Changes In Pulmonary Diffusing Capacity Research Articles

Acute effects of combined exercise and oscillatory positive expiratory pressure therapy on sputum properties and lung diffusing capacity in cystic fibrosis: a randomized, controlled, crossover trial

BackgroundRegular airway clearance by chest physiotherapy and/or exercise is critical to lung health in cystic fibrosis (CF). Combination of cycling exercise and chest physiotherapy using the Flutter® device on sputum properties has not yet been investigated.MethodsThis prospective, randomized crossover study compared a single bout of continuous cycling exercise at moderate intensity (experiment A, control condition) vs a combination of interval cycling exercise plus Flutter® (experiment B). Sputum properties (viscoelasticity, yield stress, solids content, spinnability, and ease of sputum expectoration), pulmonary diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) were assessed at rest, directly and 45 min post-exercise (recovery) at 2 consecutive visits. Primary outcome was change in sputum viscoelasticity (G’, storage modulus; G”, loss modulus) over a broad frequency range (0.1–100 rad.s− 1).Results15 adults with CF (FEV1range 24–94% predicted) completed all experiments. No consistent differences between experiments were observed for G’ and G” and other sputum properties, except for ease of sputum expectoration during recovery favoring experiment A. DLNO, DLCO, alveolar volume (VA) and pulmonary capillary blood volume (Vcap) increased during experiment A, while DLCO and Vcap increased during experiment B (all P < 0.05). We found no differences in absolute changes in pulmonary diffusing capacity and its components between experiments, except a higher VA immediately post-exercise favoring experiment A (P = 0.032).ConclusionsThe additional use of the Flutter® to moderate intensity interval cycling exercise has no measurable effect on the viscoelastic properties of sputum compared to moderate intensity continuous cycling alone. Elevations in diffusing capacity represent an acute exercise-induced effect not sustained post-exercise.Trial registrationClinicalTrials.gov; No.: NCT02750722; URL: clinical.trials.gov; Registration date: April 25th, 2016.

Effects of blood transfusion on cytokine profile and pulmonary function in patients with thalassemia major.

Thalassemia major (TM) is characterized by abnormal hemoglobin synthesis, which results in decreased oxygen delivery to the tissues, ineffective erythropoiesis and iron overload. The purpose of this study was to find out the predominant type of lung mechanical abnormalities in TM patients, the prevalence of the change in pulmonary diffusing capacity and to search the association of cytokines with pulmonary function tests (PFTs). TM patients (n = 26) who were on regular transfusion program were included in the study. Pretransfusional and posttransfusional PFTs were performed. Before transfusion, blood samples were collected for complete blood count, serum ferritin, zinc, transforming growth factor-β1 (TGF-β1), interleukin (IL)-8 and IL-10 levels. Obstructive lung pattern was the predominant pulmonary sequela. Male gender was the main risk factor for pulmonary function abnormality. Because of very low values, serum IL-10 levels of all patients were undetectable, and serum IL-8 levels could be measured only in six patients. Median serum IL-8 level was higher in patients with abnormal PFT. Pretransfusional single breath diffusion of carbon monoxide (DLCO ) correlated negatively with serum TGF-β1 and ferritin levels. After transfusion, there was a statistically significant decrease in forced expiratory volume in 1 s, forced expiratory flow between 25% and 75% of vital capacity, and airway conductance but significant increase in DLCO . Although they are mostly asymptomatic, TM patients have important PFT abnormalities. Blood transfusion may have an acute deleterious effect on pulmonary functions. The disturbed pulmonary functions were found to correlate with IL-8 and TGF-β levels. Relations of different cytokines with different PFT parameters suggest that the immune system is effective pulmonary dysfunction.

Pharmacokinetics and Metabolism of All‐trans‐and 13‐cis‐Retinoic Acid in Pulmonary Emphysema Patients

Retinoids promote lung alveolarization in animal models and were administered to patients as part of the Feasibility of Retinoid Therapy for Emphysema (FORTE) study. This FORTE substudy investigated the pharmacokinetic profiles of 2 retinoic acid isomers-all-trans-retinoic acid (ATRA) and 13-cis-retinoic acid (13-cRA)-in subjects with emphysema, evaluated strategies to overcome self-induced ATRA catabolism, and identified pharmacodynamic relationships. Comprehensive and limited pharmacokinetics were obtained at multiple visits in emphysema subjects treated with placebo (n = 30), intermittent dosing (4 days/week) with low-dose ATRA (1 mg/kg/day, n = 21), or high-dose ATRA (2 mg/kg/day, n = 25) or daily administration of 13-cRA (1 mg/kg/day, n = 40). High-dose ATRA produced the highest peak plasma ATRA Cmax. However, at follow-up, plasma ATRA C(max) was significantly decreased from baseline in subjects whose day 1 levels exceeded 100 ng/mL (P < .0001). In contrast, administration of 13-cRA produced lower plasma ATRA C(max) (<100 ng/mL), but the levels were significantly higher at follow-up than those on day 1 (P < .001). Plasma ATRA levels as determined on day 1 correlated with changes in pulmonary diffusing capacity at 6 months, consistent with concentration-dependent biologic effects (r2 = -0.25). The authors conclude that intermittent therapy with high-dose ATRA produced the greatest ATRA exposure, but alternative approaches for limiting self-induced ATRA catabolism should be sought.

Pulmonary diffusing capacity, serum angiotensin-converting enzyme activity and the angiotensin-converting enzyme gene in Japanese non-insulin-dependent diabetes mellitus patients

We investigated the independent change in pulmonary diffusing capacity (DLCO) as one manifestation of pulmonary microangiopathy and to analyze the correlation between DLCO and serum ACE. We also examined the association between DLCO and the ACE genes. We examined pulmonary functions, especially %DLCO/VA (DLCO corrected by alveolar volume, percent predicted) in 54 NIDDM patients and 34 age-matched normal control subjects. Subjects were subdivided according to the degree of retinopathy. Serum ACE level was assayed by a colorimetric method in 54 patients and an insertion/deletion polymorphism in the ACE gene was amplified using the polymerase chain reaction in 52 of the 54 patients. There was a significant reduction of %DLCO/VA (percent predicted P<0.05) in diabetic patients. In the proliferative retinopathy (PDR) group, %DLCO/VA was significantly ( P<0.05) lower than in the no diabetic retinopathy (NDR) and simple diabetic retinopathy (SDR) groups. Although the levels of serum ACE were within normal ranges in all diabetic groups, %DLCO/VA was negatively correlated with serum ACE values ( r=0.49, P<0.0002, y=−1.4 x+109.3). Differences among DD, ID and II type of the ACE gene, with respect to the incidence of abnormal values of each clinical parameter, were not significant. DLCO was significantly reduced in patients with PDR and the serum ACE was significantly related to impaired DLCO. Our study suggests the existence of microangiopathic involvement of pulmonary vessels in NIDDM patients.

Characteristics of pulmonary diffusing capacity for CO at rest and during exercise.

Characteristic patterns of changes in pulmonary diffusing capacity (DL) at rest and during exercise were investigated and characteristics of normal DL values concerned on sex, age, and ethnic groups were examined by viewing our studies and other reports. The relation of DL and pulmonary capillary blood volume (Vc) was represented as a logarithmic regression at rest and as a linear regression during exercise. The curve relation at rest is considered to show that the increase in Vc mainly reflects the process of transport from pulmonary capillary recruitment to pulmonary capillary dilation. The increasing rate of DL was not decreased during exercise, which seemed to be due to an increase in pulmonary blood flow accompanying exercise. The linear regression was also found between DL and oxygen intake during exercise and the slope was always constant among individuals and among subject groups. The general results concerned with sex difference in Japanese or ethnic difference between Japanese and Caucasians in both sexes could show that DL per stature was greater in males or Caucasians than in females or Japanese in young adults, however, the sex or ethnic difference disappeared in middle or old aged group. DL per alveolar volume which showed no sex or ethnic difference in young adults, was greater in middle or old aged group of females or Japanese than in that of males or Caucasians.

Changes in Pulmonary Diffusing Capacity at Rest under Various Conditions of Posture and Temperature in Male and Female

Changes in pulmonary diffusing capacity for carbon monoxide (DL), the diffusing capacity of the pulmonary capillary membrane (DM) and pulmonary capillary blood volume (VC) at rest were examined in eight adult subjects of both sexes by the breath-holding method under different posture and temperature conditions; i. e., in a supine position and a head-up position (45°) by the use of a tilting bed at three ambient temperatures of 15, 25 and 35°C. Under all these conditions, DL was closely related to changes in VC. Posture significantly affected DL and VC in both males and females, the degree of difference due to each posture in males being similar to that in females. Although the influence of temperature on DL and VC was significant in males, it was somewhat vague in females. The following causes of this phenomenon were suggested: the range of variation in the pulmonary arterial pressure due to thermal stimulation is narrow and the size of the lung is smaller in females than in males. The relation of DL to wide-spread changes in VC in both sexes showed the form of a curve, probably because the increase in VC mainly reflects the process of transformation of the pulmonary capillary from recruitment to dilation.

Changes in pulmonary diffusing capacity at rest under various ambient temperatures in normal young adults.

Change in pulmonary diffusing capacity for carbon monoxide (DL) with ambient temperature was investigated to compare the relation between DL and pulmonary capillary blood volume (Vc) with that occurring during exercise in the previous study and to examine the possibility of evaluating the potential capacity for increase in Vc. Five subjects were exposed to ambient temperatures of 12, 20, 28 and 36°C for about 100 min. The average DL increased by about 30% from 27.2 at 36°C to 34.9 ml/min/Torr at 12°C. DL was primarily determined by acute change in Vc which might be well related to determinants of change in stroke volume rather than cardiac output. It was implied that the mechanism of change in DL at rest might be different that during exercise. The best parameter matching for change in DL was mean skin temperature, which was considered to make possible the detection of changes in Vc. Comparison with the previous study revealed that the magnitude and pattern of change in DL with Vc was uniform whether Vc was altered either by change in ambient temperature or by performing exercise. This means that it is not always necessary to have a patient perform exercise in order to examine the potential increase in Vc. On the other hand, change in DL in this study seemed to depend mainly on the characteristics of the pulmonary arterial system while change in DL during exercise seemed to depend on the total number of the pulmonary capillaries in the previous study. Therefore, it was implied that selection of stimulation, which could either be change in thermal condition at rest or an exercise regime, could assist in the differentiation of various characteristics of pulmonary diseases.

Effects of Hypoxic and Cool Environmenton Pulmonary Diffusing Capacity for CO

The purpose of this study is to examine whether ambient temperature affects change in pulmonary diffusing capacity for carbon monoxide caused by hypoxia.Five male young adultswere exposed to the simulated altitude of 0, 2000, and 4000 m.Pulmonary diffusing capacityduring rest and exercise was tested in four different ambient temperatures of 16, 20, 24, and 28°C in each altitude.There was no temperature effect on diffusing capacity at sea level.However, at 2000 and 4000 m, diffusing capacity in a cool environment below 20°C wasincreased significantly compared with that in 28°C during rest and mild exercise(300kgm/min).Diffusing capacity during hypoxia was predicted, which was presumed that pulmonarycapmary blood volume was the same one at sea level.As aresult of comparison betweenmeasured and predicted value at high altitude, there were no differences on every occasions at 2000m, while significant increase in measured diffusing capacity was observed in a coolenvironment during rest and mild exercise at 4000m.It was implied that gas exchange surfacearea was increased during hypoxia in a cool environment caused by increase in capinary bloodvolume in itself and/or change in distribution of capinary blood flow in the lungs.However, these effects were relatively reduced at either ambient temperature above 24°C or work rateabove 300 kgm/min.It was concluded that a degree of hypoxic effects on pulmonary diffusingcapacity were related closely to ambient temperature and energy expenditure and that theseeffects became larger in a cool environment during rest at higher altitude.

Absence of positional change in pulmonary diffusing capacity in systemic sclerosis

Patients with systemic sclerosis frequently have pulmonary function abnormalities, and recent evidence suggests that pulmonary vascular involvement is a common manifestation. To test the hypothesis that patients with systemic sclerosis have impaired ability to recruit or distend the pulmonary vascular bed, the postural change in the coefficient of carbon monoxide diffusing capacity was measured in 11 patients with systemic sclerosis, and the results were compared with results from age-, smoking-, and sex-matched control subjects with rheumatoid arthritis and with results from healthy subjects. In normal subjects and patients with rheumatoid arthritis increased, the coefficient of diffusion by 9.4 percent (p < 0.005) and 8.4 percent (p < 0.01), respectively, when they moved from the sitting to the supine position. In contrast, patients with systemic sclerosis did not show a significant increase in coefficient of diffusion, even those who had otherwise normal pulmonary function. Regression analyses showed that the change in coefficient of diffusion decreased with increasing age (r = −0.57) in normal subjects, and that the change in coefficient of diffusion was a function of the percent predicted forced vital capacity, both in patients with systemic sclerosis (r = 0.59) and in those with rheumatoid arthritis (r = 0.70). Thus, these findings indicate that patients with systemic sclerosis have a nondistensible pulmonary capillary bed and that the absence of positional change in the coefficient of diffusion in systemic sclerosis is a subtle indicator of pulmonary involvement.

Changes in pulmonary diffusing capacity and closing volume after running a marathon

The purpose of this study was to evaluate changes in lung function after running a marathon. Pulmonary function tests were administered to 8 men before, immediately after, and the day following competition X ̄ run time = 3 hr 30 min ). Subjects completed maximum expiratory flow volume maneurvers breathing air and 80% He/20% O 2. Lung volumes were determined by N 2 washout and single breath He dilution. Closing volumes (CV) were determined using a single breath O 2 test. Pulmonary diffusing capacity (D L CO), pulmonary capillary blood volume (Vc), and membrane diffusing capacity (D M) were measured with the single breath technique. There were no changes in lung volumes or flow rates, except for an increase in FEV 1, after the marathon. The He/O 2 ΔV̇max 50, ΔV̇max 25, and isoflow values were similar pre- compared to post-race. There were significant decreases, however, in D L CO, D M and increases in CV prost-race. Vc remained similar to pre-race values. These results suggest that small airways obstruction does not occur after a marathon. The significant increase in alveolarcapillary membrane resistance, however, may reflect the occurence of subclinical edema. Such a change would decrease lung elastic recoil and could explain the increase in CV.

CO concentration-dependent changes in pulmonary diffusing capacity in humans.

Steady-state CO pulmonary diffusing capacity (DLCO) was measured at different inspired CO concentrations in seven males and one female during light treadmill exercise. As the CO level is increased. DLCO increases, reaches a maximum at an end-tidal CO concentration of approximately 100 ppm, and then decreases. The maximum DLCO is up to twice as large as the DLCO measured at an inspired CO concentration of approximately 1,780 ppm. These results are consistent with the presence of saturation kinetics, one of the basic properties of carrier-mediated transport systems. A similar relationship between DLCO and CO concentration was found in previous studies of mechanically ventilated dogs. Thus there is evidence for carrier-mediated transport of CO in the lungs of both humans and dogs.

Pulmonary function during pregnancy in normal women and in patients with cardiopulmonary disease.

Pulmonary function studies were carried out during pregnancy in 8 normal women, in 8 patients with valvular (either mitral or aortic) heart disease, and in 8 patients with chronic pulmonary disease (either emphysema or sarcoidosis). In healthy pregnant women, changes in lung volumes and maximal expiratory flow rates were not significant. Diffusing capacity tended to decrease associated with unchanged pulmonary capillary blood volume. In patients with valvular heart disease, ventilation and oxygen consumption increased toward the term. The patients with mitral valve lesions showed a significant decrease in diffusing capacity with an increase in pulmonary capillary blood volume. In patients wth emphysema, characteristic changes were increasing obstructive functional abnormalities associated with an increase in pulmonary diffusing capacity and pulmonary capillary blood volume. None of these patients, however, had clinical evidence of deterioration of their disease. Patients with sarcoidosis had no appreciable alteration in pulmonary function tests. The influence of various factors, such as increased ovarian hormones, ventilation-perfusion relationships, intra-abdominal distension, and cardiac haemodynamics, are discussed in relation to the change in pulmonary diffusing capacity and pulmonary capillary blood volume. From the standpoint of pulmonary function studies we think that patients with mitral heart disease and those with pulmonary emphysema tolerate pregnancy less favourably than normal subjects and patients with sarcoidosis.

PHYSICAL TRAINING IN RELATION TO THE ENERGY EXPENDITURE OF WALKING AND TO FACTORS CONTROLLING RESPIRATION DURING EXERCISE

In cloven National Service men during their preliminary training course there was ft decrease in energy expenditure and ‘ vertical work ’ done in walking at 3½ m.p.h. This is attributed to increased economy of movement since the ratio of energy expended to ‘ work ’ done remained constant. The reduction in exercise ventilation on switching the inspired gas from air to oxygen also decreased over the training period, suggesting improved oxygenation of the blood in the lungs. There was no concurrent change in pulmonary diffusing capacity or ventilation equivalent. No experimental evidence was obtained to support the hypothesis that as a result of this training the body temperature rises less on exercise and that this contributes to the changes in exercise ventilation