Search

Introduction: Abnormality in distal lung function may occur in obesity due to reduction in resting lung volume; however, airway inflammation, vascular congestion and/or concomitant intrinsic airway disease may also be present. The goal of this study is to 1) describe the phenotype of lung function in obese subjects utilizing spirometry, plethysmography and oscillometry; and 2) evaluate residual abnormality when the effect of mass loading is removed by voluntary elevation of end expiratory lung volume (EELV) to predicted FRC. Methods: 100 non-smoking obese subjects without cardio-pulmonary disease and with normal airflow on spirometry underwent impulse oscillometry (IOS) at baseline and at the elevated EELV. Results: FRC and ERV were reduced (44±22, 62±14% predicted) with normal RV/TLC (29±9%). IOS demonstrated elevated resistance at 20 Hz (R20, 4.65±1.07 cmH2O/L/s); however, specific conductance was normal (0.14±0.04). Resistance at 5–20 Hz (R5−20, 1.86±1.11 cmH2O/L/s) and reactance at 5 Hz (X5, −2.70±1.44 cmH2O/L/s) were abnormal. During elevation of EELV, IOS abnormalities reversed to or towards normal. Residual abnormality in R5−20 was observed in some subjects despite elevation of EELV (1.16±0.8 cmH2O/L/s). R5−20 responded to bronchodilator at baseline but not during elevation of EELV. Conclusions: This study describes the phenotype of lung dysfunction in obesity as reduction in FRC with airway narrowing, distal respiratory dysfunction and bronchodilator responsiveness. When R5−20 normalized during voluntary inflation, mass loading was considered the predominant mechanism. In contrast, when residual abnormality in R5−20 was demonstrable despite return of EELV to predicted FRC, mechanisms for airway dysfunction in addition to mass loading could be invoked. [ABSTRACT FROM AUTHOR]

The article presents a retrospective study which characterized a physiologic phenotype of restrictive dysfunction due to airway injury of 54 persistently symptomatic subjects, following the World Trade Center (WTC) dust exposure. It also compares the physiologic phenotype of restrictive dysfunction with the phenotype of interstitial lung disease (ILD). It explains several measurements used in the study, including spirometry, plethysmography, and diffusing capacity of lung for carbon monoxide.

Mucopolysaccharidosis type IVA (MPS IVA) or Morquio syndrome is a multisystem disorder caused by galactosamine-6-sulfatase deficiency. Skeletal manifestations, including short stature, skeletal dysplasia, cervical instability, and joint destruction, are known to be associated with this condition. Due to the severity of these skeletal manifestations, the non-skeletal manifestations are frequently overlooked despite their significant contribution to disease progression and impact on quality of life. This review provides detailed information regarding the non-skeletal manifestations and suggests long-term assessment guidelines. The visual, auditory, digestive, cardiovascular, and respiratory systems are addressed and overall quality of life as measured by endurance and other functional abilities is discussed. Impairments such as corneal clouding, astigmatism, glaucoma, hearing loss, hernias, hepatomegaly, dental abnormalities, cardiac valve thickening and regurgitation, obstructive sleep apnea, tracheomalacia, restrictive and obstructive respiratory compromise, and muscular weakness are discussed. Increased awareness of these non-skeletal features is needed to improve patient care. [ABSTRACT FROM AUTHOR]

MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management. [ABSTRACT FROM AUTHOR]

Background. Exposure to World Trade Center (WTC) dust and fumes is associated with the onset of asthma-like respiratory symptoms in rescue and recovery workers and exposed community members. Eosinophilic inflammation with increased lung and peripheral eosinophils has been described in subpopulations with asthma. We hypothesized that persistent asthma-like symptoms in WTC-exposed individuals would be associated with systemic inflammation characterized by peripheral eosinophils. Methods. The WTC Environmental Health Center (WTC EHC) is a treatment program for local residents, local workers, and cleanup workers with presumed WTC-related symptoms. Patients undergo a standardized evaluation including questionnaires and complete blood count. Between September 2005 and March 2009, 2462 individuals enrolled in the program and were available for analysis. Individuals with preexisting respiratory symptoms or lung disease diagnoses prior to September 2001 and current or significant tobacco use were excluded, Results. One thousand five hundred and seventeen individuals met the inclusion criteria. Patients had a mean age of 47 years, were mostly female (51%), and had a diverse race/ethnicity. Respiratory symptoms that developed after WTC dust/fume exposure and remained persistent included dyspnea on exertion (68%), cough (57%), chest tightness (47%), and wheeze (33%). A larger percentage of patients with wheeze had elevated peripheral eosinophils compared with those without wheeze (21% vs. 13%, p < .0001). Individuals with elevated peripheral eosinophils were more likely to have airflow obstruction on spirometry (16% vs. 7%, p = .0003). Conclusion. Peripheral eosinophils were associated with wheeze and airflow obstruction in a diverse WTC-exposed population. These data suggest that eosinophils may participate in lung inflammation in this population with symptoms consistent with WTC-related asthma. [ABSTRACT FROM AUTHOR]

Objectives. We assessed associations between new-onset (post-September 11, 2001 [9/11]) lower respiratory symptoms reported on 2 surveys, administered 3 years apart, and acute and chronic 9/11-related exposures among New York City World Trade Center-area residents and workers enrolled in the World Trade Center Health Registry. Methods. World Trade Center-area residents and workers were categorized as case participants or control participants on the basis of lower respiratory symptoms reported in surveys administered 2 to 3 and 5 to 6 years after 9/11. We created composite exposure scales after principal components analyses of detailed exposure histories obtained during face-to-face interviews. We used multivariate logistic regression models to determine associations between lower respiratory symptoms and composite exposure scales. Results. Both acute and chronic exposures to the events of 9/11 were independently associated, often in a dose-dependent manner, with lower respiratory symptoms among individuals who lived and worked in the area of the World Trade Center. Conclusions. Study findings argue for detailed assessments of exposure during and after events in the future from which potentially toxic materials may be released and for rapid interventions to minimize exposures and screen for potential adverse health effects. [ABSTRACT FROM AUTHOR]

Introduction: Pompe disease is a rare, autosomal recessive disorder caused by deficiency of the glycogen-degrading lysosomal enzyme acid alpha-glucosidase. Late-onset Pompe disease is a multisystem condition, with a heterogeneous clinical presentation that mimics other neuromuscular disorders. Methods: Objective is to propose consensus-based treatment and management recommendations for late-onset Pompe disease. Methods: A systematic review of the literature by a panel of specialists with expertise in Pompe disease was undertaken. Conclusions: A multidisciplinary team should be involved to properly treat the pulmonary, neuromuscular, orthopedic, and gastrointestinal elements of late-onset Pompe disease. Presymptomatic patients with subtle objective signs of Pompe disease (and patients symptomatic at diagnosis) should begin treatment with enzyme replacement therapy (ERT) immediately; presymptomatic patients without symptoms or signs should be observed without use of ERT. After 1 year of ERT, patients' condition should be reevaluated to determine whether ERT should be continued. Muscle Nerve, 2012 [ABSTRACT FROM AUTHOR]

There is an increasing awareness of the role of distal airways in the pathophysiology of obstructive lung diseases including asthma and chronic obstructive pulmonary disease. We hypothesize that during induced bronchoconstriction: 1) disparity between distal and proximal airway reactivity may occur; and 2) changes in distal airway function may explain symptom onset in subjects with minimal FEV1 change. 185 subjects underwent methacholine challenge testing (MCT). In addition to spirometry, oscillometry was performed at baseline and after maximum dose of methacholine; 33/185 also underwent oscillometry after each dose. Oscillometric parameters included resistance at 5 and 20 Hz (R5, R20) and heterogeneity of distal airway mechanics assessed by frequency dependence of resistance 5--20 Hz (R5--20) and reactance area (AX). R5 varied widely during MCT (range -0.8 -- 11.3 cmH2O/L/s) and correlated poorly with change in FEV1 (r == 0.17). Changes in R5 reflected changes in both R20 and R5--20 (r == 0.59, p<0.05; r == 0.87, p<0.0001). However, R20 increased only 0.3 cmH2O/L/s, while R5--20 increased 0.7 cmH2O/L/s for every 1cmH2O/L/s change in R5, indicating predominant effect of distal airway mechanics. 9/33 subjects developed symptoms despite minimal FEV1 change (<5%%), while R5 increased 42%% due to increased distal airway heterogeneity. These data indicate disparate behavior of proximal airway resistance (FEV1 and R20) and distal airway heterogeneity (R5--20 and AX). Distal airway reactivity may be associated with methacholine-induced symptoms despite absence of change in FEV1. This study highlights the importance of disparity between proximal and distal airway behavior, which has implications in understanding pathophysiology of obstructive pulmonary diseases and their response to treatment. [ABSTRACT FROM AUTHOR]

People that the editor in chief would like to thank for help in reviewing articles are mentioned.

Rapid shallow breathing may occur at any time during spontaneous breathing trials (SBT), questioning the utility of a single determination of the rapid shallow breathing index (RSBI). We hypothesize that change in RSBI during SBT may more accurately predict successful extubation than a single determination. Prospective observational study. Seventy-two subjects were extubated. At 24 h, 63/72 remained extubated (Extubation Success), and 9 were re-intubated (Extubation Failure). Respiratory rate (RR), tidal volume (VT) and RSBI were measured every 30 min during 2-h T-piece SBT. Change in respiratory parameters was assessed as percent change from baseline. Initial RSBI was similar in Extubation Success and Extubation Failure groups (77.0 ± 4.8, 77.0 ± 4.8, p = ns). Nevertheless, RSBI tended to remain unchanged or decreased in the Extubation Success group; in contrast RSBI tended to increase in the Extubation Failure group because of either increased RR and/or decreased VT ( p < 0.001 for mean percent change RSBI over time), indicating worsening of the respiratory pattern. Quantitatively, only 7/63 subjects of the Extubation Success group demonstrated increased RSBI ≥20% at any time during the SBT. In contrast, in the Extubation Failure group, RSBI increased in all subjects during the SBT, and eight of nine subjects demonstrated an increase greater than 20%. Thus, with a 2-h SBT the optimal threshold was a 20% increase (sensitivity = 89%, specificity = 89%). Similar results were obtained at 30 min (threshold = 5% increase). Percent change of RSBI predicted successful extubation even when initial values were ≥105. Percent change of RSBI during an SBT is a better predictor of successful extubation than a single determination of RSBI. [ABSTRACT FROM AUTHOR]

Pulmonary function is impaired in untreated mucopolysaccharidosis type VI (MPS VI). Pulmonary function was studied in patients during long-term enzyme replacement therapy (ERT) with recombinant human arylsulfatase B (rhASB; rh N-acetylgalactosamine 4-sulfatase). Pulmonary function tests prior to and for up to 240 weeks of weekly infusions of rhASB at 1 mg/kg were completed in 56 patients during Phase 1/2, Phase 2, Phase 3 and Phase 3 Extension trials of rhASB and the Survey Study. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and, in a subset of patients, maximum voluntary ventilation (MVV), were analyzed as absolute volume in liters. FEV1 and FVC showed little change from baseline during the first 24 weeks of ERT, but after 96 weeks, these parameters increased over baseline by 11% and 17%, respectively. This positive trend compared with baseline continued beyond 96 weeks of treatment. Improvements from baseline in pulmonary function occurred along with gains in height in the younger group (5.5% change) and in the older patient group (2.4% change) at 96 weeks. Changes in MVV occurred earlier within 24 weeks of treatment to approximately 15% over baseline. Model results based on data from all trials showed significant improvements in the rate of change in pulmonary function during 96 weeks on ERT, whereas little or no improvement was observed for the same time period prior to ERT. Thus, analysis of mean percent change data and longitudinal modeling both indicate that long-term ERT resulted in improvement in pulmonary function in MPS VI patients. [ABSTRACT FROM AUTHOR]

People who the author would like to thank for their assistance in the creation of the journal "Respiration" are mentioned.

Distal airways disease causes significant morbidity yet remains insufficiently identified. We hypothesize that: (1) when spirometry is normal impulse oscillometry may provide information about mechanical properties of the distal airways in a manner comparable to dynamic compliance and (2) variation of breathing frequency will influence oscillometric measurements similar to effects of breathing frequency on dynamic compliance. Fifty-three symptomatic subjects with normal large airway function (spirometry) were studied; distal airway dysfunction was identified by presence of frequency dependence of compliance (FDC). Oscillometric parameters evaluated were resistance at 20 Hz (R20) and 5-20 Hz (R5 - 20), reactance at 5Hz (X5), and reactance area (AX). R20 correlated with airway resistance by esophageal manometry (r = 0.74, p< 0.001); X5 correlated with dynamic compliance at a respiratory rate of 60bpm (r = 0.61, p< 0.001); R5-20 and AX correlated with FDC (r = 0.48, p< 0.001; r = 0.53, p< 0.01). IOS indices were further evaluated at increased respiratory rate (RR40). Oscillometric parameters changed minimally at RR40 in normal subjects ΔR20 = 0.20 = 0.08 cmH2O/L/s, ΔR5-20 = 0.10 ± 0.03 cmH2O/L/s, Δ AX = 0.33 ± 0.19 cmH2O/L). However, in symptomatic subjects, while R20 increased minimallyat RR40 (Δ R20 = 0.37 ± 0.10 cmH2O/L/s), R5 - 20 and AX increased markedly (Δ R5 - 20 = 0.54 ± 0.06 cmH2O/L/s, Δ AX = 4.28 ± 0.67 cmH2O/L) and reversed post bronchodilator. IOS evaluates physiology of the distal airways in a manner comparable to dynamic compliance. Elevated respiratory rate influences oscillometric parameters and must be considered when interpreting oscillometric data. IOS provides a non-invasive tool for assessment of distal airway function when spirometry is normal, which can be applied to various clinical settings including early diagnosis of COPD (GOLD stage 0), asthma in clinical remission and occupational/ environmental irritant exposure. [ABSTRACT FROM AUTHOR]

The term OBESITY HYPOVENTILATION SYNDROME (OHS) refers to the combination of obesity and chronic hypercapnia that cannot be directly attributed to underlying cardiorespiratory disease. Despite a plethora of potential pathophysiological mechanisms for gas exchange and respiratory control abnormalities that have been described in the obese, the etiology of hypercapnia in OHS has been only partially elucidated. Of particular note, obesity and coincident hypercapnia are often associated with some form of sleep disordered breathing (apnea/hypopnea or sustained periods of hypoventilation). From a conceptual point of view, even transient reductions of ventilation from individual sleep disordered breathing events must produce acute hypercapnia during the period of low ventilation. What is less clear, however, is the link between these transient episodes of acute hypercapnia and the development of chronic sustained hypercapnia persisting into wakefulness. A unifying view of how this comes about is presented in the following review. In brief, our concept is that chronic sustained hypercapnia (as in obesity hypoventilation) occurs when the disorder of ventilation that produces acute hypercapnia interacts with inadequate compensation (both during sleep and during the periods of wakefulness); neither alone is sufficient to fully explain the final result. The following discussion will amplify on both the potential reasons for acute hypercapnia in the obese and on what is known about the failure of compensation that must occur in these subjects. [ABSTRACT FROM AUTHOR]

The article focuses on physiologist Eddy and coworkers who have earned appreciation for providing basis for observation of researchers in respiratory disorders including asthma and reactive airway dysfunction syndrome and lung disease of World Trade Center (WTC). Topics discussed include decrease in Forced vital capacity (FVC) shown by nonconstructive chronic bronchitis, impairment caused by interstitial lung disease and airway obstruction in chronic obstructive pulmonary disease.

Acute hypercapnia may develop during periodic breathing from an imbalance between abnormal ventilatory patterns during apnea and/or hypopnea and compensatory ventilatory response in the interevent periods. However, transition of this acute hypercapnia into chronic sustained hypercapnia during wakefulness remains unexplained. We hypothesized that respiratory-renal interactions would play a critical role in this transition. Because this transition cannot be readily addressed clinically, we modified a previously published model of whole-body CO2 kinetics by adding respiratory control and renal bicarbonate kinetics. We enforced a pattern of 8 h of periodic breathing (sleep) and 16 h of regular ventilation (wakefulness) repeated for 20 days. Interventions included varying the initial awake respiratory CO2 response and varying the rate of renal bicarbonate excretion within the physiological range. The results showed that acute hypercapnia during periodic breathing could transition into chronic sustained hypercapnia during wakefulness. Although acute hypercapnia could be attributed to periodic breathing alone, transition from acute to chronic hypercapnia required either slowing of renal bicarbonate kinetics, reduction of ventilatory CO2 responsiveness, or both. Thus the model showed that the interaction between the time constant for bicarbonate excretion and respiratory control results in both failure of bicarbonate concentration to fully normalize before the next period of sleep and persistence of hypercapnia through blunting of ventilatory drive. These respiratory-renal interactions create a cumulative effect over subsequent periods of sleep that eventually results in a self-perpetuating state of chronic hypercapnia. [ABSTRACT FROM AUTHOR]

Presents a list of individuals who received manuscripts and books for 'Lung' in 2000.

The destruction of the World Trade Center (WTC) on 11 September 2001 in New York City resulted in the massive release of pulverized dust and combustion products. The dust and smoke settled in the surrounding area, which encompassed a large residential community. We hypothesized that previously normal residents in the community surrounding the former WTC would have an increased incidence of persistent respiratory symptoms and abnormalities in screening spirometry. A hybrid cross-sectional and retrospective cohort study using a symptom-based questionnaire and onsite screening spirometry in residents in an exposed area and in a control area was performed 12 ± 4 months after the collapse. Surveys were analyzed from 2,812 residents. New-onset respiratory symptoms were described by 55.8% of residents in the exposed area, compared with 20.1% in the control area after the event. Persistent new-onset symptoms were identified in 26.4 versus 7.5% of residents in the exposed area versus control area, respectively. No differences in screening spirometry between the groups were detected. A small pilot study suggested the possibility of an increase in bronchial hyperresponsiveness in exposed participants with persistent symptoms. The data demonstrate an increased rate of new-onset and persistent respiratory health effects in residents near the former WTC compared with a control population. [ABSTRACT FROM AUTHOR]

Longitudinal modelling of lung function in Duchenne's muscular dystrophy is complicated by a mixture of both growth and decline in lung function within each subject, an unknown point of separation between these phases and significant heterogeneity between individual trajectories. Linear mixed effects models can be used, assuming a single changepoint for all cases; however, this assumption may be incorrect. The paper describes an extension of linear mixed effects modelling in which random changepoints are integrated into the model as parameters and estimated by using a stochastic EM algorithm. We find that use of this ‘mixture modelling’ approach improves the fit significantly. [ABSTRACT FROM AUTHOR]

The author argues against the use of oscillometry for screening airway disease. He maintains that the utilization of spirometry for measuring airway obstruction is clinically valuable because it helps in diagnosing asthma and chronic obstructive pulmonary disease and serves as an index of disease severity. He explains that forced oscillation technique may be helpful for diagnosing asthma and response to therapy for children with respiratory symptoms who cannot reliably perform spirometry. [ABSTRACT FROM AUTHOR]

A list of reviewers whose comments and criticisms ensure the quality of the papers published in the journal is presented.

The article presents an acknowledgement to the reviewers, including Scott K. Aberegg and Marina Aiello.

The authors present a rebuttal to an article that rejects the use of oscillometry for screening airway disease. The article shows that forced oscillation technique (FOT) does not provide the diagnostic benefits made possible by spirometry such as the diagnosis of chronic obstructive pulmonary disease and as an independent predictor of morbidity and disease progression. The authors cite that resistance to FOT can be referenced to the functional residual capacity as specific airway conductance. [ABSTRACT FROM AUTHOR]

A response from the authors of the article "Thrombocytopenia in critically ill patients receiving thromboprophylaxis: Frequency, risk factors, and outcomes," in the October 2013 issue is presented.

A response from the authors of the article "Lessons from the World Trade Center disaster: Airway disease presenting as restrictive dysfunction," in the July 2013 issue is presented.

A letter to the editor is presented in response to the article "Thrombocytopenia in critically ill patients receiving thromboprophylaxis: Frequency, risk factors, and outcomes," in the October 2013 issue, including a response from the authors of the article David R. Williamson and colleagues.

The article lists the reviewers for the 2007 issue of "Respiration" including Scott K. Aberegg, Henri Colt, and Matteo Sofia.

Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]