BACKGROUND: Pulmonary function tests are vital for diagnosing lung diseases, assessing treatment responses, and monitoring respiratory health. Recent updates to interpretive standards by the European Respiratory and American Thoracic Societies (ERS/ATS) in 2022 introduced significant changes compared to the 2005 standards. They include incorporating lung volume measurements, non-specific and mixed disorders, introducing z-scores for functional abnormality assessment, reducing severity categories from five to three, and revising criteria for positive bronchodilator responses.
METHODS: We conducted a retrospective, multi-center study across four centers using spirometric data spanning from 2002 to 2022. We categorized spirometry results using both the 2005 and 2022 ATS/ERS standards and calculated predicted values following the GLI 2012 equation (Caucasian subset).
RESULTS: Among 79,039 subjects, we observed that 23% shifted from an obstructive diagnosis under the 2005 standard to a mixed pattern diagnosis under the 2022 standard, necessitating lung volume assessments. In the evaluation of bronchodilator responses among 59,203 tests, 12.3% of those initially classified as responders were reclassified as non-responders with the new standards. We found variations in severity categorization across age groups, with older patients tending to receive milder severity classifications and younger individuals receiving greater severity classifications under the 2022 standards.
CONCLUSIONS: The 2022 document emphasizes early lung volume assessment, potentially leading to increased utilization of more complex tests. Furthermore, the bronchodilator response was predominant in extreme age groups and among individuals with milder spirometric impairments. This shift may impact treatment decisions, potentially initiating medication in milder cases and de-escalating treatment in more severe cases.

BACKGROUND: In advanced chronic obstructive pulmonary disease (COPD), hypercapnia may occur due to severe bronchial obstruction with lung hyperinflation. Non-invasive ventilation (NIV) provides the standard of care intended to achieve physiological PCO2 levels, thereby reducing overall mortality. The present study aimed to evaluate pulmonary function parameters derived from spirometry (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1]), body plethysmography (residual volume [RV], total lung capacity [TLC]), and lung diffusion capacity for carbon monoxide (single-breath method [DCO-SB], alveolar-volume corrected values [DCO-VA]) as predictors of chronic hypercapnia in patients with advanced COPD.
METHODS: This monocentric, retrospective observational study included 423 COPD patients. Receiver operating characteristic (ROC) curve analysis and cross-validation were used to assess lung function parameters\' diagnostic accuracy for predicting chronic hypercapnia, with the resulting performance expressed as area under the ROC curve (AUROC). We performed univariable and multivariable binary logistic regression analysis to determine if these parameters were independently associated with chronic hypercapnia, with probabilities reported as odds ratios [OR] with 95% confidence intervals [95%CI].
RESULTS: FVC% (AUROC 0.77 [95%CI 0.72-0.81], P < 0.01) and FEV1% (AURIC 0.75 [95%CI 0.70-0.79], P < 0.01) exhibited reasonable accuracy in the prediction of chronic hypercapnia, whereas lung diffusion capacity performed poorly (AUROC 0.64 [95%CI 0.58-0.71] for DCO-SB%, P < 0.01). FVC% (OR 0.95 [95%CI 0.93-0.97], P < 0.01) and FEV1% (OR 0.97 [95%CI 0.94-0.99], P = 0.029) were the only parameters associated independently with chronic hypercapnia in logistic regression analysis. FVC and FEV1 thresholds that best separated hypercapnic from normocapnic subjects reached 56% and 33% of predicted values.
CONCLUSIONS: Routinely collected pulmonary function parameters, particularly FVC% and FEV1%, may predict chronic hypercapnia during COPD progression.

METHODS: Little is known about self-induced cognitive trance (SICT) on respiratory function. The aims of this prospective, single-center, non-randomized, open-label study of healthy volunteers, were to characterize spirometry changes during SICT, confirm the safety of this technique, and investigate the potential clinical benefits of SICT.
RESULTS: Nine people participated. There were no significant difference in FEV1 FVC or FEF 25-75 before, during, and after SICT. There were significant improvements in grip strength during SICT (+2.2 kg/5.7 %, p<0.05) and in self-efficacy score related to physical activity at the end of the trance. One participant had a significant worsening of FEV1 during SICT in the context of a recent upper airway infection.
CONCLUSIONS: SICT does not significantly modify spirometry data in healthy volunteers and can improve self-efficacy related to physical activity. SICT should probably be performed with caution during upper airway infections.

UNASSIGNED: The aim of this study was to estimate the effects of a pulmonary rehabilitation programme (PR) on the functional capacity and respiratory muscle strength of patients with post-COVID syndrome.
UNASSIGNED: A cross-sectional study was conducted using hospital data on patients who participated in a pulmonary rehabilitation programme at the Clinic for Lung Diseases, University Hospital Centre Zagreb, Croatia, between January 2021 and December 2022. Data on the spirometry, respiratory muscle strength, and functional exercise capacity of patients were collected at baseline and three weeks after the start of rehabilitation. The study included 80 patients (43 females, 37 males) with a mean age of 51±10 years.
UNASSIGNED: A significant increase in respiratory muscle strength (P<0.001) was observed after pulmonary rehabilitation, with effect sizes ranging from small to large (Cohen\'s d from 0.39 to 1.07), whereas the effect for PImax expressed as a percentage was large (Cohen\'s d=0.99). In addition, the pulmonary rehabilitation programme significantly improved the parameters of the six-minute walk test in patients, and the parameters of lung function, FVC, FEV1, and DLCO also improved significantly after PR (P<0.05).
UNASSIGNED: The results showed that the pulmonary rehabilitation programme has clinically significant effects on functional capacity and respiratory muscle strength in patients with post-COVID syndrome.
UNASSIGNED: Cilj te študije je bil oceniti učinek programa pljučne rehabilitacije na funkcionalno sposobnost in moč dihalnih mišic pri bolnikih z dolgim covidom.
UNASSIGNED: Opravili smo presečno študijo na podlagi bolnišničnih podatkov o bolnikih, ki so med januarjem 2021 in decembrom 2022 sodelovali v programu pljučne rehabilitacije v Kliniki za pljučne bolezni v Univerzitetnem bolnišničnem centru v Zagrebu. Podatke o spirometriji, moči dihalnih mišic in funkcionalni zmogljivosti za telesno aktivnost bolnikov smo zbrali ob izhodišču in tri tedne po začetku rehabilitacije. Študija je vključevala 80 bolnikov (43 žensk, 37 moških) povprečne starosti 51±10 let.
UNASSIGNED: Ugotovili smo bistveno povečanje moči dihalnih mišic (P < 0,001) po pljučni rehabilitaciji, pri čemer so bile velikosti učinka od majhnih do velikih (Cohen d od 0,39 do 1,07), učinek za PImax, izražen v odstotku, pa je bil velik (Cohen d = 0,99). Poleg tega je program pljučne rehabilitacije precej izboljšal parametre 6-minutnega sprehoda pri bolnikih, parametri pljučne funkcije FVC, FEV1 in DLCO pa so se po pljučni rehabilitaciji prav tako znatno izboljšali (P < 0,05).
UNASSIGNED: Rezultati so pokazali, da ima program pljučne rehabilitacije pri bolnikih z dolgim covidom klinično pomemben učinek na funkcionalno sposobnost in moč dihalnih mišic.

BACKGROUND: Forced vital capacity (FVC) is an important tool for monitoring lung functions in patients with systemic sclerosis (SSc). However, several disease manifestations may influence the quality of FVC test in SSc. We aimed to assess the quality of FVC measurements according to current guidelines in patients with SSc and determine the factors that may affect results.
METHODS: In this cross-sectional study, SSc patients and age/sex matched controls underwent spirometry. Quality of FVC measurements were graded according to updated American Thoracic Society (ATS) and European Respiratory Society (ERS) guidelines. Demographics, clinical features and parameters that may affect FVC test quality were compared between SSc patients with high and low quality FVC test.
RESULTS: 98 SSc patients (90 female) and 100 controls were included. The rate of high quality FVC measurement in SSc patients was significantly lower in SSc patients compared to controls. (80 % vs 60.2 % p = 0.002). Among SSc patients; diffuse disease, ILD, anti-topoisomerase 1 antibody positivity, immunosuppressive use, flexion contractures of hands, reduced mouth opening and decreased chest expansion were more frequent in patients with low quality FVC (p < 0.05 for all). Patients with muscle weakness and medium/high risk of malnutrition were also numerically higher in low quality FVC group. Presence of more than one condition that may affect FVC quality was significantly higher among patients with low quality FVC.
CONCLUSIONS: A significant percent of SSc patients had low quality FVC measurement. Physicians should be aware of this point while interpreting FVC test results especially in SSc patients with more than one condition that may affect the quality of the test.

OBJECTIVE: Exercise test outdoors is widely used to diagnose asthma in children, but it is unclear how much outdoor air factors affect the results.
METHODS: We analysed 321 outdoor exercise challenge tests with spirometry in children 6-16 years conducted due to suspicion of asthma or for assessing the effect of medication on asthma. We studied the association of FEV1 decrease and incidence of exercise-induced bronchoconstriction (EIB) with temperature, relative humidity (RH) and absolute humidity (AH).
RESULTS: Asthma was diagnosed in 57% of the subjects. AH ≥5 g/m3, but not RH or temperature, was associated with the EIB incidence (p = 0.035). In multivariable logistic regression, AH ≥5 g/m3 was negatively associated (OR = 0.51, 95% CI [0.28─0.92], p = 0.026) while obstruction before exercise (OR = 2.11, 95% CI [1.16─3.86], p = 0.015) and IgE-mediated sensitisation were positively associated with EIB (OR = 2.24, 95% CI [1.11─4.51], p = 0.025). AH (r = -0.12, p = 0.028) and temperature (r = -0.13, p = 0.023) correlated with decrease in FEV1. In multivariable linear regression, only AH was associated with FEV1 decrease (coefficient = -0.044, 95% CI [-0.085 to -0.004], p = 0.033).
CONCLUSIONS: AH of outdoor air associates with occurrence and severity of EIB in outdoor exercise tests in children. Care should be taken when interpreting negative outdoor exercise test results if AH of air is high.

BACKGROUND: Primary care clinicians do not adhere to national and international guidelines recommending pulmonary function testing (PFTs) in patients with suspected asthma. Little is known about why that occurs. Our objective was to assess clinician focused barriers to ordering PFTs.
METHODS: An internet-based 11-item survey of primary care clinicians at a large safety-net institution was conducted between August 2021 and November 2021. This survey assessed barriers and possible electronic health record (EHR) solutions to ordering PFTs. One of the survey questions contained an open-ended question about barriers which was analyzed qualitatively.
RESULTS: The survey response rate was 59% (117/200). The top 3 reported barriers included beliefs that testing will not change management, distance to testing site, and the physical effort it takes to complete testing. Clinicians were in favor of an EHR intervention to prompt them to order PFTs. Responses to the open-ended question also conveyed that objective testing does not change management.
CONCLUSIONS: PFTs improve diagnostic accuracy and reduce inappropriate therapies. Of the barriers we identified, the most modifiable is to educate clinicians about how PFTs can change management. That in conjunction with an EHR prompt, which clinicians approved of, may lead to guideline congruent and improved quality in asthma care.

OBJECTIVE: To determine the diagnostic utility of spirometry in distinguishing children with Induced Laryngeal Obstruction (ILO) or chronic non-specific cough (a.k.a. tic cough) from those with mild or moderate to severe asthma.
METHODS: Retrospective cross sectional design. Children diagnosed with ILO (N = 70), chronic non-specific cough (N = 70), mild asthma (N = 60), or moderate to severe asthma (N = 60) were identified from the electronic medical record of a large children\'s hospital. Spirometry was completed before ILO, non-specific cough, or asthma diagnoses were made by pediatric laryngologists or pulmonologists. Spirometry was performed following American Thoracic Society guidelines and was interpreted by a pediatric pulmonologist. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1), FEV1/FVC Ratio (FEV1/FVC), Forced Mid-Expiratory Flow 25--75 % (FEF25-75%), pulmonologist interpretation of flow volume loops, and overall exam findings were extracted from the medical record.
RESULTS: Ninety seven percent of children with ILO or chronic non-specific cough presented with spirometry values within normative range. Patients with ILO, non-specific cough, and mild asthma presented with FVC, FEV1, FEV1/FVC, and FEF25-75% values in statistically similar range. Children with moderate to severe asthma presented with significantly reduced FVC (p < .001), FEV1 (p < .001), FEV1/FVC (p < .001), and FEF25-75% (p < .001) values when compared with patients in the other groups. Flow volume loops were predominantly normal for children with ILO and non-specific cough.
CONCLUSIONS: Findings indicate that ILO and chronic non-specific cough can neither be diagnosed nor differentiated from mild asthma using spirometry alone. Spirometry should therefore be used judiciously with this population, bearing in mind the limitations of the procedure. Future research should determine the most effective and efficient ways of delineating ILO and non-specific cough from other respiratory conditions in children.

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.
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.

Long-COVID is a multisystem disease that can lead to significant impairments in health-related quality of life (HRQoL). Following COVID-19 infection, abnormalities on pulmonary function tests (PFT) are common. The primary aim of this study is to evaluate for any correlation between PFT abnormalities and impairment in HRQoL scores following COVID-19 infection.
This is an analysis of a prospective cohort of patients in Louisville, KY who were infected with COVID-19. Data collected included demographics, past medical history, laboratory tests, PFTs, and several HRQoL questionnaires such as the EuroQol 5 Dimension HRQoL questionnaire (EQ-5D-5 L), Generalized Anxiety Disorder 7 (GAD-7), Patient Health Questionnaire (PHQ-9), and Posttraumatic stress disorder checklist for DSM-5 (PCL-5). Descriptive statistics were performed, comparing PFTs (normal vs abnormal) and time since COVID-19 infection (3- vs 6- vs ≥ 12 months).
There were no significant differences in FEV1, FVC, or the percentage of patients with abnormal PFTs over time after COVID-19 infection. Following COVID-19, patients with normal PFTs had worse impairment in mobility HRQoL scores and change in GAD-7 scores over time. There were no differences over time in any of the HRQoL scores among patients with abnormal PFTs.
Among patients with an abnormal PFT, there was no temporal association with HRQoL scores as measured by EQ-5D-5 L, GAD-7, PHQ-9, and PCL-5. Among patients with a normal PFT, mobility impairment and anxiety may be associated with COVID-19 infection. Following COVID-19 infection, impairment in HRQoL scores is not completely explained by the presence of abnormalities on spirometry.