Comparison of distance covered, physiological cost, and perceived exertion in four six-minute walk test protocols.

Objective: There is evidence that indicates that the Walked Distance (WD) in the 6-Minute Walk Test (6MWT) would be sensitive to the type of track and encouragement. The aim of study was compared the impact of track type and verbal encouragement provided in the 6MWT on WD, physiological cost, perceived exertion, and gait efficiency in healthy young adults unfamiliar with the test. Method: WD, heart rate, subjective sensation of dyspnea (SSD), and fatigue (SSF) were measured in four 6MWT protocols: i) 30 m linear track and protocolized encouragement (LT + PE), ii) 30 m linear track and constant encouragement (LT + CE), iii) 81 m elliptical track and protocolized encouragement (ET + PE), and iv) 81 m elliptical track and constant encouragement (ET + CE). In addition, the Gait Efficiency Index (GIE) associated with physiological cost, dyspnea and fatigue was calculated and compared between the different protocols. Results: The WD was significantly higher in the ET + CE protocol. The percentage of the heart rate reserve used (%HRRu) at minute 6 was higher in the ET + CE protocol. The SSD and SSD had difference in startup time between the protocols. The GEI was higher in %HRRu, SSD, and SSF for the ET + CE protocol. Conclusion: The ET + CE protocol showed a significant increase in WD during the 6MWT in healthy young adults. Although it obtained the highest physiological cost, it did not present perceptual differences when entering cardiopulmonary assessment windows relevant to a more efficient test for the participant. It is advisable to discuss, based on the findings, the fundamental objective of the 6MWT and national and international recommendations to achieve a result as close as possible to the real maximal effort.

Effects of Respiratory Muscle Training on Functional Ability, Pain-Related Outcomes, and Respiratory Function in Individuals with Low Back Pain: Systematic Review and Meta-Analysis.

Objectives: The aim of this meta-analysis was to determine the effects of respiratory muscle training (RMT) on functional ability, pain-related outcomes, and respiratory function in individuals with sub-acute and chronic low back pain (LBP). Methods: The study selection was as follows: (participants) adult individuals with >4 weeks of LBP; (intervention) RMT; (comparison) any comparison RMT (inspiratory or expiratory or mixed) versus control; (outcomes) postural control, lumbar disability, pain-related outcomes, pain-related fear-avoidance beliefs, respiratory muscle function, and pulmonary function; and (study design) randomized controlled trials. Results: 11 studies were included in the meta-analysis showing that RMT produces a statistically significant increase in postural control (mean difference (MD) = 21.71 [12.22; 31.21]; decrease in lumbar disability (standardized mean difference (SMD) = 0.55 [0.001; 1.09]); decrease in lumbar pain intensity (SMD = 0.77 [0.15; 1.38]; increase in expiratory muscle strength (MD = 8.05 [5.34; 10.76]); and increase in forced vital capacity (FVC) (MD = 0.30 [0.03; 0.58]) compared with a control group. However, RMT does not produce an increase in inspiratory muscle strength (MD = 18.36 [-1.61; 38.34]) and in forced expiratory volume at the first second (FEV1) (MD = 0.36 [-0.02; 0.75]; and in the FEV1/FVC ratio (MD = 1.55 [-5.87; 8.96]) compared with the control group. Conclusions: RMT could improve expiratory muscle strength and FVC, with a moderate quality of evidence, whereas a low quality of evidence suggests that RMT could improve postural control, lumbar disability, and pain intensity in individuals with sub-acute and chronic LBP. However, more studies of high methodological quality are needed to strengthen the results of this meta-analysis.

Measuring lung diffusing capacity: an opportunity for improved medical surveillance and disability evaluation of coal miners.

OBJECTIVES: Spirometry is the primary lung function test utilised for medical surveillance and disability examination for coal mine dust lung disease. However, spirometry likely underestimates physiologic impairment. We sought to characterise abnormalities of single-breath diffusing capacity for carbon monoxide (DLCO) among a population of former coal miners. METHODS: Data from 3115 former coal miners evaluated at a West Virginia black lung clinic between 2006 and 2015 were retrospectively analysed to study the association between diffusion impairment (abnormally low DLCO), resting spirometry and the presence and severity of coal workers' pneumoconiosis on chest radiography. We developed ordinary least squares linear regression models to evaluate factors associated with per cent predicted DLCO (DLCOpp). RESULTS: Diffusion impairment was identified in 20.2% of subjects. Ten per cent of all miners with normal spirometry had diffusion impairment including 7.4% of never smokers. The prevalence of diffusion impairment increased with worsening radiographic category of pneumoconiosis. Mean DLCOpp decreased with increasing small opacity profusion subcategory in miners without progressive massive fibrosis. Linear regression analysis also showed significant decreases in DLCOpp with increasing small opacity profusion and presence of large opacities. CONCLUSIONS: Diffusion impairment is common among former coal miners, including among never smokers, miners without radiographic pneumoconiosis and miners with normal spirometry. These findings demonstrate the value of including DLCO testing in disability examinations of former coal miners and an important role for its use in medical surveillance of working miners to detect early chronic lung disease.

Prospective association between social isolation, loneliness and lung function among Chinese middle-aged and older adults.

OBJECTIVE: Previous research has highlighted a heightened occurrence of social isolation and loneliness in older adults diagnosed with chronic lung diseases. Nevertheless, there exists a dearth of studies that have explored the influence of impoverished social relationships on lung function. This study aimed to examine the longitudinal association between social isolation, loneliness and lung function over 4 years among middle-aged and older Chinese adults. METHODS: This study employed two waves (2011 and 2015) of data from the China Health and Retirement Longitudinal Study (CHARLS). The analysis was limited to participants aged 45 years and above and stratified based on gender (3325 men and 3794 women). The measurement of peak expiratory flow (PEF) served as an indicator for assessing lung function. Lagged dependent variable regression models, accounting for covariates, were employed to explore the relationship between baseline social isolation and loneliness and the subsequent PEF. RESULTS: For women, social isolation was significantly associated with the decline in PEF at follow-up (ß = -.06, p < .001) even after adjusting for all covariates; no significant correlation was observed between loneliness and PEF. Among men, there was no significant association found between either social isolation or loneliness and PEF. CONCLUSIONS: Social isolation is prospectively associated with worse lung function in middle-aged and older Chinese women but not men. The results highlight the importance of promoting social relationships in public health initiatives, especially in groups that are more vulnerable.

Clinical Characteristics and Frequency of Chronic Obstructive Pulmonary Disease Exacerbations in Korean Patients: Findings From the KOCOSS Cohort 2012-2021.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) exert a substantial burden on patients and healthcare systems; however, data related to the frequency of AECOPD in the Korean population are limited. Therefore, this study aimed to describe the frequency of severe, and moderate or severe AECOPD, as well as clinical and demographic characteristics of patients with chronic obstructive pulmonary disease (COPD) in South Korea. METHODS: Data from patients aged > 40 years with post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity ≤ 70% of the normal predicted value from the Korea COPD Subgroup Study database were analyzed (April 2012 to 2021). The protocol was based on the EXAcerbations of COPD and their OutcomeS International study. Data were collected retrospectively for year 0 (0-12 months before study enrollment) based on patient recall, and prospectively during years 1, 2, and 3 (0-12, 13-24, and 25-36 months after study enrollment, respectively). The data were summarized using descriptive statistics. RESULTS: Data from 3,477 Korean patients (mean age, 68.5 years) with COPD were analyzed. Overall, most patients were male (92.3%), former or current smokers (90.8%), had a modified Medical Research Council dyspnea scale score ≥ 1 (83.3%), and had moderate airflow limitation (54.4%). The mean body mass index (BMI) of the study population was 23.1 kg/m², and 27.6% were obese or overweight. Hypertension was the most common comorbidity (37.6%). The mean blood eosinophil count was 226.8 cells/µL, with 21.9% of patients having ≥ 300 cells/µL. A clinically insignificant change in FEV1 (+1.4%) was observed a year after enrollment. Overall, patients experienced a mean of 0.2 severe annual AECOPD and approximately 1.1 mean moderate or severe AECOPD. Notably, the rates of severe AECOPD remained generally consistent over time. Compared with patients with no exacerbations, patients who experienced severe exacerbations had a lower mean BMI (21.7 vs. 23.1 kg/m²; P < 0.001) and lower lung function parameters (all P values < 0.001), but reported high rates of depression (25.5% vs. 15.1%; P = 0.044) and anxiety (37.3% vs. 16.7%; P < 0.001) as a comorbidity. CONCLUSION: Findings from this Korean cohort of patients with COPD indicated a high exacerbation burden, which may be attributable to the unique characteristics of the study population and suboptimal disease management. This highlights the need to align clinical practices with the latest treatment recommendations to alleviate AECOPD burden in Korea. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05750810.

The Post-COVID-19 Haul on Pulmonary Function: A Prospective Cross-Sectional Study.

BACKGROUND: Long COVID syndrome, characterized by symptoms like dyspnea, fatigue, and cough, persisting for weeks to months after the initial SARS-CoV-2 infection, poses significant challenges globally. Studies suggest a potential higher risk among females aged 40-50, with symptoms affecting individuals regardless of initial COVID-19 severity, underscoring the need for comprehensive understanding and management. METHODS: A prospective longitudinal study was conducted at a teaching tertiary care institute in Central India, involving COVID-19 patients from May 2020 to September 2021. Participants, aged 18 or older, diagnosed with COVID-19 and surviving until the last follow-up, were monitored telephonically and during outpatient visits for treatment details and outcomes. Data analysis was done using R software 4.2.1. RESULTS: The baseline characteristics of the study participants showed a majority of moderate COVID-19 severity (47.5%), with a higher proportion of males (64.8%) affected. Common comorbidities included diabetes (27.1%) and hypertension (22.9%). Long COVID-19 symptoms, notably breathlessness, were prevalent, with females exhibiting a significantly higher association. Pulmonary function abnormalities were associated with both long COVID-19 symptoms and higher COVID-19 severity categories, indicating lasting respiratory impact post-infection. CONCLUSION: Long after the pandemic, COVID-19 continues to raise concerns due to persistent sequelae, with a majority experiencing long COVID symptoms, particularly those with severe initial illness, including breathlessness and abnormal lung function, highlighting prevalent restrictive lung pattern changes.

Perioperative Management in Neuromuscular Diseases: A Narrative Review.

Patients with neuromuscular diseases are particularly vulnerable in the perioperative period to the development of pulmonary and cardiac complications, or medication side effects. These risks could include hypoventilation, aspiration pneumonia, exacerbation of underlying cardiomyopathy, arrhythmias, adrenal insufficiency, prolonged neuromuscular blockade, issues related to thermoregulation, rhabdomyolysis, malignant hyperthermia, or prolonged mechanical ventilation. Interventions at each of the perioperative stages can be implemented to mitigate these risks. A careful pre-operative evaluation may help identify risk factors so that appropriate interventions are initiated, including cardiology consultation, pulmonary function tests, initiation of noninvasive ventilation, or implementation of preventive measures. Important intraoperative issues include positioning, airway and anesthetic management, and adequate ventilation. The postoperative period may require correction of electrolyte abnormalities, control of secretions with medications, manual or mechanical cough assistance, avoiding the risk of reintubation, judicious pain control, and appropriate medication management. The aim of this review is to increase awareness of the particular surgical challenges in this vulnerable population, and guide the clinician on the various evaluations and interventions that may result in a favorable surgical outcome.

Suboptimal peak inspiratory flow rate in dry-powder inhaler users for chronic obstructive pulmonary disease in Korea.

BACKGROUND: A suboptimal peak inspiratory flow rate (PIFR) in dry-powder inhaler (DPI) users can lead to insufficient therapeutic effects in the treatment of chronic obstructive pulmonary disease (COPD). However, few data on the prevalence of and factors associated with suboptimal PIFR in Korean patients with COPD are available. METHODS: We conducted a cross-sectional study of patients with COPD who had been using DPIs for more than three months. PIFR was measured using an In-Check DIAL G16 device. Suboptimal PIFR was defined as below the resistance-matched threshold. Multivariable logistic regression analysis was used to determine factors associated with suboptimal PIFR. RESULTS: Of 444 DPI users with COPD, the rate of suboptimal PIFR was 22.0 % (98/444). In a multivariable analysis, significant factors associated with suboptimal PIFR were age (adjusted odds ratio [aOR] = 1.06 by 1-year increase; 95 % confidence interval [CI] = 1.02-1.09), male sex (aOR = 0.28; 95 % CI = 0.11-0.73), body mass index (BMI) (aOR = 0.91 by 1 kg/m2 increase; 95 % CI = 0.85-0.99), post-bronchodilator forced vital capacity (FVC) %pred (aOR = 0.97 by 1%pred increase; 95 % CI = 0.95-0.99), and In-Check DIAL R2-type inhaler [medium-low resistance] use (aOR = 3.70 compared with R1-type inhalers [low resistance]; 95 % CI = 2.03-7.03). CONCLUSIONS: In Korea, more than one-fifth of DPI users with COPD had a suboptimal PIFR. The factors associated with suboptimal PIFR were age, female gender, low BMI, low FVC, and R2-type inhaler use. Therefore, clinicians should carefully evaluate the possibility of suboptimal PIFR when prescribing DPIs.

Can We Use the Maximum Phonation Time as a Screening of Pulmonary Forced Vital Capacity in Post-COVID-19 Syndrome Patients?

OBJECTIVE: To verify the accuracy of the maximum phonation time of the vowel /a/ (MPT/a/), fricative /s/ (MPT/s/), number counting (MPTC), and number reached in this count (CN) to estimate forced vital capacity (FVC) in patients with post-COVID-19 syndrome. METHOD: Cross-sectional study involving adult patients, who were admitted to the intensive care unit and referred to the Post-COVID-19 Rehabilitation Outpatient Clinic. Voice function was assessed using a Vocal Handicap Index (VHI) self-assessment questionnaire and MPT tests. To perform the phonatory tests, the patients remained in a standing posture and were instructed to inhale as much air as possible and, during a single exhalation, at usual pitch and loudness, sustain the emission of /a/ and /s/; and in another breath, to perform the ascending numerical count, starting from the number one up to the highest number they could reach. Pulmonary function was assessed by spirometry. The receiver operating characteristic (ROC) curve was plotted, and FVC values lower than the normal limit by Z-score (fifth percentile) were classified as impaired lung function. The predictive values and likelihood ratios were calculated. RESULTS: A total of 70 patients participated, with 20-30% having a high VHI. Approximately 24% had an FVC impairment and significantly low values of MPT/a/, MPT/s/, MPTC, and CN. The test results showed overall accuracy of 70% and the cutoff points of 9.69, 6.78, 10.60, and 13, respectively, with high sensitivity, predictive negative value and low specificity, predictive positive value, and positive likelihood ratio. CONCLUSIONS: Our results suggest that the MPT has moderate discriminatory power for FVC impairment, indicating that it is not a reliable indicator of pulmonary function in the population studied. Therefore, in patients with an MPT of less than 10.60 seconds, or a CN lower than 13, other criteria should be added to improve the diagnostic accuracy and support the decision to perform more complex investigations.

Novel Method for Sealing Tracheostomies Immediately after Decannulation-An Acute Clinical Feasibility Study.

Tracheostomy decannulation leaves an iatrogenic passage in the upper airways. Inadequate sealing leads to pulmonary dysfunction and reduced voice quality. This study aimed to investigate the feasibility and impact of intratracheal tracheostomy sealing on laryngeal airflow and voice quality immediately after decannulation (ClinicalTrials.gov: NCT06138093). Fifteen adult, tracheostomized, intensive care unit patients were included from our hospital. A temporary, silicone-based sealing disc was inserted in the tracheostomy wound immediately after decannulation. Spirometry with measurement of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow (PEF) were performed as measures of airway flow. Voice recordings were assessed using an equal appearing interval scale from 1 to 5. Median FVC, FEV1, PEF, and voice quality score with interquartile range (IQR) was 883 (510-1910) vs. 1260 (1005-1723) mL (p < 0.001), 790 (465-1255) vs. 870 (617-1297) mL (p < 0.001), 103 (55-211) vs. 107 (62-173) mL (p = 0.720), and 2 (1-2.5) vs. 4 (3-5) points (p < 0.001), respectively, with open tracheostomy vs. after sealing the tracheostomy with the intratracheal sealing disc. This feasibility study showed that tracheostomy sealing with the intratracheal disc was safe and led to immediate improvements in FVC, FEV1, and voice quality.

Immediate Unilateral Subpectoral Implant-Based Breast Reconstruction does not Impair Pulmonary Functions: A Preliminary Prospective Study.

BACKGROUND: Implant-based breast reconstruction is one of the most common procedures among women with breast cancer undergoing mastectomy. Prosthetic devices may be positioned either beneath or above the pectoralis major muscle, which is considered an accessory muscle of ventilation. This preliminary prospective study aimed to investigate whether subpectoral unilateral implant-based breast reconstruction has any effect on patients' pulmonary functions. METHODS: A prospective study of fourteen women who underwent immediate unilateral implant-based subpectoral breast reconstruction by a single surgeon over 10 months was conducted. Spirometry and maximal voluntary ventilation tests were conducted 1 day prior to surgery, and 1- and 3 months following breast reconstruction. ANOVA or Friedman test were used to compare pulmonary function tests before and after surgery. RESULTS: Fourteen patients completed the study protocol. No statistically significant differences were found when comparing spirometry parameters in the three time points. CONCLUSIONS: Pectoralis muscle release does not impair pulmonary function among patients undergoing immediate unilateral implant-based breast reconstruction following mastectomy. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluating performance on the Glittre-ADL test in men with long COVID 3 years after a SARS-CoV-2 infection.

Background/objective: Many COVID-19 survivors, especially those who have been hospitalized, have been suffering numerous complications that limit their activities of daily living, although changes that persist 3 years after infection are still not known. We aimed to investigate the impact of long COVID on the Glittre-ADL test (TGlittre) 3 years after acute infection in men who needed hospitalization and explore whether the performance on the TGlittre is associated with impairments in lung function, muscle strength, physical function and quality of life (QoL). Methods: Cross-sectional study with 42 men with long COVID who took the TGlittre. They underwent pulmonary function tests and measurements of handgrip strength and quadriceps strength (QS). Additionally, they also completed the Saint George Respiratory Questionnaire (SGRQ) and Functional Independence Measure (FIM). Results: The mean age was 52 ± 10.6 years, while the mean time after diagnosis of COVID-19 was 37 ± 3.5 months. The mean TGlittre time was 3.3 (3.1-4.1) min, which was 10% greater than the time expected for normal individuals to complete it. The TGlittre time was correlated significantly with the QS (rs = -0.397, p = 0.009), pulmonary diffusion (rs = - 0.364, p = 0.017), FIM (rs = -0.364, p = 0.017) and the "activity" domain score of the SGRQ (rs = 0.327, p = 0.034). Conclusion: Functional capacity on exertion as measured by the TGlittre time is normal in most men with long COVID 3 years after hospitalization. However, this improvement in functional capacity does not seem to be reflected in muscle strength or QoL, requiring continued monitoring even after 3 years.

Yogistic efficacy on cardiopulmonary capacities, endurance efficiencies and musculoskeletal potentialities in female college students.

BACKGROUND: Physical exercise participation among female students is significantly compromised throughout the academic periods of college or university due to scholastic demands and also by less parental and community encouragements. Thus, physical inactivity in female college students leads to less musculoskeletal efficiency and work performance. OBJECTIVE: Customized yogic module may be considered to enhance both aerobic and anaerobic power, pulmonary capacity and musculoskeletal efficiency for the improvement of systemic body functions among female college students. METHODS: A randomized, controlled parallel study design (n = 60; age = 20.16±2.05 years), on sedentary female college students practicing customized yogic module (n = 30) for 5 days / week for 3 months (60 min daily in the morning) to observe anthropometric, physiological, cardiopulmonary and muscular endurance indices. RESULTS: After yogic practice, a significant reduction in body fat (p <  0.05) (%), heart rate (p <  0.001), systolic blood pressure (p <  0.001), double product (p<0.01) and rate pressure product (p <  0.05) were estimated. Significant improvement (p <  0.001) in vital capacity, forced expiratory volume in 1 sec was also observed. Evaluation of hand grip strength, maximal oxygen consumption and physical work capacity showed significant increase (p <  0.01) after yogic intervention. CONCLUSIONS: A three-month customized yogic training improved resting physiological activities, cardiopulmonary functions, musculoskeletal strength and endurance fitness due to focused breathing, mindfulness meditation and by stretching-strengthening patterns for achieving recreational physical activity among female college students.

Differential decline of lung function in COPD patients according to structural abnormality in chest CT.

Background: Different progressions or prognoses of chronic obstructive pulmonary disease (COPD) have been reported according to structural abnormalities based on chest computed tomography (CT). This study aimed to investigate whether different structural abnormalities independently affect annual lung function changes and clinical prognosis in patients with COPD. Methods: This longitudinal multicenter observational study was conducted using the KOCOSS cohort (NCT02800499) database in Korea from January 2012 to December 2019. For COPD patients with chest CT findings at baseline enrolment and longitudinal spirometric data, annual forced expiratory volume in 1 s (FEV1) decline rate (mL/year) and clinical outcomes were compared according to structural abnormalities, including emphysema, bronchiectasis (BE), and tuberculosis-destroyed lung (TDL). We estimated the adjusted annual FEV1 changes using a mixed-effect linear regression model. Results: Among the enrolled 237 patients, 152 showed structural abnormalities. Emphysema, BE, and TDL were observed in 119 (78.3%), 28 (18.4%), and 27 (17.8%) patients, respectively. The annual decline in FEV1 was faster in COPD patients with structural abnormalities than those without (ß = -70.6 mL/year, P-value = 0.039). BE/TDL-dominant or emphysema-dominant structural abnormality contributed to an accelerated annual FEV1 decline compared to no structural abnormality (BE/TDL-dominant, ß = -103.7 mL/year, P-value = 0.043; emphysema-dominant, ß = -84.1 mL/year, P-value = 0.018). Structural abnormalities made no significant differences in acute exacerbation rate and mortality. Conclusion: The lung function decline rate in COPD differed according to structural abnormalities on CT. These findings may suggest that more focus should be placed on earlier intervention or regular follow-up with spirometry in COPD patients with BE or TDL on chest CT.

Physical activity and lung function association in a healthy community-dwelling European population.

BACKGROUND: The association of physical activity (PA) and lung function (LF) varies from no measurable effect to delayed LF decline. We assessed the association between accelerometery-assessed PA and LF in a sample of apparently healthy, community-dwelling subjects. METHODS: We included two cross-sectional studies using data from the PneumoLaus study (2014-17 and 2018-21), conducted in Lausanne, Switzerland. PA was assessed by accelerometry and categorised as inactivity, light, moderate or vigorous. Forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and maximal mid-expiratory flow (MMEF) were measured by spirometry and expressed in percentage of predicted value (PV). RESULTS: Overall, 1'910 (54.7% women, 62.0 ± 9.7 years) and 1'174 (53.4% women, 65.8 ± 9.5 years) participants were included in the first and the second surveys, respectively. In both surveys, moderate and vigorous PA showed a weak but significant correlation with FEV1 in percentage (PV) (R = 0.106 and 0.132 for the first and 0.111 and 0.125 for the second surveys, p < 0.001). Similar correlations with FVC (p < 0.001) were found. Associations held irrespective of smoking status and remained after multivariable adjustment. Fewer associations were detected between LF and light PA or between MMEF and PA. CONCLUSION: Moderate and vigorous intensity PA are associated with increased LF regardless of smoking status in apparently healthy community-dwelling European population. These associations are statistically but not clinically significant due to the small correlation coefficients (R < 0.30), corresponding to a weak association.

Evaluation of computed tomography in the diagnosis of ultrasound-proven diaphragm dysfunction.

INTRODUCTION: Computed tomography (CT) is routinely employed on the evaluation of dyspnea, yet limited data exist on its assessment of diaphragmatic muscle. This study aimed to determine the capability of CT in identifying structural changes in the diaphragm among patients with ultrasound-confirmed diaphragmatic dysfunction. METHODS: Diaphragmatic ultrasounds conducted between 2018 and 2021 at our center in Marseille, France, were retrospectively collected. Diaphragmatic pillars were measured on CT scans at the L1 level and the celiac artery. Additionally, the difference in height between the two diaphragmatic domes in both diaphragmatic dysfunction cases and controls was measured and compared. RESULTS: A total of 65 patients were included, comprising 24 with diaphragmatic paralysis, 13 with diaphragmatic weakness, and 28 controls. In the case group (paralysis and weakness) with left dysfunctions (n = 24), the CT thickness of the pillars at the level of L1 and the celiac artery was significantly thinner compared with controls (2.0 mm vs. 7.4 mm and 1.8 mm vs. 3.1 mm, p < 0.001 respectively). Significantly different values were observed for paralysis (but not weakness) in the right dysfunction subgroup (n = 15) (2.6 mm vs. 7.4 mm and 2.2 mm vs. 3.8 mm, p < 0.001 respectively, for paralysis vs. controls). Regardless of the side of dysfunction, a significant difference in diaphragmatic height was observed between cases and controls (7.70 cm vs. 1.16 cm and 5.51 cm vs. 1.16 cm, p < 0.001 for right and left dysfunctions, respectively). Threshold values determined through ROC curve analyses for height differences between the two diaphragmatic domes, indicative of paralysis or weakness in the right dysfunctions, were 4.44 cm and 3.51 cm, respectively. Similarly for left dysfunctions, the thresholds were 2.70 cm and 2.48 cm, respectively, demonstrating good performance (aera under the curve of 1.00, 1.00, 0.98, and 0.79, respectively). CONCLUSION: In cases of left diaphragmatic dysfunction, as well as in paralysis associated with right diaphragmatic dysfunction, CT revealed thinner pillars. Additionally, a notable increase in the difference in diaphragmatic height demonstrated a strong potential to identify diaphragmatic dysfunction, with specific threshold values.

Mechanisms and consequences of excess exercise ventilation in fibrosing interstitial lung disease.

The causes and consequences of excess exercise ventilation (EEV) in patients with fibrosing interstitial lung disease (f-ILD) were explored. Twenty-eight adults with f-ILD and 13 controls performed an incremental cardiopulmonary exercise test. EEV was defined as ventilation-carbon dioxide output (⩒E-⩒CO2) slope ≥36 L/L. Patients showed lower pulmonary function and exercise capacity compared to controls. Lower DLCO was related to higher ⩒E-⩒CO2 slope in patients (P<0.05). 13/28 patients (46.4%) showed EEV, reporting higher dyspnea scores (P=0.033). Patients with EEV showed a higher dead space (VD)/tidal volume (VT) ratio while O2 saturation dropped to a greater extent during exercise compared to those without EEV. Higher breathing frequency and VT/inspiratory capacity ratio were observed during exercise in the former group (P<0.05). An exaggerated ventilatory response to exercise in patients with f-ILD is associated with a blunted decrease in the wasted ventilation in the physiological dead space and greater hypoxemia, prompting higher inspiratory constraints and breathlessness.

Relationship between FEV1/FVC and age in children with asthma.

INTRODUCTION: Forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) normally decreases through childhood, increases briefly during early adolescence, and then declines throughout life. The physiology behind this temporary increase during early adolescence is not well understood. The objective of this study was to determine if this pattern occurs in children with asthma. DESIGN: Single-center, cross-sectional, retrospective analysis of pulmonary function tests obtained over a 5-year period in children 5-18 years of age with persistent asthma. RESULTS: A total of 1793 patients satisfied all inclusion and exclusion criteria. The mean age (±SD) was 10.4 ± 3.8 years. Forty-eight percent were female. Mean FEV1/FVC was 0.83 ± 0.09. FEV1/FVC was lower at 5 years of age than in healthy children, declined from age 5 to 11 by 5.7% compared to 7.3% in healthy girls, and 5.8% compared to 9.4% in healthy boys. FEV1/FVC increased in early adolescence, but at age 16, was 5.6% lower in male children compared to healthy children, and 5.4% lower in females. The ratio was lower in obese children at all ages but demonstrated the same curvilinear shape as healthy children. In absolute terms, FEV1 grew proportionately more than FVC during early adolescence, so the ratio of FEV1/FVC increased during that period. The curvilinear shape of the curve remained in postbronchodilator testing, though significantly blunted. CONCLUSIONS: FEV1/FVC is lower in children with persistent asthma than healthy children, but the "Shepherd's Hook" pattern is preserved. This was true in obese patients with asthma, although their FEV1/FVC ratios were lower throughout all stages of childhood and adolescence.

In utero smoking exposure induces changes to lung clearance index and modifies risk of wheeze in infants.

BACKGROUND: Fetal exposure to tobacco smoking throughout pregnancy is associated with wheezing in infancy. We investigated the influence of in utero smoking exposure on lung ventilation homogeneity and the relationship between lung ventilation inhomogeneity at 7 weeks of age and wheezing in the first year of life. METHODS: Maternal smoking was defined as self-reported smoking of tobacco or validated by exhaled (e)CO > 6 ppm. Lung function data from healthy infants (age 5-9 weeks) born to asthmatic mothers and parent-reported respiratory questionnaire data aged 12 months were collected in the Breathing for Life Trial (BLT) birth cohort. Tidal breathing analysis and SF6-based Multiple Breath Washout testing were performed in quiet sleep. Descriptive statistics and regression analysis were used to assess associations. RESULTS: Data were collected on 423 participants. Infants born to women who self-reported smoking during pregnancy (n = 42) had higher lung clearance index (LCI) than those born to nonsmoking mothers (7.90 vs. 7.64; p = .030). Adjusted regression analyzes revealed interactions between self-reported smoking and LCI (RR: 1.98, 95% CI: 1.07-3.63, 0.028, for each unit increase in LCI) and between eCO > 6 ppm and LCI (RR: 2.25, 95% CI: 1.13-4.50, 0.022) for the risk of wheeze in the first year of life. CONCLUSION: In utero tobacco smoke exposure induces lung ventilation inhomogeneities. Furthermore, an interaction between smoke exposure and lung ventilation inhomogeneities increases the risk of having a wheeze in the first year of life.