Dynamic hyperinflation is reported as a potential risk during high-frequency oscillatory ventilation (HFOV), and its existence has been documented both by physical models and by CT. The aim of this study is to determine the suitability of electrical impendence tomography (EIT) for the measurement of dynamic lung hyperinflation and hypoinflation during HFOV. Eleven healthy pigs were anaesthetized and ventilated using HFOV. The difference between the airway pressure at the airway opening and alveolar space was measured by EIT and esophageal balloons at three mean airway pressures (12, 18 and 24 cm H2O) and two inspiratory to expiratory time ratios (1:1, 1:2). The I:E ratio was the primary parameter associated with differences between airway and alveolar pressures. All animals showed hyperinflation at a 1:1 ratio (median 1.9 cm H2O) and hypoinflation at a 1:2 (median -4.0 cm H2O) as measured by EIT. EIT measurements had a linear correlation to esophageal balloon measurements (r2 = -0.915, p = 0.0085). EIT measurements were slightly higher than that of the esophageal balloon transducer with the mean difference of 0.57 cm H2O. Presence of a hyperinflation or hypoinflation was also confirmed independently by chest X-ray. We found that dynamic hyperinflation developed during HFOV may be detected and characterized noninvasively by EIT.
- Publication type
- Journal Article MeSH
The purpose of this study was to assess whether during standard methacholine (Mch) challenge (concentration up to 128 mg x mL(-1)) healthy supine subjects a) develop tidal expiratory flow limitation (FL) and hyperinflation, and b) whether the onset of tidal FL is associated with dyspnoea. Eight healthy subjects were studied. Dyspnoea was assessed using the Borg scale, FL by the negative expiratory pressure (NEP) method and hyperinflation in terms of decrease in inspiratory capacity (IC). Seven patients became flow limited at Mch doses ranging 4-64 mg x mL(-1), with FL encompassing 34-84% of the control tidal volume. In six of them the onset of tidal FL was associated with little or no dyspnoea and a modest degree of hyperinflation (deltaIC <-0.4 L). In one subject, however, onset of FL was associated with a substantial reduction in IC (0.58 L) and moderately severe dyspnoea. In all of these seven subjects FL was transiently reversed after an IC manoeuvre. In conclusion, the results show that a) most healthy subjects may develop flow limitation and hyperinflation during methacholine challenge in supine position, and b) at onset of flow limitation there is little or no dyspnoea, suggesting that onset of dynamic airway compression per se does not elicit significant dyspnoea. Significant dyspnoea probably only occurs with marked dynamic hyperinflation.
- MeSH
- Bronchoconstrictor Agents * diagnostic use MeSH
- Bronchial Provocation Tests MeSH
- Adult MeSH
- Dyspnea * diagnosis physiopathology MeSH
- Humans MeSH
- Lung Volume Measurements MeSH
- Methacholine Chloride * diagnostic use MeSH
- Statistics, Nonparametric MeSH
- Reference Values MeSH
- Regression Analysis MeSH
- Airway Resistance physiology drug effects MeSH
- Sensitivity and Specificity MeSH
- Spirometry MeSH
- Supine Position MeSH
- Forced Expiratory Volume MeSH
- Peak Expiratory Flow Rate MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Controlled Clinical Trial MeSH
- Clinical Trial MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
Poor ventilatory efficiency, defined as the increase in minute ventilation relative to carbon dioxide production during exercise (VE/VCO2 slope), may be associated with dynamic hyperinflation and thereby promote the development of prolonged air leak (PAL) after lung resection. Consecutive lung lobectomy candidates (n = 96) were recruited for this prospective two-centre study. All subjects underwent pulmonary function tests and cardiopulmonary exercise testing prior to surgery. PAL was defined as the presence of air leaks from the chest tube on the 5th postoperative day and developed in 28 (29%) subjects. Subjects with PAL were not different in terms of age, sex, American Society of Anesthesiologists class, type of surgery (thoracotomy/video-assisted thoracoscopic surgery) and site of surgery (right/left lung; upper/lower lobes). Subjects with PAL had more frequent pleural adhesions (50% vs 21%; P = 0.006) and steeper VE/VCO2 slope (35 ± 7 vs 30 ± 5; P = 0.001). Stepwise logistic regression showed that only the presence of pleural adhesions [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.4-10.9; P = 0.008] and VE/VCO2 slope (OR 1.1, 95% CI 1.0-1.2; P = 0.003) were independently associated with PAL (AUC 0.74, 95% CI 0.62-0.86). We conclude that a high VE/VCO2 slope during exercise may be helpful in identifying patients at greater risk for the development of PAL after lung lobectomy. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT03498352.
- MeSH
- Exercise physiology MeSH
- Thoracic Surgery, Video-Assisted MeSH
- Chest Tubes MeSH
- Middle Aged MeSH
- Humans MeSH
- Logistic Models MeSH
- Lung Diseases mortality physiopathology surgery MeSH
- Pulmonary Ventilation physiology MeSH
- Pneumonectomy adverse effects MeSH
- Predictive Value of Tests MeSH
- Prognosis MeSH
- Prospective Studies MeSH
- Respiratory Function Tests MeSH
- Aged MeSH
- Oxygen Consumption physiology MeSH
- Exercise Test MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Due to its effectivity in assessing functional capacity and adding prognostic information to the staging of chronic obstructive pulmonary disease (COPD) patients, the 6-min walk test (6MWT) is extensively used in clinical evaluation. Currently, there is little information about the physiological response this test elicits in patients, especially when compared to cardiopulmonary exercise test (CPET). The aim of the study was to compare ventilatory and metabolic responses between these tests commonly used for the assessment of clinical outcome. A group of 20 patients with moderate to very severe COPD were tested for their pulmonary function (flow-volume curve, static lung volumes), occlusion mouth pressures and breath-by-breath measurement of flow, volumes, and oxygen (O2) and carbon dioxide (CO2) concentration during the 6MWT and CPET. All parameters measured during both exercise tests were assessed over the throughout of the tests and compared between each other at specified time points. Serially measured inspiratory vital capacity (IVC) decreased more rapidly and extensively during the walk-test (p < 0,0001). This was accompanied by a limited increase in tidal volume (VT) and minute ventilation (VE), which were significantly lower in the course of the 6MWT (p = 0,0003 and p = 0,0097, respectively). We also noticed a significant decrease in hemoglobin oxygen saturation (SpO2) during the 6MWT which was correlated to percent decrease in IVC (p = 0,0206). Over the course of the 6MWT, oxygen consumption (VO2) and VT reached plateau within 2 min, while carbon dioxide production (VCO2) and VE within 3 min. During CPET, VO2, VCO2 and VE rose continuously, while VT reached plateau within 4 min. The 6MWT seems to be a rather endurance-based test associated with more pronounced dynamic lung hyperinflation and mechanical constraint of ventilation in comparison to cycling.
- Publication type
- Journal Article MeSH
BACKGROUND: The complex humanitarian crisis (CHC) in Venezuela is characterized by food insecurity, hyperinflation, insufficient basic services, and the collapse of the healthcare system. The evolution of the epidemiology of cardiometabolic risk factors in this context is unknown. AIM: To compile the last 20 years evidence on the prevalence of cardiometabolic risk factors in adults of Venezuela in the context of the CHC. METHODS: A comprehensive literature review of population-based studies of adults in Venezuela from 2000 to 2020. RESULTS: Seven studies (National EVESCAM 2014-2017, 3 regions VEMSOLS 2006-2010, Maracaibo city 2007-2010, Merida city 2015, Mucuchies city 2009, Barquisimeto city CARMELA 2003-2005, and Zulia state 1999-2001) with samples sizes ranging from 109 to 3414 subjects were included. Over time, apparent decrease was observed in smoking from 21.8% (2003-2005) to 11.7% (2014-2017) and for obesity from 33.3% (2007-2010) to 24.6% (2014-2017). In contrast, there was an apparent increase in diabetes from 6% (2003-2005) to 12.3% (2014-2017), prediabetes 14.6% (2006-2010) to 34.9% (2014-2017), and hypertension 24.7% (2003-2005) to 34.1% (2014-2017). The most prevalent dyslipidemia - a low HDL-cholesterol - remained between 65.3% (1999-2001) and 63.2% (2014-2017). From 2006-2010 to 2014-2017, the high total cholesterol (22.2% vs 19.8%, respectively) and high LDL-cholesterol (23.3% vs 20.5%, respectively) remained similar, but high triglycerides decreased (39.7% vs 22.7%, respectively). Using the same definition across all the studies, metabolic syndrome prevalence increased from 35.6% (2006-2010) to 47.6% (2014-2017). Insufficient physical activity remained steady from 2007-2010 (34.3%) to 2014-2017 (35.2%). CONCLUSION: Changes in the prevalence of cardiometabolic risk factors in Venezuela are heterogeneous and can be affected by various social determinants of health. Though the Venezuelan healthcare system has not successfully adapted, the dynamics and repercussions of the CHC on population-based cardiometabolic care can be instructive for other at-risk populations.
- MeSH
- Cholesterol MeSH
- Adult MeSH
- Hyperlipidemias * MeSH
- Cardiometabolic Risk Factors MeSH
- Humans MeSH
- Metabolic Syndrome * epidemiology MeSH
- Prevalence MeSH
- Risk Factors MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Geographicals
- Venezuela MeSH
This position paper has been drafted by experts from the Czech national board of diseases with bronchial obstruction, of the Czech Pneumological and Phthisiological Society. The statements and recommendations are based on both the results of randomized controlled trials and data from cross-sectional and prospective real-life studies to ensure they are as close as possible to the context of daily clinical practice and the current health care system of the Czech Republic. Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable heterogeneous syndrome with a number of pulmonary and extrapulmonary clinical features and concomitant chronic diseases. The disease is associated with significant mortality, morbidity and reduced quality of life. The main characteristics include persistent respiratory symptoms and only partially reversible airflow obstruction developing due to an abnormal inflammatory response of the lungs to noxious particles and gases. Oxidative stress, protease-antiprotease imbalance and increased numbers of pro-inflammatory cells (mainly neutrophils) are the main drivers of primarily non-infectious inflammation in COPD. Besides smoking, household air pollution, occupational exposure, low birth weight, frequent respiratory infections during childhood and also genetic factors are important risk factors of COPD development. Progressive airflow limitation and airway remodelling leads to air trapping, static and dynamic hyperinflation, gas exchange abnormalities and decreased exercise capacity. Various features of the disease are expressed unequally in individual patients, resulting in various types of disease presentation, emerging as the "clinical phenotypes" (for specific clinical characteristics) and "treatable traits" (for treatable characteristics) concept. The estimated prevalence of COPD in Czechia is around 6.7% with 3,200-3,500 deaths reported annually. The elementary requirements for diagnosis of COPD are spirometric confirmation of post-bronchodilator airflow obstruction (post-BD FEV1/VCmax <70%) and respiratory symptoms assessement (dyspnoea, exercise limitation, cough and/or sputum production. In order to establish definite COPD diagnosis, a five-step evaluation should be performed, including: 1/ inhalation risk assessment, 2/ symptoms evaluation, 3/ lung function tests, 4/ laboratory tests and 5/ imaging. At the same time, all alternative diagnoses should be excluded. For disease classification, this position paper uses both GOLD stages (1 to 4), GOLD groups (A to D) and evaluation of clinical phenotype(s). Prognosis assessment should be done in each patient. For this purpose, we recommend the use of the BODE or the CADOT index. Six elementary clinical phenotypes are recognized, including chronic bronchitis, frequent exacerbator, emphysematous, asthma/COPD overlap (ACO), bronchiectases with COPD overlap (BCO) and pulmonary cachexia. In our concept, all of these clinical phenotypes are also considered independent treatable traits. For each treatable trait, specific pharmacological and non-pharmacological therapies are defined in this document. The coincidence of two or more clinical phenotypes (i.e., treatable traits) may occur in a single individual, giving the opportunity of fully individualized, phenotype-specific treatment. Treatment of COPD should reflect the complexity and heterogeneity of the disease and be tailored to individual patients. Major goals of COPD treatment are symptom reduction and decreased exacerbation risk. Treatment strategy is divided into five strata: risk elimination, basic treatment, phenotype-specific treatment, treatment of respiratory failure and palliative care, and treatment of comorbidities. Risk elimination includes interventions against tobacco smoking and environmental/occupational exposures. Basic treatment is based on bronchodilator therapy, pulmonary rehabilitation, vaccination, care for appropriate nutrition, inhalation training, education and psychosocial support. Adequate phenotype-specific treatment varies phenotype by phenotype, including more than ten different pharmacological and non-pharmacological strategies. If more than one clinical phenotype is present, treatment strategy should follow the expression of each phenotypic label separately. In such patients, multicomponental therapeutic regimens are needed, resulting in fully individualized care. In the future, stronger measures against smoking, improvements in occupational and environmental health, early diagnosis strategies, as well as biomarker identification for patients responsive to specific treatments are warranted. New classes of treatment (inhaled PDE3/4 inhibitors, single molecule dual bronchodilators, anti-inflammatory drugs, gene editing molecules or new bronchoscopic procedures) are expected to enter the clinical practice in a very few years.
- MeSH
- Bronchodilator Agents standards therapeutic use MeSH
- Chronic Disease therapy MeSH
- Pulmonary Disease, Chronic Obstructive diagnosis genetics physiopathology therapy MeSH
- Adult MeSH
- Phenotype * MeSH
- Middle Aged MeSH
- Humans MeSH
- Patient-Centered Care standards MeSH
- Pulmonary Medicine standards MeSH
- Prospective Studies MeSH
- Cross-Sectional Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Practice Guidelines as Topic * MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
