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Background and objective During forced expiration, alveolar pressure (PALV) increases and intrathoracic gas is compressed. Thus, 1-s forced expiratory volume measured by spirometry (FEV1-sp) is smaller than 1-s forced expiratory volume measured by plethysmography (FEV1-pl). Thoracic gas compression volume (TGCV) depends on the amount of gas within the lung when expiratory flow limitation occurs in the airways. We therefore tested the hypothesis that bronchoconstrictor and bronchodilator responses using FEV1-sp are biased by height and gender, which are major determinants of lung volume. Methods We studied 54 asthmatics during methacholine challenge and 55 subjects with airway obstruction (FEV1-sp increase >200 mL and >12% after salbutamol) measuring at the same time FEV1-sp or FEV1-pl. Results During methacholine challenge, TGCV increased more in males than females, correlated with PALV, total lung capacity (TLC) and height, and the provocative dose was lower using FEV1-sp than FEV1-pl. With salbutamol, FEV1-pl increased

Chronic rhinosinusitis (CRS) is a disease related to the nose and the paranasal sinus as defined by the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) criteria. The criteria include subjective symptoms, such as nasal obstruction, and objective findings by endoscopy. Acoustic rhinometry (AR) is an objective method to determine nasal cavity geometry. The technique is based on a sound pulse reflection analysis in the nasal cavity and determines cross-sectional areas as a function of distance as well as volume. AR measurements in persons recruited from the general population, with and without CRS based on the clinical EPOS criteria, were investigated. As part of a trans-European study, 362 persons, comprising 91 persons with CRS and 271 persons without CRS, were examined by an otolaryngologist including rhinoscopy. Minimum cross-sectional area, distance to minimum cross-sectional area, and volume in the nasal cavity were measured by acoustic rhinometry and all participants underwent Peak Nasal Inspiratory Flow (PNIF) and allergy test. A difference in AR was found before and after decongestion, but no difference was seen between CRS patients and controls. Positive correlation between AR and PNIF was found and AR was capable of identifying mucosal oedema and septum deviation visualised by rhinoscopy. In conclusion, AR, as a single instrument, was not capable of discriminating persons with CRS from persons without CRS in the general population. However, AR correlates well with PNIF and was capable of identifying septum deviation and mucosal oedema.

Spirometry testing is the most widely practiced, most common and adaptable of all lung function tests and spirometers are used as a key instrument in the diagnosis of patients with respiratory disease [1]. As a leading cause of death worldwide responsible for some 9.4 million deaths [2], and further increases predicted by 2020, the management of lung disease becomes even more dependent on spirometry testing. Yet evidence of widespread under-diagnosis [3] and, as a consequence, reduced quality of life and premature death [4] present cause for concern. The grim reality evident in the presented studies highlights a real lack of training [5], under-utilisation of spirometers [6] and diagnosis based on inaccurate results [7]. It is reported that chronic obstructive pulmonary disease (COPD), the most prevalent of the lung diseases, is under-diagnosed in 75% of cases [3]. The outcome of delayed diagnosis deters effective management and treatment, which ultimately aims to relieve symptoms, prevent disease progression, improve health status and prevent premature death [4]. While educational modalities were introduced at a national level to train spirometry practice in some European countries, a survey carried out by the European Respiratory Society (ERS) in 2008 confirms that no formal training in, assessment of, or qualification in spirometry takes place in many other countries. Using the HERMES project framework (Harmonised Education of Respiratory Medicine in European Specialties), a new Spirometry initiative aspires to train and qualify healthcare professionals best able to deliver high-quality spirometry. The potential benefits of standardised educational documents and training in the practice of spirometry are real and significant, strengthening patient care and improving quality of life for respiratory disease patients. Begun in 2005, the value of the HERMES initiative is that it …

Nasal patency shows spontaneous variations but is influenced by a number of factors like exercise and allergic conditions. Nasal histamine challenge has been used to define nasal hypersensitivity. We have applied acoustic rhinometry as a new objective method to study the spontaneous variations of the nasal mucosa and its response to histamine challenge in 12 nonallergic subjects and 12 subjects with nasal allergy to pollen, but out of the pollen season. Measurements of the minimum cross-sectional area and the volume of the nasal cavities were done every 15 min for 6 h. More pronounced spontaneous variations, defined by the coefficient of variation of the measurements, were encountered in the allergic than in the nonallergic subjects, especially with regard to the minimum cross-sectional areas in the nasal cavities (P

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

Udgivelsesdato: 2007-Mar

CONCLUSION: By consulting an ENT-doctor, patients with chronic rhinosinusitis (CRS), in the general population, receive disease information and adjustment of treatment which can improve disease-specific Quality-of-Life and may improve objective measurements.OBJECTIVES: This study aims to follow persons with clinical diagnosed CRS from the general population, to evaluate their benefit from consultation with an ENT-doctor in terms of severity of symptoms and Quality-of-Life.METHODS: As part of a trans-European study, selected respondents to a survey questionnaire were invited for a clinical visit. Based on the European Position Paper on Rhinosinusitis and Nasal Polyps, persons were diagnosed with CRS and followed for 2 years. Quality-of-Life was measured using the Sino Nasal Outcome Test 22 and European Quality-of-Life - 5 Dimensions. Clinical examination included rhinoscopy, acoustic rhinometry, peak nasal inspiratory flow, smell test, and skin prick test.RESULTS: Out of 91 persons with CRS, only 42% had previously consulted an ENT-doctor, and 51% were in current treatment for CRS. Most patients were advised medical treatment and 20% underwent surgery. Disease-specific Quality-of-Life, peak nasal inspiratory flow, olfactory function, and the nasal volume significantly increased over the 2-year period.

The purpose of the study was to measure nasal passageway dimensions in guinea pigs and rats by use of acoustic rhinometry (AR) and by a previously described fluid-displacement method (FDM) (Straszek SP, Taagehoej F, Graff S, and Pedersen OF. J Appl Physiol 95: 635–642, 2003) to investigate the potential of AR in pharmacological research with these animals. We measured the area-distance relationships by AR of nasal cavities postmortem in five guinea pigs (Duncan Hartley, 400 g) and five rats (Wistar, 250 g) by using custom-made equipment scaled for the purpose. Nosepieces were made from plastic pipette tips and either inserted into or glued onto the nostrils. We used liquid perfluorocarbon in the fluid-displacement study, and it was carried out subsequent to the acoustic measurements. We found for guinea pigs that AR measured a mean volume of 98 mm3 (95–100 mm3) (mean and 95% confidence interval) of the first 2 cm of the cavity. FDM measured a mean volume of 146 mm3 (117–175 mm3), meaning that AR only measured 70% (50–90) of the volume by FDM. For rats, the volume from 0 to 2 cm was 58 mm3 (55–61 mm3) by AR and 73 mm3 (60–87 mm3) by FDM, resulting in AR only measuring 83% (66–100%) of volume by FDM (see Table 2 ). We conclude that absolute nasal cavity dimensions are underestimated by AR in guinea pigs and rats. This does not preclude that relative changes may be correctly measured. In vivo trials with AR using rats have not yet been published. The FDM is possibly the most accurate alternative to AR for measurements of the nasal cavity geometry in small laboratory animals, but it can only be used postmortem.

An increasing number of studies have used acoustic rhinometry (AR) for study of pharmacological interventions on nasal cavity dimensions in dogs and cats, but there have been no attempts to validate AR in these species. This is done in the present study. We compared area-distance relationships of nasal cavities from five decapitated dogs (3.5–41 kg) and cats (3.8–6 kg). AR was compared with magnetic resonance (MR) imaging and a fluid-displacement method (FDM) using perfluorocarbon. AR measured 88% (98–79%) (mean and 95% confidence interval) of nasal cavity volume in dogs determined by FDM and 71% (83–59%) in cats. AR markedly underestimated nasal cavity dimensions when minimum areas were below 0.1 cm2 in dogs and 0.05 cm2 in cats. AR underestimation increased with the severity of the constriction and with distance. Cross-sectional areas in the deeper parts of the cavity measured 76% (99–54%) of FDM in dogs and 52% (66–39%) in cats. AR agreed well with MR, especially in the deeper part of the cavity. MR images showed that the nasal cavities had a very complex structure not expected to be reproduced by AR. MR could not be considered a “gold standard” because definition of the cross-sectional area of the lumen depended critically on subjective choices. FDM produced repeatable measurements and possibly offers the most adequate reference in future evaluation of AR. AR underestimated what we believed were the most correct cross-sectional areas determined by FDM, especially in the deeper part of the dog and cat nasal cavities. Despite these difficulties, AR has been shown to be useful to describe qualitative changes in cross-sectional area.

Background The goal of this study was to evaluate the relationship between feline nasal cavity geometry determined in vivo by acoustic rhinometry (ARinvivo) and by nasal cavity casts. Cast cross-sectional areas were measured by acoustic rhinometry (ARcast), a fluid-displacement method (FDM), and slicing. A volume comparison between ARinvivo and ARcast was studied in cats with varying degrees of nasal obstruction after application of phenylpropanolamine, saline, or compound 48/80. Method After measurements of ARinvivo, impression material was injected into the nasal cavity to produce casts. Subsequently, the cross-sectional areas of the nasal impressions were measured by ARcast and FDM using ethanol. All casts were weighed to determine exact volume. Six casts also were sliced into segments of equal thickness for determination of cross-sectional area. Results Cast volume determined by ARcast was consistent with results obtained using FDM and weight. Volumes of the first 3 cm determined by ARinvivo ranged between 78 ± 9% of cast volumes determined by ARcast for decongested cavities and 16 ± 15% for congested cavities. Conclusion ARinvivo does not reflect cast geometry, probably because of (1) underestimation by AR because of methodological problems caused by the cavity geometry, (2) deformation of compliant structures within the nasal passageways resulting from the casting procedure, and/or (3) the casting material reaches parts of the nasal cavity not accessible to sound, e.g., sinuses or recesses. Nevertheless, this study does not preclude the use of AR as a sensitive method suited to evaluate relative changes in nasal volume caused by experimental challenges of the nasal mucosa. Compared with ARinvivo, casts still may be of use but it is less sensitive to measure relative changes after experimental challenge.

Objectives: A cross sectional study of 54 furniture factories and three control factories was conducted to investigate the relation between subjective and objective nasal obstruction and exposure to wood dust. Methods: Acoustic rhinometry was performed on 161 woodworkers and 19 controls. For each person, four measuring rounds were performed: before work, after 4 hours of work, and after 7 hours of work before and after decongestion. Before the first and third measuring round, each person rated the current feeling of nasal obstruction in the left and right nostril separately, using a visual analogue scale. Personal passive dust measurements were performed on 140 woodworkers. Results: The mean (SD) of equivalent inhalable dust was relatively low, 1.17 (0.62) mg/m3, range 0.17–3.44 mg/m3. The exposure was divided into four levels: controls, low exposure, medium exposure, and high exposure. For the two highest concentrations of exposure, a significant increase in congestion—decreased nasal cavity volume and cross sectional areas—was found after 4 and 7 hours of work, compared with before work. Multivariate linear regression analysis showed positive correlations between concentration of dust and change in mucosal swelling. A significant increase in self rated nasal obstruction was found after work compared with before work for the two highest exposure groups. No correlation between objective nasal variables and self rated nasal obstruction was found. Conclusion: Exposure to wood dust was related in a dose dependent manner to acute nasal obstruction measured by acoustic rhinometry and self reported obstruction, but no correlation was found between measured and self reported obstruction.

We evaluated which equations best predicted the lung function of a cohort of nonagenarians based on which best accounted for subsequent survival.In 1998, we measured lung function, grip strength and dementia score (Mini Mental State Examination (MMSE)) in a population-based sample of 2262 Danes born in 1905. Mortality was registered to 2011 when only five (0.2%) subjects were alive. In half the cohort, we recorded forced expiratory volume in 1 s (FEV1).Complete data were available in 592 subjects with results expressed as standardised residuals (SR) using various prediction equations. Cox proportional hazard regression found lower FEV1SR was a predictor of mortality having controlled for MMSE, grip strength and sex. The US National Health and Nutrition Examination Survey (NHANES) III (1999) equations gave a better spread of median survival by FEV1SR quartile: 3.94, 3.65, 3.51 and 2.61 years with a hazard ratio for death of 1, 1.16, 1.32 and 1.60 respectively, compared with equations derived with the inclusion of elderly subjects.We conclude that extrapolating from NHANES III equations to predict lung function in nonagenarians gave better survival predictions from spirometry than when employing equations derived using very elderly subjects with possible selection bias. These findings can help inform how future lung function equations for the elderly are derived. We evaluated which equations best predicted the lung function of a cohort of nonagenarians based on which best accounted for subsequent survival.In 1998, we measured lung function, grip strength and dementia score (Mini Mental State Examination (MMSE)) in a population-based sample of 2262 Danes born in 1905. Mortality was registered to 2011 when only five (0.2%) subjects were alive. In half the cohort, we recorded forced expiratory volume in 1 s (FEV1).Complete data were available in 592 subjects with results expressed as standardised residuals (SR) using various prediction equations. Cox proportional hazard regression found lower FEV1SR was a predictor of mortality having controlled for MMSE, grip strength and sex. The US National Health and Nutrition Examination Survey (NHANES) III (1999) equations gave a better spread of median survival by FEV1SR quartile: 3.94, 3.65, 3.51 and 2.61 years with a hazard ratio for death of 1, 1.16, 1.32 and 1.60 respectively, compared with equations derived with the inclusion of elderly subjects.We conclude that extrapolating from NHANES III equations to predict lung function in nonagenarians gave better survival predictions from spirometry than when employing equations derived using very elderly subjects with possible selection bias. These findings can help inform how future lung function equations for the elderly are derived.

During forced expiration, alveolar pressure (PALV ) increases and intrathoracic gas is compressed. Thus, 1-s forced expiratory volume measured by spirometry (FEV1-sp ) is smaller than 1-s forced expiratory volume measured by plethysmography (FEV1-pl ). Thoracic gas compression volume (TGCV) depends on the amount of gas within the lung when expiratory flow limitation occurs in the airways. We therefore tested the hypothesis that bronchoconstrictor and bronchodilator responses using FEV1-sp are biased by height and gender, which are major determinants of lung volume.We studied 54 asthmatics during methacholine challenge and 55 subjects with airway obstruction (FEV1-sp increase200 mL and12% after salbutamol) measuring at the same time FEV1-sp or FEV1-pl .During methacholine challenge, TGCV increased more in males than females, correlated with PALV , total lung capacity (TLC) and height, and the provocative dose was lower using FEV1-sp than FEV1-pl . With salbutamol, FEV1-pl increased200 mL and12% in 28 subjects, predominantly tall males, with larger TLC, TGCV and PALV .Bronchoconstrictor and bronchodilator responses are overestimated by standard spirometry in subjects with larger lungs because of TGCV.

Lung function covers several physiological measures of respiratory function and structure. Ventilation, distribution of ventilation, gas diffusion, and lung perfusion are the most common terms.

We have measured bronchial responsiveness (BR) to histamine on two occasions between 5 and 24 h apart, to determine if conventional and new indices of BR are repeatable. A random sample of 29 healthy male subjects with a mean age of 19 (SD 3.44) years from a larger study repeated a Yan method test of BR, recording both partial and maximal expiratory flow volume (PEFV and MEFV) curves. From the MEFV curves log-dose slopes (LDS) for forced expiratory volume in 1 sec (FEV1), forced expiratory flow between 25% and 75% of forced vital capacity (FVC) (FEF(25-75%)), mean expiratory flow at 30% and 40% of FVC (MEF30, MEF40), and the first moment of the spirogram (alpha1) truncated at 75% and 90% of FVC were calculated, as well as the provocative dose that induces a 20% fall in FEV1 (PD20FEV1). From the PEFV curves LDS for alpha(1)75% and alpha(1)90%, and MEF30 and MEF40 were derived. Apart from MEF30 and alpha(1)90% the second test was significantly lower (P

Nonselective adrenergic α-agonists such as phenylpropanolamine and d-pseudoephedrine are widely used as decongestants to treat nasal congestion associated with a variety of nasal diseases. Although the activity of these drugs is well established in clinical studies, a direct comparison of their nasal decongestant effect as determined by changes in nasal cavity dimensions and nasal architecture has not been studied. Using acoustic rhinometry, we evaluated the effects of these drugs on nasal cavity volume, minimum cross-sectional area (Amin), and the distance from the nosepiece to the Amin (Dmin) in a feline, pharmacological model of nasal congestion. Administration of topical compound 48/80 (1%), a mast cell histamine liberator, into the left nasal passageway decreased nasal volume by 66%, reduced Amin by 51%, and increased Dmin by 116%. The congestive responses to compound 48/80 (1%) were reproducible through six weeks. In a subset of cats, the nasal cavity volume effect of repetitive exposure to compound 48/80, given once every two weeks for six weeks, was not different from the nasal responses after the initial exposure to compound 48/80. Pretreatment with oral phenylpropanolamine (10 mg/kg) or oral d-pseudoephedrine (10 mg/kg) attenuated the nasal effects of compound 48/80, but were associated with a pronounced increase in systolic blood pressure of +51 and +82 mmHg, respectively. A similar decongestant profile was observed with phenylpropanolamine (1%) and d-pseudoephedrine (1%) when given topically. Topical phenylpropanolamine (1%) and d-pseudoephedrine (1%) 45 minutes after dosing increased blood pressure +44 and +17 mmHg, respectively, over control animals. We conclude that oral and topical phenylpropanolamine and d-pseudoephedrine display equieffective nasal decongestant activity and produce similar cardiovascular profiles characterized by significant increases in blood pressure.

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 (

Chronic inflammation and extracellular remodeling of the airway wall characterize asthma. The purpose of this study was to examine whether these features cause a change in airway mechanical properties. We examined 14 healthy and 10 young adults with long-lasting asthma, the latter treated with inhaled bronchodilators and corticosteroids. To obtain area-versus-transmural pressure (A-Ptm) curves during forced expiration (Pedersen, O. F., et al. J. Appl. Physiol. 1982;52:357-369), we used an esophageal balloon and a Pitot static probe positioned at five locations between the right lower lobe and midtrachea. Cross-sectional area (A), airway compliance (Caw = dA/dPtm), and specific airway compliance (sCaw = Caw/A) were obtained from the A-Ptm curves. Results showed that: (1) A was larger in males than in females; (2) Caw and sCaw decreased with a more downstream position; and (3) Caw and sCaw were significantly lower in the patients with asthma, with the differences between the asthmatic patients and the healthy subjects becoming smaller toward the trachea. The lower Caw and sCaw in the patients with long-lasting asthma support the concept that chronic inflammation and remodeling of the airway wall may result in stiffer dynamic elastic properties of the asthmatic airway.

The aim of this study was to assess the cytokine response after nasal exposure to organic dusts. In a double blinded, crossover study five garbage workers with occupational airway symptoms and five healthy garbage workers were intranasally exposed to endotoxin (lipopolysaccharide LPS), beta-1,3-D-glucan (GLU), Aspergillus sp., compost or the saline dilute for 15 min. Nasal cavity volume and nasal lavage (NAL) were performed at baseline and 3, 6, 11 h postexposure. NAL was analysed with differential cell counts, cysteinyl-leukotrienes, tumour necrosis factor alpha, interleukin (IL)-1beta, IL-6 and IL-8. A whole blood assay on cytokine-release was performed with LPS and GLU. NAL cytokines neutrophils, lymphocytes and albumin increased significantly at 6 h after LPS exposure. GLU induced an increase in albumin and a slight increase in IL-1beta 6-11 h post exposure. In the WBA a significant increase in all cytokines after exposure to LPS as well as GLU was found. Significantly more cells were seen in NAL of the control group 6 h post LPS exposure. In conclusion lipopolysaccharide is the most potent inducer of inflammation in the nasal mucosa whereas compost and beta-1,3-D-glucan only induce minor changes. This reaction to lipopolysaccharide is attenuated in workers with occupational airway symptoms. In whole blood assay, however, beta-1,3-D-glucan also induces cytokine release, indicating a different protective effect of the nasal mucosa towards lipopolysaccharide and beta-1,3-D-glucan.

Nasal obstruction is one of the major symptoms of allergic rhinitis. In the study of the mechanism of nasal obstruction, experiments on animal are useful. In adult humans, acoustic rhinometry has been used to evaluate nasal obstruction by determining nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. We modified the equipment used on humans to assess dimensions of nasal airway geometry of small experimental animals. The purpose of this study was to investigate the accuracy of measurement of the modified acoustic rhinometry applied to small experimental animals using nasal cavity models and guinea pigs. Measurement of the nasal cavity models (made of cylindrical silicone tubes) showed that the acoustic rhinometry estimated 85.5% of actual area and 79.0% of actual volume. In guinea pigs, nasal cavity volume determined by the acoustic rhinometry was 73.7 ± 20.0% of actual volume. The actual volume was estimated by impression material instilled into the nasal cavity of the animals (IM volume), and volume determined by acoustic rhinometry significantly correlated with IM volume. Furthermore, there was a significant negative correlation between the volume and nasal airway resistance in guinea pigs. Measurement of the nasal airway resistance is the method frequently used in the evaluation of the nasal obstruction in guinea pigs. These results suggest that acoustic rhinometry is useful in evaluating nasal obstruction in small experimental animals.

Pedersen, O. F., H. J. L. Brackel, J. M. Bogaard, and K. F. Kerrebijn. Wave-speed-determined flow limitation at peak flow in normal and asthmatic subjects. J. Appl. Physiol. 83(5): 1721–1732, 1997.—The purpose of this study was to examine whether peak expiratory flow is determined by the wave-speed flow-limiting mechanism. We examined 17 healthy subjects and 11 subjects with stable asthma, the latter treated with inhaled bronchodilators and corticosteroids. We used an esophageal balloon and a Pitot-static probe positioned at five locations between the right lower lobe and midtrachea to obtain dynamic area-transmural pressure ( A-Ptm) curves as described (O. F. Pedersen, B. Thiessen, and S. Lyager. J. Appl. Physiol. 52: 357–369, 1982). From these curves we obtained cross-sectional area ( A) and airway compliance (Caw = d A/dPtm) at PEF, calculated flow at wave speed {V˙ws = A[ A/(Caw∗ρ)0.5], where ρ is density} and speed index is (SI =V˙/V˙ws). In 13 of 15 healthy and in 4 of 10 asthmatic subjects, who could produce satisfactory curves, SI at PEF was >0.9 at one or more measured positions. Alveolar pressure continued to increase after PEF was achieved, suggesting flow limitation somewhere in the airway in all of these subjects. We conclude that wave speed is reached in central airways at PEF in most subjects, but it cannot be excluded that wave speed is also reached in more peripheral airways.

Pedersen, O. F., T. F. Pedersen, and M. R. Miller. Gas compression in lungs decreases peak expiratory flow depending on resistance of peak flowmeter. J. Appl. Physiol. 83(5): 1517–1521, 1997.—It has recently been shown (O. F. Pedersen T. R. Rasmussen, Ø. Omland, T. Sigsgaard, P. H. Quanjer, and M. R. Miller. Eur. Respir. J. 9: 828–833, 1996) that the added resistance of a mini-Wright peak flowmeter decreases peak expiratory flow (PEF) by ∼8% compared with PEF measured by a pneumotachograph. To explore the reason for this, 10 healthy men (mean age 43 yr, range 33–58 yr) were examined in a body plethysmograph with facilities to measure mouth flow vs. expired volume as well as the change in thoracic gas volume (Vb) and alveolar pressure (Pa). The subjects performed forced vital capacity maneuvers through orifices of different sizes and also a mini-Wright peak flowmeter. PEF with the meter and other added resistances were achieved when flow reached the perimeter of the flow-Vb curves. The mini-Wright PEF meter decreased PEF from 11.4 ± 1.5 to 10.3 ± 1.4 (SD) l/s ( P < 0.001), Pa increased from 6.7 ± 1.9 to 9.3 ± 2.7 kPa ( P < 0.001), an increase equal to the pressure drop across the meter, and caused Vb at PEF to decrease by 0.24 ± 0.09 liter ( P < 0.001). We conclude that PEF obtained with an added resistance like a mini-Wright PEF meter is a wave-speed-determined maximal flow, but the added resistance causes gas compression because of increased Pa at PEF. Therefore, Vb at PEF and, accordingly, PEF decrease.

The effect of macrophyte growth on microbenthicphotosynthetic activity was studied in two largeenclosures situated in a shallow, eutrophic lake.Macrophytes were allowed to develop stands of 100%coverage in one enclosure whereas they were harvestedat emergence in the other. Although less than 10% ofthe incident light reached the benthic microphytesbelow the macrophytes at mid-summer, when themacrophytes reached their maximum coverage, theseasonal productivity (April–October) of themicrobenthic community was still 355 g C m−2corresponding to 65% of the productivity in theenclosure without macrophytes. Although the lightattenuation by the macrophytes had a strong negativeeffect on microbenthic photosynthesis, the negativeeffect was partly balanced by increased watertransparency caused by increased grazing on thephytoplankton, and the shelter provided by the plantsalso resulted in less resuspension. Analysis withmicrosensors for oxygen and scalar irradiance showedthat the capacity for photosynthesis was evenlydistributed throughout the uppermost 3 mm of thesediment and in the approximately 3-mm flocculent layercovering the sediment. Microbenthic photosynthesisseemed primarily limited by light. The microsensoranalysis also demonstrated how conventional oxygenexchange experiments underestimate the truephotosynthetic rates and indicated that more realisticrates might be obtained by measuring oxygen exchangeif the exchange is facilitated by vigorousstirring.

BACKGROUND: A study was undertaken to test the long term performance of a small hand held spirometer for self-administered serial spirometric testing. METHODS: Thirty turbine pocket spirometers (MicroMedical DiaryCard) were used in a clinical trial on 22 emphysematous patients with severe alpha 1-antitrypsin deficiency. The spirometers were able to store the date, time, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), and flow-volume loop for each blow. Every four weeks when the patients came for alpha 1-antitrypsin infusions the performance of their spirometer was checked before and after retrieval of the data from the spirometer. Calibration checks were threefold and included volume calibration with a 1.0 litre and 3.0 litre syringe, and flow calibration with a decompression calibrator. RESULTS: After two years of study the mean number of spirometric recordings performed per spirometer was 693 (range 237-1178), and the mean number of calibration checks was 33 (range 2-57). The coefficient of variation of the calibration signal was 1-2% for syringes and 0.5-1% for the decompression calibrator. The bearings of one turbine exhibited excessive friction after 17 months. None of the other 29 instruments showed drift, and a general drift of all spirometers towards larger or smaller readings could not be shown. However, unforeseen problems in the stability of the calibrating devices were observed. CONCLUSIONS: The small hand held turbine spirometers are suitable for long term patient-administered serial spirometric testing. The two year durability is acceptable and the long term reproducibility excellent.

Acoustic reflections have been used in adult humans to determine nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril (J. Appl. Physiol., 66:295–303, 1989). In order to measure nasal cavity dimensions in guinea pigs, we modified equipment for use in humans by decreasing sound tube dimensions, increasing sampling frequency, and applying a special nosepiece. We measured 5 guinea pigs (Duncan Hartley strain, 500 g) on two days, before and after instillation of epinephrine and histamine in one nostril. In the control measurements, the minimum cross-sectional area of a nasal cavity was 1.1 mm2 (SD = 0.3 mm2), and the volume from the nostril to 20 mm into the nasal cavity was 60 mm3 (SD = 19 mm3). There was a tendency (P < 0.10) for epinephrine to increase minimum cross-sectional area on the treated side and volumes on both sides. Histamine decreased volume on both sides (P < 0.05), but not uniformly between animals. Measurements in a tube with 2 mm internal diameter (area 3.1 mm2) underestimated true area by approximately 30%. The method, therefore, at its present state of development, measures changes in dimensions rather than absolute values. It is concluded that the acoustic reflections technique may be a useful alternative to other, more invasive methods to assess nasal cavity dimensions in guinea pigs, but further studies are necessary to improve and validate the method.

The recommendations in this 1993 update do not differ materially from those in the previous report of the European Community for Steel and Coal [1]. However, the list of abbreviations has been extended with respect to the items covered; in addition the European Community has expanded since the previous report, and the report has accordingly been updated to cover the languages spoken in each of the member states. ### 2.1 Symbols for quantities Symbols are used to designate specific quantities, including basic quantities ( e.g. volume, time, pressure, amount of chemical substance) and derived quantities ( e.g. volume by unit time). Letters from the Latin or Greek alphabet are commonly employed as symbols, either roman type as in the USA or italics as recommended by the European Society for Clinical Respiratory Physiology [2] and adopted in the 1983 report of the ECSC. As the number of letters available is limited, inevitably one symbol may be used to designate more than one quantity ( e.g. concentration of chemical substance and compliance). Symbols for …

Dear colleagues, members of GOLD committee, This letter arises from discussions and correspondence between colleagues involved in respiratory research or the diagnosis and treatment of lung diseases, as well as from a review of the literature on chronic obstructive pulmonary disease (COPD). As discussed below, it is written in the hope that we can persuade members of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) committee to vote to change the method by which mild airway obstruction is defined by the GOLD guidelines. We very much welcome the continued efforts of the GOLD group to stimulate interest and awareness of the high prevalence of COPD, its morbidity, effects on quality of life and on mortality. There is no doubt that COPD is a major public health problem of which the public, health workers and health authorities were insufficiently aware. It is therefore an important achievement that the World Health Organization (WHO), the European Respiratory Society (ERS), the American Thoracic Society (ATS), the Asian Pacific Society of Respirology (APSR), the Asociacion Latinoamericana de Torax (ALAT), and the World Organization of Family Doctors (WONCA) and many distinguished individuals have joined forces to increase awareness about the burden of disease, by publishing reports and guidelines for diagnostic procedures and interventions which have been adopted by numerous international and national organisations. However, there is one area which has given rise to continuous published criticism: the criterion for confirming airway obstruction. It is well known that the forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio declines with increasing age and height, even in healthy lifelong nonsmokers, in whom the lower limit of normal drops below a ratio of 0.7 from about 45 yrs of age [1–6]. It has been shown 4–27 that using the fixed ratio causes up …

The purpose of this study was to measure trigeminal sensitivity of the eyes to irritative exposures and to examine the influence of individual characteristics, e.g., gender, age, and smoking, on this sensitivity. During an experimental study, 158 of 2,025 randomly selected volunteers were examined for sensory irritation threshold in the eyes to carbon dioxide (CO2). Eyes were exposed to progressive concentrations of CO2 (10, 20, 40, 80, and 160 ml/l), until the subject claimed a distinct irritation. Each exposure level lasted 2 min. A special exposure mask system was used for eyes-only exposure. No significant dependence of gender or smoking was found, but subjects who were less than 40 y of age were more sensitive than were the elderly subjects. Subjects who reported frequent "sick building syndrome" irritation symptoms had lower thresholds (i.e., higher sensitivity). The CO2 threshold was related to skin irritation sensitivity, i.e., response to lactic acid smeared on the cheek, and there were indications that occupational stress was associated with low thresholds. Studies of irritation to n-decane indicate that the CO2 threshold may be an important factor in the prediction of individual sensitivity to irritation from airborne pollutants. The CO2 threshold of the eyes may be of value in the evaluation of hypersensitivity to indoor air pollution. Furthermore, the threshold may be used to assess important relationships between the different trigeminal innervated areas, e.g., skin and eyes. Finally, the method has the advantage of avoiding interference from olfactory stimulation.

Spirometric lung function is partly determined by sex, age and height (Ht). Commonly, lung function is expressed as a percentage of the predicted value (PP) in order to account for these effects. Since the PP method retains sex, age and Ht bias, forced expiratory volume in 1 s (FEV(1)) standardised by powers of Ht and by a new sex-specific lower limit (FEV(1) quotient (FEV(1)Q)) were investigated to determine which method best predicted all-cause mortality in >26,967 patients and normal subjects. On multivariate analysis, FEV(1)Q was the best predictor, with a hazard ratio for the worst decile of 6.9 compared to 4.1 for FEV(1)PP. On univariate analysis, the hazard ratios were 18.8 compared to 6.1, respectively; FEV(1) x Ht(-3) was the next-best predictor of survival. Median survival was calculated for simple cut-off values of FEV(1)Q and FEV(1) x Ht(-3). These survival curves were accurately fitted (r(2) = 1.0) by both FEV(1)Q and FEV(1) x Ht(-3) values expressed polynomially, and so an individual's test result could be used to estimate survival (with sd for median survival of 0.22 and 0.61 yrs, respectively). It is concluded that lung function impairment should be expressed in a new way, here termed the FEV(1)Q, or, alternatively, as FEV(1) x Ht(-3), since these indices best relate spirometric lung function to all-cause mortality and survival.

Udgivelsesdato: 2009-Mar Studies relating lung function to survival commonly express lung function impairment as a percent of predicted but this retains age, height and sex bias. We have studied alternative methods of expressing forced expiratory volume in 1s (FEV(1)) for predicting all cause and airway related lung disease mortality in the Copenhagen City Heart Study data. Cox regression models were derived for survival over 25 years in 13,900 subjects. Age on entry, sex, smoking status, body mass index, previous myocardial infarction and diabetes were putative predictors together with FEV(1) either as raw data, standardised by powers of height (FEV(1)/ht(n)), as percent of predicted (FEV(1)PP) or as standardised residuals (FEV(1)SR). Quintiles of FEV(1)/ht(2) were better at predicting all cause mortality in multivariate models than FEV(1)PP and FEV(1)SR, with the hazard ratio (HR) for the worst quintiles being 2.8, 2.0 and 2.1 respectively. Cut levels of lung function were used to categorise impairment and the HR for multivariate prediction of all cause and airway related lung disease mortality were 10 and 2044 respectively for the worst category of FEV(1)/ht(2) compared to 5 and 194 respectively for the worst category of FEV(1)PP. In univariate predictions of all cause mortality the HR for FEV(1)/ht(2) categories was 2-4 times higher than those for FEV(1)PP and 3-10 times higher for airway related lung disease mortality. We conclude that FEV(1)/ht(2) is superior to FEV(1)PP for predicting survival in a general population and this method of expressing FEV(1) impairment best reflects hazard for subsequent death.

A controlled experimental study of human reactions to a mixture of 22 volatile organic compounds often found in indoor air was performed in a climate chamber. Twenty-one healthy subjects were compared with a group of 14 subjects suffering from the ‘sick building syndrome’ (SBS subjects), i.e. having symptoms related to the indoor environment (irritated mucous membranes, headache, etc.) as defined by WHO in 1982. In groups of 4 these subjects were exposed during two successive periods to either 0 and 0 mg m −3 , 25 and 0 mg m −3 , or 0 and 25 mg m −3 ; 25 mg m −3 is equivalent to the highest concentrations expected in a new building. The study was double blinded, and a latin square design was used to balance out effects of day in the week and season. Both groups reacted subjectively to the air reporting worse odor, worse indoor air quality as defined by the subject, and more irritated mucous membranes in eye, throat and nose than in the clean environment. A tendency to a stronger response was seen among the SBS subjects. Objective measures indicated among others an exposure related reduction in lung function among SBS subjects. Both groups had an increased number of polymorphonuclear leucocytes in tear fluid as a result of exposure. This was not seen for nasal secretions. Psychological performance tests indicated an exposure related diminished ability to learn. In conclusion, the experiment indicates that exposure to volatile organic compounds in low concentrations as seen in new houses causes both subjective complaints and objective signs in normal healty subjects; but more so in subjects from the sick building syndrome.

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)

Ten healthy subjects (four men and six women) were subjected to localized skin cooling by submersion for 5 min of both feet and, in another experiment, one hand and forearm into ice-cold water. Repeated measurements of nasal cavity volumes by a new method, acoustic rhinometry, showed characteristic patterns ranging from marked increases in volumes lasting the entire exposure period to transient monophasic or biphasic responses to no change at all. The pattern in individual subjects was reproducible with the two methods of cooling, and it could be characterized by five types when related to baseline measurements during the preexposure period. Because of large minute-to-minute variations, probably determined by local differences and fluctuations in blood flow in tissues through the nose, evaluation of induced changes in the nasal cavity volume cannot be based on single measurements as has frequently been done in the past by using rhinomanometry as the experimental method. The mechanisms behind the characteristic patterns in immediate human nasal response to local skin cooling challenge remains to be explored.

The acute effects of pure inhaled glucan on respiratory inflammation remain inconclusive and not sufficiently examined with regards to the simultaneous interaction of glucan, endotoxin (lipopolysaccharide, LPS), and house dust in airway inflammation. This study aims at determining effects of simultaneous exposure to office dust and glucan on nasal and pulmonary inflammation. This is relevant for humans with occupational exposure in waste handling and farming and buildings with mold problems. Office dust collected from Danish offices was spiked with 1% (1-3)-beta-glucan (curdlan). Guinea pig nasal cavity volume was measured by acoustic rhinometry (AR) and animals were exposed by inhalation for 4 h to curdlan-spiked dust, unspiked dust, purified air (negative controls), or LPS (positive controls). After exposure (+5 h) or the following day (+18 h), measurements were repeated by AR and followed by bronchoalveolar lavage (BAL). Total and differential cell counts, interleukin (IL)-8 in BAL fluid, and change in nasal volume were compared between groups. A 5-10% increase in nasal volume was seen for all groups including clean air except for a significant 5% decrease for spiked-dust inhalation (+18 h). No marked differences were observed in BAL cells or IL-8 except in LPS-exposed controls. The delayed decrease of nasal cavity volume after exposure to glucan spiked dust suggests a slow effect on the upper airways for curdlan and office dust together, though no pulmonary response or direct signs of inflammation were observed. Glucan-spiked office dust exposures produced a delayed nasal subacute congestion in guinea pigs compared to office dust alone, but extrapolated to nasal congestion in humans, paralleling the nasal congestion seen in human volunteers exposed to the same dust, this may not have clinical importance.

Only a limited reference material for acoustic rhinometry (AR) exists for school children most often calculated as the minimum cross-sectional area (MCA) in the non-decongested nose. We want to establish a set of reference values for MCA and nasal volumes for both adults and children and include values also for the decongested nose and determine the most sensitive measurement for change in nasal patency.Data from two studies were used; one comprising of 53 (20M, 33F) school children, age 9-11 years, and one comprising 146 (127M, 19F) healthy workers in the wood industry. Measurements by acoustic rhinometry were done before and after decongestion with two puffs of oxymethazoline nasal spray (1 mg/ml).We found the decongested nasal volume (2-5 cm) to be 3.71 cm3 (3.58-3.84) in school children and 5.44 cm3 (5.21-5.67) in adults. We found the volume from 2-5 cm into the nasal cavity to be the most sensitive measure of change in nasal patency by decongestion, and MCA to be the least sensitive in both adults and children.A larger study population of children, covering a broader range of age, is needed to stratify for gender and height. Our data in adults are in accordance with previous findings.We have provided a reference material for acoustic rhinometry in school children and adults. Future evaluation of change in nasal patency should contain information about nasal volume from 2-5 cm into the nasal cavity and not just MCA in adults and school children.

Udgivelsesdato: 2007-Mar

in a current paper in the Journal of Applied Physiology ([3][1]) the authors have tried to find out whether the compression of the gas in the lungs during a forced expiration influences the grading of decreased lung function in patients with sick lungs either due to emphysema or chronic bronchitis.

The goal of this study was to evaluate the relationship between feline nasal cavity geometry determined in vivo by acoustic rhinometry (AR(in vivo)) and by nasal cavity casts. Cast cross-sectional areas were measured by acoustic rhinometry (AR(cast)), a fluid-displacement method (FDM), and slicing. A volume comparison between AR(in vivo) and AR(cast) was studied in cats with varying degrees of nasal obstruction after application of phenylpropanolamine, saline, or compound 48/80.After measurements of AR(in vivo), impression material was injected into the nasal cavity to produce casts. Subsequently, the cross-sectional areas of the nasal impressions were measured by AR(cast) and FDM using ethanol. All casts were weighed to determine exact volume. Six casts also were sliced into segments of equal thickness for determination of cross-sectional area.Cast volume determined by AR(cast) was consistent with results obtained using FDM and weight. Volumes of the first 3 cm determined by AR(in vivo) ranged between 78 +/- 9% of cast volumes determined by AR(cast) for decongested cavities and 16 +/- 15% for congested cavities.AR(in vivo) does not reflect cast geometry, probably because of (1) underestimation by AR because of methodological problems caused by the cavity geometry, (2) deformation of compliant structures within the nasal passageways resulting from the casting procedure, and/or (3) the casting material reaches parts of the nasal cavity not accessible to sound, e.g., sinuses or recesses. Nevertheless, this study does not preclude the use of AR as a sensitive method suited to evaluate relative changes in nasal volume caused by experimental challenges of the nasal mucosa. Compared with AR(in vivo), casts still may be of use but it is less sensitive to measure relative changes after experimental challenge.

Udgivelsesdato: 2004-May Sixteen healthy nonsmoking subjects (7 women), 21-49 yr old, were exposed in a climate chamber to either clean air or 300 parts/billion ozone on 4 days for 5 h each day. Before each exposure, the subjects had been pretreated with either oxidants (fish oil) or antioxidants (multivitamins). The study design was double-blind crossover with randomized allocation to the exposure regime. Full and partial flow-volume curves were recorded in the morning and before and during a histamine provocation at the end of the day. Nasal cavity volume and inflammatory markers in nasal lavage fluid were also measured. Compared with air, ozone exposure decreased peak expiratory flow, forced expiratory volume in 1 s, and forced vital capacity (FVC), with no significant effect from the pretreatment regimens. Ozone decreased the ratio of maximal to partial flow at 40% FVC by 0.08 +/- 0.03 (mean +/- SE, analysis of variance: P = 0.018) and at 30% FVC by 0.10 +/- 0.05 (P = 0.070). Ozone exposure did not significantly increase bronchial responsiveness, but, after treatment with fish oil, partial flows decreased more than after vitamins during the histamine test, without changing the maximal-to-partial flow ratio. The decreased effect of a deep inhalation after ozone exposure can be explained by changes in airway hysteresis relative to parenchymal hysteresis, due either to ozone-induced airway inflammation or to less deep inspiration after ozone, not significantly influenced by multivitamins or fish oil.

Conventional measures of bronchial hyperresponsiveness (BHR) are only weakly associated with respiratory symptoms in epidemiological studies. Partial and maximal forced expiratory manoeuvres were recorded during histamine challenge testing in 1,959 young male farmers. Analysis was performed to test whether novel measures of BHR, using alternative flow and time domain indices, are more closely associated with asthma symptoms, smoking status and atopy than forced expiratory volume in one second (FEV1) and conventional measures of BHR. The first moments to 75% and 90% of the forced vital capacity (FVC) were calculated from full (F) and partial (P) forced expiratory manoeuvres (i.e. alpha1 75%F, alpha1 75%P), together with the instantaneous flows when 40% and 30% of the FVC remained to be expired (MEF40 and MEF30). BHR was measured by the provocative dose causing a 20% change (PD20) in the FEV1 and alpha1 75%, and also by the method of log dose slopes (LDS). Asthma was diagnosed from symptoms associated with asthma in 158 (8.1%) of the subjects. PD20 FEV1 could only be recorded in 190 subjects (9.7%), of whom only 48 had asthma, whereas LDSFEV1 was recorded in 1,725 (88%) subjects. From the prechallenge data, alpha1 75%, expressed as standardised residuals, showed the largest difference between smokers with and without asthma symptoms, and no indices showed significant differences between nonsmokers with and without asthma symptoms. From BHR data in both smokers and nonsmokers, LDSFEV1 showed one of the largest differences between those with and without asthma symptoms. With smoking status and atopy accounted for, the greatest partial correlation with asthma diagnosis was found for LDSMEF40P, and then for LDSFEV1, but LDSMEF40P was measurable in only just over one-half of the subjects. The authors conclude that time-domain indices are promising measures for longitudinal epidemiological studies concerning the relationship between bronchial hyperresonsiveness and environmental exposures. However, indices from the partial flow-volume loop suffer from censored data.

Previous studies have shown that the added resistance of a mini-Wright peak expiratory flow (PEF) meter reduced PEF by approximately 8% in normal subjects because of gas compression reducing thoracic gas volume at PEF and thus driving elastic recoil pressure. We undertook a body plethysmographic study in 15 patients with chronic obstructive pulmonary disease (COPD), age 65.9 +/- 6.3 yr (mean +/- SD, range 53-75 yr), to examine whether their recorded PEF was also limited by the added resistance of a PEF meter. The PEF meter increased alveolar pressure at PEF (Ppeak) from 3.7 +/- 1.4 to 4.7 +/- 1.5 kPa (P = 0.01), and PEF was reduced from 3.6 +/- 1.3 l/s to 3.2 +/- 0.9 l/s (P = 0.01). The influence of flow limitation on PEF and Ppeak was evaluated by a simple four-parameter model based on the wave-speed concept. We conclude that added external resistance in patients with COPD reduced PEF by the same mechanisms as in healthy subjects. Furthermore, the much lower Ppeak in COPD patients is a consequence of more severe flow limitation than in healthy subjects and not of deficient muscle strength.

The aim of this study was to assess the prevalence of asthma (self-reported) and relate this to lung function and factors associated with asthma in young farmers. Two hundred and ten female and 1,691 male farming students together with 407 males controls were studied. Each subject underwent a medical interview; forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were recorded using a dry wedge spirometer. Histamine bronchial reactivity was measured using the Yan method. Skin prick testing was performed using inhalant allergens. Nonsmokers had lower prevalence of asthma (5.4-10.8%) than smokers (11.3-21.0%) (p