphometry in order to compare the structural diffusion capacity for oxygen. DL02, with the oxygen consumption, VO2, measured on the same animals. VO2 was determined by short term measurements using a respirometer. DLO2 was estimated morphometrically. Both parameters demonstrated good coincidence in their allometric behaviour, establishing further progress in structure-function relationship in the respiratory apparatus. Whereas VO2 as well as DLO2 of shrews with a body weight W greater than 5 g follow the same allometric function established for mammals in general, the values for shrews with W less than 5 g exhibit significantly higher values. It appears that the pulmonary gas exchange parenchyma of these smallest mammals is well suited to supply the organism with the comparatively high levels of O2 required by the high metabolic rates, exhibiting a structural adaptation of the lung to higher VO2.

Animals↗
PubMed1987

Respiratory effects of cocaine "freebasing" among habitual users of marijuana with or without tobacco.

Use of cocaine by smoking its alkaline precursor ("freebasing") has become increasingly prevalent. Recent studies of small numbers of cocaine users suggest that freebasing frequently causes cough, dyspnea, and abnormalities in diffusing capacity (DCO), although these findings could have been due to concomitant use of other drugs. We therefore evaluated the relationship between cocaine use by freebasing and chronic respiratory symptoms and lung dysfunction in a large sample of habitual smokers of marijuana with or without tobacco who denied intravenous drug abuse. The findings suggested that, among habitual marijuana smokers, "moderate" cocaine smoking damaged both large and small airways, as reflected by functional changes that were independent of concomitant marijuana use and appeared to be synergistic with the effects of tobacco. On the other hand, no adverse influence of cocaine smoking on the pulmonary microcirculation was demonstrated in our sample of freebase users.

Adult↗
PubMed2005

Differences in pulmonary function before vs. 1 year after hypofractionated stereotactic radiotherapy for small peripheral lung tumors.

PURPOSE: To evaluate long-term pulmonary toxicity of stereotactic radiotherapy (SRT) by pulmonary function tests (PFTs) performed before and after SRT for small peripheral lung tumors. METHODS AND MATERIALS: A total of 17 lesions in 15 patients with small peripheral lung tumors, who underwent SRT between February 2000 and April 2003, were included in this study. Twelve patients had primary lung cancer, and 3 patients had metastatic lung cancer. Primary lung cancer was T1-2N0M0 in all cases. Smoking history was assessed by the Brinkman index (number of cigarettes smoked per day multiplied by number of years of smoking). Prescribed radiation doses at the 80% isodose line were 40-60 Gy in 5-8 fractions. PFTs were performed immediately before SRT and 1 year after SRT. Test parameters included total lung capacity (TLC), vital capacity (VC), forced expiratory volume in 1 s (FEV1.0), and diffusing capacity of lung for carbon monoxide (DLCO). PFT changes were evaluated in relation to patient- and treatment-related factors, including age, the Brinkman index, internal target volume, the percentages of lung volume irradiated with >15, 20, 25, and 30 Gy (V15, V20, V25, and V30, respectively), and mean lung dose. RESULTS: There were no significant changes in TLC, VC, or FEV1.0 before vs. after SRT. The mean percent change from baseline in DLCO was significantly increased by 128.2%. Univariate and multivariate analyses revealed a correlation between DLCO and the Brinkman index. CONCLUSIONS: One year after SRT as compared with before SRT, there were no declines in TLC, VC, and FEV1.0. DLCO improved in patients who had been heavy smokers before SRT, suggesting a correlation between DLCO and smoking cessation. SRT seems to be tolerable in view of long-term lung function.

Aged↗
PubMed1991

Prediction of carbon monoxide diffusing capacity of the lung in splenectomized sheep.

The steady state diffusing capacity of the lung for carbon monoxide (DLCO) was studied in 18 splenectomized adult ewes. Seven animals were anemic when studied. Weight (Wt) and, to a lesser extent, hemoglobin (Hb) level were the key predictive variables of DLCO. Sheep DLCO can be expected to range between 15 and 28 ml/min/mmHg in adult ewes which are not anemic. When DLCO measurements were repeated up to three times on the same day no significant decreases occurred. Thus, the data demonstrated no CO back-pressure caused by preceding DLCO determinations. This paper's importance is in defining a normal predictive range for this sensitive parameter of pulmonary function.

Animals↗
PubMed1985

Monitoring intrapulmonary hemorrhage in Goodpasture's syndrome.

Diffusing capacity of carbon monoxide (Dco) was measured frequently in a patient with recurrent intrapulmonary hemorrhage secondary to Goodpasture's syndrome. This simple test was found to be a sensitive and useful indicator of the presence or absence of recurrent intrapulmonary hemorrhage. As this is now the major cause of mortality in this disease, we recommended that frequent measurements of the Dco be an important part of its management.

Adult↗

Refine your search to explore more results.