Pulmonary Function Laboratory Research Articles

Implementation of an Integrated Total Quality Management System in a Pulmonary Function Laboratory.

A worldwide objective in the area of health is to offer high-quality services supported by certification strategies that contribute to improving standards for processes commonly used in medicine. However, few pulmonary function test laboratories (PFTLs) follow official standards in their daily operations or are organized around an integrated total quality management system (ITQMS) focused on their established processes. The aim was to determine the feasibility of implementing an ITQMS to accredit the International Organization for Standardization (ISO) 9001:2015 standard in a high-demand PFTL where 13 respiratory function tests are routinely performed together with teaching and research activities. This project was conducted at the PFTL of the Instituto Nacional de Enfermedades Respiratorias in Mexico City from November 2014 to August 2017 and involved the implementation of an ITQMS guided by ISO 9001:2015 in 5 phases: (1) the establishment of a work team; (2) the elaboration of situational diagnoses; (3) the development of guidelines for the ITQMS; (4) the implementation of the ITQMS model; and (5) the evaluation of the ITQMS. Upon completing the 5 phases, an evaluation of the system by an internal audit identified 3 minor cases of nonconformity (NC), while additional observations and an external audit found 5 minor cases of NC. These issues were addressed through a root-cause analysis to establish an action plan for each one. At the end of the process, the institution was granted the ISO 9001:2015 certification for its 3 processes: medical attention in support of diagnoses, teaching, and research. It is possible to implement an ISO quality management system as a routine operating methodology in a high-demand PFTL.

Multi‐disciplinary collaborative consensus guidance statement on the assessment and treatment of breathing discomfort and respiratory sequelae in patients with post‐acute sequelae of SARS‐CoV‐2 infection (PASC)

<scp>Multi‐disciplinary</scp> collaborative consensus guidance statement on the assessment and treatment of breathing discomfort and respiratory sequelae in patients with <scp>post‐acute</scp> sequelae of <scp>SARS‐CoV</scp>‐2 infection (<scp>PASC</scp>)

Spirometry for the diagnosis of airway obstruction in patients with risk factors for COPD: the GOLD and lower limit of normal criteria.

ABSTRACTObjective:The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. Methods:This was an observational study of individuals ≥ 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD−, respectively) and according to the LLN criterion (LLN+ and LLN−, respectively). We also evaluated the level of agreement between the two criteria. Results:A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (k = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals ≥ 70 years of age (k = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN− category (p = 0.03), as was the median DLCO (p = 0.04). Conclusions:The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

Volatile organic breath components and exercise induced bronchoconstriction in asthmatic children

IntroductionAsthma is one of the most common chronic diseases in childhood and is generally characterized by exercise induced bronchoconstriction (EIB). Assessing EIB is time consuming and expensive as it requires a fully equipped pulmonary function laboratory. Analysis of volatile organic compounds (VOCs) in breath is a novel technique for examining biomarkers which may associate with asthma features. The aim of this pilot study was to identify potential markers in the relationship between EIB and VOCs.MethodsChildren between four and 14 years old were asked to provide a breath sample prior to undergoing an exercise challenge test to assess for EIB.ResultsBreath samples were collected and analyzed in 46 asthmatic children, 21 with EIB and 25 without EIB (NO-EIB). Molecular features (MFs) were not significantly different between EIB and NO-EIB controls. 29 of the 46 children were corticosteroid naïve, 10 with EIB and 13 without. In the corticosteroid naïve group EIB was associated with increased MF23 and MF14 in the lower breath sample (p-value < 0.05).ConclusionThis pilot study shows that EIB was related to an increased MF14 and MF23 in corticosteroid naïve children. The tentative identities of these compounds are octanal and dodecane/tetradecane respectively. These candidate biomarkers have a potential to enable non-invasive diagnosis of EIB in steroid-naïve children.Trial registration This study is registered in the Netherlands trial register (trial no. NL6087) at 14 February 2017.

Bronchodilator Delivery via High-Flow Nasal Cannula: A Randomized Controlled Trial to Compare the Effects of Gas Flows.

(1) Background: Aerosol delivery via high-flow nasal cannula (HFNC) has attracted increasing clinical interest. In vitro studies report that the ratio of HFNC gas flow to patient inspiratory flow (GF:IF) is a key factor in the efficiency of trans-nasal aerosol delivery. (2) Methods: In a randomized controlled trial, patients with a history of COPD or asthma and documented positive responses to inhaled bronchodilators in an outpatient pulmonary function laboratory were recruited. Subjects were randomized to receive inhalation at gas flow ratio settings of: GF:IF = 0.5, GF:IF = 1.0, or GF = 50 L/min. Subjects were assigned to inhale saline (control) followed by salbutamol via HFNC with cumulative doses of 0.5 mg, 1.5 mg, 3.5 mg, and 7.5 mg. Spirometry was performed at baseline and 10–12 min after each inhalation. (3) Results: 75 subjects (49 asthma and 26 COPD) demonstrating bronchodilator response were enrolled. Per the robust ATS/ERS criteria no difference was observed between flows, however using the criteria of post-bronchodilator forced expiratory volume in the first second (FEV1) reaching the screening post-bronchodilator FEV1 with salbutamol, a higher percentage of subjects receiving GF:IF = 0.5 met the criteria at a cumulative dose of 1.5 mg than those receiving GF:IF = 1.0, and GF = 50 L/min (64% vs. 29% vs. 27%, respectively, p = 0.011). Similarly at 3.5 mg (88% vs. 54% vs. 46%, respectively, p = 0.005). The effective dose at GF:IF = 0.5 was 1.5 mg while for GF = 50 L/min it was 3.5 mg. (4) Conclusions: During salbutamol delivery via HFNC, cumulative doses of 1.5 mg to 3.5 mg resulted in effective bronchodilation. Applying the robust ATS/ERS criteria no difference was observed between the flows, however using the more sensitive criteria of subjects reaching post screening FEV1 to salbutamol via HFNC, a higher number of subjects responded to the doses of 0.5 mg and 1.5 mg when HFNC gas flow was set at 50% of patient peak inspiratory flow.

Can bronchial challenge test with adenosine or methacholine at preschool age predict school‐age asthma?

Bronchial challenge test (BCT) measures current airways-hyperreactivity, however, its predictive role in pre-school children (<6 years) for the diagnosis of asthma at school age is still debatable. We aimed to find whether preschool children with a positive adenosine or methacholine BCT are more prone to asthma at school age. We included children aged 6-13 years with respiratory symptoms that were previously referred to our pulmonary function laboratory for BCT (methacholine or adenosine, depending on the question asked) at age 10 months to 6 years (baseline). BCT was considered positive based on spirometry results or wheezing, desaturation, and tachypnea reactions. The primaryoutcome measure was asthma diagnosis at school age using the well-validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. We used logistic regression analysis to explore whether positive BCT could predict school-age asthma while including age and collected modified asthma predictive indexin the model. One hundred and fifty-one of 189 children (53% males), completed the ISAAC questionnaire (response rate = 80%). Mean ages at BCT and at follow-up were 3.9 ± 1.28 and 9.4 ± 1.85 years, respectively. At baseline, 40 of 67 had a positive adenosine test and 73 of 84 had a positive methacholine BCT. Thirty-nine children were diagnosed with asthma at school age. Logistic regression analysis showed that a positive adenosine test at pre-school age was the best predictor, significantly increasing the odds of asthma at school age by 6.34 (95% CI: 1.23-32.81, p = .028), while methacholine did not show significance (p = .69). Choosing the relevant BCT for the question asked, positive adenosine, but not methacholine test, at pre-school, may predict asthma at school age.

Development and Validation of an Algorithm for Quality Grading of Pediatric Spirometry: A Quality Improvement Initiative.

Rationale: Current spirometry quality grading for individuals 7 years and older include within-test repeatability thresholds up to 250 ml, which may be inappropriately wide for children. Objectives:1) To develop, internally validate, and implement a quality grading algorithm for forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) for school-aged children and 2) to compare the algorithm with the one proposed by the American Thoracic Society (ATS). Methods: We conducted a review of existing algorithms and obtained expert input. A pediatric quality grading algorithm was drafted and modified in an iterative process until consensus was achieved, with the main difference from current criteria being tighter volume repeatability for the pediatric quality grading. Four pulmonary function technicians evaluated the interrater agreement of the algorithm in a blinded fashion on an unselected consecutive sample of 87 prebronchodilator spirometry tests, and the grades were compared with those from the ATS algorithm in the same sample of spirometry tests. The algorithm was then implemented into the workflow of the pulmonary function laboratory. Results: For FEV1 and FVC, the interrater agreement values for the pediatric algorithm were 92% and 83%, respectively. When the ATS algorithm was used, 75.9% (n = 66) and 63.2% (n = 55) of subjects achieved a grade of A for FEV1 and FVC; when the pediatric algorithm was used, 69.0% (n = 60) and 58.6% (n = 51) met grade A criteria. There was a more uniform distribution of tests for the pediatric algorithm across grades B through F for FEV1 and FVC, and no grade C tests were observed for the ATS grading algorithm. A total of 2,464 tests graded prospectively by using the pediatric algorithm showed a median (interquartile range) FEV1 and FVC repeatability within 29 ml (13-57 ml) and 34 ml (15-66 ml), respectively. Most subjects received a grade of A for FEV1 (81.1%) and FVC (71.6%), performing a repeatable spirometry test to within 100 ml. Conclusions: A quality grading algorithm that uses smaller ranges of expired volumes to define repeatability is feasible and may be more appropriate in a pediatric pulmonary function laboratory.

Mechanics and Economics of a Negative Pressure Pulmonary Function Lab in the COVID-19 Era

The 2019 viral pandemic of SARS-CoV-2 has led to enhanced respiratory precautions because of its high infectivity.1 Aerosol-generating procedures such as pulmonary function tests (PFTs) pose an increased risk for viral transmission and therefore require adaptation by clinical personnel.

Evaluation of the relationship between laboratory parameters and pulmonary function tests in COVID-19 patients.

ObjectiveThe novel coronavirus SARS‐CoV‐2 (COVID‐19) rapidly escalated from its origin in an animal market in Wuhan, China in December 2019 to a global pandemic, and the lungs are the most frequently affected organ. The aim of this study was to investigate the relationship between pulmonary function test parameters and laboratory parameters in COVID‐19.MethodA total of 60 patients who were admitted to the chest diseases department and intensive care unit of our hospital and were diagnosed with COVID‐19 by real‐time PCR analysis of nasopharyngeal swabs were evaluated. Pulmonary function tests and laboratory parameters at admission and on day 7 of treatment were analysed.ResultsOn day 7 of treatment, white blood cell count, CRP, and fibrinogen level were significantly lower than at admission (P = .002, 0.001, and 0.001, respectively), while forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) values were significantly higher compared with admitting values (P = .001 for both). Correlation analysis showed that the decrease in CRP from admission to day 7 of treatment correlated with the increase in FEV1 (r = 0.616, P = .01) and FVC (r = 0.51, P = .01) during the same period. A decrease in the fibrinogen level was also correlated with an increase in FEV1 (r = 0.345, P = .01) and FVC (r = 0.357, P = .01).ConclusionFibrinogen and CRP levels are easily accessible parameters that may help identify improvement or deterioration in pulmonary function in COVID‐19 patients during follow‐up and discharge while reducing the risk of transmission.

Editorial introductions

Editorial introductions

Antisynthetase Syndrome-Associated Interstitial Lung Disease: Monitoring of Immunosuppressive Treatment Effects by Chest Computed Tomography.

Background: Antisynthetase syndrome (ASyS) is a rare autoimmune disease characterized by inflammatory myopathy, arthritis, fever, and interstitial lung disease (ILD). Pulmonary involvement in ASyS significantly increases morbidity and mortality and, therefore, requires prompt and effective immunosuppressive treatment. Owing to the rarity of ASyS, limited data exists on progression and prognosis of ILD under immunosuppression.Objectives: The objective of the study was to evaluate the radiological progression and outcome measures of ILD with immunosuppressive therapy in patients with ASyS.Methods: Twelve patients with ASyS-associated ILD (ASyS-ILD) were included. Demographic and clinical data, including organ involvement, pulmonary function tests (PFT), laboratory parameters, imaging studies, and treatment regimens were retrospectively analyzed from routinely collected data. The extent of ground glass opacities, fibrotic changes and honeycombing was analyzed and scored using high-resolution chest computed tomography (HRCT) scans. HRCT findings were compared between baseline and follow-up examinations. In addition, patients were stratified depending on whether they had received rituximab (RTX) or not.Results: Pulmonary function tests revealed stable lung function and follow-up HRCT scans showed an improvement of radiological alterations in the majority of ASyS patients under immunosuppressive therapy. We did not detect significant differences between the RTX- and non-RTX-treated groups, but the RTX-treated patients more frequently had myositis and relapsing disease.Conclusions: Radiographic alterations in ASyS-associated ILD respond to immunosuppressive treatment. RTX is a feasible treatment option with similar clinical and radiographic outcomes in patients with relapsing disease and clinically apparent myositis.

Kısa Etkili Bronkodilatör Yanıtı Değerlendirmede %MMEF ile sGaw, Kısmi Reversibilite ile Reversibilite Arasında Belirleyici Tanısal Bir Parametre Olabilir mi?

INTRODUCTION: By examining the relationship between changes in maximum mild-expiratory flow( MMEF) and specific airway conductance(sGaw), parameters with the change in FEV1 when evaluating the spirometer test and the bronchodilator response, we investigated their diagnostic contribution to the bronchodilator response in those with partial responses to FEV1. METHODS: The retrospective study sample consists of data from 112 patients between Jun 1, 2019, and Feb 1, 2020 who applied to the pulmonary function laboratory with a pre-diagnosis of bronchial hyperreactivity as well as body plethysmography test performed together with the reversibility test. RESULTS: MMEF% and ▲sGaw were linearly correlated with ▲FEV1 (respectively r = 0.752; p &lt;0.001, r = 0.611; p &lt;0.001). While there was a significant difference between ▲MMEF% and ▲sGaw between reversible, partially reversible, and irreversible groups (P &lt;0.001), there was no significant difference in ▲sGaw between partial reversible and reversible groups in post-hoc comparisons (P&gt; 0.05). In the binary logistic regression model created between the partially reversible and reversible groups, demographic characteristics, MMEF% and ▲sGaw variables, ▲MMEF was an independent predictor [OR: 1.132; 95% CI (1.036-1.238), p = 0.006]. The 24% threshold for absolute reversibility or partial reversibility calculated with MMEF% was significant, indicating significance at 86.2% sensitivity and 80.8% specificity (AUC: 0.811, 95% CI: 0.686-0.936; p &lt;0.001). This value we found defined 81% of the partially reversible group as reversible. DISCUSSION AND CONCLUSION: We observed that ▲sGaw alone didn' have a determinant contribution for determining reversibility in bronchodilator response, which showed partial reversibility with respect to FEV1 change. We believe that ▲MMEF% can be an independent predictor between these two groups and the calculated threshold value of 24% can be used as a criterion for determining the reversibility in cases where FEV1 is not determinant.

Reliability of Smartphone Pulse Oximetry in Subjects at Risk for Hypoxemia.

Pulse oximeters are used to measure [Formula: see text] and pulse rate. These devices are either standalone machines or integrated into physiologic monitoring systems. Some smartphones now have pulse oximetry capabilities. Because it is possible that some patients might utilize this technology, we sought to assess the accuracy and usability of smartphone pulse oximeters. This was a prospective, observational study that involved noninvasive measurements of [Formula: see text] and heart rate with 3 devices: Masimo Radical-7, Kenek Edge with the Apple iPhone 6S, and the Samsung S8 smartphone. Ambulatory adult patients visiting our institution's pulmonary function lab for a 6-min walk test were eligible to participate in the study. Pretest and posttest results for each subject were obtained simultaneously using all 3 devices. All results were analyzed with the Spearman rho correlation test, and Bland-Altman plots were used to assess the agreement of measures between the devices. Forty-seven subjects were enrolled in the study, with pulmonary hypertension (30%) and COPD (23%) being the 2 major diagnoses. The mean ± SD difference between the Masimo and Apple devices for pretest [Formula: see text] was 2.3 ± 2.4%, and the difference for posttest [Formula: see text] was 2.1 ± 3.9%. The mean difference between the Masimo and Samsung devices for pretest [Formula: see text] was 3.2 ± 2.8%, and the difference for posttest [Formula: see text] was 2.4 ± 3.5%. The number of subjects who were unable to obtain [Formula: see text] was higher with the Samsung device than with the Apple device in both pretest (14 of 47 vs 3 of 47) and posttest (17 of 47 vs 5 of 47). In contrast, the Masimo device was able to measure [Formula: see text] in all subjects. Smartphone pulse oximeters were unreliable compared to a hospital pulse oximeter. Further research is needed with evolving technology to better understand smartphone pulse oximetry. (ClinicalTrials.gov registration NCT03534271.).

A CROSS-SECTIONAL COMPARISON BETWEEN TWO TYPES OF FORCED EXPIRATORY MANEUVERS DURING PULMONARY FUNCTION SURVEILLANCE OF US COAL WORKERS, 2016-2019

SESSION TITLE: Education, Research, and Quality Improvement Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Recent spirometry standardization guidelines focus on the flow-volume loop maneuver [FVL] to measure both inspiratory and expiratory airflow during spirometry testing. However, many occupational health surveillance programs routinely perform ‘exhalation only’ maneuvers [EO]. Our aim was to determine spirometry quality differences based on the type of forced vital capacity (FVC) maneuver performed. METHODS: Between 2016–2019, the National Institute for Occupational Safety and Health (NIOSH) conducted health surveillance inclusive of spirometry testing for U.S. coal miners. Tests were conducted in a NIOSH mobile examination unit, by the same technicians using the same flow-type spirometer model. From 2016 to 2018, the EO-FVC maneuver was performed by miners. In 2018, NIOSH spirometry protocols were updated, and subsequent miners were tested using the FVL-FVC maneuver. We compared spirometry test quality differences between EO-FVC and FVL-FVC testing techniques. Quality metric variables of interest were number of acceptable maneuvers, repeatability of maneuvers, maximal expiration to zero flow, excessive hesitation, and overall test quality. Fisher’s exact tests identified univariate quality variable differences. Poisson regression models using SAS Proc GENMOD determined associations between the type of FVC maneuver and test-quality metrics with adjustment for sex, race, BMI, age, and test technician. RESULTS: We compared 2,010 EO-FVC and 3,340 FVL-FVC spirometry tests. Univariate analyses revealed that tests from FVL-FVC maneuvers were more likely to contain three acceptable maneuvers, be repeatable, and have quality grades ‘C ‘or better (p<0.0001, p=0.035, and p<0.0001, respectively). Exhalation to zero flow was more often achieved in EO-FVC maneuvers (p<0.0001). Poisson models indicated that FVL-FVC maneuvers produced significantly more tests with three acceptable maneuvers (PRR=1.07, 95% CI: 1.01, 1.15), and repeatable maneuvers (PRR=1.06, 95% CI: 1.01, 1.13). No significant associations were seen for excessive hesitation and maximal expiration to zero flow parameters. CONCLUSIONS: The type of FVC maneuver performed can influence spirometry test quality. FVL-FVC maneuvers were more likely to produce spirometry tests meeting criteria for acceptability and repeatability when compared to EO-FVC type maneuvers. CLINICAL IMPLICATIONS: Our findings will help inform occupational health surveillance programs as to which type of FVC maneuver they may choose to implement during worker spirometry testing. A change from the EO-FVC to FVL-FVC maneuver would also make occupational health surveillance spirometry records more comparable to spirometry testing being performed in acute care pulmonary function laboratories. DISCLOSURES: No relevant relationships by Kathleen Clark, source=Web Response No relevant relationships by scott hendricks, source=Web Response

Sarcoidosis-Associated Pulmonary Hypertension.

Pulmonary hypertension (PH) is a well-known complication of sarcoidosis, defined by a mean pulmonary artery pressure of ≥25 mm Hg. Since both PH and sarcoidosis are rare diseases, data on sarcoidosis-associated PH (SAPH) is retrieved mostly from small retrospective studies. Estimated prevalence of SAPH ranges from 3% in patients referred to a tertiary center up to 79% in patients awaiting lung transplant. Most patients with SAPH show advanced parenchymal disease as the underlying mechanism. However, some patients have disproportional elevated pulmonary artery pressure, and PH can occur in sarcoidosis patients without parenchymal disease. Other mechanisms such as vascular disease, pulmonary embolisms, postcapillary PH, extrinsic compression, and other sarcoidosis-related comorbidities might contribute to SAPH. The diagnosis of PH in sarcoidosis is challenging since symptoms and signs overlap. Suspicion can be raised based on symptoms or tests, such as pulmonary function tests, laboratory findings, electrocardiography, or chest CT. PH screening mainly relies on transthoracic echocardiography. Right heart catheterization should be considered on a case-by-case basis in patients with clinical suspicion of PH, taking into account clinical consequences. Treatment options are considered on patient level in a PH expert center, and might include oxygen therapy, immunosuppressive, or PH-specific therapy. However, qualitative evidence is scarce. Furthermore, in a subset of patients, interventional therapy or eventually lung transplant can be considered. SAPH is associated with high morbidity. Mortality is higher in sarcoidosis patients with PH compared with those without PH, and increases in patients with more advanced stages of sarcoidosis and/or PH.

Development of Quality Assurance and Quality Control Guidelines for Respiratory Oscillometry in Clinic Studies

The guidelines to conduct and interpret conventional pulmonary function (PFT) tests are frequently reviewed and updated. However, the quality assurance and quality control (QA/QC) guidelines for respiratory oscillometry testing remain limited. QA/QC guidelines are essential for oscillometry to be used as a diagnostic pulmonary function test (PFT) in a clinical setting. We developed a QA/QC protocol shortly after oscillometry was introduced in our laboratory as part of a clinical study. The first clinical study began after the research personnel completed 3 h of combined didactic and hands-on training and establishment of a standard operating protocol (SOP) for oscillometry testing. All oscillometry tests were conducted using the initial SOP protocol from October 17, 2017, to April 6, 2018. At this time, the first QA/QC audit took place, followed by revisions to the SOP, the addition of a QA/QC checklist, and the development of a 12-h training program. A second audit of oscillometry tests was conducted from April 9, 2018, to June 30, 2019. Both audits were completed by a registered cardiopulmonary technologist from the Toronto General Pulmonary Function Lab. The first audit evaluated 197 paired oscillometry-PFT tests and found 10 tests (5.08%) to be invalid, with a coefficient of variation > 15%. The second audit examined 1,930 paired oscillometry-PFT tests; only 3 tests (0.16%) were unacceptable, with a coefficient of variation > 15%. Improvement in QA/QC was significantly better compared to the first audit (P < .001). Although oscillometry requires minimal subject cooperation, application of the principles that govern the conduct and application of a PFT are important for ensuring that oscillometry testing is performed according to acceptability and reproducibility. Specifically, the inclusion of a SOP, a proper training program, a QA/QC checklist, and regular audits with feedback are vital to ensure that oscillometry is conducted accurately and precisely.

Effects of adopting the Global Lung Function Initiative 2017 reference equations on the interpretation of carbon monoxide transfer factor.

The recently published Global Lung Function Initiative (GLI) carbon monoxide transfer factor (T LCO) reference equations provide an opportunity to adopt a current, all-age, widely applicable reference set. The aim of this study was to document the effect of changing to GLI from commonly utilised reference equations on the interpretation of T LCO results.33 863 T LCO results (48% female, 88% Caucasian, n=930 aged <18 years) from clinical pulmonary function laboratories within three Australian teaching hospitals were analysed. The lower limit of normal (LLN) and proportion of patients with a T LCO below this value were calculated using GLI and other commonly used reference equations.The average T LCO LLN for GLI was similar or lower than the other equations, with the largest difference seen for Crapo equations (median: -1.25, IQR: -1.64, -0.86 mmol·min-1·kPa-1). These differences resulted in altered rates of reduced T LCO for GLI particularly for adults (+1.9% versus Miller to -27.6% versus Crapo), more so than for children (-0.8% versus Kim to -14.2% versus Cotes). For adults, the highest raw agreement for GLI was with Miller equations (94.7%), while for children it was with Kim equations (98.1%). Results were reclassified from abnormal to normal more frequently for younger adults, and for adult females, particularly when moving from Roca to GLI equations (30% of females versus 16% of males).The adoption of GLI T LCO reference equations in adults will result in altered interpretation depending on the equations previously used and to a greater extent in adult females. The effect on interpretation in children is less significant.

Ecuaciones de referencia para informe de espirometrías. ¿Será tiempo de adoptar las ecuaciones de la Global Initiative for Lung Function?

ATS/ERS recommend the use of national reference values for the interpretation of spirometry. Reference values were published (2014) in general adult Chilean population, which are different from those of Knudson currently in use. However, most pulmonary function laboratories continue to use these latter equations. Multi-ethnic Global Lung Function Initiative (GLI) equations were published (2012) in order to standardize the interpretation of pulmonary function tests worldwide. Our objective was to evaluate the agreement in the spirometric reports between the most used equations in Chile with those from GLI. Methods: We compared the agreement in the interpretation of the spirometric pattern (normal, obstructive and restrictive) and the degree of alteration between GLI with Gutierrez 2014, with Knudson and with NHANES III according to recommendations of the Chilean Society of Respiratory Diseases, through the Kappa concordance coefficient (K). The sample correspond to 315 adults over 40 years of age (55% women, 59.3 ± 9.2 years-old), smokers or ex-smokers, healthy or with COPD, who underwent spirometry with a bronchodilator as part of a respiratory check-up. Differences were plotted using the Bland-Altman method. Results: agreement for pattern between GLI with Gutierrez 2014, with Knudson and with NHANES III was good (K = 0.73, 0.71 and 0.77 respectively) and also was good for the pattern and degree of alteration (K = 0.68, 0.67 and 0.76 respectively). Conclusions: We found a good agreement between the equations most used in Chile and those from the GLI, for a sample that includes subjects with and without lung disease, smokers and ex-smokers.

Area under the expiratory flow–volume curve (AEX): actual versus approximated values

Previous work has shown that area under the expiratory flow–volume curve (AEX) performs well in diagnosing and stratifying respiratory physiologic impairment, thereby lessening the need to measure lung volumes. Extending...

Dose Response to Transnasal Pulmonary Administration of Bronchodilator Aerosols via Nasal High-Flow Therapy in Adults with Stable Chronic Obstructive Pulmonary Disease and Asthma

Background: There has been increasing interest in transnasal pulmonary aerosol administration, but the dose-response relationship has not been reported. Objectives: To determine the accumulative bronchodilator dose at which patients with stable mild-to-moderate asthma and chronic obstructive pulmonary disease (COPD) achieve similar spirometry responses before and after bronchodilator tests using albuterol via a metered dose inhaler with a valved holding chamber (MDI + VHC). Method: Adult patients who met ATS/ERS criteria for bronchodilator responses in pulmonary function laboratory were recruited and consented to participate. After a washout period, patients received escalating doubling dosages (0.5, 1, 2, and 4 mg) of albuterol in a total volume of 2 mL delivered by vibrating mesh nebulizer via a nasal cannula at 37°C with a flow rate of 15–20 L/min using a Venturi air entrainment device. Spirometry was measured at baseline and after each dose. Titration was stopped when an additional forced expiratory volume in 1 second (FEV₁) improvement was <5%. Results: 42 patients (16 males) with stable mild-to-moderate asthma (n = 29) and COPD (n = 13) were enrolled. FEV₁ increment after a cumulative dose of 1.5 mg of albuterol via nasal cannula at 15–20 L/min was similar to 4 actuations of MDI + VHC (0.34 ± 0.18 vs. 0.34 ± 0.12 L, p = 0.878). Using ATS/ERS criteria of the bronchodilator test, 33.3% (14/42) and 69% (29/42) of patients responded to 0.5 and 1.5 mg of albuterol, respectively. Conclusions: With a nasal cannula at 15–20 L/min, transnasal pulmonary delivery of 1.5 mg albuterol resulted in similar bronchodilator response as 4 actuations of MDI + VHC.