The lower limit for FEV1/FVC in dive medical assessments: a retrospective study

Introduction: Interpreting pulmonary function test (PFT) results requires a valid reference set and a cut-off differentiating pathological from physiological pulmonary function; the lower limit of normal (LLN). However, in diving medicine it is unclear whether an LLN of 2.5% (LLN-2.5) or 5% (LLN-5) in healthy subjects constitutes an appropriate cut-off. Methods: All PFTs performed at the Royal Netherlands Navy Diving Medical Centre between 1 January 2015 and 1 January 2021 resulting in a forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and/or FEV1/FVC with a Z-score between -1.64 (LLN-5) and -1.96 (LLN-2.5) were included. Records were screened for additional tests, referral to a pulmonary specialist, results of radiological imaging, and fitness to dive. Results: Analysis of 2,108 assessments in 814 subjects showed that 83 subjects, 74 men and nine women, mean age 32.4 (SD 8.2) years and height 182 (7.0) cm, had an FVC, FEV1 and/or FEV1/FVC with Z-scores between -1.64 and -1.96. Of these 83 subjects, 35 (42%) underwent additional tests, 77 (93%) were referred to a pulmonary specialist and 31 (37%) underwent high-resolution CT-imaging. Ten subjects (12%) were declared ‘unfit to dive’ for various reasons. Information from their medical history could have identified these individuals. Conclusions: Use of LLN-2.5 rather than LLN-5 for FEV1/FVC in asymptomatic individuals reduces additional investigations and referrals to a pulmonary specialist without missing important diagnoses, provided a thorough medical history is taken. Adoption of LLN-2.5 could save resources spent on diving medical assessments and protect subjects from harmful side effects associated with additional investigations, while maintaining an equal level of safety.

Implications of using the GLI-2012, GOLD and Australian COPD-X recommendations in assessing the severity of airflow limitation on spirometry among an Indigenous population with COPD: an Indigenous Australians perspective study

BackgroundAssessment of airflow limitation (AFL) is crucial in the clinical evaluation of patients with chronic obstructive pulmonary disease (COPD). However, in the absence of normative reference values among adult Australian Indigenous population, the implications of utilising the Global Lung Function Initiative (GLI-2012), Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the Australian concise COPD-X recommended severity classifications is not known. Moreover, spirometry values (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)) are observed to be 20%–30% lower in an apparently healthy Indigenous population in comparison to Caucasian counterparts.MethodsAdult Indigenous patients diagnosed to have COPD on spirometry (postbronchodilator (BD) FEV1/FVC <0.7 ((GOLD, (COPD-X)) and ≤lower limit of normal (others/mixed reference equations) for GLI-2012) were assessed for AFL severity classifications on Post-BD FEV1 values (mild, moderate, severe, very severe) as per the recommended classifications.ResultsFrom a total of 742 unique patient records of Indigenous Australians, 253 were identified to have COPD via GOLD/COPD-X criteria (n=238) or GLI-2012 criteria (n=238) with significant agreeance between criteria (96%, κ=0.901). Of these, the majority were classified as having moderate or severe/very-severe AFL with significant variability across classification criteria (COPD-X (40%–43%), GOLD (33%–65%), GLI-2012 (18%–75%)). The FVC and FEV1 values also varied significantly between classification criterion (COPD-X/GOLD/GLI-2012) within the same AFL category, with COPD-X ‘moderate’ AFL almost matching ‘severe’ AFL categorisation by GOLD or GLI-2012.ConclusionsHealth professionals caring for Indigenous patients with COPD should be aware of the clinical implications and consequences of utilising various recommended AFL classifications in the absence of validated spirometry reference norms among adult Indigenous patients.

Evaluation of Supranormal Spirometry Values With an Obstructive Ratio for Airway Hyperreactivity

ABSTRACT Background Published guidelines on spirometry interpretation suggest an elevated FVC and FEV1 &gt; 100% of predicted with an obstructive ratio may represent a physiological variant. Further evidence is needed on whether this finding indicates symptomatic airways obstruction and what additional evaluation should be done. Methods Participants were prospectively enrolled to undergo additional testing for a technically adequate spirometry study with an FEV1 &gt; 90% of predicted, and FEV1/FVC below the lower limit of normal, based on 95th percentile confidence intervals. Further testing consisted of full pulmonary function testing, impulse oscillometry (IOS), post-bronchodilator testing, fractional exhaled nitric oxide (FeNO), and methacholine challenge testing (MCT). Results A total of 49 patients meeting entry criteria enrolled and completed testing. Thirty-three were considered symptomatic based on clinical indications for initial testing and 16 were considered asymptomatic. Baseline pulmonary function test values were not different between groups while IOS R5 values (% predicted) were higher in the symptomatic group (126.5 ± 0.37 vs 107.1 ± 0.31). Bronchodilator responsiveness on PFT or IOS was infrequent in both groups. There was a 29% positivity rate for MCT in the symptomatic group compared to one borderline study in asymptomatic participants. FeNO was similar for symptomatic, 26.17 ± 31.3 ppb, compared to asymptomatic, 22.8 ± 13.5 ppb (p = 0.93). The dysanapsis ratio was higher in the symptomatic (0.15 ± 0.03) compared to the asymptomatic (0.13 ± 0.02) (p &lt; 0.05). Conclusion Normal FEV1 &gt; 90% of predicted and obstructive indices may not represent a normal physiological variant in all patients. In symptomatic patients, a positive MCT and elevated baseline IOS values were more common than in asymptomatic patients with similar PFT characteristics. These findings suggest that clinicians should still evaluate for airway hyperresponsiveness in patients with exertional dyspnea with airway obstruction and FEV1 &gt; 90% of predicted and consider alternative diagnoses to include a normal physiologic variant if non-reactive.

Cardiopulmonary function in adolescent patients with pectus excavatum or carinatum

BackgroundPectus excavatum (PE) and pectus carinatum (PC) have generally been considered an aesthetic issue, although there is growing evidence of associated cardiopulmonary function (CPF) impairment, especially in PE patients. The study goal was to determine any correlation between pectus malformations and cardiopulmonary symptoms and function based on systematic assessment of CPF and thoracic measurements, such as Haller Index (HI) and sternal torsion angle (STA).MethodsData from 76 adolescent patients with PE (n=30) or PC (n=46) were retrospectively collected referred between January 2015 and April 2018. CPF measurements and thoracic imaging were performed in all patients. HI and STA correction indexes were measured in all patients.FindingsMedical records from 76 patients (PE n=30; PC n=46) were analysed. Patients were predominantly male (>93.3%), and aged between 13 and 14½ old. PE was associated with airway obstruction, with a forced expiratory volume in 1 s value under the lower limit of normal in 13% of cases (p<0.001). Restrictive syndrome was observed in 23% of cases (p<0.001), with a Z score for total lung capacity under the lower limit of normal. In PC, pulmonary function was not affected. All patients showed slightly decreased values of left and right ejection fraction and cardiac index at rest, although values were within normal range. There were no significant correlations between pulmonary and cardiac functions or between low CPF and thoracic measurements.InterpretationOur results confirm the modest impact of pectus malformations on CPF at rest, without correlation with anamnestic dyspnoea on exertion, nor with chest pain or anatomical measurements. Validation of new correction indexes could be helping characterise these malformations and choose optimal therapeutic management.

Respiratory Morbidities and Lung Function Abnormalities in Survivors of Bhopal Gas Disaster: A Cross-Sectional Study

Background Respiratory morbidities remained major morbidities among the survivors of the Bhopal gas disaster. We hypothesized that underlying lung function abnormalities, especially small airway dysfunctions (SAD), were responsible for persistent respiratory morbidity. Material and methods We conducted a cross-sectional study between 2018 and 2020 in the severely exposed cohort of the Bhopal gas disaster. A standardized questionnaire was used to collect respiratory symptoms. The forced oscillation technique (FOT) and spirometry were used for assessing lung functions. Univariate and multivariate logistic regression analyses were used to examine the association. Results Total 916 individuals (men: 442) participated. The mean age was 55.2 ± 12.3 years. Breathlessness was a predominant respiratory complaint (71.7%), followed by cough (15.1%). Five hundred fifty-eight individuals participated in lung function assessment. The R5 > ULN (upper limit of normal), R5 − 19 >ULN, and X5 < LLN (lower limit of normal) were observed in 29.3%, 23.3%, and 21.2% participants, respectively. Normal, obstructive, and restrictive spirometry was observed in 46.2%, 26.1%, and 27.7% of participants, respectively. Abnormalities in FOT parameters were observed in 25.3% of individuals with normal spirometry. Individuals with obstructive spirometry had the highest risk of abnormal FOT parameters (adj OR:3.93, 95% CI: 2.24–6.89). Breathlessness showed a significant association with abnormal R5 (adj OR: 1.81; 95% CI: 1.13–2.91) and obstructive spirometry (adj OR: 2.26; 95% CI: 1.29–3.95). Conclusion Assessment of small airway functions, in addition to spirometry, will help to identify complex lung function abnormalities in the population exposed to toxic inhalation.

Pulmonary Function and Respiratory Muscle Strength in Patients with Multiple Sclerosis

Background. In patients with multiple sclerosis (MS), there is a decline in muscle strength and physical capacity due to demyelination and axonal loss in the central nervous system. In patients with advanced MS or in a later stage of the disease, also respiratory impairment may occur. The degree of pulmonary dysfunction in the earlier stages of MS has not been thoroughly described. Therefore, the primary aims of this study are to describe pulmonary function and respiratory muscle strength in patients with a moderate disease course and to identify associations between respiratory muscle strength and functional capacity. Methods. A sample of 48 patients with a diagnosis of MS and mean age 56 ± 11 years was studied using a descriptive cross-sectional design. The patients had a disease duration of 24 ± 11 years and a median Expanded Disability Status Scale (EDSS) score of 4.5 (interquartile range 4.0-6.5). Pulmonary function assessed by spirometry, respiratory muscle strength, peak cough flow and peripheral oxygen saturation, subjective breathing and coughing ability, and physical capacity measured using the 6MWT were evaluated. Results. The patients had normal pulmonary function with no significant abnormalities in dynamic spirometry (vital capacity 103 ± 16 % predicted, forced expiratory volume in 1 second 95 ± 15 % predicted). Peak expiratory flow rate 89 ± 17 % predicted was in the lower limit of normal. Respiratory muscle strength, determined by maximal inspiratory (MIP) and expiratory (MEP) static pressures, was normal but with large differences between individuals. MIP ranged from 26 to 143 cmH2O ( 98 ± 31 % predicted); the MEP values ranged from 43 to 166 cmH2O ( 104 ± 29 % predicted), with two patients having values below the lower limit of normal. Significant positive associations between MIP as well as MEP were found in several pulmonary function variables. A significant negative association was found between EDSS score and MEP ( r = − 0.312 , p = 0.031 ). Mean peak cough flow was 389 ± 70 L/min, which is comparable with the values reported for healthy adults. The patients did not experience a severely decreased ability to take deep breaths or cough. There was a moderate correlation between MEP and physical capacity, as assessed by the 6MWT ( r = 0.399 , p = 0.010 ) and between peak expiratory flow (PEF) and the 6MWT ( r = 0.311 , p = 0.048 ). Conclusion. Respiratory muscle strength, pulmonary function assessed by spirometry, and peak cough flow were normal in patients with mild to moderate MS; however, there were large individual differences demonstrating low respiratory muscle strength in some patients. Significant associations between MEP and functional capacity and between MEP and disease severity were found, indicating that patients with impaired respiratory muscle strength have lower functional capacity and more severe disease.

Airway obstruction can be better predicted using Global Lung Function Initiative spirometry reference equations in Marfan syndrome

Marfan syndrome is a genetic disorder of the connective tissue, including involvement of the lungs.Pulmonary function test was performed in 32 asymptomatic adult Marfan patients using European Community for Coal and Steel (ECCS) and Global Lung Function Initiative (GLI) reference values.Using GLI equations for reference, significantly lower lung function values were noted for forced vital capacity (FVC) (87.0 ± 16.6% vs. 97.1 ± 16.9%; P < 0.01) and forced expiratory volume in the first second (FEV1) (79.6 ± 18.9% vs. 88.0 ± 19.1%; P < 0.01) predicted compared to ECCS. Obstructive ventilatory pattern was present in 25% of the cases when calculating with GLI lower limit of normal (LLN), and it was significantly more common in men as compared to women (n = 6, 50% vs. n = 2, 10%; P = 0.03).GLI is more suitable to detect early ventilatory changes including airway obstruction in young patients with special anatomic features, and should be used as a standard way of evaluation in asymptomatic Marfan population.

Inspiratory crackles—early and late—revisited: identifying COPD by crackle characteristics

BackgroundThe significance of pulmonary crackles, by their timing during inspiration, was described by Nath and Capel in 1974, with early crackles associated with bronchial obstruction and late crackles with restrictive defects. Crackles are also described as ‘fine’ or ‘coarse’. We aimed to evaluate the usefulness of crackle characteristics in the diagnosis of chronic obstructive pulmonary disease (COPD).MethodsIn a population-based study, lung sounds were recorded at six auscultation sites and classified in participants aged 40 years or older. Inspiratory crackles were classified as ‘early’ or ‘late and into the types’ ‘coarse’ and ‘fine’ by two observers. A diagnosis of COPD was based on respiratory symptoms and forced expiratory volume in 1 s/forced inspiratory vital capacity below lower limit of normal, based on Global Lung Function Initiative 2012 reference. Associations between crackle characteristics and COPD were analysed by logistic regression. Kappa statistics was applied for evaluating interobserver agreement.ResultsOf 3684 subjects included in the analysis, 52.9% were female, 50.1% were ≥65 years and 204 (5.5%) had COPD. Basal inspiratory crackles were heard in 306 participants by observer 1 and in 323 by observer 2. When heard bilaterally COPD could be predicted with ORs of 2.59 (95% CI 1.36 to 4.91) and 3.20 (95% CI 1.71 to 5.98), annotated by observer 1 and 2, respectively, adjusted for sex and age. If bilateral crackles were coarse the corresponding ORs were 2.65 (95% CI 1.28 to 5.49) and 3.67 (95% CI 1.58 to 8.52) and when heard early during inspiration the ORs were 6.88 (95% CI 2.59 to 18.29) and 7.63 (95%CI 3.73 to 15.62). The positive predictive value for COPD was 23% when early crackles were heard over one or both lungs. We observed higher kappa values when classifying timing than type.Conclusions‘Early’ inspiratory crackles predicted COPD more strongly than ‘coarse’ inspiratory crackles. Identification of early crackles at the lung bases should imply a strong attention to the possibility of COPD.

EXPERIENCE OF APPLICATION OF METHODS OF ALTERNATIVE AND COMPLEMENTARY MEDICINE IN DIAGNOSIS AND TREATMENT OF DIFFERENT TREATMENTS IN THE PRIDNIPROVSK REGION

Keywords: integrative medicine, individual health management, TM Health Designer, psychosomatic harmoni- zation, health errors, health-creating thinking. Introduction. The generalized experience of using the methods of integrative medicine, integrative approach - “Health Designer” TM in health management in common diseases is considered. The purpose of this article is to point out the priority of health education before treating diseases, the idea that a doctor should not only “cure diseases”, but also “design health”. The materials and methods presented in the article are based on literature data obtained from a bibliographic search, used WHO recommendations, on the analysis of test results of students of health courses as a level of cognitive functions. Results. The level of cognitive functions increased by 0.8 points on the Montreal scale and approached the lower limit of normal. Emphasis is placed on the fact that You need to learn about health, you need a new prevention strategy - a strategy to manage the health of the individual, to offer doctors of all specialties to send their patients to study at a health school.