Showing papers on "Pulmonary diffusion published in 2017"

Divergent respiratory and cardiovascular responses to hypoxia in bar-headed geese and Andean birds

Abstract: Many high-altitude vertebrates have evolved increased capacities in their oxygen transport cascade (ventilation, pulmonary diffusion, circulation and tissue diffusion), enhancing oxygen transfer from the atmosphere to mitochondria. However, the extent of interspecies variation in the control processes that dictate hypoxia responses remains largely unknown. We compared the metabolic, cardiovascular and respiratory responses to progressive decreases in inspired oxygen levels of bar-headed geese (Anser indicus), birds that biannually migrate across the Himalayan mountains, with those of Andean geese (Chloephaga melanoptera) and crested ducks (Lophonetta specularioides), lifelong residents of the high Andes. We show that Andean geese and crested ducks have evolved fundamentally different mechanisms for maintaining oxygen supply during low oxygen (hypoxia) from those of bar-headed geese. Bar-headed geese respond to hypoxia with robust increases in ventilation and heart rate, whereas Andean species increase lung oxygen extraction and cardiac stroke volume. We propose that transient high-altitude performance has favoured the evolution of robust convective oxygen transport recruitment in hypoxia, whereas life-long high-altitude residency has favoured the evolution of structural enhancements to the lungs and heart that increase lung diffusion and stroke volume.

Ventilation distribution and small airway function in patients with systemic sclerosis

Abstract: Background Despite the importance of traditional pulmonary function tests (PFTs) in managing systemic sclerosis (SSc), many patients with pulmonary disease diagnosed by computed tomography (CT) present with normal PFTs. Objective To evaluate the efficacy of the nitrogen single-breath washout (N2SBW) test in diagnosing SSc and to correlate N2SBW parameters with the PFT indexes used in the follow-up of these patients, clinical data, and CT findings. Methods Cross-sectional study in which 52 consecutive SSc patients were subjected to spirometry, body plethysmography, analysis of the diffusing capacity for carbon monoxide (DLCO), analysis of respiratory muscle strength, N2SBW testing, and CT analysis. Results Twenty-eight patients had a forced vital capacity (FVC) that was 120% of the predicted value, while 15 patients had a closing volume/vital capacity (CV/VC) that was >120% of the predicted value. A significant difference in Phase III slopeN2SBW was observed when the patients with predominant traction bronchiectasis and honeycombing were compared to the patients with other CT patterns (p Conclusion Ventilation heterogeneity is a frequent finding in SSc patients that is associated with restrictive damage, changes in pulmonary diffusion, and CT patterns. In addition, approximately one-third of the patients presented with findings that were compatible with small airway disease.

Respiratory resistance and reactance in adults with sickle cell anemia: Correlation with functional exercise capacity and diagnostic use.

Abstract: Background The improvement in sickle cell anemia (SCA) care resulted in the emergence of a large population of adults living with this disease. The mechanisms of lung injury in this new population are largely unknown. The forced oscillation technique (FOT) represents the current state-of-the-art in the assessment of lung function. The present work uses the FOT to improve our knowledge about the respiratory abnormalities in SCA, evaluates the associations of FOT with the functional exercise capacity and investigates the early detection of respiratory abnormalities. Methodology/Principal findings Spirometric classification of restrictive abnormalities resulted in three categories: controls (n = 23), patients with a normal exam (n = 21) and presenting pulmonary restriction (n = 24). FOT analysis showed that, besides restrictive changes (reduced compliance; p<0.001), there is also an increase in respiratory resistance (p<0.001) and ventilation heterogeneity (p<0.01). FOT parameters are associated with functional exercise capacity (R = -0.38), pulmonary diffusion (R = 0.66), respiratory muscle performance (R = 0.41), pulmonary volumes (R = 0.56) and airway obstruction (R = 0.54). The diagnostic accuracy was evaluated by investigating the area under the receiver operating characteristic curve (AUC). A combination of FOT and machine learning (ML) classifiers showed adequate diagnostic accuracy in the detection of early respiratory abnormalities (AUC = 0.82). Conclusions In this study, the use of FOT showed that adults with SCA develop a mixed pattern of respiratory disease. Changes in FOT parameters are associated with functional exercise capacity decline, abnormal pulmonary mechanics and diffusion. FOT associated with ML methods accurately diagnosed early respiratory abnormalities. This suggested the potential utility of the FOT and ML clinical decision support systems in the identification of respiratory abnormalities in patients with SCA.

Budesonide Nebulization in the Treatment of Neonatal Ventilator Associated Pneumonia

Abstract: Objective To investigate the clinical effect of budesonide nebulization in the treatment of ventilator associated pneumonia of newborns and its safety. Methods Forty-five newborns who had ventilator associated pneumonia and were admitted into the Binzhou People's Hospital between May 2014 and May 2015 were selected and included as an observation group. Moreover, another forty-five newborns who had ventilator associated pneumonia but did not undergo budesonide treatment in 2014 were randomly selected and included as a control group. Patients in the observation group were given budesonide suspension nebulization in addition to the conventional treatment. The evaluation indicators for therapeutic effect were compared between the two groups. The changes of head circumference, height and weight and death rate were observed by follow up after treatment. Results The mechanical ventilation time, time for recovering from chest X-ray scan and hospitalization time of patients in the observation group were shorter than that of the control group, and the difference had statistical significance (P 0.05). The cumulative death rate of the observation group in the 6th month after treatment was significantly lower than that of the control group, and the difference had statistical significance (P Conclusion Treating ventilator associated pneumonia of newborns with budesonide nebulization can effectively shorten mechanical ventilation time, time for recovering from chest X-ray scan and hospitalization time, improve pulmonary diffusion function and reduce the death rate, without affecting the growth and development of patients in the future.

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise.

Abstract: Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure. At the same time, the recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) during exercise may contribute to gas exchange impairment and/or prevent large increases in pulmonary artery pressure. We describe two techniques to evaluate pulmonary diffusion and circulation at rest and during exercise. The first technique uses multiple-fraction of inspired oxygen (FIO2) DLCO breath holds to determine Vc and Dm at rest and during exercise. Additionally, echocardiography with intravenous agitated saline contrast is used to assess IPAVAs recruitment. Representative data showed that the DLCO, Vc, and Dm increased with exercise intensity. Echocardiographic data showed no IPAVA recruitment at rest, while contrast bubbles were seen in the left ventricle with exercise, suggesting exercise-induced IPAVA recruitment. The evaluation of pulmonary capillary blood volume, membrane diffusing capacity, and IPAVA recruitment using echocardiographic methods is useful to characterize the ability of the lung vasculature to adapt to the stress of exercise in health as well as in diseased groups, such as those with pulmonary arterial hypertension and chronic obstructive pulmonary disease.

Effects of aerial hypoxia and temperature on pulmonary breathing pattern and gas exchange in the South American lungfish, Lepidosiren paradoxa

Abstract: The South American lungfish Lepidosiren paradoxa is an obligatory air-breathing fish possessing well-developed bilateral lungs, and undergoing seasonal changes in its habitat, including temperature changes. In the present study we aimed to evaluate gas exchange and pulmonary breathing pattern in L. paradoxa at different temperatures (25 and 30°C) and different inspired O2 levels (21, 12, 10, and 7%). Normoxic breathing pattern consisted of isolated ventilatory cycles composed of an expiration followed by 2.4±0.2 buccal inspirations. Both expiratory and inspiratory tidal volumes reached a maximum of about 35mlkg-1, indicating that L. paradoxa is able to exchange nearly all of its lung air in a single ventilatory cycle. At both temperatures, hypoxia caused a significant increase in pulmonary ventilation (VE), mainly due to an increase in respiratory frequency. Durations of the ventilatory cycle and expiratory and inspiratory tidal volumes were not significantly affected by hypoxia. Expiratory time (but not inspiratory) was significantly shorter at 30°C and at all O2 levels. While a small change in oxygen consumption (VO2) could be noticed, the carbon dioxide release (VCO2, P=0.0003) and air convection requirement (VE/VO2, P=0.0001) were significantly affected by hypoxia (7% O2) at both temperatures, when compared to normoxia, and pulmonary diffusion capacity increased about four-fold due to hypoxic exposure. These data highlight important features of the respiratory system of L. paradoxa, capable of matching O2 demand and supply under different environmental change, as well as help to understand the evolution of air breathing in lungfish.

No compensatory lung growth after resection in a one-year follow-up cohort of patients with lung cancer.

Abstract: Background: As compensatory lung growth after lung resection has been studied in animals of various ages and in one case report in a young adult, it has not been studied in a cohort of adults operated for lung cancer. Methods: A prospective study including patients with lung cancer was conducted over two years. Parenchymal mass was calculated using computed tomography before (M0) and at 3 and 12 months (M3 and M12) after surgery. Respiratory function was estimated by plethysmography and CO/NO lung transfer (DLCO and DLNO). Pulmonary capillary blood volume (Vc) and membrane conductance for CO (DmCO) were calculated. Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) plasma concentrations were measured simultaneously. Results: Forty-nine patients underwent a pneumonectomy (N=12) or a lobectomy (N=37) thirty two completed the protocol. Among all patients, from M3 to M12 the masses of the operated lungs (239±58 to 238±72 g in the lobectomy group) and of the non-operated lungs (393±84 to 377±68 g) did not change. Adjusted by the alveolar volume (V A ), D LNO /V A decreased transiently by 7% at M3, returning towards the M0 value at M12. Both Vc and DmCO increased slightly between M3 and M12. IGF-1 and IGFBP-3 concentrations did not change at M3, IGF-1 decreased significantly from M3 to M12. Conclusions: Compensatory lung growth did not occur over one year after lung surgery. The lung function data could suggest a slight recruitment or distension of capillaries owing to the likely hemodynamic alterations. An angiogenesis process is unlikely.

Эффективность легочной вентиляции и газообмена в оценке риска хирургического лечения хронической тромбоэмболической легочной гипертензии

Abstract: Aim. To evaluate prognostic significance of diffusion capacity of the lungs and efficacy of pulmonary gas exchange in risk assessment of perioperational and early postoperational complications in patients with chronic post-thromboembolic pulmonary hypertension (CPH). Material and methods. Totally, 131 patient included, with CPH, who had undergone thrombo-endarterectomy from the branches of pulmonary artery. Before the surgery, together with standard investigation, the following methods were applied: body pletismography, lung diffusion capacity assessment, ventilation efficiency assessment. The relation was analyzed, of the parameters of pulmonary functional tests with the results of surgical treatment of CPH patients. Results . CPH patients present with a low level of pulmonary diffusion capacity and ventilation efficiency. Among the parameters of pulmonary functional tests, diffusion ability of the lungs shows the highest prediction significance in surgical risk assessment for CPH treatment. The relation found, for diffusion ability of the lungs and risk of respiratory failure (ОR 0,94 (0,91-0,99), p=0,004), heart failure (ОR 0,93 (0,87-1,00), p=0,023), short term post-operaton mortality (ОR 0,95 (0,89-0,99), p=0,034) and long-term mortality (ОR 0,94 (0,79-0,99), p=0,030). Efficacy of pulmonary ventilation showed significant relation only with the development of respiratory failure (ОR 0,91 (0,82-1,00), p=0,038) Conclusion . Decline of pulmonary diffusion ability to 45% and lower from expected level increases the risk of respiratory and heart failure development in early postoperation period, as the risk of in-hospital death and mortality throughout 1 year follow-up after thrombo-endarterectomy from the branches of pulmonary artery.

Pulmonary Diffusion Capacity for Carbon Monoxide (DLCO) in Indonesian Patients with End-stage Renal Disease.

Abstract: Objectives End-stage renal disease affects all systems in human including the respiratory system. This study aimed to discover the lung diffusion capacity of carbon monoxide (DLCO) in chronic hemodialysis patients and to establish its relation to several demographic and clinical factors as well as spirometry parameters. Material and Methods This was a cross-sectional study among chronic hemodialysis patients aged .18 years, clinically stable in the last four weeks, without prior history of lung and cardiac disorder. Spirometry and DLCO examination were performed in the span of 24 hours after hemodialysis. Outcomes There were 40 subjects analyzed. Majority of them were males (67.5%), non-smokers (55%), with a median age of 51 years, a mean body mass index of 22.6±3.9 kg/m2, a hemoglobin level of 9.5±1.3 g/dL, a median dialysis adequacy of 1.62 and a hemodialysis duration of 31.5 months. Hypertension was the most common underlying disease. About 20% of subjects had varying degrees of dyspnea. Prevalence of DLCO reduction was 52.5% with mild to moderate degree. Restrictive spirometry pattern was evident in 47.5% of subjects and obstructive pattern in 5%. There was a significant relation between DLCO reduction with smoking history (OR 4.52 [95% CI 1.04-19.6]) and also with restrictive disorder [OR 5.5 (95% CI 1.29-23.8)]. We suspected a lung parenchymal disorder as the cause of lung restriction and diffusion inhibition. Conclusions Reduction of lung diffusion capacity in chronic dialysis patients is common, although not accompanied by dyspnea. Risk factors for DLCO reduction are smoking history and restrictive disorder in spirometry.

Pulmonary Diffusion Capacity and Quality of Life during a Period of 6 Years in Patients who Survived Acute Respiratory Distress Syndrome

Abstract: Introduction: Patients who survived Acute Respiratory Distress Syndrome (ARDS) may present long term physical damage that affects their quality of life and respiratory capacity. Restrictive ventilatory disorders, decrease in pulmonary diffusing capacity and changes in quality of life were observed. Objective: Know whether there are changes in pulmonary function and quality of life of patients who were discharged from the Intensive Care Unit (ICU) from 2008 to 2013, who required mechanical ventilation and presented ARDS. Methods and Materials: Descriptive study: Observational study. Inclusion criteria: Patients older than 18 years old, who required Mechanical ventilation, presented ARDS and have been discharged from the ICU for 12 months or more. Exclusion criteria: Patients with severe ARDS caused by influenza or incapable of performing respiratory function studies. This study was conducted with institutional approval and informed consent. The following tests were carried out: Self-administered quality of life questionary (EQ–5D), spirometry, 6-minute walking test(6MWT), pulmonary diffusion test for CO (DLco), and lung volumes by nitrogen dilution performed with the computerized equipment Ultima™ Series Med Graphics. Results: 13 patients were studied. The median age was 42 ± 15 years old, 76.9% male. Quality life perception shows through EQ-5D changes in the 5 components. The biggest change occurred in the pain/discomfort dimension with a median of 1.62 ± 0.506, and the EQ% health was 80.77% ± 12.05. The median values of the rates (FEV1, FVC, FEV1/FVC, FEF25/75) were over 80%. 5 patients presented a mild restrictive pattern. Lung volumes and DLco showed median over 80%. 4 patients presented a mild alteration in diffusion and one of them presented desaturation during the 6MWT. Correlation between DLco% and EQ% health p=0.294, EQ% health- TTO p=0.001 and EQ% health-VAS p=0.001. Conclusion: Our results suggest that patients with mechanical ventilation and severe ARDS who were evaluated after a year of being discharged from the ICU present mild pulmonary sequels and their quality of life was moderately affected. These results are similar to what is reported in the bibliography. A limitation to the study is the small size of the sample.