Background: The response to a bronchial challenge is usually assessed from the changes in the forced expiratory in 1 s (FEV 1 ). Yet this measurement is negatively affected by the thoracic gas compression. Aim: To examine the effects of thoracic gas compression on the dose-response curve to methacholine (MCh) in asthma. Methods: 28 male and 25 female asthmatic patients participated in the study. Methacholine challenge was performed in a flow-type body plethysmograph to compute simultaneously FEV 1 and compression-free FEV 1 (FEV 1 PLETH). The doses of MCh that caused a decrease in FEV 1 and FEV 1 PLETH by 20% of control were calculated by linear interpolation of the dose-response curve and transformed into natural logarithm. Results: On average, lnPD20FEV 1 was significantly less that lnPD20FEV 1 PLETH (5.49±0.94 vs. 5.74±1.00, p 1 and lnPD20FEV 1 PLETH was positively correlated with absolute TLC (r2=0.40) and height in cm (r2=0.27), and it was larger in males than in females (0.34 vs. 0.14, p Conclusions: Thoracic gas compression has a significant effect on airway responsiveness, which depends on absolute lung volume and, thus, anthropometric characteristics.

Background: Short-term temporal variability of respiratory impedance is increased in asthma. Aim: To examine whether airway smooth muscle unloading alters the pattern of bronchoconstrictor response as assessed by changes in inspiratory reactance (Xrs) and resistance (Rrs). Methods: 14 mild asthmatics and 9 healthy male subjects were studied at control conditions, during methacholine (MCh)-induced bronchoconstriction, after chest wall strapping and during MCh-induced bronchoconstriction with chest wall strapped. Rrs and Xrs were measured at 5 Hz by forced oscillation technique. Rrs and Xrs variability over 5-min periods were estimated from the interquartile range of frequency distribution (RrsIQR and XrsIQR, respectively). Results: The percent increments of XrsIQR with MCh, strapping and strapping plus MCh were larger than those of RrsIQR, though statistical significance was achieved only with the combination of strapping plus MCh (p Conclusions: Activation of unloaded airway smooth muscle causes greater instability in the airways contributing to the increase in Xrs than in those contributing to Rrs in both healthy and asthmatic subjects, suggesting occurrence of clustered bronchoconstriction.

We compared the rate of perceived exertion for respiratory (RPE,resp) and leg (RPE,legs) muscles, using a 10-point Borg scale, to their specific power outputs in 10 healthy male subjects during incremental cycle exercise at sea level (SL) and high altitude (HA, 4559 m). Respiratory power output was calculated from breath-by-breath esophageal pressure and chest wall volume changes. At HA ventilation was increased at any leg power output by ∼ 54%. However, for any given ventilation, breathing pattern was unchanged in terms of tidal volume, respiratory rate and operational volumes of the different chest wall compartments. RPE,resp scaled uniquely with total respiratory power output, irrespectively of SL or HA, while RPE,legs for any leg power output was exacerbated at HA. With increasing respective power outputs, the rate of change of RPE,resp exponentially decreased, while that of RPE,legs increased. We conclude that RPE,resp uniquely relates to respiratory power output, while RPE,legs varies depending on muscle metabolic conditions.

The history of the bronchodilator test dates back to the late 1950s when airway diseases were classified as reversible or irreversible depending on the response to bronchodilators 1, 2. The hope to differentiate asthma from chronic obstructive pulmonary disease (COPD) on this basis was such that the test soon gained popularity in clinical practice. Two large trials published in the mid 1980s, however, dimmed the original enthusiasm on such a test because no clear cut-off was found between asthmatic and COPD patients 3, 4. In addition, the response depended on several factors, such as definition and severity of airflow obstruction and spirometric parameter considered for the functional response to the dilator agent together with its relevant threshold of natural variability. Finally, the test was scarcely reproducible over time in the individual patients. Somehow, these two studies challenged the common notion of that time that airway reversibility was a typical and unique feature of bronchial asthma. After more than two decades of intensive study and a long series of negative and positive publications on this issue, bronchoreversibility testing is still largely used in clinical practice and deemed to guide the clinician through the diagnostic and follow-up process 5, 6. For instance, large increments in the forced expiratory volume in 1 s (FEV1) >400 mL after an acute dose of salbutamol support the diagnosis of asthma in patients with a history compatible with the disease 7, though prospective studies confirming the validity of such a threshold have never been published and the role of similar improvements in forced vital capacity (FVC) in this respect has not been documented. A positive response …

To the Editors: A few questions have been raised following the publication in 2005 of the joint American Thoracic Society (ATS)/European Respiratory Society (ERS) series of documents on standardising lung function testing and these are answered below. The following questions and answers pertain to the standardisation document for spirometry 1. ### Start of test criteria Should blows be rejected solely on the basis of a poor back extrapolated volume (EV)? #### Reply Usually. The forced vital capacity (FVC) may be usable, but the forced expiratory volume in 1 s (FEV1) is likely to be falsely high or low. #### Rationale The acceptability criteria for spirometry were designed to help technologists improve the subject’s technique in order to get the best and most reliable result. EV is important for determining that a fast start to the blow was achieved and this is crucial for getting the best values for FEV1 and peak expiratory flow (PEF). ### End of test criteria In the original document, there was an error in table 5. #### Reply In table 5, the within-manoeuvre criteria for a satisfactory completion of a blow should have read “Duration of ≥6 s (3 s for children) and a plateau in the volume–time curve, or if the subject cannot or should not continue to exhale.” The original table had “or” in twice, whereas the accompanying text was correct, as above. #### Rationale The end of test (EOT) criteria are applied in order to ensure that efforts are made to achieve the best estimate of FVC. When a subject cannot meet the plateau criterion (<25 mL exhaled in the previous second of the blow) this may be for reasons other than premature volitional cessation of the blow. For example, in some young subjects or patients with a rigid chest wall, it is chest wall limitation that suddenly causes exhalation to stop 2 and it is difficult for …

The aim of the present study was to determine whether the combination of low forced expiratory volume in 1 s (FEV(1))/vital capacity (VC) ratio with normal FEV(1) represents a physiological variant or a sign of early airflow obstruction. We studied 40 subjects presenting with low FEV(1)/VC, but FEV(1) within the range of normality predicted by European Respiratory Society reference equations, and 10 healthy controls. All subjects completed two questionnaires and underwent comprehensive pulmonary function testing, which included methacholine challenge and single-breath nitrogen wash-out. According to the questionnaires, the subjects were assigned to three groups, i.e. rhinitis (n = 8), bronchial asthma (n = 13) and chronic obstructive pulmonary disease (COPD; n = 12). Subjects with negative responses to questionnaires were assigned to an asymptomatic group (n = 7). Airway hyperresponsiveness was found in four subjects of the rhinitis group, all of the asthma group, and 10 of the COPD group; in the last two groups, it was associated with signs of increased airway closure and gas trapping. Bronchodilator response to salbutamol was positive in only a few individuals across groups. In the asymptomatic group, no significant functional changes were observed, possibly suggesting dysanaptic lung growth. In subjects with low FEV(1)/VC and normal FEV(1), questionnaires on respiratory symptoms together with additional pulmonary function tests may help to clarify the nature of this pattern of lung function.

To the Editors: In 1986, the American Thoracic Society (ATS) first suggested a fixed ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) <0.75 to define airflow obstruction 1. Subsequent ATS documents published in 1991 2 and 1995 3 generically defined airflow obstruction as a reduction of FEV1/FVC, without recommending any numerical cut-off point. By contrast, the European Respiratory Society (ERS) guidelines 4 suggested the diagnosis of airflow obstruction be based on a ratio of FEV1 to slow vital capacity (VC) <88 and <89% of predicted in males and females, respectively. These values were not arbitrarily chosen as they roughly correspond to the lower 95th percentiles of frequency distributions of a healthy population. More importantly, they are consistent with the well-known decrease of lung elastic recoil and, by inference, of forced expiratory flow with ageing. In 2001, the Global Initiative for …

Definitions et subdivisions du volume pulmonaire 17S48 Preparation du patient 17S49 Determination des subdivisions pulmonaires ........ 17S49 Mesure de la CRF par plethysmographie corporelle 17S50 Introduction et theorie 17S50 Materiel 17S50 Technique de mesure 17S50 Controle qualite 17S51 Calculs 17S52 Mesure de la CRF par rincage de l’azote 17S52 Introduction et theorie 17S52 Materiel 17S52 Technique de mesure 17S53 Controle qualite 17S53 Calculs 17S54 Mesure de la Crf par dilution de l’helium 17S54 Introduction et theorie 17S54 Materiel 17S54 Technique de mesure 17S55 Controle qualite 17S56 Calculs 17S56 Mesure des volumes pulmonaires par des techniques d’imagerie 17S56 Radiographies conventionnelles 17S57 Tomodensitometrie 17S57 Imagerie par resonance magnetique 17S57 Controverses et questions critiques 17S57 Valeurs de reference 17S58 Prevention des infections 17S58 Abreviations 17S58

Generalites 17S80 Spirometrie 17S81 Volumes pulmonaires 17S83 Capacite de diffusion du monoxyde de carbone 17S85 Les differents types d’anomalies respiratoires 17S86

[⇓][1] SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” Edited by V. Brusasco, R. Crapo and G. Viegi Number 3 in this Series [1]: #F7

Few studies have investigated the treatment and the outcomes of patients with catheter-related thrombosis (CRT).The RIETE registry (Registro Informatizado de Enfermedad TromboEmbólica [Computerized Registry of Patients with Venous Thromboembolism]) is a prospective international registry of consecutive patients with objectively confirmed venous thromboembolism (VTE). We analyzed the characteristics, treatment, and outcomes of patients with CRT.Of 558 patients with CRT, 45 (8%) presented with a pulmonary embolism (PE) concomitantly. More patients had central line-associated thrombosis compared with port systems, but catheter type did not influence the risk of presenting with a PE. Patients with only CRT were more often prescribed low-molecular-weight heparin for the duration of their anticoagulant treatment compared with patients presenting with concomitant PE. VTE recurrences and major bleeding events occurred frequently during treatment with anticoagulation (7 per 100 patient-years and 8.9 per 100 patient years, respectively). The rates of fatal PE recurrences (1.85 per 100 patient-years) and fatal bleeding (2.32 per 100 patient-years) were similar. Patients with an additional transient risk factor for VTE had the lowest risk for VTE recurrences (odds ratio [OR], 0.07; 90% confidence interval [CI], 0.01-0.45) compared with patients with CRT and no additional transient risk factors. PE at presentation increased the risk of recurrent thrombosis by 2.4 times. Renal insufficiency was also an independent predictor of recurrent thrombosis (OR, 3.93; 90% CI, 2.0-7.7). The odds of recurrent thrombosis was decreased by 77% in patients who received anticoagulation therapy for >90 days compared with patients with a shorter treatment (OR, 0.23; 90% CI, 0.1-0.56).Concomitant PE occurs less frequently in CRT than lower extremity deep venous thrombosis, but it is associated with a worse outcome. CRT occurs in high-risk patients, and duration of anticoagulation must be predicated on balancing these risks.

High-intensity focused ultrasound (HIFU) can achieve accurate and focused deep tissue ablation through an extracorporeal emission. Cardiac ablation using HIFU applied transthoracically must overcome potential interference from intervening thoracic structures. The aim of this study was to explore the efficacy and safety of septal ablation that was induced using transthoracic HIFU.Twenty-one canines were pretreated to improve acoustic transmission. Single ablations were induced by targeting transthoracic HIFU with acoustic power of 400 W for 3 sec at the middle and basal septum in eight canines. Extended ablations were performed to create larger lesions at the basal septum in eight more canines. The three-dimensional morphology of a basal septum lesion induced by a single ablation was analyzed. The temperature at the ablative targets was measured in the other five canines.The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The three-dimensional morphology of the lesions appeared approximately as ellipsoids with a flatter endocardial side. The peak temperature at a power of 400 W for 3 sec was 93.27 ± 2.54°C, and it remained >50°C for nearly 10 sec. No procedure-related complications were observed.Ultrasound-guided transthoracic HIFU has the potential to safely create small dot or large mass lesions in the septum without a thoracotomy or a catheter.

SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” Edited by V. Brusasco, R. Crapo and G. Viegi Number 5 in this Series This section is written to provide guidance in interpreting pulmonary function tests (PFTs) to medical directors of hospital-based laboratories that perform PFTs, and physicians who are responsible for interpreting the results of PFTs most commonly ordered for clinical purposes. Specifically, this section addresses the interpretation of spirometry, bronchodilator response, carbon monoxide diffusing capacity ( D L,CO) and lung volumes. The sources of variation in lung function testing and technical aspects of spirometry, lung volume measurements and D L,CO measurement have been considered in other documents published in this series of Task Force reports 1–4 and in the American Thoracic Society (ATS) interpretative strategies document 5. An interpretation begins with a review and comment on test quality. Tests that are less than optimal may still contain useful information, but interpreters should identify the problems and the direction and magnitude of the potential errors. Omitting the quality review and relying only on numerical results for clinical decision making is a common mistake, which is more easily made by those who are dependent upon computer interpretations. Once quality has been assured, the next steps involve a series of comparisons 6 that include comparisons of test results with reference values based on healthy subjects 5, comparisons with known disease or abnormal physiological patterns ( i.e. obstruction and restriction), and comparisons with self, a rather formal term for evaluating change in an individual patient. A final step in the lung function report is to answer the clinical question that prompted the test. Poor choices made during these preparatory steps increase the risk of misclassification, i.e. a falsely negative or falsely positive interpretation for a lung function abnormality or a change …

SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” Edited by V. Brusasco, R. Crapo and G. Viegi Number 1 in this Series ⇓In preparing the joint statements on lung function testing for the American Thoracic Society (ATS) and the European Respiratory Society (ERS), it was agreed by the working party that the format of the statements should be modified so that they were easier to use by both technical and clinical staff. This statement contains details about procedures that are common for many methods of lung function testing and, hence, are presented on their own. A list of abbreviations used in all the documents is also included as part of this statement. All terms and abbreviations used here are based on a report of the American College of Chest Physicians/ATS Joint Committee on Pulmonary Nomenclature 1. The metrology definitions agreed by the International Standards Organization (ISO) are recommended 2 and some important terms are defined as follows. Accuracy is the closeness of agreement between the result of a measurement and the conventional true value. Repeatability is the closeness of agreement between the results of successive measurements of the same item carried out, subject to all of the following conditions: same method, same observer, same instrument, same location, same condition of use, and repeated over a short space of time. In previous documents, the term reproducibility was used in this context, and this represents a change towards bringing this document in line with the ISO. Reproducibility is the closeness of agreement of the results of successive measurements of the same item where the individual measurements are carried out with changed conditions, such as: method of measurement, observer, instrument, location, conditions of use, and time. Thus, if a technician tests a subject several times, this is looking at the …

[⇓][1] SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” Edited by V. Brusasco, R. Crapo and G. Viegi Number 2 in this Series [1]: #F13

To the Editors: “The devil's in the details” of the new American Thoracic Society (ATS)/European Respiratory Society (ERS) document regarding the interpretation of pulmonary function test (PFT) results 1. As a member of the Task Force, I was happy for the opportunity to help standardise the way in which clinically important PFTs are performed and interpreted. Unfortunately, the group spent almost all of the 3 yrs reaching an agreement (or compromise) on the mechanics of making accurate spirometry, diffusing capacity of the lung for carbon monoxide and lung volume measurements, but left inadequate time to thoroughly discuss the more important but controversial aspects of …

To the Editors: Pellegrino et al . 1 now define obstructive ventilatory defect not only on the basis of a low forced expiratory volume in one second (FEV1)/vital capacity (VC) ratio but also as a particular pattern with a normal FEV1/VC ratio. Although they write that “the definition of an obstructive pulmonary defect given in the present document is consistent with the 1991 American Thoracic Society 2 statement of interpretation,” a definition of an obstructive defect characterised by a normal FEV1/VC ratio cannot be found in this latter document. Incidentally, this pattern was described several years ago and called “small airways obstructive syndrome”. It is characterised by a normal total lung capacity (TLC) and …