The effect of goal-directed crystalloid versus colloid administration on postoperative spirometry parameters: a substudy of a randomized controlled clinical trial.

BACKGROUND: Pulmonary function is impaired after major abdominal surgery and might be less impaired by restrictive fluid administration. Under the assumption of a fluid-sparing effect of colloids, we tested the hypothesis that an intraoperative colloid-based goal-directed fluid management strategy impairs postoperative pulmonary function parameters less compared to goal-directed crystalloid administration. METHODS: We performed a preplanned, single-center substudy within a recently published trial evaluating the effect of goal-directed crystalloids versus colloids on a composite of major complications. Sixty patients undergoing major open abdominal surgery were randomized to Doppler-guided intraoperative fluid replacement therapy with lactated Ringer's solution (n = 31) or unbalanced 6% hydroxyethyl starch 130/0.4 (n = 29). A blinded investigator performed bedside spirometry (Spirobank-G, Medical International Research, Rome, Italy) preoperatively as well as 6, 24, and 48 h postoperatively. RESULTS: Median total intraoperative fluid requirements were significantly higher during crystalloid administration compared to patients receiving colloids (4567 ml vs. 3044 ml, p = 0.01). Six hours after surgery, pulmonary function parameters did not differ significantly between the crystalloid - and the colloid group: forced vital capacity (FVC): 1.6 l (1.2-2 l) vs. 1.9 l (1.5-2.4 l), p = 0.15; forced expiratory volume in 1 second (FEV1): 1.1 l (0.9-1.6 l) vs. 1.4 l (1.2-1.7 l), p = 0.18; and peak expiratory flow (PEF): 2 l.sec-1 (1.5 - 3.6 l.sec -1) vs. 2.3 l.sec -1 (1.8 - 3.4 l.sec -1), p = 0.23. Moreover, postoperative longitudinal time × group interactions of FVC, FEV1, and PEF between 6 and 48 postoperative hours did not differ significantly. CONCLUSION: Postoperative pulmonary function parameters were similarly impaired in patients receiving goal-directed crystalloid administration as compared to goal-directed colloid administration during open abdominal surgery. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT00517127 , registered on August 16, 2007) and EudraCT (2005-004602-86).

Impact of Volume-Oriented Incentive Spirometry on Lung Volume and Peak Expiratory Flow Rate in Patients With Tracheostomy.

Background The volume-oriented incentive spirometer is a specialized device designed to facilitate maximal inspiration, promote deep breathing exercises, and enhance lung function. The use of spirometry is challenging and not proven in patients with tracheostomy. Therefore, this study aimed to assess the impact of volume-oriented incentive spirometry on lung volume and peak expiratory flow rate (PEFR) in patients with tracheostomy. Methodology All adult patients with cuffed tracheostomy tubes with a Medical Research Council (MRC) score of more than 48 were studied. Volume-oriented incentive spirometry was performed and the PEFR was measured before and after the spirometry session. All patients underwent 28 sessions in seven days with initial few training sessions. Patient demographic information, such as age, gender, reasons for tracheostomy, MRC at the beginning of the session, volume (volume per breath, mL), and PEFR, was documented. Results Thirty patients were studied, consisting of 18 males and 12 females with initial MRC scores ranging from 48 to 60. The mean lung volume and mean PEFR at the end of seven days were 950 ± 330.9 and 134.7 ± 63.3, respectively, demonstrating safety with minimal complications, including four cases of pain at the tracheostomy site, three cases of hypotension, one case of abdominal pain, and 22 cases with no reported complications. Conclusion Volume-oriented incentive spirometry improves lung volume and PEFR in patients with a tracheostomy tube. Additionally, spirometry proved to be both feasible and effective in this patient population.

Chronic obstructive pulmonary disease (COPD) and COPD-like phenotypes.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease. Historically, two COPD phenotypes have been described: chronic bronchitis and emphysema. Although these phenotypes may provide additional characterization of the pathophysiology of the disease, they are not extensive enough to reflect the heterogeneity of COPD and do not provide granular categorization that indicates specific treatment, perhaps with the exception of adding inhaled glucocorticoids (ICS) in patients with chronic bronchitis. In this review, we describe COPD phenotypes that provide prognostication and/or indicate specific treatment. We also describe COPD-like phenotypes that do not necessarily meet the current diagnostic criteria for COPD but provide additional prognostication and may be the targets for future clinical trials.

Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 Guidelines Reviewed.

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) report is an essential resource for all clinicians who strive to provide optimal care to patients with chronic obstructive lung disease (COPD). The annual report of GOLD makes few revisions and updates besides including data from the preceding year. At an interval, GOLD comes up with a significant modification in its guidelines, which is generally a major overhaul of the pre-existing guidelines. According to the latest 2023 updates, published in November 2022, there have been significant advancements made in the field of COPD. These include the development of more precise definitions for COPD and its exacerbations, the introduction of a new set of parameters to measure exacerbation severity, and updating the COPD assessment tool. Additionally, revisions have been made to the initial and follow-up treatment guidelines. The report also simplifies the treatment algorithm and sheds light on new findings that suggest the use of pharmacological triple therapy can reduce mortality rates. Furthermore, the report includes discussions on inhaler device selection and adherence to COPD medications. These improvements demonstrate a continued effort to enhance COPD treatment and management. Although there are some areas that could benefit from more detailed guidance and explanation, such as the proper utilization of blood eosinophil counts for treatment decisions, and the establishment of treatment protocols post-hospitalization, the latest modifications to the GOLD recommendations will undoubtedly aid healthcare providers in addressing any gaps in patient care. We aim to highlight key changes in the GOLD 2023 report and present a viewpoint about their potential implications in a real-world clinical scenario.

Pulmonary function testing dataset of pressure and flow, dynamic circumference, heart rate, and aeration monitoring.

Respiratory data was collected from 20 subjects, with an even sex distribution, in the low-risk clinical unit at the University of Canterbury. Ethical consent for this trial was granted by the University of Canterbury Human Research Ethics Committee (Ref: HREC 2023/30/LR-PS). Respiratory data were collected, for each subject, over three tests consisting of: 1) increasing set PEEP from a starting point of ZEEP using a CPAP machine; 2) test 1 repeated with two simulated apnoea's (breath holds) at each set PEEP; and 3) three forced expiratory manoeuvres at ZEEP. Data were collected using a custom pressure and flow sensor device, ECG, PPG, Garmin HRM Dual heartrate belt, and a Dräeger PulmoVista 500 Electrical Impedance Tomography (EIT) machine. Subject demographic data was also collected prior to the trial, in a questionnaire, with measurement equipment available. These data aim to inform the development of pulmonary mechanics models and titration algorithms.

How to Enhance the Diagnosis of Early Stages of Chronic Obstructive Pulmonary Disease (COPD)? The Role of Mobile Spirometry in COPD Screening and Diagnosis-A Systematic Review.

COPD is the third leading cause of death worldwide. Its diagnosis can be made with spirometry, which is underused due to its limited accessibility. Portable spirometry holds promise for enhancing the efficacy of COPD diagnoses. The study aimed to estimate COPD prevalence diagnosed with a portable spirometer in high-risk patients and compare it with COPD prevalence based on data from conventional, on-site spirometry. We also evaluated the strategy of a proactive approach to identify COPD in high-risk individuals. We conducted a systematic review of original studies on COPD targeted screening and diagnosis with portable and conventional spirometers selected from 8496 publications initially found in three databases: Cochrane, PubMed, and Embase. The inclusion criteria were met by 28 studies. COPD prevalence evaluated with the use of portable spirometers reached 20.27% and was lower compared to that estimated with the use of conventional spirometers (24.67%). In 11 included studies, postbronchodilator tests were performed with portable spirometers, which enabled a bedside COPD diagnosis. Portable spirometers can be successfully used in COPD targeted screening and diagnosis and thus enhance the detection of COPD at early stages.

Impact of Isolated Exercise-Induced Small Airway Dysfunction on Exercise Performance in Professional Male Cyclists.

BACKGROUND: Professional cycling puts significant demands on the respiratory system. Exercise-induced bronchoconstriction (EIB) is a common problem in professional athletes. Small airways may be affected in isolation or in combination with a reduction in forced expiratory volume at the first second (FEV1). This study aimed to investigate isolated exercise-induced small airway dysfunction (SAD) in professional cyclists and assess the impact of this phenomenon on exercise capacity in this population. MATERIALS AND METHODS: This research was conducted on professional cyclists with no history of asthma or atopy. Anthropometric characteristics were recorded, the training age was determined, and spirometry and specific markers, such as fractional exhaled nitric oxide (FeNO) and immunoglobulin E (IgE), were measured for all participants. All of the cyclists underwent cardiopulmonary exercise testing (CPET) followed by spirometry. RESULTS: Compared with the controls, 1-FEV3/FVC (the fraction of the FVC that was not expired during the first 3 s of the FVC) was greater in athletes with EIB, but also in those with isolated exercise-induced SAD. The exercise capacity was lower in cyclists with isolated exercise-induced SAD than in the controls, but was similar to that in cyclists with EIB. This phenomenon appeared to be associated with a worse ventilatory reserve (VE/MVV%). CONCLUSIONS: According to our data, it appears that professional cyclists may experience no beneficial impacts on their respiratory system. Strenuous endurance exercise can induce airway injury, which is followed by a restorative process. The repeated cycle of injury and repair can trigger the release of pro-inflammatory mediators, the disruption of the airway epithelial barrier, and plasma exudation, which gradually give rise to airway hyper-responsiveness, exercise-induced bronchoconstriction, intrabronchial inflammation, peribronchial fibrosis, and respiratory symptoms. The small airways may be affected in isolation or in combination with a reduction in FEV1. Cyclists with isolated exercise-induced SAD had lower exercise capacity than those in the control group.

Five-Year Outcomes Among U.S. Bronchiectasis and Nontuberculous Mycobacterial Registry Patients.

RATIONALE: Nontuberculous mycobacteria (NTM) are prevalent among patients with bronchiectasis. However, the long-term natural history of patients with NTM and bronchiectasis is not well described. OBJECTIVE: To assess the impact of NTM on 5-year clinical outcomes and mortality in patients with bronchiectasis. METHODS: Patients in the United States Bronchiectasis and Nontuberculous Mycobacteria Research Registry with ≥5 years of follow-up were eligible. Data were collected for all-cause mortality, lung function, exacerbations, hospitalizations, and disease severity. Outcomes were compared between patients with and without NTM at baseline. Mortality was assessed using Cox proportional hazards models and the log-rank test. MEASUREMENTS AND MAIN RESULTS: In total, 2,634 patients were included: 1,549 (58.8%) with and 1,085 (41.2%) without NTM at baseline. All-cause mortality (95% confidence interval) at Year 5 was 12.1% (10.5%, 13.7%) overall, 12.6% (10.5%, 14.8%) in patients with NTM, and 11.5% (9.0%, 13.9%) in patients without NTM. Independent predictors of 5-year mortality were baseline forced expiratory volume in 1 second % predicted, age, hospitalization within 2 years before baseline, body mass index, and gender (all p<0.01). The probabilities of acquiring NTM or Pseudomonas aeruginosa were approximately 4% and 3% per year, respectively. Spirometry, exacerbations, and hospitalizations were similar irrespective of NTM status, except that annual exacerbations were lower in patients with NTM (p<0.05). CONCLUSIONS: Outcomes including exacerbations, hospitalizations, rate of loss of lung function, and mortality rate were similar across 5 years in patients with bronchiectasis with or without NTM.

Assessment of pulmonary function and respiratory symptoms among INDIAN textile sizing mill workers.

BACKGROUND: Textile-sizing mill workers are exposed to various hazards in the sizing units during their working hours and are at risk of acquiring lung impairments due to the usage of sizing chemicals in the sizing process. OBJECTIVE: The main aim of this study is to assess the influence of cotton dust and sizing agents on lung function and breathing difficulties among Indian textile sizing mill workers. METHODS: This cross-sectional study was carried out at a textile-sizing mill from August 2022 to September 2022. A modified questionnaire based American Thoracic Society's standard was used to assess respiratory symptoms among sizing mill workers and the pulmonary function test was conducted Spirometry. The chi-square test was used to find the difference between respiratory symptoms and the t-test was used to find the difference between spirometric parameters. RESULTS: Textile sizing mill workers showed significant (P <  0.0001) decline in peak expiratory flow rate, forced vital capacity (FVC), ratio of FEV1 and forced vital capacity, and forced expiratory volume in 1 s (FEV1). There was an association between symptoms and duration of exposure to pulmonary abnormality. Sizing mill workers showed a significant decline in lung functions and an increase in pulmonary symptoms. As the service duration of exposure in terms of years increased, respiratory symptoms increased and spirometric abnormality also increased. CONCLUSION: This study confirms that sizing agents such as polyvinyl alcohol (PVA), emulsifier, wax, carboxymethyl cellulose (CMC), and starch used in sizing mills are also responsible for respiratory illness and lung impairment among textile workers.

Post-tuberculosis respiratory impairment in Gambian children and adolescents: A cross-sectional analysis.

BACKGROUND: Although post-tuberculosis lung disease (PTLD) is a known consequence of pulmonary tuberculosis (pTB), few studies have reported the prevalence and spectrum of PTLD in children and adolescents. METHODS: Children and adolescent (≤19 years) survivors of pTB in the Western Regions of The Gambia underwent a respiratory symptom screening, chest X-ray (CXR) and spirometry at TB treatment completion. Variables associated with lung function impairment were identified through logistic regression models. RESULTS: Between March 2022 and July 2023, 79 participants were recruited. The median age was 15.6 years (IQR: 11.8, 17.9); the majority, 53/79 (67.1%), were treated for bacteriologically confirmed pTB, and 8/79 (10.1%) were children and adolescents living with HIV. At pTB treatment completion, 28/79 (35.4%) reported respiratory symptoms, 37/78 (47.4%) had radiological sequelae, and 45/79 (57.0%) had abnormal spirometry. The most common respiratory sequelae were cough (21/79, 26.6%), fibrosis on CXR (22/78, 28.2%), and restrictive spirometry (41/79, 51.9%). Age at TB diagnosis over ten years, undernutrition and fibrosis on CXR at treatment completion were significantly associated with abnormal spirometry (p = .050, .004, and .038, respectively). CONCLUSION: Chronic respiratory symptoms, abnormal CXR, and impaired lung function are common and under-reported consequences of pTB in children and adolescents. Post-TB evaluation and monitoring may be necessary to improve patient outcomes.

Residual radiological opacities correlate with disease outcomes in ICU-treated COVID-19.

Background: Few studies consider both radiological and functional outcomes in COVID-19 survivors treated in the intensive care unit (ICU). We investigated clinical findings and pulmonary abnormalities on chest computed tomography (CT) and compared outcomes of severe versus mild-moderate acute respiratory distress syndrome (ARDS) on long-term follow-up. Methods: This longitudinal cohort study included 118 COVID-19 patients (median age, 58 years; 79% men). Thoracic CT scans were performed 4, 10, and 22 months after hospital discharge. Two independent blinded radiologists analyzed the 10 months scans and scored the radiology findings semi-quantitatively, as no/minor versus widespread opacities [low-radiology opacity grade (ROG) versus high-ROG]. ARDS severity was based on the PaO2/FiO2 ratio. The 6 min walk test (6MWT) was performed after 3 and 9 months, and lung diffusion capacity for carbon monoxide (DLCO) and lung volume measurement after 9 and 15 months. Dynamic spirometry was done at all time points. Residual symptoms and health-related quality-of-life (HRQL) were evaluated using validated questionnaires. Results: At 10 months, most patients (81/118; 69%) were classified as high-ROG, of which 70% had severe ARDS during hospitalisation; 69% of those with mild-moderate ARDS also had high-ROG. Patients with high-ROG had longer ICU stay and lower PaO2/FiO2 during hospitalisation (p < 0.01). At 9 months follow-up, patients with high-ROG had smaller lung volumes as % of predicted values [mean (±CI): 80 (77-84) vs. 93 (88-98) (p < 0.001)], lower DLCO as % of predicted values [74 (70-78) vs. 87 (82-92) (p < 0.001)], lower oxygen saturation during 6MWT (p = 0.02), and a tendency to more severe dyspnoea (p = 0.07), but no difference was found in HRQL compared with no/minor ROG (p = 0.92). A higher opacity score was related to lower DLCO at follow-up (r = -0.48, p < 0.001, Spearman rank test). Severe ARDS patients had slightly more severe fatigue at 9 months compared to mild-moderate, but no differences in dyspnoea or lung function at follow-up. Fibrotic-like changes were found in 93% of patients examined with CT scans at 2 years (55/118; 47%). Severe ARDS could predict widespread opacities (ROG > 25%) in most patients at follow-up at 10 months (AUC 0.74). Conclusion: Residual radiological abnormalities in ICU-treated COVID-19 patients, evaluated for up to 2 years, relate to persisting symptoms and impaired lung function, demanding careful follow-up regardless of ARDS severity at hospitalisation.

[National Survey on the Activity of Lung Function Laboratories. Effects During the SARS-COV-2 Pandemic]. / Encuesta sobre la actividad de los laboratorios de función pulmonar. Efectos durante la pandemia por SARS-CoV-2.

Introduction: Following the SARS-CoV-2 pandemic in March 2020, pulmonary function testing (PFT) laboratories underwent a transformation, with a reduction in the number of tests or closure in some cases. The aim of this work was to know the activity of PFT in Spain and the modification of this activity due to the pandemic. Material and methods: A protocolised survey was carried out to members of the PFT laboratories through the Spanish Society of Pneumology and Thoracic Surgery (SEPAR). Results: Thirty-nine hospitals in Spain responded. The pulmonary function tests most frequently performed in the PFT laboratories were forced spirometry with bronchodilator test (100%), body plethysmography (97.4%), CO transfer capacity (97.4%), respiratory muscle strength measured in the mouth (97.4%), 6-minute walking test (94.7%), measurement of exhaled fraction of nitric oxide (92.3%) and incremental exercise test (71.8%).The pandemic led to a significant decrease in the number of tests (35.4%) during 2020 with subsequent recovery in 2021, without reaching pre-pandemic values.The most important changes were increased examination times, working with personal protective equipment and ventilation of the rooms. The performance of the nasopharyngeal swab for SARS-CoV2 testing prior to the tests was not homogeneous in the PFT laboratories. Conclusions: Most hospitals are sufficiently equipped to perform the most common pulmonary function tests. The pandemic resulted in a loss of activity in all hospitals.

A Community-Based Cross-Sectional Study on Respiratory Health and Spirometry-Assessed Pulmonary Function Among Textile Workers in Tamil Nadu, India.

Introduction The textile industry is one of the largest economic activities. Still, the laborers involved in it are exposed to various health-damaging air pollutants, putting them at risk of health issues including morbidities of the respiratory system. Therefore, this study aimed to assess the pulmonary function parameters of the workers involved in textile manufacturing-related jobs. Methodology A cross-sectional study was carried out among adult individuals who had been working in textile manufacturing-related jobs as their main work. The details such as sociodemographic, clinical, workplace conditions, and smoking habits were collected, as well as chest auscultation and lung spirometry using a hand-held spirometer. The participants who had normal and abnormal lung function patterns were statistically analyzed for potential influencing factors. Results The findings of the study conducted from 95 eligible participants identified that the pulmonary function parameters assessed by spirometry were in the abnormal range among 84 (88%) participants. Around 72 (82%) of them had a restrictive pattern, and six (6%) had both restrictive and obstructive (mixed) patterns of lung disease. Smokers and those who lacked cross-ventilation and/or fresh source of air in the workplace were more likely to have abnormal lung function. Participants who had their workplace and residence as same had significantly 6.44 (95% CI: 1.24, 33.36) times higher odds of having abnormal lung function in spirometry. Conclusion As workers involved in household-run textile manufacturing jobs are found to be at a higher risk of developing abnormal lung function, using personal protective equipment, following occupational safety measures, and improving the working environment to acceptable standards are essential to safeguard the respiratory health of laborers in such unorganized sectors.

Single breath count test and its applications in clinical practice: a systematic review.

Background: Single breath count test (SBCT) may be a reproducible, rapid, easy to perform and easy to interpret substitute to spirometry especially in low resource settings for certain conditions. Its interest has been rekindled with the recent COVID-19 pandemic and it can be done as a part of tele-medicine as well. Objectives: The objective of this review was to summarize the evidence of SBCT in clinical practice. Methods: The authors searched EMBASE, PubMed and Google Scholar for all the relevant articles as per exclusion and inclusion criteria. Two authors independently screened all the studies. Newcastle Ottawa Scale was used to assess the quality of the studies. The systematic review was carried following the PRISMA guidelines. Results: After the rigorous process of screening, a total of 13 articles qualified for the systematic review. SBCT greater than 25 had sensitivity of greater than 80% in diagnosing myasthenia gravis exacerbation and SBCT less than or equal to 5 predicted the need for mechanical ventilation in Guillain-Barre syndrome (GBS) patients with 95.2% specificity. Also, Single breath count correlated significantly with forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) in children with pulmonary pathology and in patients with COVID-19 it was used to rule out the need for noninvasive respiratory support. Conclusion: SBCT will undoubtedly be an asset in low resource settings and in tele-medicine to assess the prognosis and guide management of different respiratory and neuromuscular diseases.

Prevalence, stability, and clinical significance of an isolated low FEV1 spirometry pattern in children.

OBJECTIVES: In adults, an isolated low FEV1 pattern (an FEV1 below the lower limit of normal with a preserved FVC and FEV1/FVC) has been associated with the risk of developing airway obstruction. Our objective was to examine the prevalence, stability, and clinical significance of an isolated low FEV1 pattern in the pediatric population. METHODS: We conducted a retrospective study of spirometries from children ages 6-21 years and categorized tests into spirometry patterns according to published guidelines and recent literature. In a subgroup of tests with an isolated low FEV1 pattern, we evaluated spirometry technique. We also examined the association of having a test with an isolated low FEV1 pattern with clinical markers of disease severity in a subgroup of children with cystic fibrosis (CF). RESULTS: The isolated low FEV1 pattern was uncommon across the 29,979 tests included (n = 645 [2%]). In the 263 children with an isolated low FEV1 pattern who had a follow-up test performed, the most frequent spirometry pattern at last test was normal (n = 123 [47%]). A primary diagnosis of CF was associated with increased odds of having at least one test with an isolated low FEV1 pattern (OR = 8.37, 95% CI = 4.70-15.96, p < .001). The spirometry quality in a subgroup of tests with an isolated low FEV1 pattern (n = 50) was satisfactory. In the subgroup of children with CF (n = 102), those who had a test with an isolated low FEV1 pattern had higher odds of using oral antibiotics in the last 12 months than those who had a normal pattern (OR = 3.50, 95% CI = 1.15-10.63, p = .03). CONCLUSIONS: The isolated low FEV1 pattern can occur repeatedly over time, usually transitions to a normal pattern, is not due to a poor spirometry technique, and could be clinically relevant in children with chronic lung diseases.

Combining small airway parameters with conventional parameters obtained during spirometry to diagnose airflow obstruction: A cross-sectional study.

BACKGROUND AND OBJECTIVE: The use of small airway parameters generated by spirometry, namely forced expiratory flow between 25% and 75% of forced vital capacity (FVC) (FEF25%-75%) and forced expiratory flow at 50% and 75% of FVC (FEF50% and FEF75%, respectively), is widely discussed. We evaluated the importance of these spirometric parameters in a large Chinese population. METHODS: We conducted a cross-sectional observational study in which spirometry and bronchodilator responsiveness (BDR) data were collected in a healthcare centre from May 2021 to August 2022 and in a tertiary hospital from January 2017 to March 2022. Discordance was assessed between the classification of test results by the large airway parameters of forced expiratory volume in 1 second (FEV1) and FEV1/FVC ratio and by the small airway parameters of FEF25%-75%, FEF75% and FEF50%. The predictive power of Z-scores of spirometric parameters for airflow limitation and BDR was assessed using receiver operating characteristic curves. RESULTS: Our study included 26,658 people. Among people with a normal FVC (n = 14,688), 3.7%, 4.5% and 3.6% of cases exhibited normal FEV1/FVC ratio but impaired FEF25%-75%, FEF75% and FEF50%, respectively, while 6.8%-7.0% of people exhibited normal FEV1 but impaired FEF25%-75%, FEF75% and FEF50%. Using the Z-scores of combining both large and small airway parameters in spirometry showed the best area under the curve for predicting airflow limitation (0.90; 95% CI 0.87-0.94) and predicting BDR (0.72; 95% CI 0.71-0.73). CONCLUSION: It is important to consider both large and small airway parameters in spirometry to avoid missing a diagnosis of airflow obstruction.

Association between lung function and dyspnoea and its variation in the multinational Burden of Obstructive Lung Disease (BOLD) study.

BACKGROUND: Dyspnoea is a common symptom of respiratory disease. However, data on its prevalence in general populations and its association with lung function are limited and are mainly from high-income countries. The aims of this study were to estimate the prevalence of dyspnoea across several world regions, and to investigate the association of dyspnoea with lung function. METHODS: Dyspnoea was assessed, and lung function measured in 25,806 adult participants of the multinational Burden of Obstructive Lung Disease study. Dyspnoea was defined as ≥2 on the modified Medical Research Council (mMRC) dyspnoea scale. The prevalence of dyspnoea was estimated for each of the study sites and compared across countries and world regions. Multivariable logistic regression was used to assess the association of dyspnoea with lung function in each site. Results were then pooled using random-effects meta-analysis. RESULTS: The prevalence of dyspnoea varied widely across sites without a clear geographical pattern. The mean prevalence of dyspnoea was 13.7 % (SD=8.2 %), ranging from 0 % in Mysore (India) to 28.8 % in Nampicuan-Talugtug (Philippines). Dyspnoea was strongly associated with both spirometry restriction (FVC

Neutrophil-to-Lymphocyte Ratio and Blood Eosinophil Levels As Inflammatory Indicators in Smoker and Non-smoker Young Adult Patients With Chronic Obstructive Pulmonary Disease at a Tertiary Care Hospital.

Background Inflammatory markers are elevated in chronic obstructive pulmonary disease (COPD) and can be quantified to detect severity, prognosis, mortality risk, and response to treatment. However, the estimation costs are high. The blood neutrophil-to-lymphocyte ratio (NLR) and eosinophil levels are emerging as biomarkers in COPD, yet there is a paucity of data. Aim and objectives This study was designed to elucidate the roles of the NLR and eosinophil levels in smokers and non-smokers with stable COPD male subjects, correlating them with lung functions. Materials and methods A prospective observational clinical study was conducted from January to June 2023, after receiving approval from the Institutional Ethics Committee, on 73 COPD patients aged 30-60 years who gave voluntary informed consent. Complete blood counts and spirometry were performed. Patients with a forced expiratory volume in one second (FEV1) % predicted <70% and an FEV1/forced vital capacity (FVC) % <70% based on the pulmonary function test (MIR Spirolab) were included. They were further divided into mild (n=10), moderate (n=27), severe (n=26), and very severe (n=10) categories as per the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Subjects were also categorized into smoker (n=45) and non-smoker (n=28) groups. The complete blood count was analyzed using an automated analyzer (Beckman Coulter). Analysis was also carried out with an NLR of more or less than three. A P-value of less than 0.05 was considered significant. Results Smokers constituted 61.65% (n=45) of the subjects, and non-smokers 38.35% (n=28). Among smokers, 17.78% had very severe airflow obstruction. In all COPD subjects (n=73), lymphocytes, eosinophils, and lung functions were lower in the group where the NLR was greater than three. NLR in smokers (3.52±1.43) was higher than in non-smokers (3.39±0.94). In non-smokers (n=28), blood eosinophils and lymphocytes were elevated. In smokers (n=45), blood neutrophils, monocytes, and basophils were increased. Smokers showed a non-significant increase in RBC, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Neutrophils, monocytes, eosinophils, and NLR increased with disease severity. NLR negatively correlated with FEV1 (r=-0.350, p=0.034) and positively with pack-years (r=0.546, p<0.001) in smokers. NLR negatively correlated with eosinophils, FVC, FEV1/FVC, and FEV1 % predicted. In all COPD subjects (n=73), NLR negatively correlated with blood eosinophils (r=-0.184, p=0.12), BMI, and lung functions. Conclusion NLR is elevated in COPD subjects and can serve as a marker of inflammation and a predictor of the risk and severity of airflow limitation. NLR correlates both positively and negatively with pack-years and lung functions, respectively.

Assessment of lung function variability documents airflow limitation in many patients with long covid.

Background: It is estimated that 65 million people worldwide suffer from long covid (LC). Many LC symptoms are also reported by patients with airflow limitation, used to confirm asthma. The primary aim was to detect airflow limitation in LC patients by a methacholine bronchial provocation test (BPT) and if negative, by evaluation of diurnal variability in forced expiratory flow in 1 second (FEV1) over a two-weeks' period. The second aim was to assess responsiveness to asthma treatment on diurnal FEV1 variability and LC symptoms. Methods: Patients with LC for at least six months were recruited in this open diagnostic study. Burden of LC symptoms were reported on a 10-point Likert scale (0 = not troubled, 10 = extremely troubled) at inclusion and after three weeks' asthma treatment. A positive methacholine BPT was defined by an accumulated provocation dose (PD20)<8 µmol causing 20% fall in FEV1. App-based spirometer was used for diurnal FEV1 variability, deemed positive by diurnalvariability in FEV1 ≥12%. Results: Airflow limitation was documented by positive methacholine BPT in 8/30 (27%), or by excessive diurnal variability in FEV1 in 21/22 (95%) of the BPT negative LC patients. One patient dropped out due to personal issues. Three weeks' asthma treatment normalised mean diurnal FEV1 variability from 18.0% to 7.3%, p < 0.001. Significant reductions were observed for fatigue and dyspnoea, from 8.3 to 6.1, p < 0.001, and 3.0 to 0, p < 0.001, respectively. Conclusion: This study indicate that airflow limitation may be detected in many LC patients if evaluation of diurnal variability in FEV1 is included in the diagnostics.

Reduced lung function during childhood in identical twins with discordant fetal growth: a cohort study.

Background: Fetal growth restriction (FGR) can negatively affect lung development, leading to increased respiratory morbidity and reduced lung function later in life. Studies regarding the impact of FGR on lung function in singletons are influenced by genetic, obstetric, and maternal factors. To overcome these confounding factors, we aim to investigate lung function in identical twins with selective FGR (sFGR). Methods: Lung function assessments were performed in identical twins with sFGR born in our centre between March 1, 2002, and December 31, 2017, aged between 5 and 17 years. sFGR was defined as birthweight discordance ≥20%. Outcome measures consisted of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and transfer factor for carbon monoxide (DLCO) and were compared between the smaller and larger twin. Findings: Thirty-nine twin pairs performed spirometry of sufficient quality. Median gestational age at birth was 34.3 (interquartile range (IQR) 32.1-36.0) weeks with median birthweights of 1500 (IQR 1160-1880) grams and 2178 (IQR 1675-2720) grams for the smaller and larger twin, respectively. Smaller twins had significantly lower z-scores for FEV1 (-0.94 versus -0.41, p = 0.0015), FVC (-0.56 versus -0.06, p < 0.0001) and DLCO (-0.50 versus 0.00, p < 0.0001) compared to larger co-twins. Interpretation: Although being genetically identical, sFGR in identical twins is associated with a reduction in static and dynamic lung volume and a reduction in lung diffusion, even when taking the reduced lung volume into account. This indicates that adverse growth conditions in utero negatively affect lung development and function, potentially contributing to an increase in respiratory morbidities later in life. Funding: The Dutch Heart Foundation and The Bontius Foundation.