Lung Function Tests in Infants and Children

Lung function testing is an essential modality of investigation in children as it provides objective evidence of lung disease/ health. With advances in technology, various tests are available that can aid in the diagnosis of lung disease, assess the progression and response to therapy and document the lung development and evolving lung diseases in infants. This narrative review discusses lung function tests in infants and children. Currently, lung function tests can be performed in every age group, from neonates to the elderly. Spirometry and peak expiratory flow rate (PEFR) are the most employed tests in children more than six years of age. Spirometry helps diagnose and monitoring of both obstructive and restrictive diseases. There is a need for expertise to perform and interpret spirometry correctly. The forced oscillation technique (FOT) or impulse oscillometry (IOS) is done with tidal volume breathing and is feasible even in preschool children. Their utility is mainly restricted to asthma in children at present. Lung function tests can be performed in neonates, infants and children using infant pulmonary function test (PFT) equipment, although their availability is limited. Diffusion capacity for carbon monoxide (DLCO) is a valuable tool in restrictive lung diseases. Lung volumes can be assessed by body plethysmography and multiple washout technique. The latter can also assess lung clearance index. It is essential to perform and interpret the lung function test results correctly and correlate them with the clinical condition for optimum treatment and outcome.

Correlation Between The Parameters Of Diffusion Capacity Of Lung With Diabetic Nephropathy, A Hospital Based Study In Eastern India

Background. Diabetes mellitus is a systemic disease with complications involving eyes, kidneys, nerves and vascular system. The presence of an extensive microvasculature and abundant connective tissue raises the possibility that lung may also be a target organ in diabetes. Aims and Objectives: To compare and correlate diabetic nephropathy with parameters of diffusion capacity of lung. Methods: A total of 60 T2DM patients with or without complications of age group 35-55years and 60 age and sex matched control were included after inclusion and exclusion criteria. All subjects were evaluated for PFT with Diffusion capacity (DLCO) by single eath technique- INSPIRE HD –PFT) and status of nephropathy by microalbuminuria. DLCO was correlated with diabetic nephropathy. p<0.05 was considered as significant. Results: There was significant (P<0.05) changes in diffusion capacity (DLCO% and DL/VA%) in cases compared to controls and significant deterioration of diffusion of lung in Diabetic nephropathy(microalbuminuria) and that was negatively correlated with DLCO% (r=-o.53) and DL/VA% (r=-0.66) . Conclusion: There was significant impairment of diffusing capacity of lung in diabetic nephropathy cases compared to controls and also negative correlation found between microalbuminuria with diffusion capacity.

Influence of N-acetylcysteine on FEV1, VC, DLCO, PaO2 in patients with chronic obstructive pulmonary disease and pulmonary interstitial fibrosis / 中国基层医药

Objective@#To investigate the influence of N-acetylcysteine on forced expiratory volume in one second(FEV1), vital capacity(VC), diffusion capacity of lung carbon monoxide(DLCO), arterial oxygen partial pressure(PaO2) in patients with chronic obstructive pulmonary disease(COPD) and pulmonary interstitial fibrosis.@*Methods@#From January 2015 to July 2017, 140 COPD patients complicated with pulmonary interstitial fibrosis in the People's Hospital of Shanxi Province were chosen as study objects, and they were divided into control group and research group according to the digital table, with 70 cases in each group.The control group was treated with routine treatment, while the research group was treated with N-acetylcysteine.After treatment, the treatment effects, VC, FEV1, PaO2, DLCO, TGF-β and VEGF between the two groups were compared.@*Results@#The total effective rate of the research group was 82.86%(58/70), which of the control group was 58.57%(41/70), the difference was statistically significant (χ2=9.968, P<0.05). Before treatment, the pulmonary function between the two groups had no statistically significant difference(t=0.082, 0.028, 0.421, 0.155, all P>0.05). After treatment, the FEV1[(59.03±15.02)% vs.(53.35±13.71)%], VC[(69.95±11.83)% vs.(65.21±11.65)%], DLCO[(68.92±11.56)% vs.(64.01±11.34)%] and PaO2[(68.79±5.38)mmHg vs.(62.37±6.14)mmHg]of the research group were higher than those of the control group, the differences were statistically significant (t=2.337, 2.389, 2.537, 6.580, all P<0.05). Before treatment, the TGF-β and VEGF levels between the two groups had no statistically significant differences(t=1.230, 0.016, all P>0.05). After treatment, the VEGF[(0.32±0.04)ng/L vs.(0.44±0.05)ng/L] and TGF-β[(271.16±35.21)ng/L vs.(345.13±39.08)ng/L] levels of the research group were lower than those of the control group, the differences were statistically significant (t=11.765, 15.680, all P<0.05). There was no statistically significant difference in the incidence rate of adverse reactions between the two groups(1.43% vs 4.28%, χ2=2.323, P>0.05).@*Conclusion@#Large dose of N-acetylcysteine can effectively improve the TGF-β and VEGF levels of COPD patients complicated with pulmonary interstitial fibrosis, and promote its pulmonary function, with good safety.

Diabetic: A Comparative Study

Background and Objectives: Type II diabetes mellitus (DM) is particularly common medical disorder and is leading cause of morbidity worldwide. The complication of DM is due to micro or macro vascular damage. The presence of an extensive microvascular circulation and abundant connective tissue in the lungs raises the possibility that lung tissue may be a target organ in diabetic patients and thus pulmonary function test can be affected by DM. This study was designed to compare pulmonary function test between Type II diabetic and non-diabetic individuals; and, with the duration of DM.Material and Methods: This cross sectional comparative study was conducted at King Edward Medical University, Lahore Pakistan. Total sample consist of 91 diabetic and 91 non-diabetic grouped as group A and group B. FEV1, FVC, FEV1/FVC ratio, and PEFR were compared within two groups and with the duration of DM.Results: Total 182 sample with mean age 53.1±5.90 years, with 91(50%) male and 91(50%) female. Group A and B had 91(50%) sample each. Mean value of FVC, FEV1 and PEFR showed statistically significant difference among the both group. Mean of FVC decreases significantly with the increasing duration of DM; although, is not significant with FEV1, FEV1/FVC ratio, and PEFR.Conclusion: Diabetic group showed significantly impaired pulmonary functions test as FEV1, FVC, and PEFR as compare to non-diabetic group.

Cem anos do teste de difusão ao monóxido de carbono nas doenças pulmonares / One hundred years of carbon monoxide diffusion test in lung disease

Em 2015 fazem exatamente cem anos desde a primeira publicação a descrever um método de aferição da respiração única de permeabilidade dos gases. Atualmente, os testes são realizados por sistemas automatizados utilizando a manobra de respiração única já padronizada internacionalmente. Este artigo aborda as técnicas usadas nesta medida, as equações de normalidade existentes e como interpretar dos dados obtidos. A interpretação dos resultados obtidos devem ser feita de forma cuidadosa. Tanto doenças obstrutivas como restritivas podem causar redução da capacidade de difusão ao monóxido de carbono. Quando usado em indicações clínicas bem estabelecidas e, principalmente, quando os resultados são analisados em conjunto com a clínica, radiologia e a medida dos volumes e fluxos pulmonares, o teste da difusão pode ser uma rica ferramenta no auxílio diagnóstico e prognóstico. Os aparelhos atualmente disponíveis no mercado para realização do teste são extremamente confiáveis, provendo exames reprodutíveis e acurados, no entanto, são equipamentos caros, devendo ser importados o que dificulta a disseminação da técnica.

In 2015 make exactly one hundred years since the first report describing a single-breath method of measuring permeability of gases. Currently, tests are performed by automated systems using the single breath maneuver already internationally standardized. This article discusses the techniques used in this measure, the existing normal equations and how to interpret the data obtained. The interpretation of the results obtained should be done carefully. Both obstructive and restrictive diseases can cause reduced diffusion capacity for carbon monoxide. When used in well-established clinical indications and especially when the results are analyzed together with the clinical, radiology and the measured lung volumes and flows, the diffusion test can be a rich tool in the diagnosis and can also provide the prognosis. Devices currently available in the market for the test are extremely reliable, providing reproducible and accurate tests. However, they are expensive equipment and must be imported which hinders the spread of technology.

Estandarización de la prueba de capacidad de difusión de monóxido de carbono: Chilean Society of Respiratory Diseases guidelines / Standardization of the single-breath diffusing capacity

Since its introduction in clinical practice carbon monoxide diffusing capacity (DLCO), has been widely used in respiratory diseases, being the most common test utilized after spirometry in pulmonary function laboratories. It represents the entire diffusion process including transport through the alveolar-capillary barrier and hemoglobin binding. Its high affinity with hemoglobin and its near zero partial pressure in plasma determines that CO transfer depends specifically on diffusion. Common respiratory and cardiac diseases such as emphysema, interstitial lung diseases, lung damage by drugs, arterial pulmonary hypertension and cardiac failure, among others show a reduced DLCO. Recent theories considering red blood cells as the main factor involved in resistance to diffusion, suggest that DLCO may reflect the status of lung microcirculation. For example, in cardiac failure, DLCO does not improve in parallel with lung volume, even with cardiac stabilization or cardiac transplantation. Despite its wide utilization, DLCO measurement presents standardization and reproducibility difficulties. International guidelines and task forces recommend using representative values of the target population. After analyzing the available information a group of experts from the Pulmonary Function Commission of the Chilean Society of Respiratory Diseases has proposed guidelines for measurement techniques, quality control, equipment calibration and interpretation of results.

Desde la introducción en la práctica clínica de la prueba de difusión con monóxido de carbono (CO) a mediados del siglo pasado, su utilización ha sido ampliamente difundida en la evaluación de diversas enfermedades respiratorias, de hecho se le considera la prueba más utilizada luego de la espirometría. Desde el punto de vista conceptual aporta información global de todo el proceso de difusión, que incluye el paso a través de la barrera alvéolo capilar y su unión con la hemoglobina. Gracias a la elevada afinidad del CO por la hemoglobina y a la particularidad de que la presión parcial de CO en el plasma es prácticamente cero, la transferencia del CO depende sólo de su difusión. Patologías respiratorias y cardíacas habituales como el enfisema pulmonar, las enfermedades pulmonares intersticiales, el compromiso pulmonar por drogas neumotóxicas, la hipertensión arterial pulmonar y la insuficiencia cardíaca congestiva, entre otras, cursan con disminución de la capacidad de difusión de CO (DLCO). Un nuevo desafío plantean las hipótesis recientes que postulan que la resistencia a la difusión del monóxido de carbono depende principalmente del glóbulo rojo, por lo que ésta podría consistir en una representación de la microcirculación. Como ejemplo, en la insuficiencia cardíaca congestiva, el deterioro de la DLCO no mejora en conjunto con los volúmenes pulmonares, ni cuando estos pacientes se estabilizan o se trasplantan. Si bien se trata de una técnica de laboratorio ampliamente utilizada, aún presenta problemas de estandarización y reproducibilidad. En este documento de consenso, un grupo de estudio de la Comisión de Función Pulmonar de la Sociedad Chilena de Enfermedades Respiratorias, ha efectuado una revisión de este método, con las correspondientes proposiciones de técnicas de medición, control de calidad, calibración e interpretación.

Severe right heart failure in a patient with chronic obstructive lung disease: A diagnostic challenge.

A 55-year-old male was admitted for evaluation of severe dyspnoea and hypoxaemia. Physical examination upon admission showed elevated jugular venous pressure and an accentuated second heart sound. Chest radiograph showed cardiomegaly with increased bibasilar markings. Arterial blood gas analysis while breathing room air showed marked hypoxaemia. High resolution computed tomography angiography of the chest showed modestly enlarged mediastinal lymph nodes with discrete diffuse ground-glass attenuation especially at the lower lung zones. Positron emission tomography using 18F labelled 2-deoxy-D-glucose (FDG) demonstrated the mediastinal lymph nodes were FDG-avid. Transthoracic echocardiography showed dilated hypokinetic right heart chambers with bulging of the interventricular septum to the left, compatible with acute cor-pulmonale. From the tricuspid regurgitation jet measurement a systolic pulmonary artery pressure (PAP) of 48mmHg was estimated. Patent foramen ovale was suspected on bubble test. Right heart catheterisation confirmed pulmonary arterial hypertension: mPAP 47mmHg, pulmonary artery occlusion pressure 5mmHg, cardiac index 1.1 L/min/ m2, pulmonary vascular resistance (PVR) 959 dyne.sec.cm-5. Pulmonary function tests showed a marked diffusing capacity for carbon monoxide (DLCO) decrease of 32% predicted but no obstructive lung deficit. Before an open lung biopsy could be scheduled the patient developed acute cardiogenic shock. At autopsy pulmonary veno-occlusive disease with marked pulmonary hypertension was diagnosed.

Pulmonary membrane diffusing capacity and pulmonary capillary blood volume in patients with stable COPD / 上海第二医科大学学报

Objective To study the clinical significance of pulmonary membrane diffusing capacity(Dm) and pulmonary capillary blood volume(Vc) in patients with stable chronic obstructive pulmonary disease(COPD). Methods Spirometry was performed in 38 patients with stable COPD and 35 healthy individuals in resting condition.The changes of pulmonary parameters were obtained and compared between groups. Results Spirometry test revealed that the percent predicted forced expired volume in one second(FEV1),FEV1/forced volume capacity(FVC)and the percent predicted maximal ventilatory volume(MVV) were declined from stage Ⅰin patients with COPD in comparison with healthy individuals,while diffusing capacity for carbon monoxide of lung(DLCO),carbon monoxide diffusing capacity per liter of alveolar(DLCO/VA),Dm and Vc were declined from stage Ⅱ.Dm in patients with COPD of stageⅠwas sig-nificantly decreased compared with the controls,while Vc was increased compared with the controls(both P

To evaluate gaz diffusion capacity of pulmonary by using monoxyde carbone

The study carried on 62 patients with pathology symbol as slacken alveolus , multi-erythrocyte, sclerosis skin and anaemic who were being tested respiratory function at Cochin Paris Hospital from 2001 to 2002. Patients were measured diffusibility CO (DLCO) of pulmonary by respiratory cycle. The result showed that DLCO reduced 62% in slacken alveolus group and 70% in sclerosis skin group in comparison with theoretical valid. Adjustment DLCO according to standard Hb valid 14.6g/dl changed DLCO valid in multi-erythrocyte and anaemic group. The adjust process helped to eliminate really disffuse disorder of pulmonary. DLCO in organ transplant patients were average after adjustment according to Hb and alveolus air volume

A Morphometric Study of the Lungs in Blast Injured Rats / 第三军医大学学报

The morphological changes of the rat lung with blast injury are quantitified with a stereological method. After blast the pulmonary capillary volume and internal surface area decreased significantly, arithrnatic and harmonic mean thickness of the air-blood barrier, the volumes of P'MN and platelet in capillury increased remarkably. The morphometric lung diffusion capacity of oxygen (DLO2) is reduced markedly mainly due to the decrease of diffusion capacity of air-blood barrier and erythrocyte. The change of DLO2 is closely correlated with the arterial blood oxygen pressure, indicated that the damage of pulmonary capillary is one of the main causes of alveolar bleeding and the early respiratory insufficiency. A mathematic relation can be established between the intensity of the blast wave and the corresponding morphological changes of the injured lungs.