Normal Total Lung Capacity Research Articles

A new phenotype of patients with post-COVID-19 condition is characterised by a pattern of complex ventilatory dysfunction, neuromuscular disturbance and fatigue symptoms.

Patients with post-COVID-19 condition frequently suffer from chronic dyspnoea. The causes and mechanism for dyspnoea in these patients without evidence of structural lung disease are unclear. Patients treated for COVID-19 at Charité University Hospital in Berlin received pulmonary function testing including respiratory muscle strength tests and completed health-related quality-of-life questionnaires during follow-up. Patients with post-COVID-19 condition during outpatient follow-up with fatigue and exertional intolerance (PCF) were compared to patients with post-COVID-19 condition with evidence of chronic pulmonary sequelae (post-COVID-19 restriction (PCR)) as well as to patients without post-COVID-19 condition (NCF). A total of 170 patients presented for follow-up. 36 participants met criteria for PCF, 28 for PCR and 24 for NCF. PCF patients reported dyspnoea in 63.8%. % predicted value of respiratory muscle strength (median (IQR)) was reduced in PCF (55.8 (41.5-75.9)) compared to NCF and PCR (70.6 (66.3-88.9) and 76.8 (63.6-102.2), respectively; p=0.011). A pattern of reduced forced vital capacity (FVC), but normal total lung capacity (TLC), termed complex ventilatory dysfunction defined as TLC - FVC >10% predicted was observed and occurred more frequently in PCF (88.9%) compared to NCF and PCR (29.1% and 25.0%, respectively; p<0.001). Dyspnoea in PCF is characterised by reduced respiratory muscle strength and complex ventilatory dysfunction indicating neuromuscular disturbance as a distinct phenotype among patients with post-COVID-19 condition. These observations could be a starting point for developing personalised rehabilitation concepts.

Clinical Manifestations of Subjects With the Non-Specific Pulmonary Function Test Pattern

IntroductionNon-specific pattern (NSP) is a subgroup of preserved ratio impaired spirometry (PRISm) that requires a normal total lung capacity measurement. NSP has been historically classified as being an obstructive lung disease pattern. There has been heightened interest and investigation into PRISm recently as it has been associated with an increased likelihood of developing chronic obstructive pulmonary disease (COPD). Given the inherent challenges of understanding the clinical significance of the NSP, the aim of this study was to further explore the clinical characteristics of patients with this pulmonary function test pattern. Material and methodsWe identified 111 and 79 subjects using pre-bronchodilator (pre-BD) and post-bronchodilator (post-BD) values, respectively, that met criteria for NSP. The outpatient medical records were retrospectively reviewed for associated diagnoses that were then clustered into ‘obstructive’ or ‘non-obstructive’ groups based on the treating physician's primary pulmonary clinical diagnosis. ResultsWithin this NSP cohort, cough, wheezing and sputum production were documented more frequently in those with an obstructive lung disease diagnosis. Whether identified using pre-BD or post-BD spirometric values, those with NSP and a positive BD response were more likely to carry an obstructive lung disease diagnosis. ConclusionApproximately one third of patients with NSP in this study were not given an obstructive lung disease diagnosis by their clinician, which supports the classification of NSP as not an exclusively obstructive lung disease pattern. However, the presence of supporting clinical symptoms, such as cough with sputum production and wheeze, and/or a positive BD response on PFT, support a diagnosis of obstruction in patients with NSP.

Some results are striking - what about lung function in adults with congenital heart disease?

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Stiftung KinderHerz Weserstr. 101 45136 Essen. Background During the last years, lung function tests became of high interest in patients with a congenital heart defect (CHD). However, data are still rare and mostly concentrate on spirometry, investigating forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and its ratio (FEV1/FVC). Purpose This study prospectively examined patients with CHD regarding their lung function. Data reported were FVC, FEV1, and FEV1/FVC (spirometry) as well as total lung capacity (TLC) and residual volume, presented as its ratio to TLC (RV/TLC) and compared to the latest Global Lung Initiative reference values (2021). Methods From April 2018 to October 2022, one hundred eighty-six adults with CHD (32 ± 10 years, 83 female) participated in the study. Their results (z-scores) were compared with the student’s T-test against zero. Results Patients mostly reached normal values but differed significantly in FVC-z (-1.1 ± 1.2, p&amp;lt;0.001), FEV1-z (-1.2 ± 1.2, p&amp;lt;0.001), its ratio (FEV1/FVC-z: -0.3 ± 1.0, p&amp;lt;0.001), TLC-z (-0.6 ± 1.2, p&amp;lt;0.001) and RV/TLC-z (1.1 ± 0.9, p&amp;lt;0.001). However, with the border of z&amp;gt;-1.645 as normal results, 33% had striking results: 43 showed a reduced FVC (FVC-z&amp;lt;-1.645), and 10 an obstructive pattern (FEV1/FVC&amp;lt;-1.645). Out of the patients with reduced FVC, 17 patients (40%) had a normal TLC (TLC-z&amp;gt;-1,645), which stands for a non-specific pattern, and 26 patients (60%) had a real restriction, which was only detected via body plethysmography. Conclusions Patients with CHD and a reduced FVC in spirometry need to undergo body plethysmography. Most of them have unrevealed ventilatory restrictions that should be further analyzed and treated if needed.

Increased expiratory flows identify early interstitial lung disease.

Most interstitial lung diseases (ILDs) manifest with a restrictive ventilatory defect as the common physiologic abnormality. Low carbon monoxide diffusing capacity (Dlco) is considered to be the earliest abnormality on pulmonary function tests (PFTs) in patients with ILD. However, its measurement requires complex and expensive equipment. Our study aimed to assess if high expiratory flows are the earliest PFT abnormality in patients with idiopathic pulmonary fibrosis (IPF) and ILD. In a real-world cohort of incident cases with ILD, we identified the initial PFTs on all patients newly diagnosed with ILD at Kingston Health Sciences Center (in Kingston, Ontario, Canada) between 2013 and 2017. The diagnosis of ILD, including IPF, was established as per current guidelines. Among patients with normal forced vital capacity (FVC), total lung capacity (TLC), and Dlco, we assessed the frequency of high expiratory flows defined as forced expiratory volume in 1 s (FEV1)/FVC, FEF25, FEF25-75, FEF75, and peak expiratory flow > 95% confidence limit of normal. We adjusted for emphysema, increased airway resistance, and obesity. We assessed PFTs of 289 patients with ILD; 88 (30%) of them had normal FVC, TLC, and Dlco. Among these, high FEV1/FVC was the most common abnormality in 37% of patients, in 43% of nonobese patients, and in 58% of those with no emphysema and normal airway resistance. Results were similar in the 88 patients with IPF. High FEV1/FVC could allow identifying patients with ILD/IPF in the earliest stages of their disease with simple spirometry, leading to earlier diagnosis and treatment.

Isolated Elevation in Lung Residual Volume Is Associated With Airway Diseases.

Residual volume (RV) is a derived lung compartment that correlates with air trapping in the context of air flow obstruction on spirometry. The significance of an isolated elevation in RV in the absence of other pulmonary function test (PFT) abnormalities is not well defined. We sought to assess the clinical and radiologic findings associated with isolated elevation in RV. We searched our out-patient PFT database at Mayo Clinic (Rochester, Minnesota) from 2016-2018 for adult patients with isolated elevation in RV. We defined isolated elevation in RV as RV ≥ upper limit of normal or ≥ 130% predicted with normal total lung capacity (TLC), spirometry, and diffusion capacity of the lung for carbon monoxide (DLCO). We then matched this high-RV group by age and sex to an equal number of individuals with normal RV, TLC, spirometry, and DLCO (normal-RV group). We identified 169 subjects with isolated elevation in RV on PFTs, with a median age of 73 y; 55.6% were female, and median body mass index was 26.8 (vs 29.8 in the normal-RV group). The median RV was 3.08 L (134% predicted, interquartile range [IQR] 130-141) in the high-RV group and 2.26 L (99% predicted, IQR 90-109) in the normal-RV group (P < .001). Subjects with high RV were more likely to have smoked (54% vs 40%, P = .01) and almost twice as likely to have a maximum voluntary ventilation < 30 times the FEV1 (21% vs 12%, P = .02). Clinically, asthma (21% vs 11%, P = .01) and non-tuberculous mycobacterial lung infections (12% vs 2%, P = .001) were more prevalent in the high-RV group. On chest computed tomography, bronchiectasis (31% vs 15%, P = .008), bronchial thickening or mucus plugging (46% vs 22%, P < .001), and emphysema (13% vs 5%, P = .046) were more common in the high-RV group. Isolated elevation in RV on PFTs is a clinically relevant abnormality associated with airway-centered diseases.

Lung Restriction in Patients With Breast Cancer After Hypofractionated and Conventional Radiation Therapy: A 10-Year Follow-up

Previous studies in patients with breast cancer have shown acute radiation therapy-induced reductions of pulmonary diffusing capacity, essentially owing to lung volume restriction. We aimed to assess the long-term effect of 2 radiation therapy regimens, which differed in terms of radiation technique and dose fractionation, on lung function. From a randomized controlled trial comparing conventional 3-dimensional conformal radiation therapy (CR) and hypofractionated tomotherapy (TT), 84 patients with breast cancer (age at inclusion 54 ± 10 [standard deviation] years) could be assessed at baseline, after 3 months, and after 1, 2, 3, and 10 years. Measurements included forced vital capacity, total lung capacity (TLC), and diffusing capacity (TLco). Radiation therapy-induced lung function changes over 10 years (Δ) were similar for both treatment arms, and in a patient subgroup with negligible history of respiratory disease or smoking (n=57) these averaged: Δ forced vital capacity=-13 (± 9) percent predicted; ΔTLco=-14 (± 12) percent predicted; and ΔTLC=-11 (± 9) percent predicted. The only significant correlation was between V20 (lung volume exposed to dose exceeding 20 Gy) and ΔTLco (rho=-0.36; P=.007). In this subgroup, as well as in the entire patient cohort, the incurred pulmonary restriction in terms of TLC and TLco showed a greater decline at 3 months for CR versus TT. However, at 10 years, no significant difference could be detected between CR and TT (P=.9 for TLC and P=.2 for TLco in the entire patient cohort). Of the patients with normal TLC and TLco at baseline (ie, above lower limits of normal), respectively 94% and 96% were still normal 10 years later. In women with breast cancer, conventional 3-dimensional conformal radiation therapy and hypofractionated tomotherapy induce similar restrictive lung patterns during the course of a 10-year period, despite some treatment-dependent differences in the first 3 months. The large majority of women with normal lung function at baseline maintained a normal lung function status 10 years after radiation therapy, irrespective of treatment arm.

Peripheral obstruction without airflow limitation is rare and not specific to asthma in children.

Peripheral (or small) airway obstruction (PAO) is considered a marker of childhood asthma but the techniques able to directly measure it are rarely used in routine. Usual spirometry and plethysmography can detect a certain degree of PAO when reduced forced vital capacity (FVC) is associated to normal forced expiratory volume in 1 s (FEV1 ) to FVC ratio, and normal total lung capacity (TLC). The frequency of this functional pattern has never been studied in different pediatric respiratory conditions. To assess the prevalence and outcome of PAO in children with different diseases or symptoms, we retrospectively extracted from our database all files of Caucasian subjects encompassing spirometry and plethysmography measurements. Spirometry patterns (normal, airflow limitation [AFL; low FEV1 /FVC], low FVC [with normal FEV1 /FVC]) and final functional patterns (normal, AFL, PAO, restrictive [low TLC], or mixed) were described. We included 4394 files recorded in 1794 children (median [IQR] age: 10.7 [9.2-12.9] years). At inclusion, 125 (7%) children had low FVC of which 56 (44.8%, and 3.1% [95% CI 2.3-3.9] of the whole population) had PAO. PAO prevalence increased with age (OR (95% CI) per 2-year-increase: 2.26 (1.59-3.23); p < .001), and was more frequent in chronic bronchial diseases other than asthma (1.6% vs. 8.0%). On repeated tests, PAO frequently normalized (26.1%) or persisted (43.5%), but it less often progressed into AFL (13%) or restrictive (13%) patterns. PAO is an infrequent nonspecific and persistent functional pattern. Its prevalence increases with age and in diagnosis of chronic respiratory diseases other than asthma.

Six-minute walking test outweighs other predictors of mortality in idiopathic pulmonary fibrosis. A real-life study from the Swedish IPF registry

Background and objectiveIdiopathic pulmonary fibrosis (IPF) is a disease characterized by a progressive loss of lung function, a restrictive ventilatory impairment, and a high five-year mortality. Our aim was to characterize clinical features of IPF at baseline and to assess which of those that would predict mortality. MethodsWe used baseline data at inclusion collected from the Swedish IPF registry between January 2014 and October 2018. Patients were followed for at least six months. Demographics, lung function (forced vital capacity (FVC), total lung capacity (TLC), diffusion capacity of carbon monoxide (DLCO%)), 6-min walking test (6MWT), lowest oxygen saturation during 6MWT (L-SpO2), King's brief interstitial lung disease health status questionnaire (K-BILD) scores were collected. GAP index and Charlson Comorbidity Index (CCI) were calculated. Transplant-free survival was registered during the follow-up time. ResultsTwo hundred and twenty patients were included in the study. Fifty-seven (26%) died and six (3%) underwent lung transplant during a mean follow-up time of 24 months. Out of 220 patients, 63 patients (29%) had a FVC% equal or over 80% of predicted at baseline. Only 17 out of 155 (11%) patients had a normal TLC%. Walking distance during a 6MWT was an independent predictor of outcome death/transplant (HR 0.80, 95%CI 0.65–0.99, p = 0.037), when adjusted for TLC%, K-BILD and GAP stage in a multivariate cox regression model. ConclusionOur results confirm the relevance of the 6MWT as main predictor of mortality at diagnosis in IPF patients.

PULMONARY HYPERTENSION AND LIVER TRANSPLANTATION IN PRIMARY BILIARY CIRRHOSIS: IS IT ALWAYS PORTO PULMONARY HYPERTENSION?

SESSION TITLE: Global Case Report Posters SESSION TYPE: Global Case Reports PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Pulmonary hypertension (PHTN), both arterial and venous, has been reported in up to 20% of patients at the time of liver transplantation (LTx). This is mostly attributed to Portopulmonary Hypertension (POPH), and generally improves after transplantation. We present a case of post-transplant worsening of PHTN in a patient with primary biliary cirrhosis (PBC) and discuss likely reasons. CASE PRESENTATION: A 61-yearold Egyptian lady, nonsmoker and non-alcohol consumer with PBC complicated by esophageal varices and ascites underwent routine pre LTx pulmonary evaluation. No pulmonary symptoms or abnormal exam findings. Spirometry and lung volumes were normal but diffusion capacity (DLCO) was low at 33ml/min/mmHg (32% predicted). Arterial blood gases were normal and no orhtodeoxia was detected.Contrast transthoracic echocardiogram (TTE) showed normal ejection fraction with grade 2 diastolic dysfunction and estimated right ventricle systolic pressure (RVSP) of 35 mmHg with no right to left shunt. Right heart catheterization showed Pulmonary artery 42/24 mmHg with mean pressures (MPAP) of 31 mm Hg, Pulmonary capillary wedge pressure (PCWP) 17mmHg, Trans pulmonary pressure gradient of 7, Cardiac output (CO) of 4.45 L/min and Pulmonary vascular resistance (PVR) of 3.1 WU. This was consistent with pulmonary venous hypertension from diastolic dysfunction. She was deemed low risk from pulmonary standpoint for liver transplantation and underwent uneventful transplant. Six months post-transplant she experienced significant fatigue and progressively worsening exertional dyspnea. Hemoglobin, kidney and liver function were normal. TTE revealed normal left sided chambers with RVSP 78mmHg. Repeat right heart catheterization showed mPAP 56 mmHg, PCWP 12 mmHg, CO 3.26 L/min, and PVR 13.2 WU, with significant vasoresponsiveness after inhaled nitic oxide (mPAP 39, PVR11.5). Repeat DLCO was 26 ml/min/mmHg with normal total lung capacity. No evidence of interstitial lung disease on high resolution chest scan was noted. Ventilation –perfusion lung scan did not reveal any changes of thromboembolic disease or significant right to left shunt. Doppler studies showed normal portal pressure. On the basis telangiectasia and positive anticentromere antibody (1:1280), she was diagnosed as incomplete crest syndrome. She was diagnosed as Group 1 PHTN secondary to Connective tissue disease and started on sildenafil and amlodipine. In view of progressive PHTN with functional class 3-4, she has also been started on iloprost inhaler. DISCUSSION: Severe PHTN is a relatively contraindication for LTx. The therapeutic potential of LTx in POPH has been reported by Bozbas, et al. with significant reductions in mPAPs after LTx. [1] However there are reports of new or worsening PHTN after LTx. The onset varied greatly from 1 month to 11 years post LTx, and mortality was high (69%). [2] In the immediate posttransplant period, systemic vascular resistance increases and this is associated with a proportional decrease in cardiac output. However hyperdynamic state may persist after LTx with increased hepatic blood flow. Despite normal portal pressure, portalsystemic collateral blood flow remains elevated after orthotopic liver transplantation, possibly because of persistent collateral circulation, which may keep portal tributary blood flow elevated.Our patient had mild initial PHTN with severe PHTN post LTx, likely due to increased pulmonary blood flow after improved portal hypertension. Incomplete CREST syndrome and PBC could be the cause for her worsening PHTN. The incidence of PHTN in PBC is 11.8%, mostly POPH but 30% do not have evidence of POPH. [3] Early DLCO and TTE follow-up may have alerted us to the worsening of PHTN, with potential improved prognosis with early start of specific pulmonary vasodilator therapy. CONCLUSIONS: In patients with autoimmune causes for liver cirrhosis and pulmonary hypertension, it’s important to consider alternative etiology for PHTN and not attribute it solely to POPH. Also, these patients may benefit form early follow up DLCO and TTE post LTx to assess progression or improvement Reference #1: Savas BS, Eroglu S, Oner EF, Moray G, Haberal M. Pulmonary hypertension improves after Orthotopic liver transplant in patients with chronic liver disease. Exp Clin Transplant. 2015;13(Suppl 3):115–9. Reference #2: Koch DG, Caplan M, Reuben A. Pulmonary hypertension after liver transplantation: Case presentation and review of the literature. Liver transplantation 2009;15(4)407 -12 Reference #3: Wallwork J, Williams R, Calne RY.Transplantation of liver, heart, and lungs for primary biliary cirrhosis and primary pulmonary hypertension. Lancet. 1987 Jul 25; 2(8552):182-5. DISCLOSURES: No relevant relationships by Maha Hamza, source=Web Response No relevant relationships by Tasleem Raza, source=Web Response No relevant relationships by Merlin Thomas, source=Web Response

Functional evaluation of breath: spirometry and body plethysmography comparison in people with cystic fibrosis.

[Purpose] The aim of the present study was to establish up-to-date data regarding the lung function of cystic fibrosis (CF) patients. [Subjects and Methods] Forty-eight patients of both genders, with a diagnosis of CF, were recruited. As a result our sample presented, according to the GOLD criteria, 23 patients with mild lung obstruction (FEV1%pred: 89.86), 16 patients with moderate lung obstruction (FEV1%pred: 56.1) and 9 patients with severe obstruction (FEV1%pred: 32.1). [Results] All patients presented normal total lung capacity followed by an important residual volume increase. [Conclusion] Our results were important to illustrate the CF patient’s lung functional status and to improve the health system strategy in treating such individuals.

Prognostic Significance of Pulmonary Function Test Abnormalities in Patients with Dyskeratosis Congenita

▪Introduction: Pulmonary fibrosis (PF) is a known complication in patients with dyskeratosis congenita (DC), reported in 15-20% of patients. PF is more common in older individuals with DC who may or may not have the classical clinical features of DC. PF in younger DC patients has been reported mainly in the setting of hematopoietic cell transplantation (HCT). There are no prospective studies of pulmonary function tests (PFT) in patients with DC.Objectives: To determine baseline pulmonary function status in patients with DC, association of PFT abnormalities with development or progression of pulmonary disease, and pulmonary outcomes in patients who did or did not receive HCT.Methods: DC patients older than 5 years of age underwent PFTs as part of a prospective IRB-approved cohort study at the NIH from 2002-2015. Data were obtained from spirometry [forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC)], lung volumes [total lung capacity (TLC)] and carbon monoxide diffusion capacity (DLCO). PFT abnormalities were classified as restrictive (normal FEV1/FVC and low TLC), obstructive (low FEV1/FVC and normal TLC) or mixed (low FEV1/FVC and low TLC) according to the American Thoracic Society Task Force guidelines. A low value was < lower limit of normal adjusted for age, sex, race and height. DLCO was also adjusted for hemoglobin. PFT data were analyzed in relation to the DC triad (nail dystrophy, skin pigmentation, leukoplakia), severe bone marrow failure (BMF needing treatment) and telomere length by flow FISH. Patients were followed through 2015. Pulmonary outcomes were compared in those with or without PFT abnormalities at evaluation and in those who did or did not receive HCT. P value <0.05 was significant.Results: Fifty-one patients with DC had PFTs, median age 19 yrs (range 6 - 69). Spirometry was abnormal in 16 patients (31%): 13 had restriction, 2 had obstruction, and 1 had a mixed pattern. DLCO was reduced (<80% of the predicted) in 32/49 patients (65%): 17 had mild (>60%), 13 had moderate (40-60%) and 2 had severely reduced (<40%) DLCO. All patients with abnormal spirometry had reduced DLCO compared with 18/35 (48%) with normal spirometry (p<0.0001). Patients with abnormal spirometry were more likely to have moderate/severe diffusion defects (10/16 vs 5/35; p=0.02), and severe BMF (12/16 vs 10/35; p=0.003) than those with normal spirometry. Telomere length and 2 or more features of the DC triad were not associated with PFT abnormality.Fourteen patients (27%) developed pulmonary disease at a median follow-up of 6 yrs (range 0.1 - 12 yrs) and a median age of 17 yrs (11 - 65): 10 had PF with interstitial honeycomb pattern on chest CT and 4 had pulmonary arteriovenous malformation (AVM) and mild fibrosis. Patients with abnormal spirometry and moderate/severely reduced DLCO were more likely to develop pulmonary disease than those with normal spirometry (12/16 vs 2/35; p<0.0001). Fourteen patients received a HCT (3 prior to and 11 after PFT evaluation) at a median age of 12 yrs (range 3 - 29). Eight of the 14 (57%) developed pulmonary disease 1 - 5 yrs after HCT (median 4 yrs) while 6/37 (16%) non-HCT patients developed PF (p=0.01). Transplanted patients developed pulmonary disease at a younger age than non-transplanted (median age 15 yrs, range 11 - 22 vs 54 yrs, 25 - 65; p=0.001), and had mutations in TINF2 (n=3), RTEL1, DKC1, WRAP53 (1 each); gene unknown (n=2). DC genes mutated in older non-HCT patients with PF were TERC (n=4), TERT (n=1), and unknown (n=1). The independent impact of severe DC phenotype, BMF, and HCT on pulmonary outcome could not be distinguished in young patients as most patients with severe disease had BMF and received HCT. There was no difference in PF among those who did or did not receive radiation for HCT. Four of the 10 deaths were due to PF.Conclusion: More than 30% of patients with DC have restriction and moderate/severe diffusion defect on PFTs, and these are more common in patients with severe BMF. PFT abnormalities are significantly associated with progression to PF, although they may also signal the presence of AVMs, a less common pulmonary manifestation of DC. PF in older patients is a known manifestation of the telomere biology disorder. It is unclear whether pulmonary disease in young patients is a feature of severe DC or the toxicity of HCT preparative regimens. Larger prospective studies are needed to confirm the predictive value of PFTs for future lung disease in patients with DC. DisclosuresNo relevant conflicts of interest to declare.

Pulmonary function in pectus excavatum patients before repair with the Nuss procedure

ABSTRACTObjectives: Whether the origin of symptoms in pectus excavatum patients (Pex) is related to reduced pulmonary function or impaired cardiovascular performance is debatable. However, pulmonary function testing (PFT) is still part of the evaluation prior to surgical repair in Pex. The purpose of this study was to corroborate our hypothesis that the majority of Pex that qualified for surgery present preoperatively with normal or close to normal PFT.Methods: After institutional review board approval, preoperative PFT data of Pex who underwent surgical repair were analyzed retrospectively: total lung capacity (TLC), vital capacity (VC), functional residual capacity, forced expiratory volume in 1 second (FEV1) and maximal expiratory flow at 25% of FVC (MEF25).Results: 82 patients aged from 9 to 27 years (average, 15 years) underwent PFT. A restrictive pattern (VC<80%) was observed in 45%, an obstructive pattern (FEV1 < 75 %) in 35%, and a normal total lung capacity in 62% of the Pex. No significant correlation was noted between the increasing severity of the Haller index and the PFT.Conclusion: Adolescent Pex without relevant respiratory symptoms have nearly a normal lung function. We suggest to skip PFT from the routine preoperative assessment in asymptomatic Pex.

Idiopathic Pulmonary Fibrosis: New Insights to Functional Characteristics at Diagnosis

The lung function of patients with idiopathic pulmonary fibrosis (IPF) has not been characterized in detail. objective: To characterize the heterogeneous physiological abnormalities that exist in patients with IPF during their initial clinical evaluation. Lung function tests from 93 patients, performed within six months of the initial diagnosis of IPF, were obtained from a referral pulmonary function laboratory at a tertiary care hospital in Canada. A restrictive pattern was defined as total lung capacity (TLC) <95th percentile of predicted value. Patients with obstructive lung disease, lung cancer, emphysema and other restrictive lung diseases were excluded. On diagnosis, 73% of patients with IPF had a restrictive pattern, with a mean TLC of 72% of predicted. Mean forced vital capacity (FVC) was 71% and 44% of patients had an FVC <95th percentile. Mean diffusing capacity for carbon monoxide (DLCO) was 60% and DLCO⁄alveolar volume (VA) 92% of predicted. Increased severity of restriction - based on TLC - was associated with lower DLCO (74% of predicted in mild restriction and 39% of predicted in severe restriction) and higher forced expiratory volume in 1 s (FEV1)⁄FVC ratio (82% of predicted in mild restriction and 90% of predicted in severe restriction) but not with age (76 years in mild restriction and 69 years in severe restriction). Regardless of severity of restriction, the average DLCO⁄VA (≥86% of predicted) remained within normal limits. One in four patients with IPF had normal TLC and more than one-half had a normal FVC during initial evaluation. As the severity of the restriction increased, FEV1⁄FVC increased, DLCO decreased but DLCO⁄VA remained normal.

Bronchiolitis obliterans syndrome after allogeneic hematopoietic SCT: phenotypes and prognosis

Bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic SCT (HSCT) is recognized as a new-onset obstructive lung defect (OLD) in pulmonary function testing and is related to pulmonary chronic GVHD. Little is known about the different phenotypes of patients with BOS and their outcomes. We reviewed the data of all allogeneic HSCT recipients referred to our pulmonary department for a non-infectious bronchial disease between 1999 and 2010. We identified 103 patients (BOS (n=77), asthma (n=11) and chronic bronchitis (n=15)). In patients with BOS, we identified two functional phenotypes: a typical OLD, that is, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <0.7 (n=53), and an atypical OLD with a concomitant decrease in the FEV1 <80% and FVC <80% predicted with a normal total lung capacity (n=24). The typical OLD was characterized by more severe FEV1 and fewer centrilobular nodules on the computed tomography scan. The FEV1 was not significantly affected during the follow-up, regardless of the phenotype. In addition to acute and extensive chronic GVHD, only the occurrence of BOS soon after transplantation and the intentional treatment of BOS with steroids were associated with a poor survival. The determination of patient subgroups should be explored to improve the management of this condition.

Reduced respiratory muscle strength and endurance in type 2 diabetes mellitus

A restrictive lung function pattern is frequently observed in patients with diabetes mellitus (DM) and has been related to respiratory muscle dysfunction in type 1 DM or in mixed population. We aimed to verify whether such a relationship applies also to type 2 DM patients. The respiratory muscle function was explored in 75 non-smoking patients with type 2 DM without pulmonary or cardiac diseases and compared with that of 40 healthy non-smoking control subjects matched by age and sex. Maximal inspiratory and expiratory pressures (MIP, MEP) and maximum voluntary ventilation (MVV), which reflect respiratory muscle strength and endurance, respectively, were measured, and a complete respiratory function assessment was recorded. Patients were in stable metabolic conditions and had, on average, normal total lung capacity and diffusing lung capacity for carbon monoxide. However, MIP and MVV were significantly reduced in comparison with those of control subjects. Both MIP/MEP and MVV significantly correlated with lung volumes and diffusing lung capacity for carbon monoxide. The multiple regression analysis identified age (beta coefficient = -0.238, p = 0.046), glycated haemoglobin (beta coefficient = -0.245, p = 0.047) and total lung capacity (beta coefficient = 0.430, p = 0.016) as independent correlates of MIP, whereas male sex (beta coefficient = 0.423, p = 0.004) and diabetic complications (beta coefficient = -0.248, p = 0.044) were independent correlates of MVV. In type 2 DM, respiratory muscle strength was reduced and significantly related to lung volumes and quality of metabolic control, whereas impaired endurance of respiratory muscles prevailed in patients with microvascular complications.

PFT Interpretive Strategies: American Thoracic Society/ European Respiratory Society 2005 Guideline Gaps

All pulmonologists, including those recently completing training, should be competent in critically evaluating and interpreting pulmonary function tests (PFTs). In addition, some authorities recommend that respiratory therapists learn to provide preliminary PFT interpretations for the medical directors of PFT labs. The 2005 American Thoracic Society/European Respiratory Society guidelines for interpreting PFTs lack recommendations for the best reference equations for lung volumes and diffusing capacity of the lung for carbon monoxide (D(LCO)), and lack reference equations for non-whites. The pre-test probability of lung disease should be determined using a short questionnaire. The "nonspecific pattern" occurs in about 15% of patients referred to a PFT lab, but it has many clinical correlates and the course is usually benign. Less common PFT patterns and those resulting from comorbid conditions (such as obesity, respiratory muscle weakness, or heart failure) are not discussed by the guidelines. More than half of patients with interstitial lung disease have a normal ratio of D(LCO)/V(A) (alveolar volume), and many have a normal total lung capacity.

The Nonspecific Pulmonary Function Test: Longitudinal Follow-up and Outcomes

The nonspecific (NS) pulmonary function (PF) pattern refers to a PF test with a normal total lung capacity (TLC), normal FEV₁/FVC ratio, and a low FEV₁, a low FVC, or both. Currently, no information is available regarding the long-term stability of the NS pattern or variables that predict changes in subjects with an initial NS PF pattern. From 1990 to 2005 we identified 1,284 subjects with an NS pattern on initial PF testing with one or more follow-up PF tests 6 months or more after the initial NS test result. Lung volumes, diffusing capacity, and spirometry data were analyzed. A multivariate, multinomial logistic regression model was used to study the association between different variables and the final PF pattern. Overall, 3,674 PF tests were performed in 1,284 subjects over a median follow-up period of 3 years. At last follow-up, 818/1,284 (64%) subjects continued to show the NS pattern, whereas 208/1,284 (16%) showed a restrictive pattern, 191/1,284 (15%) an obstructive pattern, 42/1,284 (3%) a normal pattern, and 25/1,284 (2%) a mixed pattern. The multinomial logistic regression analysis showed that increasing values for specific airway resistance and the difference between TLC and alveolar volume were predictors of a change to an obstructive pattern on follow-up. The NS pattern is a distinct and stable PF test pattern with roughly two-thirds of patients continuing to show this pattern on follow-up testing. Current interpretation guidelines erroneously label the NS pattern as representing obstruction and need to be changed to reflect these data.

Impaired lung compliance and DL,CO but no restrictive ventilatory defect in sarcoidosis

Sarcoidosis is a systemic granulomatous disease with predominant manifestation in the lungs, often presenting as interstitial lung disease. Pulmonary function abnormalities in sarcoidosis include restriction of lung volumes, reduction in diffusing capacity of the lung for carbon monoxide (D(L,CO)), reduced static lung compliance (C(L,s)) and airway obstruction. The aim of the present study was to assess various lung function indices, including C(L,s) and D(L,CO), as markers of functional abnormality in sarcoidosis patients. Results from 830 consecutive patients referred for lung function tests with a diagnosis of sarcoidosis (223 in stage I, 486 in stage II and 121 in stage III) were retreospectively analysed. The mean ± sd age of the patients was 40 ± 11 yrs; 18% were active smokers and 24% were former smokers. Normal total lung capacity was found in 772 (93%) patients. Of these cases, 24.5% had a low C(L,s) and 21.5% had a low D(L,CO). At least one abnormality was observed in 39.3% of these patients, whereas, in restrictive patients, this figure was 88%. Airway obstruction was present in 11.7% of cases. Lung volumes usually remain within the normal range and measurement of either C(L,s) or D(L,CO) often reveal impaired lung function in sarcoidosis patients, even when their lung volumes are still in the normal range; these two measurements provide complementary information.

Obstructive Airways Disease With Air Trapping Among Firefighters Exposed to World Trade Center Dust

The World Trade Center (WTC) collapse produced a massive exposure to respirable particulates in New York City Fire Department (FDNY) rescue workers. This group had spirometry examinations pre-September 11, 2001, and post-September 11, 2001, demonstrating declines in lung function with parallel declines in FEV(1) and FVC. To date, the underlying pathophysiologic cause for this has been open to question. Of 13,234 participants in the FDNY-WTC Monitoring Program, 1,720 (13%) were referred for pulmonary subspecialty evaluation at a single institution. Evaluation included 919 full pulmonary function tests, 1,219 methacholine challenge tests, and 982 high-resolution chest CT scans. At pulmonary evaluation (median 34 months post-September 11, 2001), median values were FEV(1) 93% predicted (interquartile range [IQR], 83%-101%), FVC 98% predicted (IQR, 89%-106%), and FEV(1)/FVC 0.78 (IQR, 0.72-0.82). The residual volume (RV) was 123% predicted (IQR, 106%-147%) with nearly all participants having normal total lung capacity, functional residual capacity, and diffusing capacity of carbon monoxide. Also, 1,051/1,720 (59%) had obstructive airways disease based on at least one of the following: FEV(1)/FVC, bronchodilator responsiveness, hyperreactivity, or elevated RV. After adjusting for age, gender, race, height and weight, and tobacco use, the decline in FEV(1) post-September 11, 2001, was significantly correlated with increased RV percent predicted (P < .0001), increased bronchodilator responsiveness (P < .0001), and increased hyperreactivity (P = .0056). CT scans demonstrated bronchial wall thickening that was significantly associated with the decline in FEV(1) post-September 11, 2001 (P = .024), increases in hyperreactivity (P < .0001), and increases in RV (P < .0001). Few had evidence for interstitial disease. Airways obstruction was the predominant physiologic finding underlying the reduction in lung function post-September 11, 2001, in FDNY WTC rescue workers presenting for pulmonary evaluation.

Asystole and increased serum myoglobin levels associated with ‘packing blackout’ in a competitive breath‐hold diver

Many competitive breath-hold divers use 'glossopharyngeal insufflation', also called 'lung packing', to overfill their lungs above normal total lung capacity. This increases intrathoracic pressure, decreases venous return, compromises cardiac pumping, and reduces arterial blood pressure, possibly resulting in a syncope breath-hold divers call 'packing blackout'. We report a case with a breath-hold diver who inadvertently experienced a packing blackout. During the incident, an electrocardiogram (ECG) and blood pressure were recorded, and blood samples for determinations of biomarkers of cardiac muscle perturbation (creatine kinase-MB isoenzyme (CK-MB), cardiac troponin-T (TnT), and myoglobin) were collected. The ECG revealed short periods of asystole during the period of 'packing blackout', simultaneous with pronounced reductions in systolic, diastolic, and pulse pressures. Serum myoglobin concentration was elevated 40 and 150 min after the incident, whereas there were no changes in CK-MB or TnT. The ultimate cause of syncope in this diver probably was a decrease in cerebral perfusion following glossopharyngeal insufflation. The asystolic periods recorded in this diver could possibly indicate that susceptible individuals may be put at risk of a serious cardiac incident if the lungs are excessively overinflated by glossopharyngeal insufflation. This concern is further substantiated by the observed increase in serum myoglobin concentration after the event.